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.

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.

Bisphenol-A disruption of the endocrine pancreas and blood glucose homeostasis

The link between endocrine disruptors and altered blood glucose homeostasis has been recently suggested. Epidemiological studies have correlated levels of phthalates, dioxins and persistent organic pollutants with alterations of blood glucose homeostasis in humans. Environmentally relevant doses of the ubiquitous endocrine disruptor bisphenol-A (BPA) have profound effects on mice endocrine pancreas--an essential tissue involved in glucose metabolism. BPA exerts rapid non-genomic effects on insulin releasing beta-cells and glucagon releasing alpha-cells within freshly isolated islets of Langerhans. In vivo, a single BPA injection of 10 microg/kg rapidly increases plasma insulin and concomitantly decreases glycaemia. When mice were treated with BPA 100 microg/kg/day for 4 days, the environmental oestrogen produced an increase in beta-cell insulin content along with a post-prandial hyperinsulinaemia and insulin resistance. The results reviewed here demonstrate that doses well below the current lowest observed adverse effect level considered by the US-EPA, disrupt pancreatic beta-cell function producing insulin resistance in male mice. Therefore, this altered blood glucose homeostasis by BPA exposure may enhance the risk of developing type II diabetes.

The binding interface database (BID): a compilation of amino acid hot spots in protein interfaces

SUMMARY

To make information about protein interactive function easily accessible, we are mining the primary scientific literature for detailed data about protein interfaces. The Binding Interface Database (BID) organizes the vast amount of protein interaction information into tables, graphical contact maps and descriptive functional profiles. Currently data on 170 interacting protein pairs are available with over 1300 mutations described.

AVAILABILITY

The BID database is freely available at http://tsailab.org/BID/ To have your protein of interest entered, contact Tiffany Fischer (tiffbrink@neo.tamu.edu) or Jerry Tsai at the email below

Nongenomic actions of estrogens and xenoestrogens by binding at a plasma membrane receptor unrelated to estrogen receptor alpha and estrogen receptor beta

The molecular mechanism used by environmental chemicals to exert their hormone-like actions is still only partially resolved. Although it generally is accepted that xenoestrogens act at the genomic level by binding to intracellular estrogen receptors, we have shown here that they trigger nongenomic effects in pancreatic beta cells. Both xenoestrogens and the circulating hormone, 17beta-estradiol, bind with high affinity to a common membrane binding site unrelated to the intracellular estrogen receptors ERalpha and ERbeta. This binding site is shared by dopamine, epinephrine, and norepinephrine and has the pharmacological profile of the gammaadrenergic receptor. This study provides an outline of the membrane receptor involved in rapid xenoestrogen actions.

Nutrient toxicity in pancreatic beta-cell dysfunction

Nutrients, such as glucose and fatty acids, have a dual effect on pancreatic beta-cell function. Acute administration of high glucose concentrations to pancreatic beta-cells stimulates insulin secretion. In addition, short term exposure of this cell type to dietary fatty acids potentiates glucose-induced insulin release. On the other hand, long-term exposure to these nutrients causes impaired insulin secretion, characterized by elevated exocytosis at low concentrations of glucose and no response when glucose increases in the extracellular medium. In addition, other phenotypic changes are observed in these conditions. One major step in linking these phenotypic changes to the diabetic pathology has been the recognition of both glucose and fatty acids as key modulators of beta-cell gene expression. This could explain the adaptative response of the cell to sustained nutrient concentration. Once this phase is exhausted, the beta-cell becomes progressively unresponsive to glucose and this alteration is accompanied by the irreversible induction of apoptotic programs. The aim of this review is to present actual data concerning the development of the toxicity to the main nutrients glucose and fatty acids in the pancreatic beta-cell and to find a possible link to the development of type 2 diabetes.

Engineering pancreatic islets

Pancreatic islets are neuroendocrine organs that control blood glucose homeostasis. The precise interplay of a heterogeneous group of cell populations (beta, alpha, delta and PP cells) results in the fine-tuned release of counterbalanced hormones (insulin, glucagon, somatostatin and pancreatic polypeptide respectively). Under the premises of detailed knowledge of the physiological basis underlying this behaviour, two lines of investigation might be inferred: generating computational and operational models to explain and predict this behaviour and engineering islet cells to reconstruct pancreatic endocrine function. Whilst the former is being fuelled by new computational strategies, giving biophysicists the possibility of modelling a system in which new "emergent" properties appear, the latter is benefiting from the useful tools and strategic knowledge achieved by molecular, cell and developmental biologists. This includes using tumour cell lines, engineering islet cell precursors, knowledge of the mechanisms of differentiation, regeneration and growth and, finally, therapeutic cloning of human tissues. Gaining deep physiological understanding of the basis governing these processes is instrumental for engineering new pancreatic islets.

