Bovine Herpes Virus Type 1 (BoHV-1) seroprevalence, risk factor and Bovine Viral Diarrhoea (BVD) co-infection analysis from Ireland

Surveillance of endemic pathogens is essential for disease control, providing an evidence base for policy and advice. Bovine Herpes Virus Type 1 (BoHV-1), the causative agent of Infectious Bovine Rhinotracheitis (IBR), has been found to have high seroprevalence within the Irish cattle population. The aim of the present study was to establish seroprevalence levels for culled cattle in Ireland aged < 30 months and to establish whether BVD exposure and other factors was associated with BoHV-1 exposure. We employed random effects logit models coupled with repeated bootstrap sampling to provide robust estimates. The final dataset contained results for 5273 animals tested over two study years, 2018 and 2020. The animal-level seroprevalence of BoHV-1 was 21.43% (1130/5273; 95%CI: 20.32-22.53%). Univariable analysis suggested that BoHV-1 seropositivity risk was associated with BVDV serodiagnosis status, age, sex, year sampled, herd type, herd-size, and metrics of movement into the herd. Final random-effects multivariable models suggested increased risk associated with increasing herd size of the last herd, movements made by animals during the previous year, and the year the animal was sampled. Despite BVDV status and sex being retained in the final model, repeated bootstrap sampling of the regression model to estimate biased-corrected 95%CI suggested that these associations were not robust. The overall apparent prevalence of BoHV-1 exposure for culled cattle in Ireland declined in 2020 relative to 2018 (from 23.32 to 17.61%). Herd-size and the movement of animals were found to be important factors associated with animal-level risk, but there was less statistical support for sex-based or BVDV status associations.

In-hospital mortality risk stratification in children aged under 5 years with pneumonia with or without pulse oximetry: A secondary analysis of the Pneumonia REsearch Partnership to Assess WHO REcommendations (PREPARE) dataset

OBJECTIVES

We determined the pulse oximetry benefit in pediatric pneumonia mortality risk stratification and chest-indrawing pneumonia in-hospital mortality risk factors.

METHODS

We report the characteristics and in-hospital pneumonia-related mortality of children aged 2-59 months who were included in the Pneumonia Research Partnership to Assess WHO Recommendations dataset. We developed multivariable logistic regression models of chest-indrawing pneumonia to identify mortality risk factors.

RESULTS

Among 285,839 children, 164,244 (57.5%) from hospital-based studies were included. Pneumonia case fatality risk (CFR) without pulse oximetry measurement was higher than with measurement (5.8%, 95% confidence interval [CI] 5.6-5.9% vs 2.1%, 95% CI 1.9-2.4%). One in five children with chest-indrawing pneumonia was hypoxemic (19.7%, 95% CI 19.0-20.4%), and the hypoxemic CFR was 10.3% (95% CI 9.1-11.5%). Other mortality risk factors were younger age (either 2-5 months [adjusted odds ratio (aOR) 9.94, 95% CI 6.67-14.84] or 6-11 months [aOR 2.67, 95% CI 1.71-4.16]), moderate malnutrition (aOR 2.41, 95% CI 1.87-3.09), and female sex (aOR 1.82, 95% CI 1.43-2.32).

CONCLUSION

Children with a pulse oximetry measurement had a lower CFR. Many children hospitalized with chest-indrawing pneumonia were hypoxemic and one in 10 died. Young age and moderate malnutrition were risk factors for in-hospital chest-indrawing pneumonia-related mortality. Pulse oximetry should be integrated in pneumonia hospital care for children under 5 years.

Assembling a global database of child pneumonia studies to inform WHO pneumonia management algorithm: Methodology and applications

Background

The existing World Health Organization (WHO) pneumonia case management guidelines rely on clinical symptoms and signs for identifying, classifying, and treating pneumonia in children up to 5 years old. We aimed to collate an individual patient-level data set from large, high-quality pre-existing studies on pneumonia in children to identify a set of signs and symptoms with greater validity in the diagnosis, prognosis, and possible treatment of childhood pneumonia for the improvement of current pneumonia case management guidelines.

Methods

Using data from a published systematic review and expert knowledge, we identified studies meeting our eligibility criteria and invited investigators to share individual-level patient data. We collected data on demographic information, general medical history, and current illness episode, including history, clinical presentation, chest radiograph findings when available, treatment, and outcome. Data were gathered separately from hospital-based and community-based cases. We performed a narrative synthesis to describe the final data set.

Results

Forty-one separate data sets were included in the Pneumonia Research Partnership to Assess WHO Recommendations (PREPARE) database, 26 of which were hospital-based and 15 were community-based. The PREPARE database includes 285 839 children with pneumonia (244 323 in the hospital and 41 516 in the community), with detailed descriptions of clinical presentation, clinical progression, and outcome. Of 9185 pneumonia-related deaths, 6836 (74%) occurred in children <1 year of age and 1317 (14%) in children aged 1-2 years. Of the 285 839 episodes, 280 998 occurred in children 0-59 months old, of which 129 584 (46%) were 2-11 months of age and 152 730 (54%) were males.

Conclusions

This data set could identify an improved specific, sensitive set of criteria for diagnosing clinical pneumonia and help identify sick children in need of referral to a higher level of care or a change of therapy. Field studies could be designed based on insights from PREPARE analyses to validate a potential revised pneumonia algorithm. The PREPARE methodology can also act as a model for disease database assembly.

Abstract 2400: Fucosyltransferase expression is associated with head and neck cancer survival

Introduction: Head and neck (H&N) cancers account for 5-7% of new cancer cases in the United States, and most manifest as head and neck squamous cell carcinomas (HNSCC). Fucosyltransferases (FUTs) contribute to the formation of sialofucosylated epitopes, which alter cellular signaling and mediate early steps in metastasis. However, few studies have examined the effect of FUT expression on H&N cancer survival. Here, we sought to examine the association between fucosyltransferase expression and H&N survival and investigate the mechanistic role of fucosylation in H&N cancer.

Methods: FUT1-11 expression (mRNA) data was extracted from the Cancer Genome Atlas (TCGA) HNSCC dataset (n=499). Kaplan-Meier, logrank, and Cox proportional hazards tests were conducted. Levels of α1,2-fucosylated epitopes H-antigen, Lewis Y (LeY), and Lewis B (LeB) were measured in normal, dysplastic, and H&N tumor cell lines via flow cytometry, and RT-qPCR was performed to assess FUT expression. To identify fucosylated signaling and adhesion molecules, fucosylated glycopeptides were enriched from CAL27 and HSC-3 tongue squamous cell carcinoma (SCC) lysates via AAL lectin, followed by nLC-MS/MS. EGFR signaling was assessed via western blot, and parallel plate flow assays were performed to assess in vitro metastatic potential, in tumor cell lines with differential FUT expression.

Results: In TCGA analyses, the median survival time (MST) of the FUT2 high expression group was 4.7 years, while low expression group MST was 2.7 years, with an adjusted hazard ratio (aHR) of 0.72 (CI = 0.54-0.95). The FUT6-high group MST was 4.7 years versus 2.9 years for low expression (aHR = 0.62, CI = 0.47-0.83). The FUT7-high group MST was 4.7 years versus 3.5 years for low expression (aHR = 0.72, CI = 0.54-0.95). Expression of the LeY epitope, with both α1,2- and α1,3-linked fucose, varied widely in tongue SCC lines, while pharyngeal SCC lines FaDu and Det-562 displayed intermediate LeY levels, via flow cytometry. EGFR, CD44, and integrins, were among the fucosylated glycoproteins identified via mass spectrometry. HSC-3 cells, sorted into low- and high-LeY populations, demonstrated differential EGFR Tyr-1086 phosphorylation, and differences in adhesion to endothelial cells under flow conditions (in vitro), with implications for tumor metastasis.

Conclusion: Overexpression of FUT2, FUT6, and FUT7 were associated with statistically significant increases in survivorship. FUT6 and FUT7 are prominently expressed in immune cells, while FUT2 is expressed in endoderm-derived epithelium. Therefore, FUT6 and FUT7 expression may indicate immune cell infiltration into tumor tissue. Future studies will seek to sort tumor tissue based on cell type, to gain an understanding of the cell-type specific glycosyltransferase expression in HNSCC tumors. Our current results will serve as the foundation to interrogate the role of fucosylated glycoproteins in HNSCC metastasis.

Citation Format: Kevin Brown Chandler, Brittany Montesino, Nan Hu, Juan M. Lozano, Robert Sackstein. Fucosyltransferase expression is associated with head and neck cancer survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2400.

Derivation and validation of a novel risk assessment tool to identify children aged 2–59 months at risk of hospitalised pneumonia-related mortality in 20 countries

Introduction

Existing risk assessment tools to identify children at risk of hospitalised pneumonia-related mortality have shown suboptimal discriminatory value during external validation. Our objective was to derive and validate a novel risk assessment tool to identify children aged 2–59 months at risk of hospitalised pneumonia-related mortality across various settings.

