Use of diagnostic tests in elderly patients consulting the emergency department. Analysis of the emergency department and elder needs cohort (EDEN-8)

OBJECTIVE

Analyse the association between the use of diagnostic tests and the characteristics of older patients 65 years of age or more who consult the emergency department (ED).

METHODS

We performed an analysis of the EDEN cohort that includes patients who consulted 52 Spanish EDs. The association of age, sex, and ageing characteristics with the use of diagnostic tests (blood tests, electrocardiogram (ECG), microbiological cultures, X-ray, computed tomography, ultrasound, invasive techniques) was studied. The association was analysed by calculating the adjusted odds ratios (aOR) and their 95 % confidence intervals (CI) using a logistic regression model.

RESULTS

A total of 25,557 patients were analysed. There was an increase in the use of diagnostic tests based on age, with an aOR for blood test of 1.805 (95 %CI 1.671 - 1.950), ECG 1.793 (95 %CI 1.664 - 1.932) and X-ray 1.707 (95 %CI 1.583 - 1.840) in the group of 85 years or more. The use of diagnostic tests is lower in the female population. Most ageing characteristics (cognitive impairment, previous falls, polypharmacy, dependence, and comorbidity) were independently associated with increased use of diagnostic tests.

CONCLUSIONS

Age, and the characteristics of ageing itself are generally associated with a greater use of diagnostic tests in the ED.

Seven- and thirty-day mortality in digoxin poisoning: Results from the DIGITOX study

BACKGROUND

Digoxin poisonings are relatively common and potentially fatal, requiring immediate therapeutic intervention, with special attention to the patient's hemodynamic status and the presence of electrocardiographic and electrolytic disturbances.

OBJECTIVE

To identify factors associated with seven-day and thirty-day mortality in digoxin poisoning.

DESIGN, SETTINGS AND PARTICIPANTS

A retrospective, observational, multicenter study was conducted across 15 Hospital Emergency Departments (HED) in Spain. All patients over 18 years of age who presented to participating HEDs from 2015 to 2021 were included. The inclusion criteria encompassed individuals meeting the criteria for digoxin poisoning, whether acute or chronic.

OUTCOMES MEASURE AND ANALYSIS

To identify independent factors associated with 7-day and 30-day mortality, a multivariate analysis was conducted. This analysis included variables of clinical significance, as well as those exhibiting a trend (p < 0.1) or significance in the bivariate analysis.

MAIN FINDINGS

A total of 658 cases of digoxin poisoning were identified. Mortality rates were 4.5% (30 patients) at seven days and 11.1% (73 patients) at thirty days. Regarding 7-day mortality, the mean age of deceased patients was comparable to survivors (84.7 (8.9) vs 83.9 (7.9) years; p = ns). The multivariate analysis revealed that factors independently associated with 7-day mortality encompassed the extent of dependence assessed by the Barthel Index (BI 60-89 OR 0.28; 95% CI 0.10-0.77; p = 0.014 and BI>90 OR 0.22; 95% CI 0.08-0.63; p = 0.005), the identification of ventricular arrhythmias (OR 1.34; 95% CI 1.34-25.21; p = 0.019), and the presence of circulatory (OR 2.84; 95% CI 1.19-6.27; p = 0.019) and neurological manifestations (OR 2.67; 95% CI 1.13-6.27; p = 0.025). Factors independently associated with 30-day mortality encompassed extent of dependence (BI 60-89 OR 0.37; 95% CI 0.20-0.71; p = 0.003 and BI>90 OR 0.18; 95% CI 0.09-0.39; p < 0.001) and the identification of circulatory (OR 2.13; 95% CI 1.10-4.15; p = 0.025) and neurological manifestations (OR 2.39; 95% CI 1.25-3.89; p = 0.006).

CONCLUSIONS

The study identifies the degree of dependency assessed by the Barthel Index and the presence of cardiovascular and neurological symptoms as independent predictors of both 7-day and 30-day mortality. Additionally, the detection of ventricular arrhythmia is also an independent factor for 7-day mortality.

