Environmental geochemistry of ancient volcanic ashes

Volcanic ashes from the Puna and surrounding Andean areas in northern Argentina show that sometimes volcanic ash deposits are very well preserved (up to several million years) and can remain a potential hazard for the environment in a similar way as current deposits. Eight ashes have been characterized by SEM-EDX and DRX, and their potential released geochemical fluxes were examined by using water and nitric acid batches, which are analyzed by ICP-OES, ICP-MS and ISE (F). Results demonstrate that water batch system is better medium than nitric acid for this study. The high and fast reactivity of these ancient ashes is mainly associated with their high content in glass. The order of magnitude of released contents of implied elements is consistent among the samples, i.e., Al>B>Fe>Zn>F>P>Mn>Ba>Sr>Li>Ti>Rb>Cu>Ni>Sb>Pb>As>Cr>V. Ash-water interaction, although infrequent in arid regions such as the Puna Region in northern Argentina, introduces rapid changes in the geochemical fluxes of elements and pH and may constitute a potential hazard for the environment. In fact, many of these elements are included in the drinking water guidelines due to their potential toxicity and may constitute potential hazards for the environment and human health.

The US National Cholesterol Education Programme Adult Treatment Panel III (NCEP ATP III): prevalence of the metabolic syndrome in postmenopausal Latin American women

BACKGROUND

Metabolic syndrome (METS) is a strong predictor of cardiovascular risk. Since the prevalence of METS increases after menopause, gynecological routine consultation offers an excellent screening opportunity.

OBJECTIVES

To assess the prevalence of METS in Latin American postmenopausal women and factors modifying its risk; as well as to assess the role of simple routine care measurements in the diagnosis of the METS.

METHODS

A total of 3965 postmenopausal women, aged 45-64 years, seeking health care at 12 gynecological centers in major Latin American cities were included in this cross-sectional study. The US National Cholesterol Education Programme Adult Treatment Panel III (NCEP ATP III) guidelines were applied to assess METS. This was present if three or more of the following conditions were present: waist circumference > or = 88 cm; blood pressure > or = 130/85 mmHg; fasting plasma triglycerides > or = 150 mg/dl; high density lipoprotein (HDL) cholesterol < 50 mg/dl; glucose > or = 110 mg/dl or subjects were receiving treatment for their condition.

RESULTS

The prevalences of having at least two, three, four or five components were 62.5, 35.1, 13.5 and 3.2%, respectively. The prevalence increased from 28.1% in those aged 40-44 years to 42.9% in those aged 60-64 years. The risk of METS detection (multivariate analysis) increased with age (odds ratio (OR) 1.22, 95% confidence interval (CI) 1.03-1.43), time elapsed since menopause (OR 1.18, 95% CI 1.00-1.38), smoking cigarettes (OR 1.40, 95% CI 1.19-1.65), obesity (OR 13.01, 95% CI 10.93-15.49) and hypertension (OR 9.30, 95% CI 7.91-10.94). In contrast, hormone therapy reduces this risk (OR 0.59, 95% CI 0.51-0.70).

CONCLUSION

There is a high prevalence of the metabolic syndrome in postmenopausal Latin American women seeking gynecologic health care. Age, years since menopause, obesity and hypertension are strong predictors of this condition.

The use of neural network technology to model swimming performance

to identify the factors which are able to explain the performance in the 200 meters individual medley and 400 meters front crawl events in young swimmers, to model the performance in those events using non-linear mathematic methods through artificial neural networks (multi-layer perceptrons) and to assess the neural network models precision to predict the performance. A sample of 138 young swimmers (65 males and 73 females) of national level was submitted to a test battery comprising four different domains: kinanthropometric evaluation, dry land functional evaluation (strength and flexibility), swimming functional evaluation (hydrodynamics, hydrostatic and bioenergetics characteristics) and swimming technique evaluation. To establish a profile of the young swimmer non-linear combinations between preponderant variables for each gender and swim performance in the 200 meters medley and 400 meters font crawl events were developed. For this purpose a feed forward neural network was used (Multilayer Perceptron) with three neurons in a single hidden layer. The prognosis precision of the model (error lower than 0.8% between true and estimated performances) is supported by recent evidence. Therefore, we consider that the neural network tool can be a good approach in the resolution of complex problems such as performance modeling and the talent identification in swimming and, possibly, in a wide variety of sports. Key pointsThe non-linear analysis resulting from the use of feed forward neural network allowed us the development of four performance models.The mean difference between the true and estimated results performed by each one of the four neural network models constructed was low.The neural network tool can be a good approach in the resolution of the performance modeling as an alternative to the standard statistical models that presume well-defined distributions and independence among all inputs.The use of neural networks for sports sciences application allowed us to create very realistic models for swimming performance prediction based on previous selected criterions that were related with the dependent variable (performance).