Non-genomic actions of 17beta-oestradiol in mouse pancreatic beta-cells are mediated by a cGMP-dependent protein kinase

1. Intracellular calcium concentration ([Ca2+]i) was measured in mouse whole islets of Langerhans using the calcium-sensitive fluorescent dye Indo-1. 2. Application of physiological concentrations of 17beta-oestradiol in the presence of a stimulatory glucose concentration (8 mM) potentiated the [Ca2+]i signal in 83 % of islets tested. Potentiation was manifested as either an increase in the frequency or duration of [Ca2+]i oscillations. 3. The effects caused by 17beta-oestradiol were mimicked by the cyclic nucleotide analogues 8-bromoguanosine-3',5'-cyclic monophosphate (8-Br-cGMP) and 8-bromoadenosine-3',5'-cyclic monophosphate (8-Br-cAMP). 4. Direct measurements of both cyclic nucleotides demonstrated that nanomolar concentrations of 17beta-oestradiol in the presence of 8 mM glucose increased cGMP levels, yet cAMP levels were unchanged. The increment in cGMP was similar to that induced by 11 mM glucose. 5. Patch-clamp recording in intact cells showed that 8-Br-cGMP reproduced the inhibitory action of 17beta-oestradiol on ATP-sensitive K+ (KATP) channel activity. This was not a membrane-bound effect since it could not be observed in excised patches. 6. The action of 17beta-oestradiol on KATP channel activity was not modified by the specific inhibitor of soluble guanylate cyclase (sGC) LY 83583. This result indicates a likely involvement of a membrane guanylate cyclase (mGC). 7. The rapid decrease in KATP channel activity elicited by 17beta-oestradiol was greatly reduced using Rp-8-pCPT-cGMPS, a specific blocker of cGMP-dependent protein kinase (PKG). Conversely, Rp-cAMPS, which inhibits cAMP-dependent protein kinase (PKA), had little effect. 8. The results presented here indicate that rapid, non-genomic effects of 17beta-oestradiol after interaction with its binding site at the plasma membrane of pancreatic beta-cells is a cGMP-dependent phosphorylation process.

Lysophospholipids trigger calcium signals but not DNA synthesis in cortical astrocytes

Astrocytes generate calcium signals and proliferate in response to a growth factor-like lipid bound to plasma and serum albumin, in a process likely to be important in the formation of glial scars. A number of potential candidates for the physiologically active lipid were investigated. Lysophosphatidic acid, lysophosphatidylcholine, sphingomyelin, and platelet-activating factor all elicited calcium signals of varying magnitudes in cortical astrocytes, although only lysophosphatidic acid elicited calcium signals comparable in amplitude to those induced by the active physiological lipid. None of these lipids, however, caused cell division in astrocytes. There is therefore no invariable relationship between the ability of lipids to induce calcium signals and mitogenic activity. None of the lipids investigated demonstrate the activity of the natural lipid factor in generating both calcium signals and mitotic activity in astrocytes.

Actions of serum and plasma albumin on intracellular Ca2+ in human endothelial cells

1. The effects of serum and plasma albumin on [Ca2+]i in human endothelial cells were examined using single-cell Ca2+ imaging. Two types of endothelial cell were used: human umbilical vein endothelial cells (HUVEC) in primary culture, and the endothelial-derived cell line ECV304. 2. Serum albumin caused a large and transient rise in [Ca2+]i, due to Ca2+ release from an IP3-sensitive internal store, followed by a maintained elevation in [Ca2+]i attributable to Ca2+ influx from the external medium. A half-maximal rise in [Ca2+]i was produced by a concentration of serum albumin of about 1 microgram ml-1. 3. The Ca(2+)-releasing action of serum albumin is abolished by methanol extraction and is therefore attributable to an attached polar lipid. A possible candidate is lysophosphatidic acid, known to be released from platelets during blood coagulation, which produced similar effects to those of serum albumin. 4. In HUVEC, plasma albumin caused a sustained decrease in [Ca2+]i from the mean resting level of 114 nM to 58 nM. No effect of plasma albumin was observed in ECV304 cells. 5. The decrease in [Ca2+]i caused by plasma albumin is due to an uptake into intracellular stores. The store loading substantially potentiates the action of Ca(2+)-releasing agonists such as histamine. 6. The results show that normal plasma albumin, which carries few lipids, lowers [Ca2+]i and potentiates the actions of Ca(2+)-releasing agonists by promoting Ca2+ uptake into intracellular stores. When converted to the serum form, by binding lysophosphatidic acid released during blood coagulation, albumin has a potent effect in elevating [Ca2+]i. Blood coagulation may therefore play a role in regulating vascular tone and capillary permeability.