Use of resources in elderly patients consulting the emergency department: analysis of the Emergency Department and Elder Needs Cohort (EDEN-21)

The elderly population frequently consults the emergency department (ED). This population could have greater use of EDs and hospital health resources. The EDEN cohort of patients aged 65 years or older visiting the ED allowed this association to be investigated. To analyse the association between healthcare resource use and the characteristics of patients over 65 years of age who consult hospital EDs. We performed an analysis of the EDEN cohort, a retrospective, analytical, and multipurpose registry that includes patients over 65 years of age who consulted in 52 Spanish EDs. The impact of age, sex, and characteristics of ageing on the following outcomes was studied: need for hospital admission (primary outcome) and need for observation, stay in the ED > 12 h, prolonged hospital stay > 7 days, need for intensive care unit (ICU) and return to the ED at 30 days related to the index visit (secondary outcomes). The association was analysed by calculating the adjusted odds ratios (aOR) and their 95% confidence intervals (CI), using a logistic regression model. A total of 25,557 patients with a mean age of 78.3 years were analysed, 45% were males. Of note was the presence of comorbidity, a Charlson index ≥ 3 (33%), and polypharmacy (66%). Observation in the ED was required by 26%, 25.4% were admitted to the hospital, and 0.9% were admitted to the ICU. The ED stay was > 12 h in 12.5% and hospital stay > 7 days in 13.5% of cases. There was a progressive increase in healthcare resource use based on age, with an aOR for the need for observation of 2.189 (95% CI 2.038-2.352), ED stay > 12 h 2.136 (95% CI 1.942-2.349) and hospital admission 2.579 (95% CI 2.399-2.772) in the group ≥ 85 years old. Most of the characteristics inherent to ageing (cognitive impairment, falls in the previous 6 months, polypharmacy, functional dependence, and comorbidity) were associated with significant increases in the use of healthcare resources, except for ICU admission, which was less in all the variables studied. Age and the characteristics inherent to ageing are associated with greater use of structural healthcare resources.

Characteristics of digoxin toxicity attended in Spanish emergency departments according to type of poisoning and administration of digoxin antibodies: the DIGITOX study

OBJECTIVES

Digoxin toxicity accounts for a small percentage of poisonings attended by emergency departments. This study aimed to describe differences between acute and chronic digoxin toxicity and assess the use of digoxin-specific antibody fragments (digoxin-Fab) as an antidote.

MATERIAL AND METHODS

Retrospective, observational, multicenter study in 15 hospital emergency departments in 8 Spanish autonomous communities in 7 years. We collected patient, clinical and treatment variables, and discharge destination. Patients were classified according to whether toxicity was acute or chronic and whether digoxin-Fab was administered or not.

RESULTS

Twenty-seven acute and 631 chronic digoxin poisonings were attended. The mean (SD) patient age was 83.9 (7.9) years, and 76.9% were women. Patients with acute toxicity were younger (80.0 [12] years) than those with chronic toxicity (84.1 [7.7] years) (P .038), and accidental poisoning was less common (in 85.2% vs 100% in chronic toxicity; P .001). Cases of acute toxicity were also more serious (Poison Severity Score (29.6% vs 12.5% in chronic toxicity; P .001). Thirty-four patients were treated with digoxin-Fab (5.4%). These patients were younger (78.7 [11.5] years vs 84.2 (7.6) years), their toxicity was more often acute (in 20.6% vs 3.2% in chronic toxicity), more had attempted suicide (8.8% vs 0.2% with chronic toxicity), and more had severe symptoms (50% vs 11.2%) (P .001, all comparisons). Hospital admission was required for 76.1%. Overall, mortality was 11.4%.

CONCLUSION

Chronic toxicity accounts for most digoxin poisoning cases, and most patients are women. Acute toxicity is more serious. Patients who required digoxin-Fab have more severe poisoning. Such patients usually have acute toxicity, and attempted suicide is more often the reason for the emergency.

