Influence of time-to-diagnosis on time-to-percutaneous coronary intervention for emergency department ST-elevation myocardial infarction patients: Time-to-electrocardiogram matters

Objectives

Earlier electrocardiogram (ECG) acquisition for ST-elevation myocardial infarction (STEMI) is associated with earlier percutaneous coronary intervention (PCI) and better patient outcomes. However, the exact relationship between timely ECG and timely PCI is unclear.

Methods

We quantified the influence of door-to-ECG (D2E) time on ECG-to-PCI balloon (E2B) intervention in this three-year retrospective cohort study, including patients from 10 geographically diverse emergency departments (EDs) co-located with a PCI center. The study included 576 STEMI patients excluding those with a screening ECG before ED arrival or non-diagnostic initial ED ECG. We used a linear mixed-effects model to evaluate D2E's influence on E2B with piecewise linear terms for D2E times associated with time intervals designated as ED intake (0-10 min), triage (11-30 min), and main ED (>30 min). We adjusted for demographic and visit characteristics, past medical history, and included ED location as a random effect.

Results

The median E2B interval was longer (76 vs 68 min, p < 0.001) in patients with D2E >10 min than in those with timely D2E. The proportion of patients identified at the intake, triage, and main ED intervals was 65.8%, 24.9%, and 9.7%, respectively. The D2E and E2B association was statistically significant in the triage phase, where a 1-minute change in D2E was associated with a 1.24-minute change in E2B (95% confidence interval [CI]: 0.44-2.05, p = 0.003).

Conclusion

Reducing D2E is associated with a shorter E2B. Targeting D2E reduction in patients currently diagnosed during triage (11-30 min) may be the greatest opportunity to improve D2B and could enable 24.9% more ED STEMI patients to achieve timely D2E.

Prevalence of pulmonary hypertension in COPD patients living at high altitude

BACKGROUND

Pulmonary hypertension (PH) is associated with poor prognosis for patients with chronic obstructive pulmonary disease (COPD). Most of the knowledge about PH in COPD has been generated at sea level, with limited information associated with high altitude (HA).

OBJECTIVES

To assess the prevalence and severity of PH in COPD patients living in a HA city (2,640 m).

METHODS

Cross-sectional study in COPD patients with forced expiratory volume in the first second / forced vital capacity ratio (FEV1/FVC) post-bronchodilator <0,7. Transthoracic echocardiography (TTE), spirometry, carbon monoxide diffusing capacity, and arterial blood gasses tests were performed. Patients were classified according to the severity of airflow limitation. PH was defined by TTE as an estimated systolic pulmonary artery pressure (sPAP) > 36 mmHg or indirect PH signs; severe PH as sPAP > 60 mmHg; and disproportionate PH as an sPAP > 60 mmHg with non-severe airflow limitation (FEV1 > 50% predicted).

RESULTS

We included 176 COPD patients. The overall estimated prevalence of PH was 56.3% and the likelihood of having PH increased according to airflow-limitation severity: mild (31.6%), moderate (54.9%), severe (59.6%) and very severe (77.8%) (p = 0.038). The PH was severe in 7.3% and disproportionate in 3.4% of patients.

CONCLUSIONS

The estimated prevalence of PH in patients with COPD at HA is high, particularly in patients with mild to moderate airflow limitation, and greater than that described for COPD patients at low altitude. These results suggest a higher risk of developing PH for COPD patients living at HA compared to COPD patients with similar airflow limitation living at low altitude.

Core content for venous and Lymphatic Medicine: 2022 revision

The core content for a medical specialty outlines the scope of the discipline as well as the categories of knowledge considered essential to practice in the field. It provides a template for the development of curricula for medical school, graduate, and postgraduate education, as well as for creating certification standards. Venous and Lymphatic Medicine (VLM) is a specialty that has benefitted from contributions from specialists from several medical disciplines. Optimally, the societies, boards, and residency review committees representing these disciplines would uniformly recognize the scope of VLM to develop education and assessment standards to allow training and identification of qualified practitioners. In order to inform the standard setting bodies and other stakeholders of the current scope of VLM, a task force of VLM experts from cardiology, dermatology, emergency medicine, general surgery, interventional radiology, vascular medicine, and vascular surgery was formed to revise a 2014 consensus document defining the core content of the specialty of VLM.

Impact of the COVID-19 pandemic on the mental health of the general population and health care workers

The Health Sciences Foundation has assembled a multidisciplinary group around a series of questions about the impact of the COVID-19 pandemic on the mental health of the general population and specific groups within that population, particularly healthcare workers. In the general population, the most prevalent mental disorders have been anxiety, sleep disorders and affective disorders, primarily depression. There has been a considerable increase in suicidal behavior, especially in young women and men over 70 years of age. There has been an increase in alcohol abuse and nicotine, cannabis and cocaine use. In contrast, the use of synthetic stimulants during periods of confinement has decreased. With regard to non-substance addictions, gambling was very limited, pornography consumption increased significantly and there was an increase in compulsive shopping and the use of video games. Particularly vulnerable groups include adolescents and patients with autism spectrum disorders. Healthcare workers suffered an increase in depression, anxiety and post-traumatic stress, especially those who were exposed during the early stages of the pandemic. Female sex, being a nurse, proximity to patients with COVID-19, working in a rural environment and having previous psychiatric or organic illnesses were some of the most frequently repeated factors in various studies in this population group. The media have shown a good degree of knowledge about these problems and have dealt with them frequently and from the point of view of ethics, crisis situations, such as the one experienced, have triggered not only physical but also moral claudications.

Disparities in Emergency Medical Services Care Delivery in the United States: A Scoping Review

BACKGROUND

Emergency medical services (EMS) often serve as the first medical contact for ill or injured patients, representing a critical access point to the health care delivery continuum. While a growing body of literature suggests inequities in care within hospitals and emergency departments, limited research has comprehensively explored disparities related to patient demographic characteristics in prehospital care.