[Integral management of vascular access by nephrologist. Three years work outcome]

Delay in perform the arteriovenous fistula (AVF) to begin haemodialysis is a major problem in the renal units in our country. Two nephrologists initiated, to solve this problem in its own hospital, to perform AVF from December 2001 to December 31st, 2004. Results were compared to surgical service which performed AVF until December 2001. Reduction in surgical waiting time to perform AVF and percent of patients without AVF at time of initiate haemodialysis treatment are the main results in nephrologists group. No technical differences are found between both groups. These differences come from integral management of AVF, with own and programmed surgical theatre, managed in the office, individualized the patients requirements, and a major surgical flux managed by nephrologists. We conclude that hospitals with a program similar to us with integral approach of AVF and vascular access coordinator, the vascular access could be managed in an efficacy way.

Correlations of smoothness index and trough-to-peak ratio with left ventricular mass index changes induced by lercanidipine in hypertensive patients. A pilot trial

AIM

The aim of this study was to determine the correlation of changes in left ventricular mass, with changes in office blood pressure (BP) and in 24-h ambulatory (ABP), with the trough-to-peak (T/P) ratio and with the smoothness index (SI), as induced by antihypertensive treatment with lercanidipine.

METHODS

This was done through an observational, prospective, open, non-comparative, single centre, pilot study in patients naïve to antihypertensive therapy. All patients were treated with lercanidipine 10-20 mg/day plus hydrochlorothiazide 12.5-25 mg/day if treated BP exceeded an arbitrarily defined safety level (>160/100 mmHg) after 1 month on monotherapy. ABP monitoring was repeated after 1 month and after 6 months. Two-dimensional mode echocardiography was performed twice, at the beginning and end of the study. Seventeen patients were included in the final analysis (aged 45.8 +/- 10.7 years, 35% women).

RESULTS

Treatment-induced changes in left ventricular mass index (LVMI) were not found to correlate neither with changes in office BP, with changes in ABP values, nor with T/P. However, a significant correlation was found between LVMI changes and SI at 6 months (r=0.50, P=0.039).

CONCLUSION

The results of this study suggest that the SI has a higher predictive value, compared to other BP-derived parameters, for treatment-induced LVMI changes, in hypertensive patients treated with lercanidipine.

BMS-284756 in experimental cephalosporin-resistant pneumococcal meningitis

BMS-284756 is a novel des-fluoro(6) quinolone with a broad antimicrobial activity, including Streptococcus pneumoniae. The purpose of this study was to evaluate the pharmacodynamic profile and effectiveness of BMS-284756 for therapy of experimental meningitis caused by penicillin- and cephalosporin-resistant S. pneumoniae (CRSP). Meningitis was induced in rabbits by intracisternal inoculation of CRSP. BMS-284756 was given intravenously 16 h after intracisternal inoculation in single doses of 2.5 (n = 5 animals), 5 (n = 6), 10 (n = 6), 20 (n = 8), and 30 mg/kg (n = 6), in two doses of 10 mg/kg each separated by 5 h (n = 4), and as a 20-mg/kg dose followed 5 h later by 10 mg/kg (n = 5). The MICs and MBCs of BMS-284756, ceftriaxone, and vancomycin were 0.06 and 0.06, 4 and 4, and 0.25 and 0.25 microg/ml, respectively. After single doses of 10, 20, and 30 mg/kg, the maximum concentrations in cerebrospinal fluid (CSF) (mean +/- standard deviation) were 0.32 +/- 0.12, 0.81 +/- 0.38, and 1.08 +/- 0.43 microg/ml, respectively; the elimination half-life in CSF was 4.5 to 6.3 h. The CSF bacterial killing rates (BKR) at 5 h of the single-dose regimens of 10, 20 and 30 mg/kg were -0.84 +/- 0.48, -1.09 +/- 0.32, and -1.35 +/- 0.05 Deltalog(10) CFU/ml/h. The BKR(0-5) of the divided regimens (10 mg/kg twice and 20 mg/kg followed by 10 mg/kg) was -0.82 +/- 0.52 and -1.24 +/- 0.34 Deltalog(10) CFU/ml/h, respectively. The BKR(0-5) of the combined therapy with vancomycin and ceftriaxone was -1.09 +/- 0.39 Deltalog(10) CFU/ml/h. The penetration of BMS-284756 into purulent CSF relative to plasma was 14 to 25%. The bactericidal effect of BMS-284756 in CSF was concentration dependent. BMS-284756 at 30 mg/kg as a single or divided dose was as effective as standard therapy with vancomycin and ceftriaxone.

