Distribution of Escherichia coli Pathotypes along an Urban-Rural Gradient in Ecuador

Diarrheal diseases are a leading cause of mortality and morbidity in low- and middle-income countries. Diarrhea is associated with a wide array of etiological agents including bacterial, viral, and parasitic enteropathogens. Previous studies have captured between- but not within-country heterogeneities in enteropathogen prevalence and severity. We conducted a case-control study of diarrhea to understand how rates and outcomes of infection with diarrheagenic pathotypes of Escherichia coli vary across an urban-rural gradient in four sites in Ecuador. We found variability by site in enteropathogen prevalence and infection outcomes. Any pathogenic E. coli infection, coinfections, diffuse adherent E. coli (DAEC), enteroinvasive E. coli (EIEC), and rotavirus were significantly associated with acute diarrhea. DAEC was the most common pathotype overall and was more frequently associated with disease in urban areas. Enteropathogenic E. coli (EPEC) and enterotoxigenic E. coli (ETEC) were more common in rural areas. ETEC was only associated with diarrhea in one site. Phylogenetic analysis revealed that associations with disease were not driven by any single clonal complex. Higher levels of antibiotic resistance were detected in rural areas. Enteropathogen prevalence, virulence, and antibiotic resistance patterns vary substantially by site within Ecuador. The variations in E. coli pathotype prevalence and virulence in this study have important implications for control strategies by context and demonstrate the importance of capturing within-country differences in enteropathogen disease dynamics.

Corrigendum: Extended-Spectrum Beta-Lactamase Producing-Escherichia coli Isolated From Irrigation Waters and Produce in Ecuador

[This corrects the article DOI: 10.3389/fmicb.2021.709418.].

Extended-Spectrum Beta-Lactamase Producing-Escherichia coli Isolated From Irrigation Waters and Produce in Ecuador

In cities across the globe, the majority of wastewater – that includes drug resistant and pathogenic bacteria among other contaminants – is released into streams untreated. This water is often subsequently used for irrigation of pastures and produce. This use of wastewater-contaminated streams allows antibiotic-resistant bacteria to potentially cycle back to humans through agricultural products. In this study, we investigated the prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolated from produce and irrigation water across 17 provinces of Ecuador. A total of 117 vegetable samples, 119 fruit samples, and 38 irrigation water samples were analyzed. Results showed that 11% of the samples were positive for E. coli including 11 irrigation water samples (29%), and samples of 13 vegetables (11%), and 11 fruits (9%). Among the 165 E. coli isolates cultured, 96 (58%) had the ESBL phenotype, and 58% of ESBL producing E. coli came from irrigation water samples, 11% from vegetables, and 30% from fruits. The bla_CTX–M–55, bla_{CTX–M 65}, and bla_{CTX–M 15} genes were the most frequently found gene associated with the ESBL phenotype and coincided with the bla_CTX–M alleles associated with human infections in Ecuador. Three isolates had the mcr-1 gene which is responsible for colistin resistance. This report provides evidence of the potential role of irrigation water in the growing antimicrobial resistance crisis in Ecuador.

Gut Microbiome Changes with Acute Diarrheal Disease in Urban Versus Rural Settings in Northern Ecuador

Previous studies have reported lower fecal bacterial diversity in urban populations compared with those living in rural settings. However, most of these studies compare geographically distant populations from different countries and even continents. The extent of differences in the gut microbiome in adjacent rural versus urban populations, and the role of such differences, if any, during enteric infections remain poorly understood. To provide new insights into these issues, we sampled the gut microbiome of young children with and without acute diarrheal disease (ADD) living in rural and urban areas in northern Ecuador. Shotgun metagenomic analyses of non-ADD samples revealed small but significant differences in the abundance of microbial taxa, including a greater abundance of Prevotella and a lower abundance of Bacteroides and Alistipes in rural populations. Greater and more significant shifts in taxon abundance, metabolic pathway abundance, and diversity were observed between ADD and non-ADD status when comparing urban to rural sites (Welch's t-test, P < 0.05). Collectively our data show substantial functional, diversity, and taxonomic shifts in the gut microbiome of urban populations with, ADD supporting the idea that the microbiome of rural populations may be more resilient to ADD episodes.