Multifunctional TiO2 coatings developed by plasma electrolytic oxidation technique on a Ti20Nb20Zr4Ta alloy for dental applications

A newly developed β-Ti alloy based on the Ti-Nb-Zr-Ta system (Ti20Nb20Zr4Ta) has been subjected to Plasma Electrolytic Oxidation (PEO) treatment to obtain a multifunctional ceramic-like (TiO₂) coating with superior tribocorrosion (wear and corrosion) resistance and improved biocompatibility. For this aim, elements such as Ca, P, and Ag NPs have been incorporated into the oxide film to obtain bioactive and biocide properties. The chemical composition and morphology of the TiO₂-PEO coating was characterized, and its multifunctionality was addressed by several means, including antibacterial activity assessment, formation of bone-like apatite, metallic ion release evaluation, in vitro cellular response analysis, and corrosion and tribocorrosion tests in artificial saliva. The developed coatings enhanced the corrosion and tribocorrosion resistance of the bare alloy and exhibited antibacterial ability with low cytotoxicity and negligible ion release. Furthermore, they were able to sustain MC3T3-E1 preosteoblast viability/proliferation and osteogenic differentiation. Altogether, the results obtained demonstrate the potential of the TiO₂ coating incorporating Ca, P, and Ag NPs to be used for dental applications.

Predictors of revisits within 1 year by patients after acute COVID-19: the HUBCOVID365 cohort study

OBJECTIVES

To analyze the frequencies of 3 types of hospital revisits by patients after treatment for COVID-19 in the emergency department.

MATERIAL AND METHODS

Retrospective observational study of consecutive patients who came to the emergency department in March and April 2020 and were discharged alive with a diagnosis of COVID-19. Baseline and acute episode data were collected and the patients were followed for 1 year. We analyzed variables associated with revisits for any reason, revisits related to COVID-19, and early COVID-19-related revisits (within 30 days).

RESULTS

A total of 1352 patients with a mean age of 62.1 years (52.9% male) were studied. A total of 553 revisits were made by 342 patients (25.3%) for any reason; 132 (9.8%) revisited in relation to COVID-19 at least once. Of those, 103 (7.6%) revisited within 30 days (early) and 29 (2.2%) came later. COVID-19-related revisits were associated with thrombotic events (odds ratio [OR], 7.58; 95% CI, 1.75-32.81) and pulmonary fibrosis (OR, 4.95; 95% CI, 1.27-19.24); early revisits were inversely associated with follow-up management by a contracted health care support service (OR, 0.18; 95% CI, 0.03-0.92). Hospital admission during the initial visit was significantly associated with fewer revisits for any reason or related to COVID-19 at any time.

CONCLUSION

Fewer than half the total number of emergency department revisits after initial care for COVID-19 were related to the novel coronavirus infection. Revisits occurred more often in the first 30 days after discharge. Later COVID-19-related revisits were uncommon, but given the large number of patients with this infection, such visits can be expected.

Poisoning cases in Catalonia: characteristics according to age groups in the Intox.28 study

OBJECTIVES

The Toxicology Working Group of the Catalan Society of Emergency Medicine (SoCMUETox) began the Intox-28 study in 2013. The aim was to identify differences in poisoning cases between 3 age groups.

MATERIAL AND METHODS

Descriptive observational study of poisoning cases managed in 8 hospital emergency departments on the 28th day of each month from 2013 to 2019. We gathered information on patient particulars, type of poison, clinical data, and discharge destination. The patient sample was distributed into 3 groups for comparison: minors under the age of 17 years, adults aged 17 to 65 years, and adults over the age of 65 years.

RESULTS

The hospitals registered 1088 cases: 132, 859, and 97 in each age group. In comparisons between the minors and the adults aged 65 years or younger, the minors had more females (58.3% vs 46.1%), fewer recreational poisonings (22% vs 46.1%) more poisonings inside the home (67.4% vs 51.1%), more medication poisonings (49.2% vs 31.1%), and less often received treatment (43.2% vs 73%) (P .001, all comparisons). The proportion of older adults receiving treatment (73.2%) was similar to that of the younger adults.