Methods

We used primary, baseline, patient-level data from 11 studies, including children evaluated for pneumonia in 20 low-income and middle-income countries. Patients with complete data were included in a logistic regression model to assess the association of candidate variables with the outcome hospitalised pneumonia-related mortality. Adjusted log coefficients were calculated for each candidate variable and assigned weighted points to derive the Pneumonia Research Partnership to Assess WHO Recommendations (PREPARE) risk assessment tool. We used bootstrapped selection with 200 repetitions to internally validate the PREPARE risk assessment tool.

Results

A total of 27 388 children were included in the analysis (mean age 14.0 months, pneumonia-related case fatality ratio 3.1%). The PREPARE risk assessment tool included patient age, sex, weight-for-age z-score, body temperature, respiratory rate, unconsciousness or decreased level of consciousness, convulsions, cyanosis and hypoxaemia at baseline. The PREPARE risk assessment tool had good discriminatory value when internally validated (area under the curve 0.83, 95% CI 0.81 to 0.84).

Conclusions

The PREPARE risk assessment tool had good discriminatory ability for identifying children at risk of hospitalised pneumonia-related mortality in a large, geographically diverse dataset. After external validation, this tool may be implemented in various settings to identify children at risk of hospitalised pneumonia-related mortality.

Identification of α1,2-fucosylated signaling and adhesion molecules in head and neck squamous cell carcinoma

Head and neck cancer is the seventh most common cancer in the world, and most cases manifest as head and neck squamous cell carcinoma. Despite the prominent role of fucosylated carbohydrate antigens in tumor cell adhesion and metastasis, little is known about the functional role of fucose-modified glycoproteins in head and neck cancer pathobiology. Inactivating polymorphisms of the fut2 gene, encoding for the α1,2-fucosyltransferase FUT2, are associated with an increased incidence of head and neck cancer among tobacco users. Moreover, the presence of the α1,2-fucosylated Lewis Y epitope, with both α1,2- and α1,3-linked fucose, has been observed in head and neck cancer tumors while invasive regions lose expression, suggesting a potential role for α1,2-fucosylation in the regulation of aggressive tumor cell characteristics. Here, we report an association between fut2 expression and head and neck cancer survival, document differential surface expression of α1,2-fucosylated epitopes in a panel of normal, dysplastic, and head and neck cancer cell lines, identify a set of potentially α1,2-fucosylated signaling and adhesion molecules including the epidermal growth factor receptor (EGFR), CD44 and integrins via tandem mass spectrometry, and finally, present evidence that EGFR is among the α1,2-fucosylated and LeY-displaying proteins in head and neck cancer. This knowledge will serve as the foundation for future studies to interrogate the role of LeY-modified and α1,2-fucosylated glycoproteins in head and neck cancer pathogenesis. Data are available via ProteomeXchange with identifier PXD029420.

Comparison of the Demographics and Visit Characteristics of Patients Who Left the Pediatric Emergency Department Without Being Seen With Those Who Were Evaluated in the Emergency Department

BACKGROUND

We compared those patients who left without being seen (LWBS) with those who stay for evaluation and determined which subsets were more likely to depart prematurely in the largest pediatric population studied to date.

METHODS

We retrospectively extracted data from the electronic medical records of all pediatric patients who visited the emergency department between January 1, 2013, and December 31, 2015. The demographics and visit characteristics were compared between patients who LWBS and those seen by a provider. Bivariate and multivariate analyses were used to determine the odds for premature departure of specific groups within the population.

RESULTS

Of the 271,364 pediatric patients visiting the emergency department during the 3-year study period, 3835 (1.4%) LWBS by a provider. The mean age of those LWBS was younger, and the odds of leaving slightly decreased as the patient's age increased (odds ratio [OR], 0.98). Those triaged as having "nonurgent" medical conditions had a statistically significant increase in odds of premature departure when compared with those with "urgent" medical conditions (OR, 1.16). Patients arriving during the evening and overnight hours had a much greater odds of LWBS (OR, 6.7 and 7.3, respectively).

CONCLUSIONS

Our findings demonstrated and confirmed that age, time of arrival, and acuity level upon presentation were predictors of patients leaving before evaluation. This can guide institutions with staffing and flow processes as they attempt to reduce LWBS rates but also raises further questions as to whether these subsets go forward to have worse clinical outcomes after leaving prematurely.

Strategies discussed at the XIIth international conference on Kangaroo mother care for implementation on a countrywide scale

AIM

Building strategies for the country-level dissemination of Kangaroo mother care (KMC) to reduce the mortality rate in preterm and low birth weight babies and improve quality of life. KMC is an evidence-based healthcare method for these infants. However, KMC implementation at the global level remains low.

METHODS

The international network in Kangaroo mother brought 172 KMC professionals from 33 countries together for a 2-day workshop held in conjunction with the XIIth International KMC Conference in Bogota, Colombia, in November 2018. Participants worked in clusters to formulate strategies for country-level dissemination and scale-up according to seven pre-established objectives.

RESULTS

The minimum set of indicators for KMC scale-up proposed by the internationally diverse groups is presented. The strategies for KMC integration and implementation at the country level, as well as the approaches for convincing healthcare providers of the safety of KMC transportation, are also described. Finally, the main aspects concerning KMC follow-up and KMC for term infants are presented.

CONCLUSION

In this collaborative meeting, participants from low-, middle- and high-income countries combined their knowledge and experience to identify the best strategies to implement KMC at a countrywide scale.

Pediatric psychiatric emergency department visits during a full moon

OBJECTIVE

This study aimed to verify the hypothesis that the lunar cycle influences the number of pediatric psychiatric emergency department (ED) visits.

METHODS

Pediatric psychiatric ED visits between 2009 and 2011 were obtained retrospectively. Patients aged between 4 and 21 years presenting to Miami Children's Hospital ED with a primary psychiatric complaint were included in the study. Patients with a concomitant psychiatric problem and a secondary medical condition were excluded. The number of psychiatric visits was retrieved for the full moon dates, control dates as well as the day before and after the full moon when the moon appears full to the naked eye (full moon effect). A comparison was made using the 2-sample independent t test.

RESULTS

Between 2009 and 2011, 36 dates were considered as the true full moon dates and 108 dates as the "full moon effect." A total of 559 patients were included in the study. The 2-sample independent t tests were performed between the actual full moon date and control dates, as well as between the "full moon effect" dates and control dates. Our results failed to show a statistical significance when comparing the number of pediatric psychiatric patients presenting to a children's hospital ED during a full moon and a non-full moon date.

CONCLUSIONS

Our study's results are in agreement with those involving adult patients. The full moon does not affect psychiatric visits in a children's hospital.

Prophylactic probiotics to prevent death and nosocomial infection in preterm infants

BACKGROUND AND OBJECTIVE

It has been suggested that probiotics may decrease infant mortality and nosocomial infections because of their ability to suppress colonization and translocation of bacterial pathogens in the gastrointestinal tract. We designed a large double-blinded placebo-controlled trial using Lactobacillus reuteri to test this hypothesis in preterm infants.

METHODS

Eligible infants were randomly assigned during the first 48 hours of life to either daily probiotic administration or placebo. Infants in the intervention group were administered enterally 5 drops of a probiotic preparation containing 10(8) colony-forming units of L reuteri DSM 17938 until death or discharge from the NICU.

RESULTS

A total of 750 infants ≤ 2000 g were enrolled. The frequency of the primary outcome, death, or nosocomial infection, was similar in the probiotic and placebo groups (relative risk 0.87; 95% confidence interval: 0.63-1.19; P = .376). There was a trend toward a lower rate of nosocomial pneumonia in the probiotic group (2.4% vs 5.0%; P = .06) and a nonsignificant 40% decrease in necrotizing enterocolitis (2.4% vs 4.0%; P = .23). Episodes of feeding intolerance and duration of hospitalization were lower in infants ≤ 1500 g (9.6% vs 16.8% [P = .04]; 32.5 days vs 37 days [P = .03]).

CONCLUSIONS

Although L reuteri did not appear to decrease the rate of the composite outcome, the trends suggest a protective role consistent with what has been observed in the literature. Feeding intolerance and duration of hospitalization were decreased in premature infants ≤ 1500 g.

Funding agencies in low- and middle-income countries: support for knowledge translation

OBJECTIVE

The aim was to describe how selected health research funding agencies active in low- and middle-income countries promote the translation of their funded research into policy and practice.

METHODS

We conducted inductive analysis of semi-structured interviews with key informants from a purposive sample of 23 national and international funding agencies that fund health research in Brazil, Colombia, India, the Philippines, South Africa and Thailand. We also surveyed web sites.