OBJECTIVE

We aimed to summarize the existing literature on disparities in prehospital care delivery for patients identifying as members of an underrepresented race, ethnicity, sex, gender, or sexual orientation group.

METHODS

We conducted a scoping review of peer-reviewed and non-peer-reviewed (gray) literature. We searched PubMed, CINAHL, Web of Science, Proquest Dissertations, Scopus, Google, and professional websites for studies set in the U.S. between 1960 and 2021. Each abstract and full-text article was screened by two reviewers. Studies written in English that addressed the underrepresented groups of interest and investigated EMS-related encounters were included. Studies were excluded if a disparity was noted incidentally but was not a stated objective or discussed. Data extraction was conducted using a standardized electronic form. Results were summarized qualitatively using an inductive approach.

RESULTS

One hundred forty-five full-text articles from the peer-reviewed literature and two articles from the gray literature met inclusion criteria: 25 studies investigated sex/gender, 61 studies investigated race/ethnicity, and 58 studies investigated both. One study investigated sexual orientation. The most common health conditions evaluated were out-of-hospital cardiac arrest (n = 50), acute coronary syndrome (n = 36), and stroke (n = 31). The phases of EMS care investigated included access (n = 55), pre-arrival care (n = 46), diagnosis/treatment (n = 42), and response/transport (n = 40), with several studies covering multiple phases. Disparities were identified related to all phases of EMS care for underrepresented groups, including symptom recognition, pain management, and stroke identification. The gray literature identified public perceptions of EMS clinicians' cultural competency and the ability to appropriately care for transgender patients in the prehospital setting.

CONCLUSIONS

Existing research highlights health disparities in EMS care delivery throughout multiple health outcomes and phases of EMS care. Future research is needed to identify structured mechanisms to eliminate disparities, address clinician bias, and provide high-quality equitable care for all patient populations.

Fallacy of Median Door‐to‐ECG Time: Hidden Opportunities for STEMI Screening Improvement

Background

ST‐segment elevation myocardial infarction (STEMI) guidelines recommend screening arriving emergency department (ED) patients for an early ECG in those with symptoms concerning for myocardial ischemia. Process measures target median door‐to‐ECG (D2E) time of 10 minutes.

Methods and Results

This 3‐year descriptive retrospective cohort study, including 676 ED‐diagnosed patients with STEMI from 10 geographically diverse facilities across the United States, examines an alternative approach to quantifying performance: proportion of patients meeting the goal of D2E≤10 minutes. We also identified characteristics associated with D2E>10 minutes and estimated the proportion of patients with screening ECG occurring during intake, triage, and main ED care periods. We found overall median D2E was 7 minutes (IQR:4–16; range: 0–1407 minutes; range of ED medians: 5–11 minutes). Proportion of patients with D2E>10 minutes was 37.9% (ED range: 21.5%–57.1%). Patients with D2E>10 minutes, compared to those with D2E≤10 minutes, were more likely female (32.8% versus 22.6%, P=0.005), Black (23.4% versus 12.4%, P=0.005), non‐English speaking (24.6% versus 19.5%, P=0.032), diabetic (40.2% versus 30.2%, P=0.010), and less frequently reported chest pain (63.3% versus 87.4%, P<0.001). ECGs were performed during ED intake in 62.1% of visits, ED triage in 25.3%, and main ED care in 12.6%.

Conclusions

Examining D2E>10 minutes can identify opportunities to improve care for more ED patients with STEMI. Our findings suggest sex, race, language, and diabetes are associated with STEMI diagnostic delays. Moving the acquisition of ECGs completed during triage to intake could achieve the D2E≤10 minutes goal for 87.4% of ED patients with STEMI. Sophisticated screening, accounting for differential risk and diversity in STEMI presentations, may further improve timely detection.

Comparing the Timeliness of Treatment in Younger vs. Older Patients with ST-Segment Elevation Myocardial Infarction: A Multi-Center Cohort Study

BACKGROUND

ST-segment elevation myocardial infarction (STEMI) predominantly affects older adults. Lower incidence among younger patients may challenge diagnosis.

OBJECTIVES

We hypothesize that among patients ≤ 50 years old, emergent percutaneous coronary intervention (PCI) for STEMI is delayed when compared with patients aged > 50 years.

METHODS

This 3-year, 10-center retrospective cohort study included emergency department (ED) STEMI patients ≥ 18 years of age treated with emergent PCI. We excluded patients with an electrocardiogram (ECG) completed prior to ED arrival or a nondiagnostic initial ECG. Our primary outcome was door-to-balloon (D2B) time. We compared characteristics and outcomes among younger vs. older STEMI patients, and among age subgroups.

RESULTS

There were 576 ED STEMI PCI patients, of whom 100 were ≤ 50 years old and 476 were > 50 years old. Median age was 44 years in the younger cohort (interquartile range [IQR] 41-47) vs. 62 years (IQR 57-70) among older patients. Median D2B time for the younger cohort was 76.5 min (IQR 67.5-102.5) vs. 81.0 min (IQR 65.0-105.5) in the older cohort (p = 0.91). This outcome did not change when ages 40 or 45 years were used to demarcate younger vs. older. The younger cohort had a higher prevalence of nonwhite races (38% vs. 21%; p < 0.001) and those currently smoking (36% vs. 23%; p = 0.005). The very young (≤30 years; 6/576) and very old (>80 years; 45/576) had 5.51 and 2.2 greater odds of delays.

CONCLUSION

We found no statistically significant difference in D2B times between patients ≤ 50 years old and those > 50 years old. Nonwhite patients and those who smoke were disproportionately represented within the younger population. The very young and very old had higher odds of D2B times > 90 min.