Pre-treatment with candesartan protects from cerebral ischaemia

Angiotensin II (Ang II) regulates cerebral blood flow by stimulating cerebral vasoconstriction via AT1-receptors. In adult spontaneously hypertensive rats (SHR), the cerebrovascular autoregulatory curve is shifted to the right, in the direction of higher blood pressures, an indication of excessive cerebrovascular vasoconstriction. A restricted capacity to dilate cerebral blood vessels may be responsible for the enhanced vulnerability to cerebrovascular ischaemia during hypertension. We found that chronic treatment with the AT1-receptor antagonist, candesartan, (0.5 mg/kg/day for 14 days, via osmotic minipumps implanted in the subcutaneous tissue) blocked Ang II binding to AT1-receptors in cerebral blood vessels and in brain areas involved in the regulation of cerebrovascular flow, and increased the ratio of lumen-wall area in the middle cerebral artery. Candesartan treatment normalised the lower part of the autoregulatory curve in SHR, and markedly decreased cerebral ischaemia as a consequence of middle cerebral artery occlusion with reperfusion. Protection from ischaemia is related to arterial remodelling, enhanced compensatory vasodilatation in the peripheral area of ischaemia, decreased reduction in cerebral blood flow following the occlusion of a major cerebral blood vessel, and protection from injury in the periphery of the lesion. Our results indicate that pre-treatment with AT1-antagonists such as candesartan could be of benefit in the prevention and treatment of brain ischaemia.

[Pseudoneurotic schizophrenia: a case report]

We report a 34-years old woman, with a history of social anxiety, specific phobias and generalized anxiety symptoms, who presented for treatment with panic attacks and depression. She was started on paroxetine and presented exacerbation of the affective syndrome and onset of psychotic symptoms that persisted after the suspension of the antidepressant and responded to sulpiride and later to thioridazine. We discuss the pertinence of the diagnosis of pseudoneurotic schizophrenia and the comorbidity between psychosis and anxiety symptoms.

Hydatid disease of the interventricular septum causing pericardial effusion

Echinococcal infestation of the heart is uncommon. We report a case of a 35-year-old man with an hydatid cyst located in distal interventricular septum. Clinical presentation was chest pain and urticaria. Diagnosis was made by echocardiography and magnetic resonance imaging. Surgical resection was performed; the cyst was punctured and its content was drained, hypertonic glucose solution was instilled for sterilization, and it was removed. The patient did well and remains asymptomatic. Diagnosis and ultimate surgical treatment of this disease prevented potentially lethal complications such as cyst rupture with embolic phenomena and anaphylactic shock.

[Costs of chronic dialysis in a public hospital: myths and realities]

In this study regular dialysis treatment costs during 1998 and 1999 in a public hospital, which is responsible for a population of 178,000, has been analysed. Hemodialysis (HD) and peritoneal dialysis (PD) costs have been differentiated and compared with those of external providers. The best technical and productive efficiency of both treatments have been estimated by analyzing the "treatment cost/human resources of the community utilized" relationship. The HD treatment costs per patient per year were 20,343 and 18,871 euros in 1988 and 1,999, respectively, lower than the costs reported in other studies. In 1999 these costs were similar to those of external providers and lower than the PD treatment costs (23,295 euros). HD retains its advantage even after costs of erythropoietin, hospital admissions and transport are included. In the hospital studied, the best technical efficiency in HD would be reached with 64 patients on treatment (17,851 euros per patient per year) and in PD with 48 patients (21,167 euros per patient per year). If we take into account our population characteristics and consider a patient distribution of 70% on HD and 30% on PD, the best productive efficiency would be reached with 56 patients on HD (17,916 euros per patient per year) and 24 patients on PD (21,813 euros per patient per year). HD confers the greatest economic and social benefits on the population supplied by the hospital since it provides the community with more jobs than PD in relation to treatment costs while the two yield the same clinical results. In conclusion, HD in a public hospital, at least in our environment, may be efficient and competitive with HD from external providers and it may be more efficient and provide a bigger economic and social profit for the population serviced by the hospital than PD, at least while the current supply systems for this treatment in our country are maintained.

Probiotics and infectious diarrhea

Numerous probiotic agents have been studied for the management of diarrheal disease. In particular, the prevention and management of acute viral diarrhea, the treatment of recurrent Clostridium difficile diarrhea, as well as the control of antibiotic-associated diarrhea seem to be areas of significant potential benefit. A few agents, including Lactobacillus GG, Lactobacillus reuteri, and Saccharomyces boulardii, seem to be promising agents for the amelioration of the course of acute diarrhea in children when used therapeutically. The use of other agents, particularly Bifidobacteria, supplementing the regular feed of infants may have an effect as prophylactic agents against acute diarrheal diseases. In general, in pediatric populations, the effect of probiotic agents appears to be most significant against viral (rotaviral) diarrhea, suggesting that an immunological mechanism is responsible for the beneficial effects. The numerous agents, doses, and populations used make generalization difficult. Nevertheless, it is clear probiotic agents are becoming an important part of the armamentarium against gastrointestinal problems in infants and children.