CONCLUSION

The characteristics of poisonings vary according to age. Differences lie in gender, intentionality, and type of poison.

[Radiological and functional results in high-energy tibial plate fractures]

INTRODUCTION

The tibial plateau fractures due to high-energy mechanisms are serious injuries that occur on a load bearing joint. These are difficult to approach because, also affect the bone structure of the leg, they usually have associated soft tissue injuries.

OBJECTIVE

To evaluate the radiological and functional results of high-energy tibial plateau fractures with a minimum follow-up of one year.

MATERIAL AND METHODS

Retrospective, observational and multicenter study. Analysis of radiological and functional outcomes in the treatment of high-energy tibial plateau fractures, treated by open reduction and internal fixation (ORIF) between 2014 and 2019.

RESULTS

54 fractures treated by ORIF. Follow-up one year. 98.1% consolidation in 13 weeks on average. 83.4% without alterations of the axis in the coronal plane. 74% without postoperative joint widening. Functional scores: Lysholm 82.1 average points and Oxford Knee Score (OKS) 39.5 average points.

CONCLUSION

The joint range of motion was reduced after a high-energy tibial plateau fracture, but with good functional results. The less off axis and less post-operative radiographic widening, the better results are obtained.

Cracks in consolidants containing TiO2 as a habitat for biological colonization: A case of quaternary bioreceptivity

The recently proposed concept of quaternary bioreceptivity applies to substrates treated with coating materials and it is considered in the present study with the alga Bracteacoccus minor and the cyanobacterium Nostoc sp. onto granite specimens treated with ethyl silicate and nano-sized silica doped with different amounts of TiO₂ (0, 0.5, 1 and 3 wt%). The findings showed a lack of correlation between the amount of TiO₂ and the level of colonization (main bioreceptivity estimator) to the presence of cracks on the surface, which annul the biocidal power of TiO₂. Crack formation, which depends on the mechanical properties, greatly influences the bioreceptivity of the material. Thus, the cracks provided anchor points where water is retained, in turn strongly influencing the early stages of colonization kinetics, to a greater extent than the biocidal power of TiO₂, which will probably increase as the biofilm develops over the entire surface. In addition, although the cracks were more abundant and wider in the ethyl silicate-based consolidant, the nano-sized silica provided better anchoring points, making the material treated with the corresponding consolidant more bioreceptive.

Psychological impact of the SARS-CoV-2 outbreak on the staff of a French hospital

Background

The outbreak of SARS-CoV-2 has resulted in anxiety, depression and post-traumatic stress disorder (PTSD) among hospital staff. The factors associated with this psychological impact remain to be determined.

Methods

A cross-sectional study using an online questionnaire completed by the staff of a French hospital, two months after the SARS-CoV-2 outbreak.

Results

Among the 353 participants (of whom 67% were healthcare professionals), 32% had symptoms of anxiety, 16% of depression and 16% of PTSD. Eleven per cent had initiated or increased treatment with sleeping pills, and 6% with anxiolytics. In a multivariate analysis, factors independently associated with anxiety were: change of professional team, having a relative infected by SARS-CoV-2 and a new/increased treatment with sleeping pills or anxiolytics. The only factor associated with depression was the feeling of risk during professional practice. The factors associated with PTSD were: having a relative infected by SARS-CoV-2, the feeling of risk during professional practice, the increase in smoking and treatment with sleeping pills. The observance of transmission preventive measures (TPM) was not associated with the psychological impact of SARS-CoV-2. A personal history of SARS-CoV-2 infection and age < 36 years were associated with insufficient use of protective equipment. Age < 36 years, and being a healthcare professional were associated with the non-observance of social distancing.

Conclusion

The hospital staff displayed psychological consequences, resulting in the use of anxiolytics and sleeping pills. Belonging to a group with low-risk of severe disease was associated with lower observance of TPM.