Determination of ultra-low concentrations of gaseous 14C-bearing hydrocarbons produced during corrosion of irradiated steel using accelerator mass spectrometry

Compound-specific radiocarbon analysis (CSRA) was developed to identify and quantify gaseous 14C-bearing carbon compounds at the pico- to femtomolar concentration range and employed in a corrosion experiment with small specimens of irradiated steel. The approach is based on gas chromatographic separation of single 14C-bearing carbon compounds, their oxidation to 14CO2, sampling with a custom-made fraction collector and quantification by accelerator mass spectrometry (AMS). In addition to CSRA, a method allowing the quantification of the total 14C content of the gas phase was developed and tested. After validation of the two set-ups with standards, the gaseous 14C-bearing carbon compounds produced during alkaline anoxic corrosion of irradiated steel were quantified. Small hydrocarbons (HCs) like methane (14CH4) and ethane (14C2H6) were the only 14C-bearing compounds identified in the gas phase above the detection limit. 14CH4 was the main species (on average 5.4 × 10-14 mol L-1 gas) and contributed >90% to the total 14C content, whereas the concentration of 14C2H6 was much lower (7.9 × 10-16 mol L-1 gas). To our knowledge, this is the first study reporting CSRA of gaseous 14C-bearing HCs produced during anoxic corrosion of irradiated metallic radioactive waste at ultra-low concentrations.

[Massive rotator cuff injury: arthroscopic treatment with upper capsular reconstruction]

Massive rotator cuff injuries (LMMRs) are those breaks of more than 5 cm either the anteroposterior plane, or lateromedial plane. Some authors consider them to be complete ruptures of at least two rotator cuff tendons. The clinical case of a 63-year-old man with this type of injury that was resolved by the superior capsule reconstruction technique is presented, technical details and some of the literature review to carry out the procedure are shown.

Analysis of 14C-bearing compounds released by the corrosion of irradiated steel using accelerator mass spectrometry

The combination of ion chromatography (IC) with accelerator mass spectrometry (AMS) was developed to determine the speciation of 14C-(radiocarbon) bearing organic compounds in the femto to pico molar concentration range. The development of this compound-specific radiocarbon analysis (CSRA) of carboxylic acids is reported and the application of the method on a leaching solution from neutron-irradiated steel is demonstrated. The background and the dynamic range of the AMS-based method were quantified. On using 14C-labelled standards, the measurements demonstrate the repeatability of the analytical method and the reproducible recovery of the main target carboxylic acids (i.e., acetate, formate, malonate, and oxalate). The detection limit was determined to be in the mid fmol 14C per L level while the dynamic range of the analytical method covers three orders of magnitude from the low fmol to the mid pmol 14C per L level. Cross contamination was found to be negligible during IC fractionation and was accounted for during eluate processing and 14C detection by AMS. The 14C-bearing carboxylates released from an irradiated steel nut into an alkaline leaching solution were analysed using the CSRA-based analytical method with the aim to check the applicability of the approach and develop appropriate sample preparation. The concentrations of 14C-bearing formate and acetate, the main organic corrosion products, were at a low pmol 14C per L level for convenient dimensions of the alkaline leaching experiment which demonstrates that compound-specific 14C AMS is an extremely sensitive analytical method for analysing 14C-bearing compounds. The content of total organic 14C in solution (TO14C) determined by the direct measurement of an aliquot of the leaching solution agrees well with the sum of the 14C concentrations of the individual carboxylates within the uncertainty of the data. Furthermore, the TO14C content is in good agreement with the calculated value using the corrosion rate determined from the 60Co release and the 14C inventory of the irradiated steel specimen.

Measuring outcome differences associated with STEMI screening and diagnostic performance: a multicentred retrospective cohort study protocol

INTRODUCTION

Advances in ST-segment elevation myocardial infarction (STEMI) management have involved improving the clinical processes connecting patients with timely emergency cardiovascular care. Screening upon emergency department (ED) arrival for an early ECG to diagnose STEMI, however, is not optimal for all patients. In addition, the degree to which timely screening and diagnosis are associated with improved time to intervention and postpercutaneous coronary intervention outcomes, under more contemporary practice conditions, is not known.

METHODS

We present the methods for a retrospective multicentre cohort study anticipated to include 1220 patients across seven EDs to (1) evaluate the relationship between timely screening and diagnosis with treatment and postintervention clinical outcomes; (2) introduce novel measures for cross-facility performance comparisons of screening and diagnostic care team performance including: door-to-screening, door-to-diagnosis and door-to-catheterisation laboratory arrival times and (3) describe the use of electronic health record data in tandem with an existing disease registry.

ETHICS AND DISSEMINATION

The completion of this study will provide critical feedback on the quality of screening and diagnostic performance within the contemporary STEMI care pathway that can be used to (1) improve emergency care delivery for patients with STEMI presenting to the ED, (2) present novel metrics for the comparison of screening and diagnostic care and (3) inform the development of screening and diagnostic support tools that could be translated to other care environments. We will disseminate our results via publication and quality performance data sharing with each site. Institutional ethics review approval was received prior to study initiation.

Zinc regulates Nox1 expression through a NF-κB and mitochondrial ROS dependent mechanism to induce senescence of vascular smooth muscle cells

AIMS

The role of oxidative stress and inflammation in the development and progression of cardiovascular diseases (CVD) is well established. Increases in oxidative stress can further exacerbate the inflammatory response and lead to cellular senescence. We previously reported that angiotensin II (Ang II) and zinc increase reactive oxygen species (ROS) and cause senescence of vascular smooth muscle cells (VSMCs) and that senescence induced by Ang II is a zinc-dependent process. Zinc stimulated NADPH oxidase (Nox) activity; however, the role of Nox isoforms in zinc effects was not determined.