[NUTRITIONAL CONSIDERATIONS AND MANAGEMENT OF SHORT BOWEL SYNDROME]

Few conditions pose as great a challenge, in terms of long term nutritional care, as short bowel syndrome (SBS). Despite the complexity of care which children with SBS require, the great improvement in the prognosis and outcome over the past few decades can be attributed, in great measure, to advancements in both parenteral and enteral nutrition support. Most children can maintain normal growth and development while intestinal adaptation occurs, and ultimately achieve independence from parenteral nutrition. This review focuses on the nutritional consequences of severe malabsorption clinical problems which influence nutritional status, and parenteral and enteral nutritional recommendations. The importance of aggressive and persistant efforts with enteral feeding as a primary therapy to enhance bowel adaptation and tominimize complications is emphasized.

Elevated cytokine concentrations in the nasopharyngeal and tracheal secretions of children with respiratory syncytial virus disease

BACKGROUND

Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract disease in infants. The role of inflammatory mediators in the pathogenesis of RSV disease is not well-understood. The present study was designed (1) to determine whether RANTES (regulated on activation, normal T cell expressed and presumably secreted), macrophage-inflammatory protein-1-alpha (MIP-1-alpha), interleukin (IL)-6, IL-8 and IL-10 can be detected in respiratory secretions of children with RSV infection and (2) to assess whether the concentrations of these cytokines in respiratory secretions correlate with white blood cell (WBC) counts and RSV concentrations and with disease severity.

METHODS

During the 1996 to 1997 RSV season, we studied prospectively 14 intubated and 14 nonintubated children hospitalized with RSV disease. Nasal wash (NW) and tracheal aspirate (TA) samples were obtained from intubated patients on Hospital Days 1, 3 and 5. NW samples were obtained from nonintubated patients on hospital days 1 and 3. Seven healthy children undergoing elective surgery served as controls. All samples were analyzed for: (1) WBC and differential counts; (2) concentrations of RANTES, MIP-1-alpha, IL-6, IL-8 and IL-10; and (3) quantitative RSV cultures, except in control patients.

RESULTS

RANTES, MIP-1-alpha, IL-6, IL-8 and IL-10 were detected in NW and TA samples from all children with RSV infection. The concentrations of these cytokines in samples obtained from children with RSV infection were significantly greater than those in samples obtained from control children. NW WBC counts significantly correlated with NW RANTES, IL-6, IL-8 and IL-10 concentrations, whereas TA WBC counts significantly correlated with TA IL-6, IL-8, IL-10 and MIP-1-alpha concentrations. NW RSV concentrations correlated with NW WBC counts and with NW cytokine concentrations. Among children with RSV infection nonintubated patients had greater NW WBC counts and NW RANTES concentrations than intubated patients. TA RANTES, IL-8 and IL-10 concentrations inversely correlated with clinical markers of RSV disease severity.

CONCLUSION

The presence of cytokines in NW and TA samples of children with RSV infection suggests that they have a role in mediating the respiratory tract inflammation induced by RSV. These observations could have implications for designing new therapeutic strategies directed at immunomodulation of RSV disease.

Rapid and large-scale method to detect K-ras gene mutations in tumor samples

We have developed a rapid and large-scale method for the detection of K-ras gene mutations in tumors. First, DNA is amplified by an asymmetric PCR; second, the single-strand dinitrophenyl (DNP)-labeled amplified DNA is hybridized specifically to oligonucleotide probes affixed on a tube. Finally, perfectly matched duplexes are easily detected by a monoclonal anti-DNP antibody bearing 125I. The usefulness of this technique is illustrated by analyzing K-ras codon 12 mutations in human colorectal samples. This reliable assay procedure can be applied to the rapid screening of virtually any genetic disease caused by previously described point mutations.

Evaluation of the automated fluorescent analysis of the H-ras minisatellite after optimized PCR amplification in comparison with a standardized Southern blot technique

Determination of allele sizes? loss of heterozygosity or genetic instability at minisatellite VNTR loci, are routinely performed by the conventional Southern technique. We have investigated the potential use of automated DNA sequencer for the analysis of the H-ras minisatellite. We report the modifications of amplification parameters and electrophoresis conditions on the sequencer. Seventy-one colorectal carcinomas and the corresponding normal tissues were amplified with fluorescent-labeled primers, analyzed on sequencer, and concurrently controlled by Southern blotting. The results on sequencer showed that a Hydrolink matrix used in non-denaturing conditions and a specific analysis software facilitate a more accurate fragment size calculation.