Locals get travellers' diarrhoea too: risk factors for diarrhoeal illness and pathogenic Escherichia coli infection across an urban-rural gradient in Ecuador

OBJECTIVES

Diarrhoea is a common and well-studied cause of illness afflicting international travellers. However, traveller's diarrhoea can also result from travel between high and low disease transmission regions within a country, which is the focus of this study.

METHODS

We recruited participants for a case-control study of diarrhoea at four sites along an urban-rural gradient in Northern Ecuador: Quito, Esmeraldas, Borbón and rural communities outside of Borbón. At each of these sites, approximately 100 subjects with diarrhoea (cases) were recruited from Ministry of Health clinics and were age-matched with subjects visiting the same clinics for other complaints (controls).

RESULTS

Travellers to urban destinations had higher risk of diarrhoea and diarrhoeagenic Escherichia coli (DEC) infections. Travel to Quito was associated with diarrhoea (aOR = 2.01, 95% CI = 1.10-3.68) and travel to Guayaquil (another urban centre in Ecuador) was associated with Diffuse Adherent E. coli infection (OR = 2.09, 95% CI = 1.01-4.33). Compared to those not travelling, urban origins were also associated with greater risk of diarrhoea in Esmeraldas (aOR = 2.28, 95% CI = 1.20-4.41), and with higher risk of diarrhoeagenic E. coli infections in Quito (aOR = 2.61, 95% CI = 1.16-5.86), with >50% of travel from Quito and Esmeraldas specified to another urban destination.

CONCLUSIONS

This study suggests that individuals travelling from lower-transmission regions (rural areas) to higher transmission regions (urban centres) within a single country are at a greater risk of acquiring a diarrhoea-related illness. Investments to improve water, sanitation and hygiene conditions in urban areas could have impacts on outlying rural areas within a given country.

Live birth after replacement of an embryo obtained from a spontaneously in vitro matured metaphase-I oocyte

This case report describes a live birth after the fresh replacement of an embryo obtained from a spontaneously in vitro matured oocyte. The patient was subjected to controlled ovarian stimulation for IVF treatment, obtaining two oocytes. One was found to be immature at the time of denudation, at metaphase-I. This immature oocyte was kept in culture overnight in standard conditions along with the second oocyte - which was mature but failed to fertilize - spontaneously achieving metaphase-II, and was subjected to ICSI. The resulting embryo was replaced on the second day of development, producing a pregnancy that resulted in a healthy live birth. Post-denudation in vitro maturation could be considered as a tool to improve reproductive outcomes in selected patients, such as poor responders.

Hydroxypropyl cellulose supplementation in vitrification solutions: a prospective study with donor oocytes

PURPOSE

Hydroxypropyl cellulose (HPC), a polysaccharide that forms a viscous gel under low temperatures, is a promising substitute of the blood-derived macromolecules traditionally used in cryopreservation solutions. The performance of a protein-free, fully synthetic set of vitrification and warming solutions was assessed in a matched pair analysis with donor oocytes.

METHODS

A prospective study including 219 donor MII oocytes was carried out, comparing the laboratory outcomes of oocytes vitrified with HPC-based solutions and their fresh counterparts. The primary performance endpoint was the fertilization rate. Secondary parameters assessed were embryo quality on days 2 and 3.

RESULTS

70/73 (95.9%) vitrified MII oocytes exhibited morphologic survival 2 h post-warming, with 49 (70.0%) presented normal fertilization, compared to 105 of 146 (71.9%) MII fresh oocytes. Similar embryo quality was observed in both groups. A total of 18 embryos implanted, out of 38 embryos transferred (47.3%), resulting in 13 newborns.

Thermal and clinical performance of a closed device designed for human oocyte vitrification based on the optimization of the warming rate

Although it was qualitatively pointed out by Fahy et al. (1984), the key role of the warming rates in non-equillibrium vitrification has only recently been quantitatively established for murine oocytes by Mazur and Seki (2011). In this work we study the performance of a closed vitrification device designed under the new paradigm, for the vitrification of human oocytes. The vitrification carrier consists of a main straw in which a specifically designed capillary is mounted and where the oocytes are loaded by aspiration. It can be hermetically sealed before immersion in liquid nitrogen for vitrification, and it is warmed in a sterile water bath at 37 °C. Measured warming rates achieved with this design were of 600.000 ºC/min for a standard DMEM solution and 200.000 ºC/min with the vitrification solution for human oocytes. A cohort of 143 donor MII sibling human oocytes was split into two groups: control (fresh) and vitrified with SafeSpeed device. Similar results were found in both groups: survival (97.1%), fertilization after ICSI (74.7% in control vs. 77.3% in vitrified) and good quality embryos at day three (54.3% in control vs. 58.1% in vitrified) were settled as performance indicators. The pregnancy rate was 3/6 (50%) for the control, 2/3 (66%) for vitrified and 4/5 (80%) for mixed transfers.