RESULTS

Here, we show that downregulation of Nox1, but not Nox4, by siRNA prevented both Ang II- and zinc-induced senescence in VSMCs. On the other hand, overexpression of Nox1 induced senescence, which was associated with reduced proliferation, reduced expression of telomerase and increased DNA damage. Zinc increased Nox1 protein expression, which was inhibited by chelation of zinc with TPEN and by overexpression of the zinc exporters ZnT3 and ZnT10. These transporters work to reduce cytosolic zinc, suggesting that increased cytosolic zinc mediates Nox1 upregulation. Other metals including copper, iron, cobalt and manganese failed to upregulate Nox1, suggesting that this pathway is zinc specific. Nox1 upregulation was inhibited by actinomycin D (ACD), an inhibitor of transcription, by inhibition of NF-κB, a known Nox1 transcriptional regulator and by N-acetyl cysteine (NAC) and MitoTEMPO, suggesting that NF-κB and mitochondrial ROS mediate zinc effects. Supporting this idea, we found that zinc increased NF-κB activation in the cytosol, stimulated the translocation of the p65 subunit to the nucleus, and that zinc accumulated in mitochondria increasing mitochondrial ROS, measured using MitoSox. Further, zinc-induced senescence was reduced by inhibition of NF-κB or reduction of mitochondrial ROS with MitoTEMPO. NF-κB activity was also reduced by MitoTEMPO, suggesting that mitochondrial ROS is upstream of NF-κB.

INNOVATION AND CONCLUSION

Our data demonstrate that altered zinc distribution leading to accumulation of zinc in the mitochondria increases mitochondrial ROS production causing NF-κB activation which in turn upregulates Nox1 expression inducing senescence of VSMCs.

Performance of Emergency Department Screening Criteria for an Early ECG to Identify ST-Segment Elevation Myocardial Infarction

Background

Timely diagnosis of ST‐segment elevation myocardial infarction (STEMI) in the emergency department (ED) is made solely by ECG. Obtaining this test within 10 minutes of ED arrival is critical to achieving the best outcomes. We investigated variability in the timely identification of STEMI across institutions and whether performance variation was associated with the ED characteristics, the comprehensiveness of screening criteria, and the STEMI screening processes.

Methods and Results

We examined STEMI screening performance in 7 EDs, with the missed case rate (MCR) as our primary end point. The MCR is the proportion of primarily screened ED patients diagnosed with STEMI who did not receive an ECG within 15 minutes of ED arrival. STEMI was defined by hospital discharge diagnosis. Relationships between the MCR and ED characteristics, screening criteria, and STEMI screening processes were assessed, along with differences in door‐to‐ECG times for captured versus missed patients. The overall MCR for all 7 EDs was 12.8%. The lowest and highest MCRs were 3.4% and 32.6%, respectively. The mean difference in door‐to‐ECG times for captured and missed patients was 31 minutes, with a range of 14 to 80 minutes of additional myocardial ischemia time for missed cases. The prevalence of primarily screened ED STEMIs was 0.09%. EDs with the greatest informedness (sensitivity+specificity−1) demonstrated superior performance across all other screening measures.

Conclusions

The 29.2% difference in MCRs between the highest and lowest performing EDs demonstrates room for improving timely STEMI identification among primarily screened ED patients. The MCR and informedness can be used to compare screening across EDs and to understand variable performance.

Measurement of Electron Neutrino Quasielastic and Quasielasticlike Scattering on Hydrocarbon at ⟨E_{ν}⟩=3.6 GeV

The first direct measurement of electron neutrino quasielastic and quasielasticlike scattering on hydrocarbon in the few-GeV region of incident neutrino energy has been carried out using the MINERvA detector in the NuMI beam at Fermilab. The flux-integrated differential cross sections in the electron production angle, electron energy, and Q^{2} are presented. The ratio of the quasielastic, flux-integrated differential cross section in Q^{2} for ν_{e} with that of similarly selected ν_{μ}-induced events from the same exposure is used to probe assumptions that underpin conventional treatments of charged-current ν_{e} interactions used by long-baseline neutrino oscillation experiments. The data are found to be consistent with lepton universality and are well described by the predictions of the neutrino event generator GENIE.

Ubiquitous healthy diatoms in the deep sea confirm deep carbon injection by the biological pump

The role of the ocean as a sink for CO₂ is partially dependent on the downward transport of phytoplankton cells packaged within fast-sinking particles. However, whether such fast-sinking mechanisms deliver fresh organic carbon down to the deep bathypelagic sea and whether this mechanism is prevalent across the ocean requires confirmation. Here we report the ubiquitous presence of healthy photosynthetic cells, dominated by diatoms, down to 4,000 m in the deep dark ocean. Decay experiments with surface phytoplankton suggested that the large proportion (18%) of healthy photosynthetic cells observed, on average, in the dark ocean, requires transport times from a few days to a few weeks, corresponding to sinking rates (124–732 m d⁻¹) comparable to those of fast-sinking aggregates and faecal pellets. These results confirm the expectation that fast-sinking mechanisms inject fresh organic carbon into the deep sea and that this is a prevalent process operating across the global oligotrophic ocean.

Sinking of organic matter represents the dominant mechanism for sequestration of anthropogenic CO₂ in the deep sea. Here, the authors report the presence of healthy photosynthetic cells in the deep dark ocean, implying the fast injection of fresh organic carbon at depth across the global oligotrophic ocean.

Metoclopramide as an analgesic in severe migraine attacks: an open, single-blind, parallel control study

Metoclopramide is a well-known anti-emetic drug with central and peripheral pharmacological effects. Some authors have reported metoclopramide as an adjunct therapy to other analgesics in patients with migraine attacks. Treatment of migraine headache using a mix of metoclopramide and an NSAID has been patented (European Patent EP1014961) as well as a short series showing great efficacy and tolerability of metoclopramide in patients wtih migraine attacks. We decided to conduct an open, single-blind, parallel control study in the emergency department to evaluate the efficacy and tolerability of metoclopramide in patients with severe migraine attacks. 93 consecutive patients with severe migraine attacks were randomized into two groups (groups A and B). Patients in group A received 10mg of intravenous metoclopramide and patients in group B received 1 g of intravenous paracetamol. Patients were evaluated 5 minutes before (baseline), 15, 30, 60 and 120 minutes after drug delivery, and before being discharged from the emergency department They were then contacted by phone 48 hours after being discharged from the hospital (phone questionnaire). Patients treated with either metoclopramide or paracetamol showed a significant reduction in the intensity of pain at the 120 minute time point, with an 86% and 82% improvement respectively. However, patients treated with metoclopramide showed a more rapid improvement at the 15 and 30 minute evaluations. Patients with severe migraine attacks treated with metoclopramide as monotherapy showed a significant improvement in terms of pain relief and a faster improvement in pain intensity compared to those treated with paracetamol. Metoclopramide and other dopamine antagonistic drugs should be considered a therapeutic option in severe migraine headache attacks.

