Characterization of enteroaggregative Escherichia coli strains isolated from children with acute diarrhea, in Mendoza, Argentina

Enteroaggregative Escherichia coli (EAEC) is an increasingly recognized cause of diarrhea in children in developing and developed countries. EAEC is recognized by a characteristic aggregative pattern of adherence to human epithelial (HEp-2) cells cultured in vitro. This is the gold standard assay. The aggregative phenotype is associated with the presence of a 65 MDa plasmid (pAA) that also encodes several other putative virulence factors, such as the aggregative adherence fimbria I (AAF/I) and the enteroaggregative heat-stable enterotoxin (EAST1). The objective of this work was to evaluate the application of PCR (polymerase chain reaction) to identify EAEC strains in cases of acute diarrhea. A total of 87 E. coli strains, isolated from patients under 2 years of age with acute diarrhea in Mendoza, Argentina, were characterized by the reference method (HEp-2 assay), and by AAF/I- and EAST1-PCR. PCR sensitivity and specificity in comparison with the cell culture assay showed 94.4% sensitivity and 78.26% specificity. EAST1- and AAF/I-PCR could be recommended as a screening test, applicable to epidemiologic studies.

Combined therapy in the treatment of primary mediastinal B-cell lymphoma: conventional versus escalated chemotherapy

Treatment of patients with primary mediastinal B-cell lymphoma (PMBCL) remains controversial. We started a controlled clinical trial to evaluate the efficacy and toxicity of a conventional versus more intensive regimen of combined chemotherapy followed by radiotherapy to the mediastinum with the mantle technique. From 1989 to 1997, 68 patients diagnosed with previously untreated PMBCL, aged 18-65 years and negative for immunodeficiency virus test, were considered candidates to receive either conventional chemotherapy with CEOP-Bleo (cyclophosphamide 750 mg/m(2), vincristine 1.4 mg/m(2), prednisone 40 mg/m(2), epirubicin 70 mg/m(2), and bleomycin 10 mg/m(2)) or mega CEOP-Bleo (cyclophosphamide 1000 mg/m(2), epirubicin 120 mg/m(2), vincristine, prednisone, and bleomycin at the same doses) every 21 days for six cycles, followed by radiotherapy to the mediastinum with the mantle technique (35-45 Gy, mean 38 Gy). Complete response (CR) rates were not statistically different: 64% [95 percent confidence interval (CI): 58 percent to 70 percent] for conventional arm vs 81 percent (95 CI: 77-86 percent) in the intensive group (p=0.2). However, failure-free survival (FFS) and overall survival (OS) had statistical differences. At 5 years, actuarial FFS for patients treated with conventional chemotherapy was 51 percent (95 percent CI: 44-59 percent) compared to 70 percent (95 percent CI: 65-76 percent) in the intensive arm (p>0.01). OS rates were also different: 54 percent (95 percent CI: 48-57 percent) vs 70 percent (95 percent CI: 65-76 percent), respectively (p<0.01). Toxicity was mild and no therapy-related deaths were observed. At a median follow-up of 7.3 years, no second neoplasia or acute leukemia has been observed. The international prognostic index was not useful to define clinical risk in this selected group of patients. Multivariate analysis identified pleural and pericardial effusion and chemotherapy regimen as prognostic factors influencing FFS and OS. We feel that patients with PMBCL should be treated with more intensive, but not myeloablative chemotherapy, followed by adjuvant radiotherapy to achieve an improvement in outcome in this setting of patients. Patients with pleural or pericardial effusion are considered at high risk for failure with the actual programs of treatment and probably will be considered for experimental therapeutic approaches.

Evaluation of the residual antigenicity and allergenicity of cow's milk substitutes by in vitro tests

BACKGROUND

This study aimed the to investigate presence of residual allergenic cow's milk proteins (CMP) in some milk substitutes employed in the treatment of cow's milk allergy (CMA). These allergens may interfere with the treatment, and elicit allergic reactions in sensitized individuals.