Application of Hansen solubility approach for the subcritical and supercritical selective extraction of phlorotannins from Cystoseira abies-marina

A new theoretical approach based on Hansen solubility parameters has been employed for the first time to select the best green solvent to extract complex bioactive molecules such as phlorotannins from brown macroalgae Cystoseira abies-marina.

COPD patients with and without metabolic syndrome: clinical and functional differences

Chronic obstructive pulmonary disease (COPD) and the metabolic syndrome (MetS) are considered public health challenges of the 21st century. The coexistence of MetS in COPD patients and any clinical differences between COPD patients with and without MetS have not been extensively studied. We aimed to describe the clinical characteristics of patients with MetS and COPD. An observational, multicenter study of 375 patients hospitalized for a COPD exacerbation with spirometric confirmation was performed. We measured the components of the MetS and collected comorbidity information using the Charlson index and other conditions. Dyspnea, use of steroids, exacerbations, and hospitalizations were also investigated. The overall prevalence of MetS in COPD patients was 42.9 %, was more frequent in women (59.5 %) than men (40.8 %), p = 0.02, but with no differences in age and smoking history. COPD patients with MetS had greater % predicted FEV1, more dyspnea, and more comorbidity and used more inhaled steroids (all p < 0.05). Diabetes, osteoporosis, coronary artery disease, and heart failure were more frequent in patients with MetS. They had been hospitalized more frequently for any cause but not for COPD. In multivariate analysis, the presence of MetS was independently associated with greater FEV1, inhaled steroids use, osteoporosis, diabetes, and heart failure. MetS is a frequent condition in COPD patients, and it is associated with greater FEV1, more dyspnea, and more comorbidities.

Factors associated with mortality in patients with exacerbation of chronic obstructive pulmonary disease hospitalized in General Medicine departments

We aim to improve knowledge on risk factors that relate to mortality in subjects with exacerbation of chronic obstructive pulmonary disease (COPD) who are hospitalized in General Medicine departments. In a cross-sectional multicenter study, by means of a logistic regression analysis, we assessed the possible association of death during hospitalization with the following groups of variables of participating patients: sociodemographic features, treatment received prior to admission and during hospitalization, COPD-related clinical features recorded prior to admission, comorbidity diagnosed prior to admission, clinical data recorded during hospitalization, laboratory results recorded during hospitalization, and electrocardiographic findings recorded during hospitalization. A total of 398 patients was included; 353 (88.7%) were male, and the median age of the patients was 75 years. Of these patients, 21 (5.3%) died during hospitalization. Only 270 (67.8%) received inhaled β(2) agonists during hospitalization, while 162 (40.7%) received angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers. The median of predicted FEV(1) prior to admission was 42%. A total of 350 patients (87.9%) had been diagnosed with two or more comorbid conditions prior to admission. An association was found between increased risk of death during hospitalization and the previous diagnoses of pneumonia, coronary heart disease, and stroke. In conclusion, comorbidity is an important contributor to mortality among patients hospitalized in General Medicine departments because of COPD exacerbation.

[Study of the comorbidities in hospitalized patients due to decompensated chronic obstructive pulmonary disease attended in the Internal Medicine Services. ECCO Study]

OBJECTIVE

Evaluate comorbidity in patients hospitalized due to COPD in the Internal Medicine services.

METHODS

An observational, prospective and multicenter study. The Charlson index and a specific questionnaire were used.

RESULTS

A total of 398 patients, 353 men (89%), with mean age of 73.7 years (8.9) and mean FEV(1) of 43.2% (12.5), were included. The most frequent comorbidities were: arterial hypertension (55%), arrhythmias (27%) and diabetes mellitus (26%). A total of 27% suffered heart failure, 17% coronary disease and 9% previous myocardial infarction. The number of associated chronic diseases was 3.6 (1,8). Score on Charlson index was 2.72 (2).