Complexes of Pro-Apoptotic siRNAs and Carbosilane Dendrimers: Formation and Effect on Cancer Cells

This paper examines the complexation of anti-cancer small interfering RNAs (siRNAs) by cationic carbosilane dendrimers, and the interaction of the formed complexes with HeLa and HL-60 cancer cells. Stepwise formation of the complexes accompanied by the evolution of their properties has been observed through the increase of the charge ratio (dendrimer/siRNA). The complexes decrease the viability of both “easy-to-transfect” cells (HeLa) and “hard-to transfect” ones (HL-60), indicating a high potential of the cationic carbosilane dendrimers for siRNA delivery into tumor cells.

Anti-aggregation effect on platelets of Indiplon a hypnotic sedative non-benzodiazepine drug

Cardiovascular diseases are one of the main public health problems, and many of them, their pathophysiology involves alterations in platelet activity. Platelet activation is an essential event that is regulated by the intracellular concentrations of Ca2+ and cAMP. Interestingly, it has been shown that the activation of adenosine A2A receptors increases cAMP levels and produces the inhibition of platelet aggregation, which appears as a potential target for regulation of platelet activity. Therefore, we tried to activate A2A receptors using Indiplon, a drug developed for the treatment of insomnia, and analyze its effect on platelet activity in vitro. Our results indicate that Indiplon is able to interact in silico with the adenosine A2A receptor (ΔG_bind of -73.321 kcal/mol, similar to that obtained with adenosine), which is involved in the regulation of platelet cAMP levels. In functional studies using PRP, a reduction in platelet aggregation induced by ADP was observed in the presence of Indiplon at 500 μM with a percentage of inhibition 70%, where the use of specific inhibitors (ZM241385 and MSX-2) of the A2A receptor also blocked these effects reducing the percentage of inhibition to 41% and 34.1%, respectively. Also, the use of Indiplon produced a decrease in the expression in the membrane of P-selectin. Thus, Indiplon acts as an A2A receptor agonist and whose activation results in inhibition of platelet aggregation and activation, showing a possible cardiovascular protective role.

The cAMP/PKA Pathway Inhibits Beta-amyloid Peptide Release from Human Platelets

The main component of Alzheimer's disease (AD) is the amyloid-beta peptide (Aβ), the brain of these patients is characterized by deposits in the parenchyma and cerebral blood vessels known as cerebral amyloid angiopathy (CAA). On the other hand, the platelets are the major source of the Aβ peptide in circulation and once secreted can activate the platelets and endothelial cells producing the secretion of several inflammatory mediators that finally end up unchaining the CAA and later AD. In the present study we demonstrate that cAMP/PKA pathway plays key roles in the regulation of calpain activation and secretion of Aβ in human platelets. We confirmed that inhibition of platelet functionality occurred when platelets were incubated with forskolin (molecule that rapidly increased cAMP levels). In this sense we found that platelets pre-incubated with forskolin (20 μM) present a complete inhibition of calpain activity and this effect is reversed using an inhibitor of protein kinase A. Consequentially, when platelets were inhibited by forskolin a reduction in the processing of the APP with the consequent decrease in the Aβ peptide secretion was observed. Therefore our study provides novel insight in relation to the mechanism of processing and release of the Aβ peptide from human platelets.

Altered S-nitrosothiol homeostasis provides a survival advantage to breast cancer cells in HER2 tumors and reduces their sensitivity to trastuzumab