Comparison of two different PCR detection methods. Application to the diagnosis of pulmonary tuberculosis

The objectives are to assess the influence of the detection of the amplified DNA fragment on the sensitivity and specificity of the polymerase chain reaction (PCR). One hundred seventy-five sputum samples from 123 patients were processed. Sixty samples were taken from 60 subjects without tuberculosis, and the rest were taken from subjects with tuberculosis confirmed by culture. A fragment of the IS6110 sequence of Mycobacterium tuberculosis, which was detected using two different methods, was amplified. The detection methods used were a digoxigenin-labeled specific probe and chemiluminescent development and reamplification (nested PCR) combined with agarose gel electrophoresis. Sensitivity with probe detection was 75.65% and specificity 100%. Using the nested PCR technique, sensitivity rose to 93.04%, but specificity decreased to 96.6%. PCR is a quick and adequate way to diagnose pulmonary tuberculosis in cases where staining is negative yet there is a clinical suspicion of tuberculosis, even though a standardization process and large scale evaluation are still needed to determine its true usefulness.

[Detection of Mycobacterium tuberculosis in sputum using PCR and chemoluminescent display]

BACKGROUND

Polymerase chain reaction (PCR) using a probe with revealed chemoluminescence applied to the rapid diagnosis of pulmonary tuberculosis was used to detect Mycobacterium tuberculosis in sputum samples.

METHODS

The sputum samples were treated with proteinase K, SDS, NaOH and CTAB. A fragment of the IS6110 sequence of Mycobacterium tuberculosis detected by a probe marked with digoxigenin and revealed chemoluminescence was amplified.

RESULTS

The detection limit of the technique was situated at 10 mycobacteria per sample. Of 120 samples with a positive culture, 88 were positive by chemoluminescence probe (73.3%). The sensitivity decreased to 68.6% (35/51) in samples with negative staining and positive culture.

CONCLUSIONS

The application of molecular biology techniques are a good diagnostic alternative in samples with negative staining and clinical suspicion of tuberculosis. Our system is a cheaper alternative than the commercial systems and is applicable in laboratories unable to use radioactive isotopes.

Plasma albumin induces calcium waves in rat cortical astrocytes

Changes in intracellular calcium were monitored in cultured cortical astrocytes stimulated with albumin. Albumin elicited intracellular calcium mobilisation from intracellular stores, inducing repetitive intracellular calcium oscillations. The oscillations were not blocked by ryanodine, a blocker of the Ca-induced Ca release mechanism, and the release occurred from the same store as is accessed by glutamate and bradykinin, both of which release calcium by an IP3-dependent mechanism. Calcium signals induced by albumin appear therefore to occur via a pure IP3-dependent mechanism. When albumin was applied to confluent monolayers of astrocytes, the oscillations in individual cells were initially unsynchronised, but after several minutes of application, the Ca2 oscillations were observed to synchronise and spread through the astrocyte network as a wave. These intercellular calcium waves were inhibited by the gap junction blocker halothane. Using the fluorescence recovery after photobleaching (FRAP) technique, we demonstrate that the development of propagated waves with prolonged exposure to albumin does not result from an increase in cell coupling. The development of calcium waves on exposure to albumin may be important in the formation of glial scars in the CNS after breakdown of the blood-brain barrier.

Adenosine 5'-triphosphate (ATP) receptors induce intracellular calcium changes in mouse leydig cells