CONCLUSIONS

The patients hospitalized due to decompensated COPD had an elevated comorbidity.

Chemical characterization of emissions from modern two-stroke mopeds complying with legislative regulation in Europe (EURO-2)

In view of a new amendment to the European legislative regulation on emissions from two-stroke mopeds a study was carried out to comprehensively characterize exhaust gases of mopeds complying current EURO-2 emission standards. Three mopeds with different engine types (carburetor, direct injection, and electronic carburetion system ECS) where investigated by applying two different driving cycles, the legislative cycle ECE47 and the worldwide motorcycle test cycle WMTC. Thereby, particulate matter (PM), regulated compounds, carbonyls, volatile hydrocarbons (VOC), and particle-associated polyaromatic hydrocarbons (PAH) were analyzed and ozone formation potentials (OFP) as well as toxicity equivalents (TEQ) determined. The ECE47 emission factors for almost all species and moped types were much higher in the nonregulated, prior cold phase than in the hot phase, which is considered for legislation. Great differences for the mopeds could be observed for NO(x), VOC, and PM, whereas discrepancies between the driving cycles ECE47 and WMTC were smaller. In addition, a positive influence on exhaust composition caused by technical modifications of the ECS engine was determined. Results indicate that regulation of total hydrocarbons (THC) alone might not be sufficient to regulate PM, especially for direct injection engines. Moreover, recommendations for a revised future test protocol are demonstrated and discussed, whereby the cold phase and the hot phase are taken into account.

Human c-Myc isoforms differentially regulate cell growth and apoptosis in Drosophila melanogaster

The human c-myc proto-oncogene, implicated in the control of many cellular processes including cell growth and apoptosis, encodes three isoforms which differ in their N-terminal region. The functions of these isoforms have never been addressed in vivo. Here, we used Drosophila melanogaster to examine their functions in a fully integrated system. First, we established that the human c-Myc protein can rescue lethal mutations of the Drosophila myc ortholog, dmyc, demonstrating the biological relevance of this model. Then, we characterized a new lethal dmyc insertion allele, which permits expression of human c-Myc in place of dMyc and used it to compare physiological activities of these isoforms in whole-organism rescue, transcription, cell growth, and apoptosis. These isoforms differ both quantitatively and qualitatively. Most remarkably, while the small c-MycS form truncated for much of its N-terminal trans-activation domain efficiently rescued viability and cell growth, it did not induce detectable programmed cell death. Our data indicate that the main functional difference between c-Myc isoforms resides in their apoptotic properties and that the N-terminal region, containing the conserved MbI motif, is decisive in governing the choice between growth and death.

Optimized method for the determination of 25 polychlorinated biphenyls in water samples using stir bar sorptive extraction followed by thermodesorption-gas chromatography/mass spectrometry

An optimized method using stir bar sorptive extraction (SBSE) for the determination of 25 polychlorinated biphenyls (PCBs) from water samples among them three of the most toxic coplanar PCBs (PCB 77, PCB 126 and PCB 169) was developed. Since the investigated PCBs comprise all steps of chlorination (from PCB 1 as monochlorobiphenyl to PCB 209 as decachlorobiphenyl) the results should be representative for the total class of the 209 PCB congeners. For 8 ml spiked water samples with 2 ml methanol addition and 2 h exposure time of stir bars recoveries between 28% (PCB 209) and 93% (PCB 1, PCB 52, PCB 77) were found. Detection limits between 0.05 ng/l and 0.15 ng/l were calculated for the combination of SBSE and thermodesorption-GC/MS. The procedure was applied to the investigation of groundwater and river water samples from the industrial region of Bitterfeld northern Leipzig, Germany.

Determination of phenols in lake and ground water samples by stir bar sorptive extraction–thermal desorption–gas chromatography–mass spectrometry

A simple and inexpensive method for sorptive extraction of phenols from water samples is presented. A polydimethyl siloxane (PDMS) stir bar (Twister) is used as an extraction medium for derivatized phenols, which is thermally desorbed and analyzed by gas chromatography-mass spectrometry (GC-MS). Its performance was illustrated and evaluated for the enrichment of microg l(-1) to ng l(-1) of phenol and selected chlorophenols in water samples. The method showed good linearity, recoveries and blank levels, as well as advantages such as sensitivity, simplicity, low cost and high feasibility, being successfully applied for the analysis of phenolic compounds in natural water samples.