METHODS

The protein composition of the different extracts was evaluated by Lowry's method and tricine SDS-PAGE. Different immunoenzymatic methods were used (ELISA, EAST and immunoblotting) to quantify total serum IgE and specific serum IgE, as well as to detect the presence of antigenic and allergenic components.

RESULTS

The results showed a higher protein content in mammalian milks (cow, sheep, mare, goat, and human) than in hydrolyzed substitutes (partially or extensively hydrolyzed casein or whey proteins). Residual native, processed, or contaminant polypeptides have been identified in the moderate hydrolysates, whereas extensive hydrolysates did not show the presence of residual components by immunoblotting. However, specific antibodies with capacity to bind to peptides have been detected by EAST and ELISA, suggesting that extensive hydrolysates contain residual peptides that preserve immunoreactive epitopes. We were unable to demonstrate either residual antigenicity or allergenicity in an amino-acid-based formula.

CONCLUSIONS

Immunoenzymatic methods were used to detect the presence of cross-reactive components in mammalian milks. Residual allergenic components from cow's milk could be identified in both the moderate and extensive hydrolysates analyzed. This information may be relevant to the treatment of CMA.

[Late rupture of central catheter implanted through subclavian route]

A 68-year-old woman with a subcutaneous reservoir and central venous catheter implanted in the left subclavian vein for chemotherapy developed a late fracture of the catheter 220 days after implantation, with migration of the distal fragment to the pulmonary artery. After diagnosis of the complication, the distal fragment had to be removed by radiologic intervention and the reservoir was withdrawn. The need for central venous treatments, whether for definitive parenteral nutrition or prolonged antibiotic infusion, pain therapy, chemotherapy or, lately, for hemodialysis has made the placement and use of implantable systems a routine procedure for anesthesiology services. However, such techniques are not free of multiple complications, some of which are serious and which may be caused by poor technique during insertion of the catheter. We consider careful selection of the point of subclavian vein insertion to be important. The scheduling of follow-up chest films is also crucial for ruling out a "pinch-off phenomenon".

Molecular and cytogenetic characterization of highly repeated DNA sequences in the vole Microtus cabrerae

The genus Microtus presents several species with extremely large sex chromosomes that contain large blocks of constitutive heterochromatin. Several cytogenetic and molecular studies of the repetitive sequences in species of the genus Microtus have demonstrated that the heterochromatin is highly heterogeneous. We have cloned and characterized a family of repetitive DNA sequences from M. cabrerae, a species with large heterochromatic blocks on the giant sex chromosomes. These repetitive sequences are 65.84% A-T rich, organized in tandem, with a 161-bp unit and are located on the centromeric region of autosomes and the X chromosome. In addition, this repetitive DNA is located throughout the entire heterochromatic block of the X chromosome and on three interstitial bands in the heterochromatic block of the Y chromosome. Comparative analysis of this family of repetitive sequences from three Microtus species revealed that the development of these sequences has occurred by concerted evolution. Our results support the hypothesis that the heterochromatic blocks from the sex chromosomes of different species are evolving independently and they probably have the genetic capacity to amplify and retain different satellite DNAs. For a topic related to the location of these repetitive DNA sequences on the Y chromosome of M. cabrerae, we propose a model to explain the origin of a length polymorphism previously described for this chromosome.