Cytoplasmic calcium ([Ca(2+)](i)) changes evoked by adenosine 5(1)-triphosphate (ATP) were recorded in cultured individual Leydig cells within 10-18 h after cell dispersion. [Ca(2+)](i) was monitored using Fura-2AM loaded cells with a digital ratio imaging system. Five micromolars ATP induced biphasic [Ca(2+)](i) responses in most cells (94%,n=100), characterized by a fast increase from a basal level (126±5 nMSE,n=60 cells) to a peak (5-7 times above basal levels) within seconds, followed by a slow decrease toward a plateau level (2-3 times above basal) within 5 min. The peak phase of the [Ca(2+)](i) response increased with ATP concentrations (1-100 μM ATP) in a dose-dependent manner with an IC(50) of 5.9±1.2 μM, and it desensitized in a reversible manner with repeated application of 5 μM ATP at <5-min intervals. The [Ca(2+)](i) peak response was dependent on Ca(2+) release from an intracellular pool, whereas the plateau phase was dependent on extracellular [Ca(2+)]. ATP did not appear to induce formation of nonspecific membrane pores, since stimulation for 10 min with ATP (10-100 μM) in the presence of extracellular Lucifer yellow (LY) (5 mg/mL) did not result in dye loading of the cells. [Ca(2+)](i) transients were elicited by other adenosine nucleotides with an order of potencies (ATP>Adenosine diphosphate [ADP]>Adenosine> Adenosine monophosphate [AMP]) that was compatible with the expression of P(2) receptors. [Ca(2+)](i) responses were suppressed by the purinergic P(2) receptor antagonist, suramin. These results provide functional evidence for the expression of purinergic P(2) receptors in Leydig cells.

Albumin stimulates uptake of calcium into subcellular stores in rat cortical astrocytes

1. When albumin from either plasma or serum is applied at low concentrations to cortical astrocytes a decrease in the level of [Ca2+]i is observed. At higher concentrations trains of calcium spikes are seen. 2. Removal of the polar lipids which are normally bound to native albumin abolishes the ability to induce spikes, but the decrease in [Ca2+]i is unaffected. The decrease is abolished by the denaturation of albumin and is not reproduced by a number of other proteins, and is therefore a specific action of albumin. We conclude that native albumin has a dual agonist action: the decrease in [Ca2+]i is induced by the albumin protein molecule, while the spikes are induced by a lipid normally bound to it. 3. The decrease is rapid (fastest tau = 12 s) and the rate is dependent on the concentration of albumin. [Ca2+]i falls from 77 nM to around 34 nM in the presence of saturating levels of albumin, and this level appears to be maintained indefinitely. 4. The decrease is due to an uptake of calcium into subcellular stores, as it is not abolished by removal of external Ca2+ or Na+ but is abolished by thapsigargin and cyclopiazonic acid, which are specific inhibitors of the endoplasmic reticulum Ca(2+)-ATPase. 5. When the state of store filling after albumin application is probed with a pulse of glutamate it can be seen that stores fill with the same time course as the decrease in [Ca2+]i. The low level of [Ca2+]i in albumin must therefore be maintained by a suppression of calcium influx rather than by a continued uptake into stores. 6. The calcium uptake potentiates the efficacy of low concentrations of calcium-releasing agonists such as glutamate and bradykinin by almost an order of magnitude. 7. A possible function for the calcium uptake caused by albumin is to potentiate the production of calcium spike trains by promoting refilling of calcium stores in the intervals between spikes. The uptake may play a role in the response of astrocytes to damage in the CNS.

Plasma albumin is a potent trigger of calcium signals and DNA synthesis in astrocytes

Cells in the central nervous system are normally prevented from coming into contact with albumin and other protein components of blood by the existence of a tight blood-brain barrier. Astrocytes and other glial cells proliferate to form glial scars when the blood-brain barrier is breached. In this report we show that albumin is an important blood component responsible for inducing astrocyte proliferation. Albumin also generates maintained trains of calcium spikes in astrocytes. Neither activity depends on blood coagulation, as albumins from both serum and plasma are approximately equally effective. Methanol extraction of albumin abolishes both actions, and recombination of the methanol-extracted factor with extracted albumin restores full activity indistinguishable from that of native albumin. The factor is sensitive to lipase, and the solvent extraction profile is that of a polar lipid.

[Reticulocytopenia and neutropenia in 3 patients with idiopathic autoimmune hemolytic anemia]

Retyculocytopenia and neutropenia or both abnormalities are very infrequent findings during the evolution of patients with acquired autoimmune hemolytic anemia (AIHA). In this paper we describe the clinical cases of three patients with AIHA in whom six different periods of reticulocytopenia were identified; the first two patients also had neutropenia. At the moment of the diagnosis of the cytopenias, the patients did not have a systemic disease, a viral infection or received immunosuppression able to produce them. In every patient the bone marrow cellularity was increased mostly at the expense of normal and macroerythroblasts, containing significant amounts of the other hematopoietic cells. After the diagnosis of AIHA, the patients received supplementary treatment with folic acid which did not produce a remission. The remissions were related to steroids: the neutrophil counts increased importantly one to ten days after starting the steroid administration, whereas reticulocytes reappeared more slowly from 7 to 30 days post-initiation. In patients with AIHA the occurrence of reticulocytopenia and neutropenia have been related to several causes. The favorable responses to steroids in our cases suggests a relationship of steroid with the immunological changes in AHA. It should be pointed out that it is necessary to prolong the followup as done in our three cases. Although these cytopenias may be independent from the hemolytic anemia, we feel our cases suggest that they could be manifestations of a pathologic state not yet characterized.