The monoclonal antibody trastuzumab against HER2/neu, which is overexpressed in 15-20% of breast cancers, has clinical efficacy but many patients do not respond to initial treatment or develop resistance during treatment. Nitric oxide (NO) regulates cell signaling by targeting specific cysteine residues in proteins, forming S-nitrosothiols (SNO) in a process known as S-nitrosylation. We previously reported that molecular characteristics in breast cancer may dictate the tumor response to impaired SNO homeostasis. In the present study, we explored the role of SNO homeostasis in HER2 breast tumors. The antiproliferative action of trastuzumab in HER2-overexpressing BT-474 and SKBR-3 cells was suppressed when S-nitrosoglutathione reductase (GSNOR/ADH5) activity, which plays a key role in SNO homeostasis, was specifically inhibited with the pyrrole derivative compound N6022. Moreover, GSNOR inhibition restored the activation of survival signaling pathways involved in the resistance to anti-HER2 therapies (AKT, Src and c-Abl kinases and TrkA/NRTK1, TrkB/NRTK2, EphA1 and EphA3 receptors) and reduced the apoptotic effect of trastuzumab. Accordingly, GSNOR inhibition augmented the S-nitrosylation of apoptosis-related proteins, including Apaf-1, pSer73/63 c-Jun, calcineurin subunit α and HSF1. In agreement with in vitro data, immunohistochemical analyses of 51 breast tumors showed that HER2 expression was associated with lower expression of GSNOR protein. Moreover, gene expression analysis confirmed that high ADH5/GSNOR gene expression was associated with high patient survival rates in HER2 tumors. In conclusion, our data provide evidence of molecular mechanisms contributing to the progression of HER2+ breast cancers and could facilitate the development of therapeutic options to counteract resistance to anti-HER2 therapies.

Consumption of peptide-included and free tryptophan induced by peroxyl radicals: A kinetic study

It is well-known that tryptophan residues are efficiently oxidized by peroxyl radicals, generating kynurenine, and N-formyl kynurenine as well as hydroperoxide derivatives as products. In the present work we studied the kinetic of such reaction employing free and peptide-included tryptophan. Two azocompounds were used to produce peroxyl radicals: AAPH (2,2'-Azobis(2-methylpropionamidine) dihydrochloride) and ABCVA (4,4'-Azobis(4-cyanovaleric acid)), which generate cationic and anionic peroxyl radicals, respectively. Tryptophan consumption was assessed by fluorescence spectroscopy and the reactions were carried out in phosphate buffer (75mM, pH 7.4) at 45°C. Only a slight effect of the peroxyl radical charge was evidenced on the consumption of free tryptophan and the dipeptide Gly-Trp. Employing AAPH as peroxyl radical source, at low free tryptophan concentrations (1-10µM) near 0.3 mol of tryptophan were consumed per each mol of peroxyl radicals introduced into the system. However, at high free tryptophan concentrations (100µM-1mM) such stoichiometry increased in a tryptophan concentration-way. At 1mM three moles of tryptophan were consumed per mol of AAPH-derived peroxyl radicals, evidencing the presence of chain reactions. A similar behavior was observed when di and tri-peptides (Gly-Trp, Trp-Gly, Gly-Trp-Gly, Trp-Ala, Ala-Trp-Ala) were studied. Nonetheless, at low initial concentration (5µM), the initial consumption rate of tryptophan included in the peptides was two times higher than free tryptophan. In contrast, at high concentration (1mM) free and peptide-included tryptophan showed similar initial consumption rates. These results could be explained considering a disproportionation process of tryptophanyl radicals at low free tryptophan concentrations, a process that would be inhibited when tryptophan is included in peptides.

Protective mechanisms of adenosine 5'-monophosphate in platelet activation and thrombus formation