Effect of two antihypertensive combinations on metabolic control in type-2 diabetic hypertensive patients with albuminuria: a randomised, double-blind study

The objective of this study was to compare, at equal blood pressure (BP) reduction, the effect of two different combinations on metabolic control and albuminuria in type 2 diabetic hypertensive patients with albuminuria. This was a prospective, randomised, double-blind, parallel, controlled trial carried out in 11 Spanish hospitals. A total of 103 type 2 diabetic patients with stable albuminuria and BP not controlled on monotherapy were randomised of which 93 finished the study. After a 4-week single-blind placebo period, patients were randomised to verapamil SR/trandolapril 180/2 mg (VT) or to enalapril/hydroclorothiazide 20/12.5 mg (EH). Treatment duration was 6 months. The main outcome measures were changes in BP, 24-h albuminuria, blood glucose and glycated haemoglobin. Overall BP was significantly reduced from 157.3 +/- 12.0/98.3 +/- 6.4 mm Hg to 140.5 +/- 14.5/86.1 +/- 8.2 mm Hg (P < 0.001) and albuminuria significantly decreased from 508.6 +/- 693.8 mg/24 h to 253.4 +/- 517.2 mg/24 h (P < 0.001), both without significant differences between treatments. Glycated haemoglobin was not modified on VT: baseline, 5.91 +/- 1.43%; end of treatment, 5.94 +/- 1.62%, but increased on EH: baseline, 5.96 +/- 1.25%; final, 6.41 +/- 1.51%, (ANOVA interaction P = 0.040). At the end of the study, a blood glucose <126 mg/dL was attained in 72.7% of the VT group-improving in 29.5% and worsening in 6.8% of patients (P = 0.021)-and in 50% of the EH group, 13.6% of patients improved and 11.4% worsened (P = 1.000). There were no changes in body weight, serum creatinine, uric acid, potassium, cholesterol, tryglicerides and serum albumin. In hypertensive type 2 diabetic patients not controlled on monotherapy, both treatments similarly reduced albuminuria. The combination verapamil/ trandolapril seems to allow a better metabolic control than enalapril/hydroclorothiazide.

[Non-small cell bronchogenic carcinoma in advanced stages: prognostic value of weight loss and clinical implications]

This study of advanced-stage non-small cell bronchogenic carcinoma aimed 1) to identify prognostic factors collected at the moment of diagnosis, 2) to determine whether weight loss is a useful parameter to screen for subjects who will receive greater benefit from anticancer therapy.Patients and methods. Eighty-one patients were enrolled after diagnosis of stage III-B and IV non-small cell bronchogenic carcinoma and levels of activity < 2 according to Eastern Co-operative Oncology Group classification. The variables studied were age, sex, smoking history, associated disease, clinical data (weight loss, dyspnea, superior vena cava syndrome), laboratory parameters [hemoglobin, serum albumin, total lymphocytes, serum lactate dehydrogenase (LDH), calcium and liver enzymes], tumor-node-metastasis (TNM) staging, histologic type, activity, treatment received and survival in weeks. The results were analyzed in two groups: 1) the general group consisting of results for all patients, and 2) the no-weight-loss group consisting of results for those whose weight had been stable. Student t, chi-squared, Kaplan Meier, log-rank and Cox's regression model were used to analyze data and survival.

RESULTS

Mean survival was 29 weeks (21-37). Survival was significantly related to weight loss, total lymphocytes, serum LDH, TNM and activity level in the general group. Only two factors continued to have prognostic value in the multivariate study: weight loss (OR: 1.48 (1.14-1.92), p = 0.002) and TNM (OR: 0.72 (0.54-0.96), p = 0.02). Among the patients with no weight loss, treatment received and TNM were significantly related to survival in univariable analysis and in Cox's regression model.

CONCLUSIONS

In our experience with advanced lung cancer subjected to anticancer therapy, the presence of weight loss is the variable with the greatest prognostic value, such that it may be useful to consider it routinely, along with activity level, to try to identify patients who will receive the most benefit from cytostatic treatment.

Non-invasive mechanical ventilation in status asthmaticus

OBJECTIVE

To evaluate our clinical experience with the use of non-invasive mechanical ventilation (NIMV) in patients with an acute asthmatic attack.

DESIGN

Seven-year period retrospective observational study.

SETTING

General intensive care department (ICU) of a county hospital.

PATIENTS

From 1992 to 1998, we documented clinical data, gas exchange and outcome of every asthmatic patient admitted to our ICU because of status asthmaticus (SA) refractory to initial medical therapy.