FINDINGS

We found a commitment to knowledge translation in the mandate of 18 of 23 agencies. However, there was a lack of common terminology. Most of the activities were traditional efforts to disseminate to a broad audience, for example using web sites and publications. In addition, more than half (13 of 23) of the agencies encouraged linkage/exchange between researchers and potential users, and 6 of 23 agencies described "pull" activities to generate interest in research from decision-makers. One-third (9 of 23) of funding agencies described a mandate to enhance health equity through improving knowledge translation. Only 3 of 23 agencies were able to describe evaluation of knowledge translation activities. Furthermore, we found national funding agencies made greater knowledge translation efforts when compared to international agencies.

CONCLUSION

Funding agencies are engaged in a wide range of creative knowledge translation activities. They might consider their role as knowledge brokers, with an ability to promote research syntheses and a focus on health equity. There is an urgent need to evaluate the knowledge translation activities of funding agencies.

Commercial versus home-made spacers in delivering bronchodilator therapy for acute therapy in children

BACKGROUND

Strong evidence supports the use of metered-dose inhalers combined with a spacer for delivering rapid-acting inhaled beta-2 agonists in the treatment of acute exacerbations of asthma in children. The high cost and lack of availability of commercially produced spacers however, have limited their use in developing countries.

OBJECTIVES

The aim of this review was to compare the response to inhaled beta-2 agonists delivered through metered-dose inhaler using home-made spacers, to the use of commercially produced spacers, in children with acute exacerbations of wheezing or asthma.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) The Cochrane Library Issue 3, 2007,(up to August 2007) MEDLINE , EMBASE, CINHAL, LILACS and reference lists of included studies. We contacted authors and known experts in the field, and approached pharmaceutical companies that manufacture inhalation spacers to identify additional published or unpublished data. No language restrictions were applied.

SELECTION CRITERIA

Trials comparing treatment with rapid acting beta 2-agonists delivered though MDI attached to home-made spacers, with the same bronchodilator therapy delivered with MDI and commercially produced spacers, in children under 18 years with acute exacerbations of wheezing or asthma.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted the data and assessed trial quality. Missing data were obtained from the authors or estimated from information available in published reports.

MAIN RESULTS

Six trials with 658 participants met the inclusion criteria . At the time of this report, five trials were published in full text, and one study was available in abstract form only. No significant differences were demonstrated between the two delivery methods in terms of need for hospital admission (RR 1.00, 95% CI 0.63 to 1.59), change in oxygen saturation (SMD -0.03, 95% CI -0.39 to 0.33), PEFR (SMD 0.04, 95% CI -0.72 to 0.80), clinical score (WMD 0.00, 95% CI -0.37 to 0.37), in terms of need for additional treatment (RR 1.18, 95% CI 0.84 to 1.65), or regarding change in heart rate per minute (SMD 0.09, 95% CI -0.24 to 0.42).

AUTHORS' CONCLUSIONS

Overall, this review supports did not identify a difference between these two methods for delivering bronchodilator therapy to children with acute asthma or lower airways obstruction attacks. Care should be taken in the interpretation and applicability of our results because of the small number of RCTs along with few events available meeting the criteria for inclusion in the review, absence of the primary outcome of interest and other clinically important outcomes in the majority of included studies. The possible need for a face-mask in younger children using home-made spacers should also be considered in practice.

WITHDRAWN: Glucocorticoids for acute viral bronchiolitis in infants and young children

BACKGROUND

Systemic glucocorticoids have been widely prescribed for use in infants and young children with acute viral bronchiolitis but the actual benefit of this intervention requires clarification.

OBJECTIVES

To systematically review the evidence on the effectiveness of systemic glucocorticoids for the treatment of infants and young children with acute viral bronchiolitis.

SEARCH STRATEGY

Multiple strategies were incorporated to maximize identification of suitable studies. The following databases were searched: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2003); MEDLINE (January 1966 to September 2003); Current Contents (1998 to 2000); EMBASE (January 1990 to September 2003); and Sci Search. Handsearches through cited references and contacts with experts were also used.

SELECTION CRITERIA

Only randomised controlled trials (RCT) were eligible for inclusion. Studies were included if participants were diagnosed with acute viral bronchiolitis and treated with systemic (oral, intramuscular or intravenous) corticosteroids. Three reviewers independently selected potentially relevant articles. Four reviewers evaluated these studies, determined eligibility and assessed the methodological quality of each RCT.

DATA COLLECTION AND ANALYSIS

The primary outcome of interest was length of hospital stay (LOS). Secondary outcomes were: respiratory rate, haemoglobin oxygen saturation, and hospital admission and revisit rates. Data were extracted independently by the four reviewers and the results compiled and compared. Two reviewers reassessed studies to clarify points of discrepancy in the data extraction and database entry processes. Missing data were requested from the authors or calculated from other data presented in the study report.

MAIN RESULTS

There was complete agreement on the inclusion of 13 trials and the exclusion of five studies. Two main study recruitment groups were identified: a) infants and young children within the first 48 hours of hospitalisation (10 trials), and b) outpatient infants and young children who were randomised from the emergency department and who may nor may not have required hospital admission (three trials).A total of 1,198 children aged 0 to 30 months were treated with the equivalent of 0.5 to 10 mg/kg of systemic prednisone for two to seven days. Outcomes of interest were not measured in each RCT. In the pooled analysis of seven trials, there was a decrease in LOS in treated children of 0.38 days (95% confidence interval (CI) -0.81 to 0.05), indicating no significant difference between treatment groups. In the pooled analysis of eight trials, the day three clinical score measured: a standard mean difference (SMD) of -0.20 (95% CI -0.73 to 0.32), indicating no difference between treatment groups. Subgroup analyses for base LOS and clinical score outcomes were performed on infants who were a) less than 12 months of age, b) all respiratory syncytial virus (RSV) positive, c) treated with less than 6 mg/kg of prednisone equivalent throughout the illness and d) first-time wheezers. These were limited by the small number of studies in each subgroup. Hospital admission rates were examined in three trials and no difference was seen between treatment groups (odds ratio (OR) 1.05 (95% CI 0.23 to 4.87). Readmission rates were reported in six studies; with no significant differences between treatment groups. Hospital revisit rates were reported in three studies, with a significant difference between treatment groups reported in one study only. The respiratory rate and haemoglobin oxygen saturation were reported descriptively in six RCTs; no differences were found between groups. Co-interventions (oxygen, supportive fluids and bronchodilators) were used similarly between treatment groups in all RCTs.

AUTHORS' CONCLUSIONS

No benefits were found in either LOS or clinical score in infants and young children treated with systemic glucocorticoids as compared to placebo. There were no differences in these outcomes between treatment groups; either in the pooled analysis or in any of the sub analyses. Among the three studies evaluating hospital admission rates following the initial hospital visit there was no difference between treatment groups. There were no differences found in respiratory rate, haemoglobin oxygen saturation, hospital revisit or readmission rates. Subgroup analyses were significantly limited by the low number of studies in each comparison. Marked study heterogeneity and occasionally conflicting direction of benefit between trials suggests that these results should be interpreted with caution. Specific data on the harm of corticosteroid therapy in this patient population are lacking. Available evidence suggests that corticosteroid therapy is not of benefit in this patient group.

International collaborative research: a Colombian model that promotes infant health and research capacity

Current collaborative efforts in international research with resource-poor nations are frequently paternalistic and deprive these nations of the skills necessary to build independent research capacity. Resource-poor nations have become progressively suspicious of research endeavors originated in industrialized nations that have minimal impact on the health care needs of their populations. The current trend toward globalization requires that certain standards be established to guide these collaborative efforts to create strong partnerships that promote independent evidence-based health research. The objective of this paper is to present a comprehensive approach to health-related international collaborative research with resource-poor nations using as an example a model that has been developed in Colombia, South America.

Open letter to the leader of academic medicine

As their campaign comes to a close, ICRAM presents a challenge to academic medicine's invisible leaders

sHLA-G levels in the monitoring of immunosuppressive therapy and rejection following heart transplantation

The aim of this study was to further determine the immediate influence, over a 12-h period, after the initiation of daily immunosuppressive treatment on the serum levels of sHLA-G in heart transplant patients during the post-transplant period (1 month). It was found that there are two patterns of patients in term of the changes observed in their levels of sHLA-G in response to the immunosuppressive treatment. One group (group A) showed no changes on sHLA-G while the other group (group B) a significant rise in sHLA-G levels was observed at 2 to 4 h post dose. Interestingly, it was observed that the patients in group B have better prognosis of acceptance of the heart graft than those of group A. On the other hand it was found that the patients with high levels of sHLA-G (77.3+/-34.8 ng/ml) in pre-transplant sera have a better prognosis of acceptance of the heart graft than those with low sHLA-G levels (9.7+/-7.1 ng/ml). In conclusion, both the intensity of changes of sHLA-G levels induced by immunosuppression and basal levels in pre-transplant could be used in the monitoring of the immunosuppression as well as the heart transplant evolution.