Plasma zinc concentration, body composition and physical activity in obese preschool children

Zinc (Zn) deficiency and obesity can be observed together in some developing countries. Zn deficiency may enhance fat deposition and decrease lean mass accrual, which in turn, appears to influence physical activity (PA), although this has not yet been evaluated in obese children. The objective of the study was to find out the association between measurements of plasma Zn and serum leptin, body composition, and PA in Chilean obese preschool children. Seventy-two 18- to 36-month-old obese children [weight-for-length/height z score (WHZ) > 2.0 SD], belonging to low socioeconomic communities, participated in the study. Plasma Zn, serum leptin, weight, waist circumference, height, total body water (TBW) assessed by deuterium isotopic dilution technique and daily activity, measured by registering 48 h with an accelerometer, were evaluated. We found 82% of children with WHZ > 3 SD. The geometric mean Zn intake was 6.2 +/- 2.5 mg/day. The mean plasma Zn was 91.8 +/- 11.4 microg/dL, with 10% of the children having levels <80 microg/dL. No correlation was found between plasma Zn concentrations and either weight, WHZ, or waist circumference. Serum leptin was lower in males than in females (2.9 +/- 2.8 vs 6.8 +/- 5.0 ng/mL, respectively; p < 0.001). TBW was different between males and females (56.2 +/- 5.4 vs 52.8 +/- 4.3% body weight, respectively; p = 0.004), but no significant association was found between TBW and plasma Zn. Moderate + intense PA, (as percentage of wake time), was greater in males than in females (6.3 +/- 3.1% vs 3.4 +/- 2.3%, respectively; p < 0.001), but it was not significantly correlated to plasma Zn. In conclusion, plasma Zn was not associated with body composition as assessed by TBW, serum leptin, or with the magnitude of physical activity in Chilean overweight preschool children.

Family interactions of liver transplanted children: are they normal?

Several psychosocial and behavioral problems have been reported in liver transplanted children. Most publications have focused on them, without considering their family environment. The aim of this study was to evaluate the interaction between liver transplanted children and their families, compared with a healthy control group. We selected liver transplanted children, between 8 and 12 years of age, with at least 6 months follow-up posttransplantation and in good clinical condition. Family structure also included 1 to 3 other children. Evaluable patients must have been living with their parents throughout the whole posttransplantation period. They were compared with a similar group of children without any chronic disease. A written informed consent was signed by both parents. All families were evaluated using a standard test consisting of different situations. The information was evaluated by 3 independent experts. Factors evaluated were limits (rules and limits of behavior), alliance-opposition (interaction between members to act), and hierarchy. Scoring was given to all observed acts. Statistical analysis was performed using chi-square tests with P < .05 considered significant. No statistical differences were found between groups in limits, alliance, and hierarchy. Our results showed that there were no differences in family structure and behavior between families of liver-transplanted and healthy children belonging to a similar socioeconomic level.

HLA-B35 upregulates the production of endothelin-1 in HLA-transfected cells: a possible pathogenetic role in pulmonary hypertension

HLA-B35 is associated with an increased risk for developing isolated pulmonary hypertension (iPHT) in systemic sclerosis, but the mechanisms underlying this association have not been fully elucidated yet. Endothelin-1 (ET-1) is the main pathogenetic molecule implied in the development of iPHT; therefore, we sought to determine if ECV304 cells transfected with the HLA-B35 allele produce increased amounts of ET-1 after incubation with physiological concentrations of interleukin-1 beta (IL-1beta). ECV304 cells transfected with HLA-B*3501 and HLA-B*0801 polymorphic alpha chain or with pIRESneo2 were incubated with 100 U/ml of IL-1beta for 6, 12, 24, 36 and 48 h. ET-1 levels were determined using EIA kit (CAYMAN Chemical, Ann Arbor, MI) in supernatants from different cell cultures; the relative expression of the preproendothelin-1 (PPET-1) gene was also determined by reverse transcription-polymerase chain reaction. Cells expressing the HLA-B35 allele showed significantly increased levels of ET-1 at all the selected times compared with controls or HLA-B8-transfected cells. The relative expression of the PPET-1 gene was also increased in a proportionally direct manner. The HLA-B35 allele influences the production of ET-1 in HLA-B35-transfected ECV304 cells by promoting the expression of its precursor, PPET-1. Our results provide an explanation for the epidemiological association existing between iPHT and HLA-B35.

BLOC-1 complex deficiency alters the targeting of adaptor protein complex-3 cargoes

Mutational analyses have revealed many genes that are required for proper biogenesis of lysosomes and lysosome-related organelles. The proteins encoded by these genes assemble into five distinct complexes (AP-3, BLOC-1-3, and HOPS) that either sort membrane proteins or interact with SNAREs. Several of these seemingly distinct complexes cause similar phenotypic defects when they are rendered defective by mutation, but the underlying cellular mechanism is not understood. Here, we show that the BLOC-1 complex resides on microvesicles that also contain AP-3 subunits and membrane proteins that are known AP-3 cargoes. Mouse mutants that cause BLOC-1 or AP-3 deficiencies affected the targeting of LAMP1, phosphatidylinositol-4-kinase type II alpha, and VAMP7-TI. VAMP7-TI is an R-SNARE involved in vesicle fusion with late endosomes/lysosomes, and its cellular levels were selectively decreased in cells that were either AP-3- or BLOC-1-deficient. Furthermore, BLOC-1 deficiency selectively altered the subcellular distribution of VAMP7-TI cognate SNAREs. These results indicate that the BLOC-1 and AP-3 protein complexes affect the targeting of SNARE and non-SNARE AP-3 cargoes and suggest a function of the BLOC-1 complex in membrane protein sorting.