INTERVENTIONS

Clinical charts were reviewed and patients were allocated to two groups according to their suitability as participants in an NIMV trial. Patients who arrived in respiratory arrest and those who ultimately improved with medical management alone were not considered candidates for NIMV. For the present analysis, the rest of the patients were considered candidates for NIMV, while the decision to start a NIMV trial or to perform endotracheal intubation (ETI) remained at the discretion of the attending physician. When patients failed to improve with NIMV, standard mechanical ventilation (MV) with ETI was initiated.

MEASUREMENTS AND RESULTS

Fifty-eight patients were included in the study. Twenty-five patients (43%) were not eligible for NIMV: 11 patients (19%) because of respiratory arrest on their arrival at the Emergency Room and 14 patients (24%) because of improvement with medical management (bronchodilators, corticoids and oxygen). The remaining 33 patients were eligible for NIMV (57%): 11 patients (33%) received invasive MV and 22 patients (67%) were treated with NIMV. Three NIMV patients (14%) needed ETI. We compared data at baseline, 30 min, 2-6 h and 6-12 h after the onset of ventilatory support. Significant differences were observed in arterial blood gases on admission to the Emergency Room between MV and NIMV: PaCO2 (89 +/- 29 mmHg vs 53 +/- 13 mmHg, p < 0.05), pH (7.05 +/- 0.21 vs 7.28 +/- 0.008, p < 0.05) and HCO3- level (22 +/- 5 mmol/l vs 26 +/- 6 mmol/l, p < 0.05). No differences were found in the median length of ICU stay (4.5 vs 3 days), median hospital stay (15 vs 12 days) and mortality (0 vs 4%).

CONCLUSION

Face mask NIMV appears to be a suitable method for improving alveolar ventilation and can reduce the need for intubation in a selected group of patients with SA.

Biologically active APRIL is secreted following intracellular processing in the Golgi apparatus by furin convertase

Tumor necrosis factor (TNF) ligand family members are synthesized as transmembrane proteins, and cleavage of the membrane-anchored proteins from the cell surface is frequently observed. The TNF-related ligands APRIL and BLyS and their cognate receptors BCMA/TACI form a two ligand/two receptor system that has been shown to participate in B- and T-cell stimulation. In contrast to BLyS, which is known to be cleaved from the cell surface, we found that APRIL is processed intracellularly by furin convertase. Blockage of protein transport from the endoplasmic reticulum to the Golgi apparatus by Brefeldin A treatment abrogated APRIL processing, whereas monensin, an inhibitor of post-Golgi transport, did not interfere with cleavage of APRIL, but blocked secretion of processed APRIL. Thus, APRIL shows a unique maturation pathway among the TNF ligand family members, as it not detectable as a membrane-anchored protein at the cell surface, but is processed in the Golgi apparatus prior to its secretion.

[Listeria monocytogenes infections in the adult. Clinical and microbiological issues of a changing disease]

Thirty-one cases of human listeriosis seen from 1971-1999 were reviewed. cases were grouped as follows: Group I composed of 14 patients were studied in the period 1971-1984; and group II composed of 17 cases studied in the period 1985-1999. We tried to assess changes in the incidence, clinical findings and outcome in both periods. The incidence of listeriosis remained constant along the years, 1.2 cases/20,000 discharges. The mean age of the patients significantly increased along the years (55 11 years versus 68 12 years; p 0.002). 77% of cases had one or more underlying diseases predisposing to listeriosis. We observed an increasing number of listeriosis in patients without chronic diseases in recent years. Listeriosis presented as meningitis or primary sepsis. Mortality was 61% and was strictly associated with the severity of the underlying disease. Patients with meningoencephalitis and seizures had a worse prognosis. We did not observe differences in mortality of patients who were treated with beta-lactam monotherapy in comparison with those who were treated with beta-lactam/aminoglucoside combination. Cotrimoxazole was uniformly successful treatment of human listeriosis in this series.