Nucleoside reverse transcriptase inhibitors are able and protease inhibitors unable to induce the tolerogenic molecule HLA-G1 on monocytes from HIV-1 infected patients

Our group has previously reported that a significantly larger proportion of peripheral monocytes from human immunodeficiency virus type 1 (HIV-1) seropositive individuals receiving highly active antiretroviral therapy (HAART) express HLA-G1 and also that one of the HAART components, the nucleoside reverse transcriptase inhibitors (NRTIs), may be involved in this effect. Because protease inhibitors (PIs) are another component of HAART that are administered with NRTIs, the aim of this work was to determine whether or not PIs are also involved in the HLA-G1 changes previously observed in treated HIV-1 positive patients. CD14(+) cells expressing HLA-G1 were therefore measured in 7 HIV-1 positive patients whose initial HAART was changed to a protease inhibitor-only regime due to drug toxicity and/or virologic resistance. Our results indicate that PIs do not appear to be implicated in the rise of HLA-G1 expression on CD14(+) cells from HIV-1 infected individuals receiving HAART, while we further confirm that NRTIs are involved in the surface induction of HLA-G1.

Randomized, multicenter trial of conventional ventilation versus high-frequency oscillatory ventilation for the early management of respiratory failure in term or near-term infants in Colombia

OBJECTIVE

To determine the efficacy and safety of high-frequency oscillatory ventilation (HFOV) compared to conventional ventilation (CV) for the treatment of respiratory failure in term and near-term infants in Colombia.

STUDY DESIGN

Eligible infants with moderate to severe respiratory failure were randomized to early treatment with CV or HFOV. Ventilator management and general patient care were standardized. The main outcome was neonatal death or pulmonary air leak.

RESULTS

A total of 119 infants were enrolled (55 in the HFOV group; 64 in the CV group) during the study period. Six infants in the HFOV group (11%) and two infants in the CV group (3%) developed the primary outcome (RR: 3.6, 95% CI: 0.8-16.9). Five infants in the HFOV group (9%) and one infant in the CV (2%) died before 28 days of life (RR: 5.9 CI: 0.7-48.2). Secondary outcomes were similar between groups.

CONCLUSION

HFOV may not be superior to CV as an early treatment for respiratory failure in this age group. Standardization of ventilator management and general patient care may have a greater impact on the outcome in Colombia than mode of ventilation.

Epidemiology of nosocomial infections in selected neonatal intensive care units in Colombia, South America

OBJECTIVE

The epidemiology of nosocomial infections (NI) in neonatal intensive care units in developing countries has been poorly studied. We conducted a prospective study in selected neonatal units in Colombia, SA, to describe the incidence rate, causative organisms, and interinstitutional differences.

STUDY DESIGN

Data were collected prospectively from February 20 to August 30, 2001 from eight neonatal units. NI was defined as culture-proven infection diagnosed after 72 h of hospitalization, resulting in treatment with antibiotics for >3 days. Linear regression models were used to describe associations between institutional variables and NI rates.

RESULTS

A total of 1504 infants were hospitalized for more than 72 h, and therefore, at risk for NI. Of all, 127 infections were reported among 80 patients (5.3%). The incidence density rate was 6.2 per 1000 patient-days. Bloodstream infections accounted for 78% of NIs. Gram-negative organisms predominated over gram-positive organisms (55 vs 38%) and were prevalent in infants < or =2000 g (54%). The most common pathogens were Staphylococcus epidermidis (26%) and Klebsiella pneumonia (12%).

CONCLUSION

Gram-negative organisms predominate in Colombia among infants <2000 g. The emergence of gram-negative organisms and their associated risk factors requires further study.

Risk factors for nosocomial infections in selected neonatal intensive care units in Colombia, South America

OBJECTIVE

This study was designed to identify risk factors for nosocomial infections among infants admitted into eight neonatal intensive care units in Colombia. Knowledge of modifiable risk factors could be used to guide the design of interventions to prevent the problem.

STUDY DESIGN

Data were collected prospectively from eight neonatal units. Nosocomial infection was defined as culture-proven infection diagnosed after 72 hours of hospitalization, resulting in treatment with antibiotics for >3 days. Associations were expressed as odds ratios. Logistic regression was used to adjust for potential confounders.

RESULTS

From a total of 1504 eligible infants, 80 were treated for 127 episodes of nosocomial infection. Logistic regression analysis identified the combined exposure to postnatal steroids and H2-blockers, and use of oral gastric tubes for enteral nutrition as risk factors significantly associated with nosocomial infection.

CONCLUSION

Nosocomial infections in Colombian neonatal intensive care units were associated with modifiable risk factors including use of postnatal steroids and H2-blockers.

Progesterone can block the preovulatory gonadotropin-releasing hormone/luteinising hormone surge in the ewe by a direct inhibitory action on oestradiol-responsive cells within the hypothalamus

Elevated oestradiol concentrations during the follicular phase stimulate a surge in gonadotropin-releasing hormone (GnRH) and luteinising hormone (LH) concentrations, which leads to ovulation. Progesterone can block the oestradiol-induced GnRH/LH surge, but the mechanism that is involved is unclear. We examined the effect of progesterone on oestradiol-induced activation of cells within the ovine hypothalamus/preoptic area (POA) to determine: (i) in which regions progesterone acts to block the GnRH/LH surge and (ii) whether progesterone directly or indirectly prevents activation of oestradiol-responsive cells. Cellular activation was assessed by measuring the number of cells that expressed Fos (an immediate early gene). Exposure to increased oestradiol concentrations in the absence of progesterone (which normally stimulates a LH surge) did not cause any region-specific changes in hypothalamic Fos expression during the activation stage of the LH surge-induction process (Experiment 1). The same treatment significantly increased cellular activation within the POA, lateral septum (LS), and arcuate nucleus at the time of surge onset (Experiment 2). Concurrent exposure to increased oestradiol and progesterone concentrations during the activation stage of the surge-induction process (which normally blocks the LH surge) was associated with significantly reduced cellular activation within the ventromedial hypothalamus and anterior hypothalamic area, relative to the positive controls (oestradiol increment alone) and arcuate nucleus relative to the negative controls (no increment in oestradiol) during the activation stage (Experiment 1). At the time of surge onset (Experiment 2), exposure to progesterone during the activation period prevented the oestradiol-induced increase in cellular activation that occurred in the POA, LS and arcuate nucleus of the positive controls. These results demonstrated that oestradiol and progesterone induced differential region- and time-specific effects on cellular activation within the regions of the ovine brain that generate the preovulatory GnRH/LH surge. Moreover, the lack of cellular activation within the POA, LS and arcuate nucleus at the time of surge onset in animals exposed to progesterone during the activation stage is consistent with the hypothesis that progesterone can block the preovulatory surge by direct inhibition of oestradiol-induced cellular activation in these areas.

Effect of plane of nutrition on endometrial sex steroid receptor expression in ewes

The effect of plane of nutrition on progesterone receptor (PR) and estrogen receptor alpha (ERalpha) expression in ovine endometrium was investigated. Rasa Aragonesa ewes (n=26) were fed diets to provide either 1.5 (Group C) or 0.5 (Group L) times the daily maintenance requirement and were slaughtered at Days 5 or 10 of the estrous cycle (Day 0=estrus). PR and ERalpha immunoreactivity were analyzed in eight endometrial cell compartments, defined by cell type and location. Group L had less PR immunostaining on Day 5 (P<0.05), which is consistent with lesser endometrial content of progesterone found in such animals. Most cell types of Group C had down regulation of PR at Day 10, but in Group L, this pattern was observed only in three cell compartments. The lesser PR contents found at Day 5 in Group L ewes may explain the lack of inhibition of PR. No effect of treatment or day of the estrous cycle was observed in ERalpha. Results indicate that endometrial PR is affected in a cell type, in specific manner, by plane of nutrition.

Oral amoxicillin versus injectable penicillin for severe pneumonia in children aged 3 to 59 months: a randomised multicentre equivalency study

BACKGROUND

Injectable penicillin is the recommended treatment for WHO-defined severe pneumonia (lower chest indrawing). If oral amoxicillin proves equally effective, it could reduce referral, admission, and treatment costs. We aimed to determine whether oral amoxicillin and parenteral penicillin were equivalent in the treatment of severe pneumonia in children aged 3-59 months.

METHODS

This multicentre, randomised, open-label equivalency study was undertaken at tertiary-care centres in eight developing countries in Africa, Asia, and South America. Children aged 3-59 months with severe pneumonia were admitted for 48 h and, if symptoms improved, were discharged with a 5-day course of oral amoxicillin. 1702 children were randomly allocated to receive either oral amoxicillin (n=857) or parenteral penicillin (n=845) for 48 h. Follow-up assessments were done at 5 and 14 days after enrollment. Primary outcome was treatment failure (persistence of lower chest indrawing or new danger signs) at 48 h. Analyses were by intention-to-treat and per protocol.

FINDINGS

Treatment failure was 19% in each group (161 patients, pencillin; 167 amoxillin; risk difference -0.4%; 95% CI -4.2 to 3.3) at 48 h. Infancy (age 3-11 months; odds ratio 2.72, 95% CI 1.95 to 3.79), very fast breathing (1.94, 1.42 to 2.65), and hypoxia (1.95, 1.34 to 2.82) at baseline predicted treatment failure by multivariate analysis.