Platelet activation is relevant to a variety of acute thrombotic events. We sought to examine adenosine 5'-monophosphate (AMP) mechanisms of action in preventing platelet activation, thrombus formation and platelet-related inflammatory response. We assessed the effect of AMP on 1) P-selectin expression and GPIIb/IIIa activation by flow cytometry; 2) Platelet aggregation and ATP secretion induced by ADP, collagen, TRAP-6, convulxin and thrombin; 3) Platelet rolling and firm adhesion, and platelet-leukocyte interactions under flow-controlled conditions; and, 4) Platelet cAMP levels, sP-selectin, sCD40L, IL-1β, TGF-β1 and CCL5 release, PDE3A activity and PKA phosphorylation. The effect of AMP on in vivo thrombus formation was also evaluated in a murine model. The AMP docking with respect to A2 adenosine receptor was determined by homology. AMP concentration-dependently (0.1 to 3 mmol/l) inhibited P-selectin expression and GPIIb/IIIa activation, platelet secretion and aggregation induced by ADP, collagen, TRAP-6 and convulxin, and diminished platelet rolling and firm adhesion. Furthermore, AMP induced a marked increase in the rolling speed of leukocytes retained on the platelet surface. At these concentrations AMP significantly decreased inflammatory mediator from platelet, increased intraplatelet cAMP levels and inhibited PDE3A activity. Interestingly, SQ22536, ZM241385 and SCH58261 attenuated the antiplatelet effect of AMP. Docking experiments revealed that AMP had the same orientation that adenosine inside the A2 adenosine receptor binding pocket. These in vitro antithrombotic properties were further supported in an in vivo model of thrombosis. Considering the successful use of combined antiplatelet therapy, AMP may be further developed as a novel antiplatelet agent.

Maintenance of S-nitrosothiol homeostasis plays an important role in growth suppression of estrogen receptor-positive breast tumors

Introduction

Protein denitrosylation by thioredoxin reductase (TrxR) is key for maintaining S-nitrosothiol (SNO) homeostasis, although its role in tumor progression is unknown. Therefore, the present study aimed to assess the role of altered SNO homeostasis in breast cancer cells.

Methods

The impairment of SNO homeostasis in breast cancer cells was achieved with the highly specific TrxR inhibitor auranofin and/or exposure to S-nitroso-L-cysteine. S-nitrosylated proteins were detected using the biotin switch assay. Estrogen receptor (ER) alpha knockdown was achieved using RNA silencing technologies and subcellular localization of ERα was analyzed by confocal microscopy. The Oncomine database was explored for TrxR1 (TXNRD1) expression in breast tumors and TrxR1, ER and p53 expression was analyzed by immunohistochemistry in a panel of breast tumors.

Results

The impairment of SNO homeostasis enhanced cell proliferation and survival of ER+ MCF-7 cells, but not of MDA-MB-231 (ER-, mut p53) or BT-474 (ER+, mut p53) cells. This enhanced cell growth and survival was associated with Akt, Erk1/2 phosphorylation, and augmented cyclin D₁ expression and was abolished by the ER antagonist fulvestrant or the p53 specific inhibitor pifithrin-α. The specific silencing of ERα expression in MCF-7 cells also abrogated the growth effect of TrxR inhibition. Estrogenic deprivation in MCF-7 cells potentiated the pro-proliferative effect of impaired SNO homeostasis. Moreover, the subcellular distribution of ERα was altered, with a predominant nuclear localization associated with phosphorylation at Thr311 in those cells with impaired SNO homeostasis. The impairment of SNO homeostasis also expanded a cancer stem cell-like subpopulation in MCF-7 cells, as indicated by the increase of percentage of CD44⁺ cells and the augmented capability to form mammospheres in vitro. Notably, ER+ status in breast tumors was significantly associated with lower TXNDR1 mRNA expression and immunohistochemical studies confirmed this association, particularly when p53 abnormalities were absent.

Conclusion

The ER status in breast cancer may dictate tumor response to different nitrosative environments. Impairment of SNO homeostasis confers survival advantages to ER+ breast tumors, and these molecular mechanisms may also participate in the development of resistance against hormonal therapies that arise in this type of mammary tumors.

Structural characterization and mechanical performance of calcium phosphate scaffolds and natural bones: a comparative study

PURPOSE

The knowledge of the mechanical response of bones and their substitutes is pertinent to numerous medical problems. Understanding the effects of mechanical influence on the body is the first step toward developing innovative treatment and rehabilitation concepts for orthopedic disorders.

METHODS

This was a comparative study of 5 synthetic scaffolds based on porous calcium phosphates and natural bones, with regard to their microstructural, chemical, and mechanical characterizations. The structural and chemical characterizations of the scaffolds were examined by means of X-ray diffraction, scanning electron microscopy, and X-ray spectroscopy analysis. The mechanical characterization of bones and bone graft biomaterials was carried out through compression tests using samples with noncomplex geometry.