[Total parenteral nutrition. A 1-year experience with 96 patients]

In 1987, ninety-six surgical patients, of whom 44 were premature or newborn babies and 52 were infants or older children, received total parenteral nutrition (T.P.N.) at our hospital. A peripheral venous line was utilized on forty patients in the first group and only on 9 in the second group. The excellent results yielded by T.P.N. are self-evident from the low mortality showed by these patients. Thirty-three out of the 44 neonates and premature infants with serious surgical problems survived, being noteworthy the occurrence of just 3 deaths within a series of 13 necrotizing enterocolitis. In the series of 52 infants and older children, composed of 13 digestive patients (with 5 liver transplants), 6 tumoral, 9 neurologic, 4 renal (2 transplantations), 18 cardiac, 1 thoracic and 1 burnt, only 9 patients died. The average duration of T.P.N. was 10 days in the group of premature and newborn infants and 6 days for the nursing infants and older children, save for the 8 patients in whom the treatment had to be prolonged for a few months. We conclude that T.P.N., when applied in time and of short duration should entail no risk at all. In neonate and premature infant a peripheral vein shall be the route of choice. In the nursing infant and older child a central venous line is preferable, if possible the superior vena cava or its major tributary veins.

[Bolande's tumor: significance of its early diagnosis and treatment]

Four patients diagnosed of having a tumor of Bolande and treated at our institution in the past ten years are presented. In two of them, early diagnosis was aided by prenatal echographic techniques; the other two diagnoses were suspected ar three and ten days of age because of an abdominal mass. The four of them underwent a complete study which included: a plain abdominal film, an ultrasound scan and an intravenous urogram; the last three patients were also surveyed by a CT scan of the abdomen. Surgery was undertaken early on all the patients, the time of operation being in every instance within the first month of life. A laparotomy was performed and, once the contralateral kidney had been carefully examined, a nephroureterectomy was implemented, having been able to preserve in all the cases the suprarenal gland in view of the benign nature of the tumor. A histologic study confirmed the diagnosis and revealed the complete delimitation of the tumor by the renal capsule. The authors underscore the importance of this tumor's suspicion in the face of any solid renal mass detected by prenatal echography or in the neonatal period, since early diagnosis and treatment are imperative in order to prevent the ensuing complications in the rare and unfortunate cases that show a malignant tumoral trend.

[The use of clomiphene and menotropins as inducers of multiple follicular growth in a program of in vitro fertilization]

In our IVF & related techniques program, clomiphene 50 mg was used from days 2 to 6 of the cycle in 20 patients and 20 cycles. (17 IVF patients and 3 GIFT patients) menotropins were also used in 2 different schemes: a) 2 ampules in alternated days (12 cases) and b) one ampule daily (8 cases). The patients with the daily scheme required lesser total dose of menotropins and developed higher estradiol levels, although this had none statistic significance, and they also developed a greater number of follicles. There were 16 laparoscopies for ovum capture and 53 oocytes were retrieved (30.2% mature) 10 oocytes were from the GIFT patients. 16 oocytes were fertilized and 8 cleaved. There was only one pregnancy from and IVF patient with the alternated scheme that ended with a first trimester abortion.

[Mediastinal teratomas. A clinical and pathologic study of 3 pediatric cases]

Mediastinal teratomas are reported in three children. Two cases: an eighteen-month-old female and a twelve-years-old female, were diagnosed of mature cystic teratoma. Third patient was a twelve-year-old male with an immature mediastinal teratoma. All tumors were located in anterior mediastinum. Mediastinal mature cystic teratomas were completely excised and their evolution were favourable. However, immature mediastinal teratoma infiltrated lung parenchyma and great blood vessels; in this case only a biopsy was performed. This patient died a month after surgical procedure. Clinical, radiological and pathological findings of mediastinal teratomas in childhood are commented. Prognostic factors and evolution of different histological types of mediastinal teratomas are evaluated.