INTERPRETATION

Injectable penicillin and oral amoxicillin are equivalent for severe pneumonia treatment in controlled settings. Potential benefits of oral treatment include decreases in (1) risk of needle-borne infections; (2) need for referral or admission; (3) administration costs; and (4) costs to the family.

Glucocorticoids for acute viral bronchiolitis in infants and young children

BACKGROUND

Systemic glucocorticoids have been widely prescribed for use in infants and young children with acute viral bronchiolitis but the actual benefit of this intervention requires clarification.

OBJECTIVES

To systematically review the evidence on the effectiveness of systemic glucocorticoids for the treatment of infants and young children with acute viral bronchiolitis.

SEARCH STRATEGY

Multiple strategies were incorporated to maximize identification of suitable studies. The following databases were searched: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2003); MEDLINE (January 1966 to September 2003); Current Contents (1998 to 2000); EMBASE (January 1990 to September 2003); and Sci Search. Handsearches through cited references and contacts with experts were also used.

SELECTION CRITERIA

Only randomised controlled trials (RCT) were eligible for inclusion. Studies were included if participants were diagnosed with acute viral bronchiolitis and treated with systemic (oral, intramuscular or intravenous) corticosteroids. Three reviewers independently selected potentially relevant articles. Four reviewers evaluated these studies, determined eligibility and assessed the methodological quality of each RCT.

DATA COLLECTION AND ANALYSIS

The primary outcome of interest was length of hospital stay (LOS). Secondary outcomes were: respiratory rate, haemoglobin oxygen saturation, and hospital admission and revisit rates. Data were extracted independently by the four reviewers and the results compiled and compared. Two reviewers reassessed studies to clarify points of discrepancy in the data extraction and database entry processes. Missing data were requested from the authors or calculated from other data presented in the study report.

MAIN RESULTS

There was complete agreement on the inclusion of 13 trials and the exclusion of five studies. Two main study recruitment groups were identified: a) infants and young children within the first 48 hours of hospitalisation (10 trials), and b) outpatient infants and young children who were randomised from the emergency department and who may nor may not have required hospital admission (three trials).A total of 1,198 children aged 0 to 30 months were treated with the equivalent of 0.5 to 10 mg/kg of systemic prednisone for two to seven days. Outcomes of interest were not measured in each RCT. In the pooled analysis of seven trials, there was a decrease in LOS in treated children of 0.38 days (95% confidence interval (CI) -0.81 to 0.05), indicating no significant difference between treatment groups. In the pooled analysis of eight trials, the day three clinical score measured: a standard mean difference (SMD) of -0.20 (95% CI -0.73 to 0.32), indicating no difference between treatment groups. Subgroup analyses for base LOS and clinical score outcomes were performed on infants who were a) less than 12 months of age, b) all respiratory syncytial virus (RSV) positive, c) treated with less than 6 mg/kg of prednisone equivalent throughout the illness and d) first-time wheezers. These were limited by the small number of studies in each subgroup. Hospital admission rates were examined in three trials and no difference was seen between treatment groups (odds ratio (OR) 1.05 (95% CI 0.23 to 4.87). Readmission rates were reported in six studies; with no significant differences between treatment groups. Hospital revisit rates were reported in three studies, with a significant difference between treatment groups reported in one study only. The respiratory rate and haemoglobin oxygen saturation were reported descriptively in six RCTs; no differences were found between groups. Co-interventions (oxygen, supportive fluids and bronchodilators) were used similarly between treatment groups in all RCTs.

REVIEWERS' CONCLUSIONS

No benefits were found in either LOS or clinical score in infants and young children treated with systemic glucocorticoids as compared to placebo. There were no differences in these outcomes between treatment groups; either in the pooled groups; either in the pooled analysis or in any of the sub analyses. Among the three studies evaluating hospital admission rates following the initial hospital visit there was no difference between treatment groups. There were no differences found in respiratory rate, haemoglobin oxygen saturation, hospital revisit or readmission rates. Subgroup analyses were significantly limited by the low number of studies in each comparison. Marked study heterogeneity and occasionally conflicting direction of benefit between trials suggests that these results should be interpreted with caution. Specific data on the harm of corticosteroid therapy in this patient population are lacking. Available evidence suggests that corticosteroid therapy is not of benefit in this patient group.

Protection against liver injury by PGE1 or anti-TNF-alpha is associated with a reduction of TNF-R1 expression in hepatocytes

BACKGROUND

Tumour necrosis factor-alpha (TNF-5) has been shown to exacerbate or protect against liver injury in different experimental models. In a previous study, we observed that enhancement of TNF-alpha expression in hepatocytes by prostaglandin E1 (PGE1) pre-administration induced iNOS expression and cytoprotection against experimental liver injury in rats. Nevertheless, the reduction of TNF-alpha bioactivity by anti-TNF-alpha antibodies also reduced liver injury by D-GalN. The purpose of the present study was to evaluate whether protection by PGE1 or anti-TNF-alpha was related to a common effect on the membrane-bound TNF-alpha receptor expression.

METHODS

Liver injury was induced in male Wistar rats by intraperitoneal injection of D-galactosamine (D-GalN) (1 g/kg). PGE1 or anti-TNF-alpha was administered at 30 or 60 min before D-GalN, respectively. Liver injury was evaluated by alanine aminotransferase (ALT) activity in serum and histological examination in liver sections. TNF-alpha was determined by ELISA in serum. The expression of TNF-alpha receptor type 1 (TNF-R1) and TNF-alpha receptor type 2 (TNF-R2) in hepatocytes was assessed by immunohistochemistry and immunoprecipitation + Western-blot analysis.

RESULTS

PGE1 or anti-TNF-alpha reduced liver injury induced by D-GalN. Although PGE1 enhanced and anti-TNF-alpha reduced TNF-alpha concentration in serum, both protective treatments reduced the expression of TNF-R1 in hepatocytes. TNF-R2 was not detected in our experimental conditions.

CONCLUSIONS

Our study showed that reduction of liver injury by PGE1 or anti-TNF-alpha antibodies was related to a reduction of TNF-R1 expression in hepatocytes.

Influence of nutrition on the effectiveness of superovulation programmes in ewes: effect on oocyte quality and post-fertilization development

Two experiments were carried out to study the effect of nutrition on embryo development in two periods in superovulated ewes (Expt 1) and on oocyte developmental capacity during the late follicular phase (Expt 2). In Expt 1, a lower superovulation response in terms of animals ovulating (P < 0.05), ovulation rate per ewe ovulating (P = 0.1) and number of good quality embryos per animal treated (P < 0.07) was noted in ewes fed an ad libitum diet compared with ewes offered control (1.5 times the daily maintenance energy requirements, 1.5 x M) or low energy (0.5 x M) diets. Nutrition also modified the morphological and functional quality of the oocytes and embryos recovered. Thus, 92% of day 4 embryos recovered from ewes offered the control diet were classified as good embryos, compared with 70 and 82% of those recovered from ewes offered the ad libitum and low diets, respectively (P < 0.05). Ewes offered the ad libitum diet had a greater percentage of poorly developed embryos compared with ewes offered the control or low diets (P < 0.05). Ewes fed the low diet tended to have more non-fertilized oocytes than ewes offered the control diet (P = 0.09). Diet of recipient ewes to which good quality embryos were transferred on day 4 did not affect embryo quality, when assessed 12 days later (day 16 of pregnancy). However, recipient diet affected prostaglandin F(2alpha) (PGF(2alpha)) production in vitro, and uterine tissue that originated from recipient ewes on the low diet secreted more PGF(2alpha) relative to uterine tissue that originated from recipients on the control diet (P < 0.05). In Expt 2, fewer total (P < 0.05) and good quality (P < 0.01) oocytes and a lower percentage of good quality oocytes (P < 0.01) were obtained from superovulated ewes offered the ad libitum diet compared with ewes offered the low diet. In addition, cleavage rate tended to be higher (51 versus 35%, P = 0.09) in ewes offered the low diet compared with ewes offered the ad libitum diet. In conclusion, changes in diet can affect the quality of the oocyte and embryo in superovulated sheep. A lower superovulation response and a decrease in the quality of oocytes and embryos indicate that ad libitum diets are highly detrimental for superovulatory programmes when compared with low and control diets. In addition, the results from the present study indicate that a low energy diet during early embryo development increased the uterine production in vitro of PGF(2alpha) which could lead to a poor uterine environment thereby compromising the development of the embryo.