Energy balance and physical activity in obese children attending day-care centres

OBJECTIVE

To evaluate energy balance and physical activity in obese preschool children attending day-care centres.

DESIGN

Cross-sectional study.

SUBJECTS

Twenty-four 3-5 years old obese children selected at random from four different day-care centres in Santiago City, Chile. Total energy expenditure (TEE) was measured by doubly labelled water and physical activity as recorded by TRITRAC R3D motion sensor. Energy intake was assessed by measuring food intake while at the centre, along with the recording of additional food intake in the home.

RESULTS

Obese children had a 5.4% higher weighed energy intake than their energy requirements 2001. Energy intake during the week was 7716+/-1092 kJ/day and 7401+/-1023 kJ/day in boys and girls, respectively. Minimal activity was higher in the day-care centres (62%) compared to 52% during the weekend at home. Light activity was higher during the weekend at home than during the week (25 versus 20%), but moderate-intense activity was similar (3-5%).

CONCLUSIONS

Reduction in dietary energy provided at the day-care centres helps to balance energy requirements during the week. Obese children had marked sedentary characteristics with regards to physical activity, although children are more active at home in weekends. This situation suggests that educators and parents need to improve children's physical activity levels and nutrition habits.

Total energy expenditure, resting metabolic rate and physical activity level in free-living rural elderly men and women from Cuba, Chile and México

OBJECTIVE

The objective of this study was to assess total energy expenditure (TEE), resting metabolic rate (RMR) and physical activity level (PAL), and to estimate energy requirements (ERs) in free-living elderly subjects from Cuba, Chile and Mexico.

DESIGN

Cross-sectional study designed to estimate ERs.

SETTING

Rural regions of Cuba, Chile and Mexico.

SUBJECTS

Forty subjects >60 years old were selected to participate in this study.

INTERVENTIONS

A dose of doubly labeled water (DLW) was administered and urine samples were collected in the following 12-14 days. From the isotopic analysis, TEE was derived. RMR was measured by indirect calorimetry.

RESULTS

TEE in Chilean (8.8+/-1.6 MJ/day) and Cuban (8.3+/-1.3 MJ/day) elderly was not different, and was higher for the Mexican group (9.5+/-1.5 MJ/day) (P < 0.0001). RMR was not different between countries. PAL and activity energy expenditure (AEE) were only different between Chile and Mexico (P < 0.002). For the three regions, overall PALs were 1.70+/-0.16 for male and 1.62+/-0.13 for female subjects (P < 0.02), and AEE was 3.05+/-0.66 and 2.27+/-0.66 MJ/day for male and female subjects, respectively (P < 0.001). Predictive equations (MJ/day) were RMR = 1.6447 + 0.05714 x weight (kg) + 0.449 sex (male = 1; female = 0) (R2 = 0.75; SEE = 0.479) and TEE = 3.414 + 0.0795 x weight (kg) + 1.227 x sex (male = 1; female = 0) (R2 = 0.75; SEE = 0.668).

CONCLUSIONS

There were differences in TEE and PAL owing to sex and region. The average PAL in men was higher than the PAL reported either with factorial approach or with the DLW method in elderly. Predictive ER equations based on RMR and TEE gave very similar results to calculations from the 2004 FAO/WHO/UNU report.

Sensorimotor integration in patients with parkinsonian type multisystem atrophy

Sensorimotor integration is an essential feature of the central nervous system that contributes to the accurate performance of motor tasks. Some patients with multiple system atrophy with parkinsonian features (MSAp) exhibit clinical signs compatible with an abnormal central nervous system excitability to somatosensory inputs, such as action myoclonus or enhanced cutaneo-muscular reflexes. To investigate further the site where such dysfunction in sensorimotor integration takes place, we examined the inhibitory effects of a cutaneous afferent volley at two different levels of the motor system in 10 MSAp patients and in 10 age-matched healthy volunteers. Electrical digital nerve stimuli were given as the conditioning stimulus for the motor evoked potentials (MEP) elicited by transcranial magnetic stimulation in hand muscles, and for the blink reflex responses obtained in the orbicularis oculi muscles by supraorbital nerve stimulation. Intervals for the conditioning were 20 to 50 ms for the MEP and 90 to 110 ms for the blink reflex. The MEP was significantly inhibited in test trials in healthy volunteers, reaching a mean of 32% of the baseline values at the ISI of 35 ms. Significant inhibition occurred also in the blink reflex, in which the R2 response was a mean of 12% of baseline values at the ISI of 100 ms. The inhibitory effects were abnormally reduced in 8 patients on the MEP, and in 7 patients on the blink reflex. There were significant group differences between patients and control subjects in the size of the conditioned MEP and blink reflex. These results suggest that sensorimotor integration is abnormal in patients with MSAp in at least two central nervous system sites: the sensorimotor cortex, and the brainstem reticular formation.

Nitrogen and organic matter removal from slaughterhouse wastewater in a lab-scale aerobic fixed-film bioreactor

This paper presents the behaviour of a laboratory scale Aerobic Fixed-Film Bioreactor (Ae-FFB) with arranged media including its initial start up phase. It examines the viability of the Ae-FFB to remove nitrogen and organic matter from poultry slaughterhouse wastewater. After 12 days of operation while rapid growth of nitrifying bacteria took place, nitrogen and organic loading rates were increased progressively by up to 0.2 kg TKN m(-3) day(-1) and 0.8 kg COD m(-3) day(-1) respectively, reaching nitrogen and organic matter removal efficiencies of up to 92%. Heterotrophic bacteria, mainly placed in the suspended biomass accumulated at the bottom of the reactor, were found to be competing with nitrifying bacteria for oxygen, which limited nitrification efficiency. Despite operating with dissolved oxygen concentrations of around 3.5 mg 1(-1), an important contribution of the denitrification process was observed that removed up to 50% of oxidised nitrogen, depending on the availability of biodegradable organic matter.