Polydimethylsiloxane rod extraction, a novel technique for the determination of organic micropollutants in water samples by thermal desorption-capillary gas chromatography-mass spectrometry

A novel, simple and inexpensive approach to absorptive extraction of organic compounds from environmental samples is presented. It consists of a polydimethylsiloxane rod used as an extraction media, enriched with analytes during shaking, then thermally desorbed and analyzed by GC-MS. Its performance was illustrated and evaluated for the enrichment of sub- to ng/l of selected chlorinated compounds (chlorobenzenes and polychlorinated biphenyls) in water samples. The new approach was compared to the stir bar sorptive extraction performance. A natural ground water sample from Bitterfeld, Germany, was also extracted using both methods, showing good agreement. The proposed approach presented good linearity, high sensitivity, good blank levels and recoveries comparable to stir bars, together with advantages such as simplicity, lower cost and higher feasibility.

Measurements of atmospheric carboxylic acids and carbonyl compounds in São Paulo City, Brazil

Winter atmospheric measurements of gaseous lower carbonyl and carboxylic acids were carried out simultaneously (in 1999) at two distinct urban sites located in the city of São Paulo, Brazil. The greater metropolitan area of São Paulo is the largest industrialized region of Latin America and has a highly polluted atmosphere. It has an unconventional mix of vehicle types in that a variety of gasoline blends, including oxygenated ones, are used. Mixing ratios of formic and acetic acids ranged, respectively, from 0.6 to 19.4 and from 0.1 to 10.6 ppbv in one of the sites studied and from 1.4 to 18.4 and from 0.4 to 6.7 ppbv in the other site. High values of formic to acetic ratios were found, especially in the latter site (average = 4.3), suggesting that photochemical production was the predominant source of the formic and acetic acid during the afternoon. Differing from the acids, levels of carbonyls were similar at both sites. Higher average mixing ratios of acetaldehyde and formaldehyde were found in the morning (18.9 and 17.2 ppbv) and gradually decreased from midday (9.5 and 11.8 ppbv) to evening (7.2 and 10.2 ppbv). In the morning, vehicular direct emission seemed to be the main primary source of formaldehyde and acetaldehyde, whereas at midday and evening these compounds appeared to be mainly formed by photochemistry. Secondary photochemical production of organic acids and aldehydes (rather than primary emissions from vehicles) was shown to be more important in São Paulo's atmosphere from midday to evening, particularly on days with strong solar radiation.

Regulation by p38 mitogen-activated protein kinase of adenylate- and uridylate-rich element-mediated urokinase-type plasminogen activator (uPA) messenger RNA stability and uPA-dependent in vitro cell invasion

MDA-MB-231 cells are highly metastatic breast tumor cells. Their high invasiveness is thought to be due to constitutively high levels of urokinase-type plasminogen activator (uPA) and its receptor. Previously (R. Nanbu et al., C. Eur. J. Biochem., 247: 169-174, 1997), we showed that uPA mRNA in these cells is stable and that mRNA degradation mediated by an AU-rich element (ARE) is impaired. Here we report that treatment of MDA-MB-231 cells with SB203580, an inhibitor of the stress-activated p38 mitogen-activated protein (MAP) kinase, strongly destabilized uPA mRNA in an ARE-dependent manner. In contrast, in LLC-PK1 and HeLa cells, uPA mRNA is unstable, and an ARE present in the 3' untranslated region plays a role in its degradation. Enhanced ARE-mediated mRNA destabilization induced by SB203580 was also observed in both LLC-PK1 and HeLa cells with a globin chimeric mRNA harboring two copies of the ARE (globin-2ARE) from uPA mRNA. Overexpression of constitutively active MKK6, a p38 upstream activator kinase, increased the stability of the globin-2ARE message in LLC-PK1 cells, confirming the participation of p38 in the regulation of ARE-mediated mRNA decay. Interestingly, the half-life of the uPA mRNA in the three cell lines studied correlated with the basal levels of active p38. SB203580 treatment of MDA-MB-231 cells decreased cell-associated uPA activity and dramatically reduced in vitro cell invasiveness. These results suggest the participation of p38 in the control of invasiveness through regulation of the stability of uPA and uPA receptor mRNA, which is also destabilized by p38.