Influence of nutrition on the effectiveness of superovulation programmes in ewes: effect on oocyte quality and post-fertilization development

Two experiments were carried out to study the effect of nutrition on embryo development in two periods in superovulated ewes (Expt 1) and on oocyte developmental capacity during the late follicular phase (Expt 2). In Expt 1, a lower superovulation response in terms of animals ovulating (P < 0.05), ovulation rate per ewe ovulating (P = 0.1) and number of good quality embryos per animal treated (P < 0.07) was noted in ewes fed an ad libitum diet compared with ewes offered control (1.5 times the daily maintenance energy requirements, 1.5 x M) or low energy (0.5 x M) diets. Nutrition also modified the morphological and functional quality of the oocytes and embryos recovered. Thus, 92% of day 4 embryos recovered from ewes offered the control diet were classified as good embryos, compared with 70 and 82% of those recovered from ewes offered the ad libitum and low diets, respectively (P < 0.05). Ewes offered the ad libitum diet had a greater percentage of poorly developed embryos compared with ewes offered the control or low diets (P < 0.05). Ewes fed the low diet tended to have more non-fertilized oocytes than ewes offered the control diet (P = 0.09). Diet of recipient ewes to which good quality embryos were transferred on day 4 did not affect embryo quality, when assessed 12 days later (day 16 of pregnancy). However, recipient diet affected prostaglandin F(2alpha) (PGF(2alpha)) production in vitro, and uterine tissue that originated from recipient ewes on the low diet secreted more PGF(2alpha) relative to uterine tissue that originated from recipients on the control diet (P < 0.05). In Expt 2, fewer total (P < 0.05) and good quality (P < 0.01) oocytes and a lower percentage of good quality oocytes (P < 0.01) were obtained from superovulated ewes offered the ad libitum diet compared with ewes offered the low diet. In addition, cleavage rate tended to be higher (51 versus 35%, P = 0.09) in ewes offered the low diet compared with ewes offered the ad libitum diet. In conclusion, changes in diet can affect the quality of the oocyte and embryo in superovulated sheep. A lower superovulation response and a decrease in the quality of oocytes and embryos indicate that ad libitum diets are highly detrimental for superovulatory programmes when compared with low and control diets. In addition, the results from the present study indicate that a low energy diet during early embryo development increased the uterine production in vitro of PGF(2alpha) which could lead to a poor uterine environment thereby compromising the development of the embryo.

Ethical challenges in pharmacoepidemiological research in Colombia

PURPOSE

To illustrate and to discuss some ethical challenges encountered during pharmacoepidemiological research in a developing country (Colombia), as well as the decisions made to solve them.

METHODS

The authors in Bogotá describe three recent studies. The first one collected data from clinical records to evaluate the prescriptions patterns in recently graduated physicians. The second used an interrupted time series design, with a set of observations prior and after a combined intervention, to assess whether it improved the quality of intravenous antibiotic prescribing practices in a university-based hospital. The third evaluated pharmacists' advice in childhood acute respiratory infection and acute diarrhea through a community survey, followed by focus groups and in-depth interviews of key informers.

RESULTS

The ethical issues raised by these studies include the need for obtaining informed consent from participants (physicians in Study 1 and drug sellers in Study 3), deciding when to intervene in case of gross prescription mistakes detected during the collection of data as part of the time series assessment (Study 2), the use of simulated clients to collect data in the community survey, and the use of study resources to buy, in some cases, useless medications (Study 3).

CONCLUSION

Although ethical challenges in pharmacoepidemiology in non-industrialized countries like Colombia may be different from those in developed nations, ethical principles that guide research remain the same. The processes to safeguard these principles in Colombia for virtually all research are also universal in nature, and include the ethical review committee, subject privacy, informed consent, and disclosure of funding sources.

Cultivation and characterization of stable Leishmania guyanensis complex axenic amastigotes derived from infected U937 cells

The study of the differential regulation of several genes, in both Leishmania parasite life cycle forms, has been simplified by the development of in vitro axenic amastigote culture. Different reports have described extracellular amastigote production and maintenance from several Leishmania spp. A general approach to induce amastigote-like transformation includes progressive pH and temperature changes. Production of axenic amastigotes in continuous cultures using amastigotes recovered from macrophages is described in this report. Leishmania (Viannia) panamensis (M/HOM/PA/71/LS94) and Leishmania (V). guyanensis (M/HOM/BR/75/M4147) intracellular amastigotes were recovered from the human macrophage-like U937 cell line previously infected with promastigotes. The parasites were immediately adapted for growth and kept as axenic amastigotes at 34 degrees C and acidic pH. These organisms were able to infect macrophage cell lines, maintain amastigote morphologic features, and express stage-specific transcripts. The relevance of axenic amastigotes in characterizing virulence factors in American leishmaniasis is discussed.

Epidemiology of hypoxaemia in children with acute lower respiratory infection

OBJECTIVES

To determine the prevalence of hypoxaemia in children aged under 5 years suffering acute lower respiratory infections (ALRI), the risk factors for hypoxaemia in children under 5 years of age with ALRI, and the association of hypoxaemia with an increased risk of dying in children of the same age.

DESIGN

Systematic review of the published literature.

SETTINGS

Out-patient clinics, emergency departments and hospitalisation wards in 23 health centres from 10 countries.

SUBJECTS

Cohort studies reporting the frequency of hypoxaemia in children under 5 years of age with ALRI, and the association between hypoxaemia and the risk of dying.

MAIN OUTCOME MEASURES

Prevalence of hypoxaemia measured in children with ARI and relative risks for the association between the severity of illness and the frequency of hypoxaemia, and between hypoxaemia and the risk of dying.

RESULTS

Seventeen published studies were found that included 4,021 children under 5 with acute respiratory infections (ARI) and reported the prevalence of hypoxaemia. Out-patient children and those with a clinical diagnosis of upper ARI had a low risk of hypoxaemia (pooled estimate of 6% to 9%). The prevalence increased to 31% and to 43% in patients in emergency departments and in cases with clinical pneumonia, respectively, and it was even higher among hospitalised children (47%) and in those with radiographically confirmed pneumonia (72%). The cumulated data also suggest that hypoxaemia is more frequent in children living at high altitude. Three papers reported an association between hypoxaemia and death, with relative risks varying between 1.4 and 4.6. Papers describing predictors of hypoxaemia have focused on clinical signs for detecting hypoxaemia rather than on identifying risk factors for developing this complication.

CONCLUSION

Hypoxaemia is a common and potentially lethal complication of ALRI in children under 5, particularly among those with severe disease and those living at high altitude. Given the observed high prevalence of hypoxaemia and its likely association with increased mortality, efforts should be made to improve the detection of hypoxaemia and to provide oxygen earlier to more children with severe ALRI.

Factors predicting nutritional derangements in patients with obstructive jaundice: multivariate analysis

Patients with obstructive jaundice (OJ) that requires surgery often have malnutrition associated with increased perioperative morbidity. This study investigated the factors influencing nutritional derangements in these patients. A series of 46 OJ patients were investigated prospectively (28 malignant tumors, 18 benign obstructions). A nutritional risk index of < 83.5 was used to define protein-calorie malnutrition. Liver function, cholecystokinin (CCK), tumor necrosis factor-alpha (TNFalpha), and endotoxin levels were determined. A multivariate analysis was performed, and an obstructive jaundice malnutrition index (OJMI) was obtained. Altogether, 22 (48%) OJ patients had malnutrition (33% with benign obstructions, 57% with malignant disease). Malnourished patients had higher serum bilirubin levels (258 +/- 120 vs. 154 +/- 62 mmol/L; p = 0.005), longer duration of jaundice (16 +/- 9 vs. 9 +/- 5 days; p = 0.03), and higher plasma levels of CCK (4.0 +/- 1.3 vs. 1.7 +/- 1.0 pmol/L; p = 0.005), alanine aminotransferase (ALT) (226 +/- 209 vs. 187 +/- 161 UI/L; p = 0.01), endotoxin (15 +/- 10 vs. 6.5 +/- 7.0 EU/L; p = 0.007), and TNFalpha (69 +/- 82 vs. 23 +/- 15 pg/ml; p = 0.008) than those without malnutrition. However, only serum bilirubin, CCK, ALT, and patient age were predictors for malnutrition by multivariate analysis. Malnutrition might be expected (95% confidence interval) in patients older than 68 years with increased bilirubin (> 290 mmol/L) and ALT (> 210 UI/L) levels that corresponded with an OJMI > 55. It was concluded that nutritional alterations in patients with obstructive jaundice were determined by the intensity of the biliary obstruction correlated with increased plasma CCK levels as well as with liver dysfunction and patient age.

GGRGDSPCA peptide: a new antiscarring agent on glaucoma filtration surgery

BACKGROUND AND OBJECTIVE

GGRGDSPCA synthetic peptide competes for integrin receptor in scar formation after glaucoma filtering surgery in a rabbit model. The purpose of this study was to evaluate the use of this peptide and compare it with mitomycin on glaucoma filtering surgery.

MATERIALS AND METHODS

Posterior sclerectomy was performed in both eyes of 17 rabbits. The right eye received GGRGDSPCA (p605) at 0, 4, 8, 12, and 16 days after. Nine left eyes received saline as a control; the remaining 8 eyes received mitomycin C at 0.5 mg/mL intraoperative. Intraocular pressures and biomicroscopy were evaluated as well as bleb function.