Determination of body composition using air displacement plethysmography, anthropometry and bio-electrical impedance in rural elderly Mexican men and women

BACKGROUND AND AIMS

Air displacement plethysmography with the BOD-POD is a new densitometry technique, and has been found to be an accurate method to measure body composition. The aim of this study was to assess body composition in a group of free living healthy subjects 60 years of age or older from a rural area of Northwest Mexico, and to evaluate body composition by anthropometry and bioelectrical impedance (BIA) using equations reported for other elderly populations.

METHODS

Body composition was evaluated in 21 women and 26 men with the BOD-POD, by anthropometry, and BIA and compared to different equations using the Bland- Altman procedure.

RESULTS

Body fat in elderly women and men was 42.7 and 30.2 % respectively. In women, Segal's equation using BIA 1, based on standing height, showed no significant differences with the BOD-POD. There was satisfactory agreement between Segal's equation and BOD-POD. In men similar results was found with Deurenberg's equation using B1A 2 based on recumbent length.

CONCLUSIONS

Segal's and Deurenberg's equations were accurate and precise for the estimation of body fat in the elderly of this study. The use of these equations could improve the estimation of body composition for similar elderly subjects. Further studies are recommended with a larger size samples to include elderly subjects from other Latin American countries.

Body composition by hydrometry (deuterium oxide dilution) and bioelectrical impedance in subjects aged >60 y from rural regions of Cuba, Chile and Mexico

BACKGROUND

In Latin American and Caribbean countries such as Chile, Mexico and Cuba, the population over 60 y has increased steadily. In this age group, there is scarce information about body composition, particularly for those living in rural areas.

OBJECTIVE

The purpose of this study was to determine body composition in free-living and healthy elderly subjects >60 y from rural areas of Chile, Cuba and Mexico using deuterium oxide dilution and bioelectrical impedance (BIA) and to develop and cross-validate a predictive equation for this group of subjects by BIA for future use as a field technique.

SUBJECTS

The study included 133 healthy subjects (73 males and 60 females) >60 y from rural regions of Cuba, Chile and Mexico.

MEASUREMENTS

Total body water, body weight, height and other anthropometric and BIA variables (resistance and reactance) were measured.

METHODS

Total body water was determined by deuterium oxide dilution, and fat-free mass (FFM)/fat mass were derived from this measurement. The total sample was used in a split-sample internal cross-validation. BIA and other anthropometric variables were integrated to multiple regression model to design the best predictive equation, which was validated in the other sample. ANOVA, multiple regression and Bland and Altman's procedure were used to analyze the data.

RESULTS

Body weight, percentage of fat and fat-free mass were lower in the Cuban men and women compared with Chilean and Mexican men and women. The best predictive equation of the FFM was: FFM kg=(-7.71+(H(2)/R x 0.49)+(country or ethnicity x 1.12)+(body weight x 0.27)+(sex x 3.49)+(Xc x 0.13)), where H(2) is height(2) (cm); R is resistance (Omega); country: Chile=1, Mexico=2 and Cuba=3; sex: women=0 and men=1; body weight (kg) and Xc is reactance (Omega). R(2) was 0.944 and the root mean square error (RMSE) was 2.08 kg. The mean+/-s.d. of FFM prediction was 44.2+/-9.2 vs 44.6+/-10.1. The results of cross-validation showed no significant difference with the line of identity, showing that the predicted equation was accurate. The intercept (=-0.32) was not significantly different from zero (P=0.89) and the slope (=1.02) not significantly different from 1.0 (P>0.9). The R(2) was 0.86, RMSE=3.86 kg of FFM and the pure error was 3.83.

CONCLUSION

The new BIA equation is accurate, precise and showed good agreement. The use of this equation could improve the estimates of body composition for the elderly population for these regions, as well as enhancing the opportunity to conduct studies in the elderly population from Latin America.

Start-up of a pilot-scale anaerobic fixed film reactor at low temperature treating slaughterhouse wastewater

A pilot-scale anaerobic fixed film reactor (AFFR) with vertically arranged PVC tubes as biomass carrier, treating poultry slaughterhouse wastewater was started-up in 74 days at temperatures between 20-24 degrees C. The start-up process consisted of a long acclimatization phase followed by a low loaded growth phase, a gradual increase of OLR upto 9.2 kg COD/m3d, and a final maturation phase at moderated loads of 2.7 kg COD/m3d at which total COD removal efficiencies of 57% were achieved. Alkalinity ratio IA:PA was found to be the best control parameter to avoid VFA accumulation. OLR increase based on pH control was not satisfactory because changes in CO2 solubility caused daily by temperature and flow variations led to pH oscillations of 0.2 units. The low wastewater alkalinity, 260 mg/l CaCO3 was insufficient to buffer the pH system, therefore the pH decrease associated with the VFA accumulation was not easily detected and could not be used as a way of OLR control. Organic matter removal took place by accumulation and biodegradation processes. Limitation in the reactor hydrodynamics and particulate fraction hydrolysis was detected at high flow rates.