Stereoselective nucleophilic formylation and cyanation of alpha-alkoxy- and alpha-aminoaldehydes

The spontaneous 1,2-addition of formaldehyde N,N-dialkylhydrazones to carbohydrate-derived alpha-alkoxyaldehydes takes place under neutral conditions and in the absence of catalysts or promoters to afford the corresponding alpha-hydroxyhydrazones in good to excellent yields and with highly anti diastereoselectivities. Subsequent transformations of the hydrazono group into aldehydes and nitriles following known procedures provide a new entry into the homologation of carbohydrates and the synthesis of cyanohydrins, respectively. Additionally, reaction of methyleneaminopyrrolidine with N-Boc-protected alpha-aminoaldehydes from natural amino acids efficiently affords the corresponding adducts under the same conditions. From these adducts, a variety of biologically interesting alpha-hydroxy-beta-aminocarbonyl compounds can be accessed upon manipulation of the hydrazone moiety.

Bcl-2 targets protein phosphatase 1 alpha to Bad

The diverse forms of protein phosphatase 1 (PP1) in vivo result from the association of the catalytic subunit with different regulatory subunits. We recently have described that PP1alpha is a Ras-activated Bad phosphatase that regulates IL-2 deprivation-induced apoptosis. With the yeast two-hybrid system, GST fusion proteins, indirect immunofluorescence, and coimmunoprecipitation, we found that Bcl-2 interacts with PP1alpha and Bad. In contrast, Bad did not interact with 14-3-3 protein. Bcl-2 depletion decreased phosphatase activity and association of PP1alpha to Bad. Bcl-2 contains the RIVAF motif, analogous to the well characterized R/KXV/IXF consensus motif shared by most PP1-interacting proteins. This sequence is involved in the binding of Bcl-2 to PP1alpha. Disruption of Bcl-2/PP1alpha association strongly decreased Bcl-2 and Bad-associated phosphatase activity and formation of the trimolecular complex. These results suggest that Bcl-2 targets PP1alpha to Bad.

Mitochondrial DNA sequences for 118 individuals from northeastern Spain

A population database was generated from 118 unrelated Caucasoid individuals living in Spain. Sequence polymorphisms of the mitochondrial DNA (mtDNA) control region, hypervariable regions I and II (HVRI and HVRII) were determined using the polymerase chain reaction (PCR) and direct sequencing. A total of 102 different sequences were found as defined by 105 variable positions. The most common sequence occurred six times, and this sequence is also the most frequent in other European populations such as Austria, Germany and Britain. The mean pair-wise difference for the two HVR regions taken together was 7.74. The study revealed that transitions made up the majority of the variations (88%), whereas we observed a significantly lower frequency of transversions (8%). Also one individual in this study was observed with two positions of heteroplasmy at nucleotides 150 (C/T) and 153 (G/A). A statistical estimate of the results for this population showed a genetic diversity of 0.99. The probability of two random individuals showing identical mtDNA haplotypes is 1.3%. In order to use the mtDNA analysis in forensic casework, we consider that it is of crucial importance to know the frequency of the different sequences of mtDNA, and this data base study could be a useful tool to statistically evaluate the results.