RESULTS

Intraocular pressure decreased significantly in both the peptide and mitomycin treated eyes in comparison with the saline group (P = 0.0003). Pressure was similar in both groups. The blebs showed filtrating function in a functional analysis at day 21 and 41 in the mitomycin cases as well as in the peptide group. Histologic analysis performed in both peptide and mitomycin groups showed inhibitory effect in fibrocellular and collagen organization with bleb formation.

CONCLUSIONS

The p605 peptide showed to be similar to mitomycin C in controlling and improving glaucoma filtering surgery in rabbits. This alternative may potentially be useful for similar purposes in humans for the control of glaucoma and improvement of filtering surgery.

Cytokines and acute-phase response markers derangements in patients with obstructive jaundice

BACKGROUND/AIMS

Prolonged acute-phase response and increase of cytokines have been associated with higher mortality and surgical complications. This study investigated the status of cytokines and acute-phase response markers in patients with obstructive jaundice.

METHODOLOGY

Forty-one patients were investigated. Endotoxin, tumor necrosis factor-alpha, interleukin-6, nitric oxide, C-reactive protein, liver enzymes, albumin and percentage of weight loss were determined at admission.

RESULTS

Endotoxin, interleukin-6 and C-reactive protein were significantly elevated in both benign and malignant obstructive jaundice. Increased plasma levels of tumor necrosis factor-alpha were only detected in malignant tumors (68 vs. 24 pg/mL; P < 0.001). Patients with positive acute-phase response (C-reactive protein > mean + 2 SD of controls) had greater weight loss (P = 0.02), endotoxin (P = 0.03) and interleukin-6 plasma levels (P = 0.05) than those with no inflammatory response. Prolonged biliary obstruction (> 10 days) was associated with higher weight loss (P = 0.04), tumor necrosis factor-alpha (P = 0.003) and interleukin-6 (P = 0.05) plasma levels.

CONCLUSIONS

A prolonged high-grade biliary tract obstruction prompted an increase in endotoxin levels, associated with a positive acute-phase response and cytokine elevation.

TNF-alpha dependent production of inducible nitric oxide is involved in PGE(1) protection against acute liver injury

BACKGROUND

Tumour necrosis factor alpha (TNF-alpha) and nitric oxide modulate damage in several experimental models of liver injury. We have previously shown that protection against D-galactosamine (D-GalN) induced liver injury by prostaglandin E(1) (PGE(1)) was accompanied by an increase in TNF-alpha and nitrite/nitrate in serum.

AIMS

The aim of the present study was to evaluate the role of TNF-alpha and nitric oxide during protection by PGE(1) of liver damage induced by D-GalN.

METHODS

Liver injury was induced in male Wistar rats by intraperitoneal injection of 1 g/kg of D-GalN. PGE(1) was administered 30 minutes before D-GalN. Inducible nitric oxide synthase (iNOS) was inhibited by methylisothiourea (MT), and TNF-alpha concentration in serum was lowered by administration of anti-TNF-alpha antibodies. Liver injury was evaluated by alanine aminotransferase activity in serum, and histological examination and DNA fragmentation in liver. TNF-alpha and nitrite/nitrate concentrations were determined in serum. Expression of TNF-alpha and iNOS was also assessed in liver sections.

RESULTS

PGE(1) decreased liver injury and increased TNF-alpha and nitrite/nitrate concentrations in serum of rats treated with D-GalN. PGE(1) protection was related to enhanced expression of TNF-alpha and iNOS in hepatocytes. Administration of anti-TNF-alpha antibodies or MT blocked the protection by PGE(1) of liver injury induced by D-GalN.

CONCLUSIONS

This study suggests that prior administration of PGE(1) to D-GalN treated animals enhanced expression of TNF-alpha and iNOS in hepatocytes, and that this was causally related to protection by PGE(1) against D-GalN induced liver injury.

TNF-alpha but not IL-1alpha is correlated with PGE1-dependent protection against acute D-galactosamine-induced liver injury

BACKGROUND

Prostaglandin E1 (PGE1) treatment of humans and rodents during acute hepatic failure ameliorates different parameters of hepatic dysfunction.

PURPOSE

To investigate whether prevention of acute liver injury induced by D-galactosamine (D-GalN) with preadministration of PGE1 is correlated with a change in the concentration of two proinflammatory cytokines, as tumour necrosis factor-alpha (TNF-alpha) and interleukin (IL)-1alpha, and/or nitrite+nitrate (NOx), as nitric oxide-related end products in serum.

RESULTS

D-GalN significantly increased alanine aminotransferase (ALT) and TNF-alpha concentration in serum 5 and 10 mins, respectively, after treatment compared with the control group (P< or =0.05). D-GalN did not change the IL-1alpha concentration at any time during the study. Preadministration of PGE1 to D-GalN-treated rats significantly reduced the ALT content and increased significantly the TNF-alpha concentration in serum 1, 2.5, 5 and 10 mins after D-GalN treatment compared with the D-GalN group (P< or =0.05). Nitric oxide was not involved in either the toxic effect due to D-GalN or the protection observed with PGE1 against D-GalN toxicity.

CONCLUSIONS

Acute liver injury induced by D-GalN is correlated with an increased TNF-alpha release. Preadministration of PGE1 to D-GalN-treated rats exerted a priming effect on inflammatory cells to release enhanced levels of TNF-alpha but not IL-1alpha. These findings indicate that stimulation of TNF-alpha release may be involved in the acute D-GalN-induced liver injury and also in PGE1 protection from hepatotoxicity in clinical and experimental studies.

Clinical epidemiological principles in bedside teaching

Medical education emphasises the transmission of large amounts of short-lived medical information. Strategies must be developed to generate in the students, attitudes towards the independent search for and critical appraisal of evidences. Two complementary strategies are particularly well suited to promote these types of attitudes: clinical epidemiology and evidence-based clinical practice. Clinical epidemiology (CE) has been defined as "the science of making predictions about individual patients by counting clinical events in similar patients, using strong methods for studies of groups of patients to ensure that the predictions are accurate. The purpose of CE is to develop and apply methods of clinical observation that will lead to valid conclusions by avoiding being misled by systematic error and chance". On the other hand, evidence based practice has been defined as "an approach to the practice of medicine in which the clinician is aware not only of the evidences which support clinical practice, but the strength and soundness of such evidences". The paper discusses the usefulness of clinical epidemiology and evidence-based health practice for rational decision making at the bedside, and also as tools for clinical teaching. An example involving evidence-based strategies for the management of a patient with bronchiolitis in the emergency room is discussed.

Reading a journal article

Journal reading is an important continuing educational activity in terms of physician preference, frequency of use amount of time devoted to it and impact in changing practice. Clinicians trying to obtain information from journals face several tasks, including the need to assess both the quality and the applicability of the information found in published articles. This article describes the general principles for reading, critically, scientific papers that report clinical research results, which include establishing the kind of question that the authors were trying to answer, the type of study done, if the research design was appropriate for the question, and if it was conducted correctly. According to several available guidelines, once the reader has a clear idea of the study question it is necessary to assess the methods described by the authors in order to evaluate whether the research strategy used is likely to have errors resulting from bias and chance (random) variation. If the paper methodology seems to be adequate, the reader should proceed to determine the results of the article and their potential clinical impact. Finally, the reader must establish the extent to which the results are helpful in caring for his or her own patients, which means assessing the external validity and other related issues. The use of these strategies will improve the efficiency of readers for incorporating research results to their practice.

A preliminary report on the effect of dietary energy on prostaglandin F2 alpha production in vitro, interferon-tau synthesis by the conceptus, endometrial progesterone concentration on days 9 and 15 of pregnancy and associated rates of embryo wastage in ewes

Two groups of ewes were fed to provide 1.70 x (high energy group; n = 15) or 0.56 x (low energy group; n = 15) energy requirements for maintenance of liveweight from 14 d before a synchronized mating in November until slaughter at 9 or 15 d after mating. We investigated the effects on interferon-tau (IFN tau) secretion by the conceptuses, prostaglandin F2 alpha (PG) production in vitro by endometrial tissue, and associated rates of embryo mortality, endometrial progesterone content and progesterone production by luteal tissue. No differences between groups in pregnancy rate were detected on Day 9 between the 2 groups. Proportionately (6/6 vs 2/5), there were more pregnant ewes in the high energy group on Day 15, although this difference did not reach significance (P = 0.06). The proportion of corpora lutea represented by embryos was significantly lower in undernourished ewes (P < 0.05). Secretion in vitro of PG was lower in the 2 pregnant ewes of the low energy group on Day 15, and it was accompanied by higher IFN tau secretion by conceptuses recovered from these ewes. However, the limited number of pregnant ewes recorded on Day 15 prevented any statistical comparison. Neither mean endometrial content of progesterone nor ovarian venous progesterone concentrations and production of progesterone by luteal were affected by nutrition. The provisional results of the present experiment indicate that undernutrition may induce a reduction in the rate of secretion of IFN tau and can therefore increase production of PG from the endometrium. This could initiate luteolysis. The lower pregnancy rates observed in underfed ewes could be mediated through this alteration in the signal of maternal recognition of pregnancy. However, these findings remain to be shown in further experiments including a larger number of animals, as they only represent data from 2 undernourished animals.