Informed consent procedures: responsibilities of researchers in developing countries

We describe the informed consent procedures in a research clinic in Santiago, Chile, and a qualitative study that evaluated these procedures. The recruitment process involves information, counseling and screening of volunteers, and three or four visits to the clinic. The study explored the decision-making process of women participating in contraceptive trials through 36 interviews. Women understood the research as experimentation or progress. The decision to participate was facilitated by the information provided; time to consider it and to discuss it with partners or relatives; and perceived benefits such as quality of care, non-cost provision of methods and medical care. For some women, participation was an opportunity to express altruism. The main obstacles for participation were perceived side effects or risks. The final risk-benefit balance was strongly influenced by women's needs. Women perceived that the consent form benefited the clinic, proving that participants had made a free decision, and benefited the volunteers by warranting their right to free medical care. The most important problem detected was occasional misunderstanding of the information given on the form. We concluded that a full decision-making process enhances women's ability to exercise their right to choose, and assures research institutions that trials are conducted without coercion and that the participants are committed to the study. Researchers have the responsibility of conducting this process.

Resumption of ovarian function during lactational amenorrhoea in breastfeeding women with polycystic ovarian syndrome: metabolic aspects

BACKGROUND

Polycystic ovarian syndrome (PCOS) is a common endocrine-metabolic disorder in women, a high percentage of whom exhibit peripheral insulin resistance. After delivery, in normal women, lactation imposes a metabolic adaptation, the impact of which on the insulin resistance of PCOS patients is not known. The aim of this study was to evaluate the effect of lactation on insulin resistance, glucose and insulin metabolism, and sex hormone-binding globulin (SHBG) and insulin-like growth factor binding protein-1 (IGFBP)-1 concentrations in fully breast-feeding normal and PCOS women during the postpartum period (lactational amenorrhoea) and also after weaning.

METHODS

Twelve lactating PCOS (LPCOS) women and six normal lactating (NL) women of similar age and body mass index (BMI) were selected for the study. At the 4th and the 8th week postpartum (pp), and 8 weeks after weaning, a 2 h, 75 g oral glucose tolerance test (oGGT) was performed, followed by an insulin tolerance test 2 days later. For the oGGT, glucose and insulin were measured in each sample and SHBG and IGFBP-1 were determined in the fasting sample.

RESULTS

During lactation, fasting insulin levels were similar in both groups. In LPCOS women 2 h insulin concentrations were significantly higher, and SHBG and IGFBP-1 concentrations were significantly lower, than those observed in NL women. In both groups, insulin sensitivity evaluated by the insulin tolerance test was not modified. After weaning, in LPCOS women, SHBG and IGFBP-1 concentrations remained lower and insulin concentrations remained higher than those observed in NL women ( P < 0.05 ).

CONCLUSIONS

In PCOS women, insulin resistance is not modified during lactation. Lactation has a transitory beneficial effect on insulin levels and biological markers of insulin resistance.

Role of the Sp family of transcription factors on glucagon receptor gene expression

The glucagon receptor mediates the actions of glucagon on carbohydrate metabolism by the liver and on insulin release by the pancreatic beta-cell, which are key processes in the control of glucose homeostasis. The 5'-region of the mouse glucagon receptor gene has been recently cloned and two functional promoters were characterized. In the present study, we show that most of the glucagon receptor mRNA was transcribed from the distal promoter, in the mouse liver. In the distal promoter region, a GC-rich sequence with five putative binding sites for the Sp family of transcription factors was localized. To elucidate the role of these Sp1-binding sites in the mouse MIN6 beta-cell line, the expression of reporter gene constructs containing deletion or point mutation of each site was carried out. Selective mutation of the second Sp1-binding site decreased the activity of the distal promoter. Electrophoretic mobility shift assay with a DNA fragment spanning the three first Sp1 sites confirmed that the second site bound specifically MIN6 nuclear proteins, and supershift using specific Sp antibodies demonstrated that it interacted with Sp3 but not Sp1 transcription factors. These data illustrate that the basal expression of the mouse glucagon receptor gene, driven by the distal promoter, requires an Sp1-binding site that binds Sp3 proteins.

Characterization of an enhancer element in the proximal promoter of the mouse glucagon receptor gene

The 5'-flanking region of the mouse glucagon receptor has been previously cloned and two promoter regions were characterized. Functional analysis of the proximal promoter was now performed to characterize cis-acting element(s) regulating basal gene expression. Promoter analysis using deletion constructs in a rat cell line (CA-77) expressing the glucagon receptor, showed that the region from -64 to +127 relative to the proximal transcription start site was sufficient for maximal proximal promoter activity. A DNA sequence spanning the -28 to -16 region organized as an imperfect palindrome was demonstrated to be functional as a cis-acting enhancer. Constructs including several copies of this motif strongly increased activity of the heterologous thymidine kinase promoter. Gel mobility shift assays performed with different DNA fragments spanning this region confirmed that it specifically bound nuclear protein(s) from CA-77 cells, mouse MIN-6 cells or mouse liver. Mutations in the core sequence of this site impaired both reporter gene activity and nuclear protein binding. The palindrome is a novel DNA sequence with no homology to existing transcription factor binding site database. This is the first characterization of a functional cis-acting sequence into the proximal promoter of the mouse glucagon receptor that may support constitutive expression of the gene.

Energy requirements in Chilean infants

AIM

To evaluate the energy requirements of breast fed infants.

METHODS

The study was conducted in 17 healthy exclusively breast fed infants of normal birth weight (mean (SD) 3332 (280) g). Energy expenditure by the doubly labelled water method and milk intake by the dose to infant method were measured at 34 (4) days. A dose of 0. 2 g/kg deuterium oxide (99.8%) and 2.0 g/kg 10% (18)O labelled water was given to the infants, and urine samples were collected for seven consecutive days after dosing.

RESULTS

The mean (SD) weight of the infants during the period of evaluation was 4617 (343) g and weight gain 34.0 (7.5) g/day. Daily milk intake was 728 (101) g and its metabolisable energy content 2.71 kJ/g. The energy expenditure of the infants was 1205 (312) kJ/day and energy required for growth was 607 (130) kJ/day. When combined this produced an energy requirement of 391 kJ/kg/day for these infants.

CONCLUSION

These data agree with those from other studies in the United Kingdom and the United States and suggest that adequate growth can be achieved with 19.4% less energy than recommended by FAO/WHO/UNU.