Platinum and rhodium distribution in airborne particulate matter and road dust

In this work the platinum and rhodium content in the atmosphere of Madrid was monitored for 1 year at seven different sites. Samples were taken with medium volume PM-10 collectors (< 10 microm) for 48 h and analysed by ICP-MS. The Pt and Rh content was dependent on the sampling site, ranging from < 0.1 to 57.1 and < 0.2 to 12.2 pg m(-3) with a medium value of 12.8 and 3.3 pg m(-3), respectively. These results show that the Pt and Rh content in airborne samples depends on the traffic density per day and also on medium driving speed. Road dust < 63 microm was analysed at the same time and at the same location. The Pt and Rh content at the six sites analysed was in the 31-2252 and 11-182 ng g(-1) range with an average of 317 and 74 ng g(-1), respectively. The average Pt/Rh ratio obtained was 4.3. similar to that obtained for airborne particles (4.0), and agrees with that of the more commonly used gasoline car catalyst [J.J. Mooney, Encyclopaedia of Chemical Technology (1996) 982]. Platinum distribution as a function of particle size in airborne particulate matter was also studied, by sampling with two high-volume sample collectors, a five-stage WRAC (from 10 to 65.3 microm and total) and a seven-stages PM-10) cascade impactor (from 9 to < 0.39 microm). Platinum is associated with a wide range of particle diameters. Due to the ultratrace level of Pt in airborne samples, its distribution in the atmosphere could not be considered as homogeneous. No trend could be established in Pt distribution in the different fractions, except that in most cases the highest value of Pt was obtained in the < 0.39-microm fraction. The Pt content was usually high in airborne samples when the Pb, Ce, Zr and Hf content was also high, thus confirming that the source of these pollutants is from traffic.

Two natural products from the algae Laurencia scoparia

The structures and absolute stereochemistries of two chamigrene-type metabolites (spiro[5.5]undecane derivatives) isolated from the red algae Laurencia scoparia are described. One, a non-sesquiterpene named maĩlione (8-bromo-9-hydroxy-7,7-dimethyl-11-methylenespiro[5.5]undec-1-en-3-one), C(14)H(19)BrO(2), was detected previously in Laurencia cartilaginea, while the other, the sesquiterpene isorigidol (8-bromo-3,7,7-trimethyl-11-methylenespiro[5.5]-undec-1-ene-3,9-diol), C(15)H(23)BrO(2), is a new isomer of rigidol, first isolated from Laurencia rigida. The A rings of these spirocyclic compounds show the same carbon skeleton. However, the relative stereochemistry of the 8-Br and 9-OH substituents is different. While maĩlione displays the usual syn (or cis) relative stereochemistry of the bromohydroxy vicinal group, isorigidol shows an anti (or trans) arrangement. The 8-Br and 9-OH groups are both in equatorial positions in isorigidol, while the 9-OH group is axial in maĩlione, as in most chamigrenes. The absolute configurations of the chiral centers were determined as 6S, 8S and 9R in maĩlione, and 3R, 6S, 8S and 9S in isorigidol.

Reference doses in dental radiodiagnostic facilities

The present work describes an experiment undertaken using thermoluminescent dosemeters to obtain a local reference dose level in orthopantomography, based on patient measurements in 11 dentistry installations. In addition, a critical audit of the dose recommended by the International Atomic Energy Agency for intraoral X-ray diagnostics is performed, based on data gathered from over 300 intraoral X-ray facilities. The provisional local reference levels proposed are 0.7 mGy entrance surface dose at the occipital region for orthopantomography and 3.5 mGy entrance surface dose for intraoral radiology.

[Addisonian crisis as first manifestation of adrenal gland insufficiency in patient diagnosed with lung cancer]

Adrenal insufficiency or Addison's disease is actually a rare illness associated with numerous pathologies. We describe the case of a fifty years old male with lung adenocarcinoma and metastasis in both adrenal glands, who was receiving chemotherapy with mytomicin, ifosfamide and cisplatin (MIC), and was diagnosed of adrenal insufficiency as a result of acute episode addisonian crisis. Many times, the clinic symptoms of adrenal insufficiency can go unnoticed due to its low specifity and to mixing up with other syndromes. Hypoadrenalism has been described in association with many tumours, specially with non-Hodgkin's lymphoma. It seems that there is a discordance between the number of patients with bilateral metastatic adrenal destruction and the documented cases of clinic insufficiency. Once the adrenal failure is suspected, the diagnosis and hormone replacement treatment are really easy. Addison's disease ethiologies are revised putting special emphasis on those related with cancer patients.