The effects on reproductive performance in the short and medium term of the combined use of exogenous melatonin and progestagen pessaries in ewes with a short seasonal anoestrous period

The effects on reproductive performance in the short and medium term of the combined use of exogenous melatonin and progestagen pessaries in ewes with a short seasonal anoestrous period.

Reduced amide pseudopeptide analogues of a malaria peptide possess secondary structural elements responsible for induction of functional antibodies which react with native proteins expressed in Plasmodium falciparum erythrocyte stages

A psi[CH2NH] isoster bond was introduced by replacing one peptide bond at a time within the 1513 malaria peptide KEKMV motif to obtain a set of five pseudopeptides. The motif belongs to a Plasmodium falciparum malarial peptide coded 1513, derived from the MSP-1 protein. This high-binding motif included in the 1513 peptide is involved in the attachment of the malarial parasite to human erythrocytes. The novel malaria 1513 psi[CH2NH] surrogates were analyzed using RP-HPLC and MALDI-TOF mass spectrometry techniques. Nuclear magnetic resonance experiments allowed definition of the five pseudopeptide analogues' secondary structural features. Such structures are present in only a very few molecules in the 1513 parent peptide. A molecular model demonstrating the solution of the three-dimensional structure of the 1 513 peptide Pse-437 analogue was constructed on the basis of 1H-NMR spectral parameters. Monoclonal antibodies were generated to the five 1513 malaria peptide pseudopeptide analogues. These antibodies not only recognize the native MSP-1 (195 kDa) and its 83 kDa and 42 kDa proteolytic processing proteins but also different SPf(66)n malaria vaccine batches containing the native sequence. In addition, the mAbs were able to modify the kinetics of Plasmodium falciparum parasites' intraerythrocytic development and their ability to invade new RBCs. The presented evidence suggests that peptide bond-modified peptides could reproduce a transient state in 1513's native sequence and represent useful candidates in the development of a second generation of effective malarial vaccines.

Opioidergic and nutritional involvement in the control of luteinizing hormone secretion of postpartum Rasa Aragonesa ewes lambing in the mid-breeding season

The role of endogenous opioids and nutrition on the inhibition of luteinizing hormone (LH) secretion during the postpartum period was investigated in a Spanish breed of sheep lambing in the mid-late breeding season. Two groups of adult Rasa Aragonesa ewes housed in individual pens and lambing on 30 December were fed during the suckling period to provide maintenance requirements and the production of 1.1 (M; n = 8) or 0.55 (L; n = 8) kg of milk per day. On days 10, 20 and 30 after lambing, the effect of a treatment with the opiate receptor antagonist naloxone (1 mg/kg at four hourly intervals) on LH secretion was assessed in half of the ewes of each group, the remaining females receiving four saline injections. After weaning, animals were fed to provide requirements for maintenance of liveweight. Blood samples were collected twice a week from day 20 postpartum until the end of March, and assayed for progesterone and prolactin. Although underfed ewes showed significantly lower mean plasma concentrations during the control period on day 20 postpartum, nutrition did not seem to modify LH secretion before naloxone or saline injections. Moreover, no differences between nutritional groups in the response to naloxone injections on pattern of LH secretion were found. In fact, naloxone treatment induced an increase of mean LH concentrations on days 10, 20 and 30 postpartum (at least, P < 0.05), of LH pulse frequency on days 20 and 30 (P < 0.05), and of LH pulse amplitude on days 10 and 20 (P < 0.05). Underfed ewes during the postpartum period showed a slower decline in plasma prolactin levels, with significant differences on days 29, 36 and 39 after lambing (P < 0.05). Only 3 M ewes ovulated before the onset of the seasonal anoestrus period. It is concluded that endogenous opioids are involved in the inhibition of LH secretion during the early suckling period of a reduced seasonality breed of sheep without any influence of nutrition on the response to naloxone treatment; however, ewes underfed before weaning failed to reactivate their cyclicity prior to the onset of the seasonal anoestrus.

The effects of RGD (Arg-Gly-Asp) peptides on glaucoma filtration surgery in rabbits

BACKGROUND AND OBJECTIVE

Integrins are the main mediators of the interaction between fibroblasts and extracellular matrix (ECM) during scar formation. The adhesion motive RGD (Arg-Gly-Asp) is contained in the ECM and is recognized by the integrin receptor. Soluble peptides containing the RGD sequence can compete with -RGD- contained in the ECM for binding to the integrin receptor and thus prevent cell adhesion and scar formation.

MATERIALS AND METHODS

The peptides RGD (p602), GRGDSP (p603), GRGDSPCA (p604), and GGRGDSPCA (p605) were used in 25 glaucoma filtering surgeries in rabbits (five eyes per peptide and five with saline).

RESULTS

Postoperative subconjunctival injections of peptides were given at days 0, 4, 8, 12, and 16. Bleb size, bleb survival, and signs of toxicity were examined. The GRGDSPCA and GGRGDSPCA showed an increase in bleb formation, size, and survival with no clinical signs of toxicity compared with controls (P < .008). Histopathologic evaluation confirmed inhibitory effects in scar formation with bleb formation, and transmission electron microscopy demonstrated that there was no toxicity to the ciliary body.

CONCLUSION

These peptides were effective in controlling scar formation in glaucoma filtering surgery.

Effect of undernutrition on the distribution of progesterone in the uterus of ewes during the luteal phase of the estrous cycle

The effect of undernutrition on ovarian and uterine venous progesterone concentrations and endometrial progesterone content on Days 5 and 10 of the estrous cycle were studied. Forty ewes were synchronized using progestagen pessaries. At pessary withdrawal, the ewes were fed diets to provide either 1.5 or 0.5 times the daily maintenance requirement (Group H, n = 20 and Group L, n = 20, respectively). Ewes fed the low nutrition diet (Group L) had higher mean peripheral progesterone concentrations than those fed the high plane diet (Group H; P < 0.05) but lower endometrial progesterone content on Day 5 (P < 0.05). Neither ovarian nor uterine venous levels were affected by nutrition on either Day 5 or 10. Progesterone concentrations in blood samples collected ipsilateral to ovaries bearing a corpus luteum (CL) were higher than in the contralateral samples (P < 0.001). It is concluded that undernutrition can produce a reduction of endometrial content of progesterone the first week after mating. Since no differences in ovarian venous concentrations were observed, it remains to be shown whether this variation is due to other variables, such as the population of endometrial progesterone receptors or other nonhormonal factors.

Effect of PGE1 on TNF-alpha status and hepatic D-galactosamine-induced apoptosis in rats

Prostaglandin E1 has hepatoprotective properties in several clinical and experimental models of liver dysfunction. Hepatotoxicity induced by D-galactosamine (D-GalN) is a suitable animal model of human acute hepatic failure. The aim of the study was to investigate if prostaglandin E1 (PGE1) protection against hepatic D-GalN-induced apoptosis was related to tumour necrosis factor-alpha (TNF-alpha) content in serum. This cytokine is associated with in vitro apoptosis and general inflammatory disorders. In this study, PGE1 was administered 30 min before D-GalN to rats. In other experiments, several doses of TNF-alpha were administered 15min after PGE1 to D-Ga1N-treated rats. Several parameters related to apoptosis and necrosis were measured by flow cytometry, gel electrophoresis, biochemical analysis, and optical and electron microscopy. Tumour necrosis factor-alpha was quantified by competitive enzyme-linked immunosorbent assay (ELISA). PGE1 by itself did not modify the cell cycle of hepatocytes and liver toxicity, but increased TNF-alpha in serum in comparison with the control group. D-Galactosamine increased the percentage of hepatocytes in apoptosis and in the S phase of the cell cycle, and decreased those in G0/G1. Such an increase of hepatocytes in apoptosis was correlated with a higher number of apoptotic bodies and DNA fragmentation in liver than control samples. Also, D-GalN increased alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase and TNF-alpha in serum compared with the control group. Pre-administration of PGE1 to D-GalN-treated rats reduced all the parameters of apoptosis and necrosis in liver, and increased additionallyTNF-alpha content in serum. In those experiments where low doses of TNF-alpha were administered to PGE1 and D-GalN-treated rats an inverse relationship appeared between TNF-alpha and ALT content in serum. In conclusion, the protective effects of PGE1 on D-GalN-induced apoptosis may be linked to its capacity to modulate cell division and/or its immunomodulatory activity. In this sense, our experimental results suggest that TNF-alpha could be involved in protection or exacerbation of liver damage in relation to the pathophysiological status of the liver.