The plasminogen activator system: biology and regulation

The regulation of plasminogen activation involves genes for two plasminogen activators (tissue type and urokinase type), two specific inhibitors (type 1 and type 2), and a membrane-anchored urokinase-type plasminogen-activator-specific receptor. This system plays an important role in various biological processes involving extracellular proteolysis. Recent studies have revealed that the system, through interplay with integrins and the extracellular matrix protein vitronectin, is also involved in the regulation of cell migration and proliferation in a manner independent of proteolytic activity. The genes are expressed in many different cell types and their expression is under the control of diverse extracellular signals. Gene expression reflects the levels of the corresponding mRNA, which should be the net result of synthesis and degradation. Thus, modulation of mRNA stability is an important factor in overall regulation. This review summarizes current understanding of the biology and regulation of genes involved in plasminogen activation at different levels.

[Prevalence of the 185Ag deletion of the BRCA1 gene in Chilean women with breast neoplasm]

BACKGROUND

The most important identified pathogenic factor for breast cancer is the presence of mutations in BRCA1 gene. These are associated with familial breast cancer in up to 80% of cases. The most frequent mutation of BRCA1 gene in Caucasian populations is the exon 2 185AG deletion.

AIM

To study the presence of 185AG deletion in Chilean women with sporadic or familial breast cancer.

PATIENTS AND METHODS

We studied 15 women with familial breast cancer, in whom at least one close relative was affected, and 40 women with sporadic breast cancer. In genomic DNA obtained from a blood sample, an allele specific polymerase chain reaction was done. This reaction allows the identification of 185AG deletion and uses two pairs of primers. One for the native form that renders a 118 base pairs product and one for the deletion that renders a 170 base pairs product, both with a respective 280 base pairs internal control.

RESULTS

The diagnosis of breast cancer was done at 40 +/- 5 and 65 +/- 10 years old in women with familial and sporadic breast cancer, respectively. In none of the samples, the amplification of the 170 base pairs band that corresponds to 185AG deletion, was obtained. In both groups, the product of the amplification was the 118 base pairs band, that corresponds to the native form of BRCA1 gene. The polymerase chain reaction was optimized for a duration of 90 minutes.

CONCLUSIONS

185AG deletion of BRCA1 gene was not detected in this group of Chilean women with sporadic or familial breast cancer.

Insulin inhibits delta-aminolevulinate synthase gene expression in rat hepatocytes and human hepatoma cells

Insulin has been known to regulate intracellular metabolism by modifying the activity or location of many enzymes but it is only in the past few years that the regulation of gene expression is recognized to be a major action of this hormone. The present work provides evidences that insulin inhibits delta-aminolevulinate synthase (ALA-S) gene expression, the enzyme which governs the rate-limiting step in heme biosynthesis. The addition of 5 nM insulin to hepatocytes culture led to a significant decrease of both basal and phenobarbital-induced ALA-S mRNA in a dose-dependent manner, as measured by Northern and slot-blot analysis. Several clues as to how insulin regulates ALA-S transcription were determined. The inhibitory effect is achieved at physiological concentrations but much higher proinsulin doses are needed. Insulin's effect is rapid, quite specific, and protein synthesis is not required. Moreover, ALA-S mRNA half-life is not modified by the presence of the peptidic hormone. Our results demonstrate that the insulin effect is dominant; it overrides 8-CPT-cAMP plus phenobarbital-mediated induction. Also, insulin requires the activation of protein kinase C to exert its full effect. On the other hand, a 870-bp fragment of the ALA-S promoter region is able to sustain the inhibition of CAT expression in plasmid-transfected HepG2 cells. Thus, these results indicate that insulin plays an important role in regulating ALA-S expression by inhibiting its transcription.