RESULTS

Analysis of the chemical composition, surface features, porosity, and compressive strength indicates that hydroxyapatite-based materials and trabecular bone have similar properties.

[Core needle biopsy of papillary breast lesions: impact on patient management]

OBJECTIVES

To evaluate the clinical and radiological presentations of papillary breast lesions and to evaluate the performance of core needle breast biopsy in papillary lesions.

MATERIAL AND METHODS

We retrospectively studied 55 papillary breast lesions in 46 patients aged 28 to 87 years diagnosed using core needle biopsy in the period 1994-2005. We reviewed the clinical and radiological presentations of the lesions, the findings at histological study after percutaneous biopsy, and the correlation of these findings with those of the surgical biopsy (44 cases) and/or radiological follow-up (42 cases).

RESULTS

The most common mammographic presentation was circumscribed or ill-defined, single or multiple nodules. Ill-defined lesions were significantly associated with malignancy (p < 0.05). The results of the percutaneous biopsy were: benign papillary lesion (n = 32), papillary lesion with atypia (n = 9), and malignant papillary lesion (n = 14). The diagnostic accuracy of core needle biopsy calculated from the 44 cases with surgical confirmation was: sensitivity 63%, specificity 100%, predictive positive value 100%, predictive negative value 73%, and rate of underestimation 25%. During follow-up, increased lesion size or the appearance of new lesions was seen in four patients.

CONCLUSIONS

The diagnosis can be suspected in cases of postmenopausal patients with multiple circumscribed or ill-defined, solid or mixed lesions at ultrasound study. Although the finding of an invasive malignant papillary lesion after percutaneous biopsy enables treatment to be planned, in the remaining situations (benign papillary lesion, with atypia, or carcinoma in situ) underestimation is common and the lesion should be surgically excised. Vacuum-assisted biopsy systems might improve these results.

Presence of functional cannabinoid receptors in human endocrine pancreas

AIMS/HYPOTHESIS

We examined the presence of functional cannabinoid receptors 1 and 2 (CB1, CB2) in isolated human islets, phenotyped the cells producing cannabinoid receptors and analysed the actions of selective cannabinoid receptor agonists on insulin, glucagon and somatostatin secretion in vitro. We also described the localisation on islet cells of: (1) the endocannabinoid-producing enzymes N-acyl-phosphatidyl ethanolamine-hydrolysing phospholipase D and diacylglycerol lipase; and (2) the endocannabinoid-degrading enzymes fatty acid amidohydrolase and monoacyl glycerol lipase.

METHODS

Real-time PCR, western blotting and immunocytochemistry were used to analyse the presence of endocannabinoid-related proteins and genes. Static secretion experiments were used to examine the effects of activating CB1 or CB2 on insulin, glucagon and somatostatin secretion and to measure changes in 2-arachidonoylglycerol (2-AG) levels within islets. Analyses were performed in isolated human islets and in paraffin-embedded sections of human pancreas.

RESULTS

Human islets of Langerhans expressed CB1 and CB2 (also known as CNR1 and CNR2) mRNA and CB1 and CB2 proteins, and also the machinery involved in synthesis and degradation of 2-AG (the most abundant endocannabinoid, levels of which were modulated by glucose). Immunofluorescence revealed that CB1 was densely located in glucagon-secreting alpha cells and less so in insulin-secreting beta cells. CB2 was densely present in somatostatin-secreting delta cells, but absent in alpha and beta cells. In vitro experiments revealed that CB1 stimulation enhanced insulin and glucagon secretion, while CB2 agonism lowered glucose-dependent insulin secretion, showing these cannabinoid receptors to be functional.

CONCLUSIONS/INTERPRETATION

Together, these results suggest a role for endogenous endocannabinoid signalling in regulation of endocrine secretion in the human pancreas.