Enhanced stability of urokinase-type plasminogen activator mRNA in metastatic breast cancer MDA-MB-231 cells and LLC-PK1 cells down-regulated for protein kinase C--correlation with cytoplasmic heterogeneous nuclear ribonucleoprotein C

In LLC-PK1 cells, urokinase-type plasminogen activator (uPA) mRNA has a short half-life of 70 min. We have previously demonstrated that most of the regulatory regions responsible for the rapid turnover of uPA mRNA in LLC-PK1 cells reside in its 3' untranslated region (3' UTR), where there are at least three regulatory sites, one of which is A+U-rich. This A+U-rich sequence mediates uPA mRNA stabilization induced by protein kinase C (PKC) down-regulation. In this work, we found that uPA mRNA is rather stable in MDA-MB-231 cells with a half-life of 17 h. We compared the stability of hybrid globin mRNA containing different parts of uPA mRNA in its 3' UTR and found that the A+U-rich sequence of uPA mRNA renders otherwise stable globin mRNA unstable in LLC-PK1 cells but not in MDA-MB-231 cells. We identified a cytoplasmic protein of 40 kDa (p40) which specifically interacts with the A+U-rich sequence. Levels of p40 activity as detected by ultraviolet cross-linking were higher in MDA-MB-231 and PKC-down-regulated LLC-PK1 cells than in untreated LLC-PK1 cells. Prior treatment of the cytoplasm with a specific antibody against heterogeneous nuclear ribonucleoprotein C (hnRNP C) significantly reduced p40 activity. These results suggest a correlation between the A+U-rich sequence-dependent uPA mRNA stabilization in vivo and the binding of hnRNP C to the A+U-rich sequence in vitro.

Single aberrant umbilical artery in a fetus with severe caudal defects: sirenomelia or caudal dysgenesis

We describe a 1,000-g twin fetus with absent kidneys and ureters, anal atresia and minimal evidence of external genitalia, and hypoplastic lower limbs with absent feet. A postmortem arteriogram showed a large single umbilical artery in direct continuation with the abdominal aorta, a unique anomaly almost always related to sirenomelia. We discuss the possible diagnosis of this case as sirenomelia or caudal dysgenesis, and the controversy as to whether they are two related or separate entities.

A comparative study of the efficacy, safety and tolerability of azithromycin and cefaclor in the treatment of children with acute skin and/or soft tissue infections

An open, multicentre study was carried out in 200 paediatric patients between 6 months and 12 years of age with skin and/or soft tissue infections (mild-to-moderate dermatological conditions and abscesses) to compare the efficacy and safety of azithromycin and cefaclor oral suspensions. Patients were randomly assigned to receive either azithromycin (10 mg/kg once daily for 3 days) or cefaclor (20 mg/kg/day in three divided doses for 10 days). The clinical efficacy of both treatments was comparable: 92/98 (94%) of the evaluable azithromycin patients were cured or improved as were 93/98 (95%) of those treated with cefaclor. Before treatment, 74 pathogens were isolated from 60 of the azithromycin- and 80 pathogens from 66 of the cefaclor-treated patients. In the azithromycin group, 70/74 (95%) pathogens were eradicated, as were 79/80 (99%) pathogens in the cefaclor group. All 200 patients were evaluable for safety analyses. Both drugs were well tolerated, with a low incidence of side-effects: 3/100 (3%) in the azithromycin group and 2/100 (2%) in the cefaclor group. No patient in either treatment group withdrew from the study because of adverse events. In conclusion, azithromycin is as effective and as well tolerated as cefaclor in the treatment of children with skin and/or soft tissue infections.

Enzymatic and immunological detection of G protein alpha-subunits in the pathogenic fungus Candida albicans

GTP stimulation of adenylyl cyclase from the dimorphic pathogenic fungus Candida albicans is greatly enhanced by preincubation of membrane proteins with cholera toxin, NAD and ATP. In the presence of [32P]NAD the toxin catalyzes the covalent incorporation of radioactivity into a membrane protein of 40 kDa. Pertussis toxin catalyzes the transference of the radioactivity from [32P]NAD to a 32 kDa protein. Two major proteins of 40-42 and 30-32 kDa can also be recognized in Western blots by an anti G alpha-common antibody. The results support the idea that G proteins are part of the hormone sensory transduction chain of Candida [(1990) Biochem. Biophys. Res. Commun. 167, 1177-1183].

[Gastric neurofibroma. Report of 2 cases]

Two patients consulting for upper gastrointestinal bleeding, associated to impaired gastric emptying in one, were studied with X rays and endoscopy. A gastric neurofibroma was confirmed by histologic study in both patients. One patient was submitted to subtotal gastrectomy. An endoscopic resection of the tumor was performed in the other.