LiDAR-based reference aboveground biomass maps for tropical forests of South Asia and Central Africa

Accurate mapping and monitoring of tropical forests aboveground biomass (AGB) is crucial to design effective carbon emission reduction strategies and improving our understanding of Earth's carbon cycle. However, existing large-scale maps of tropical forest AGB generated through combinations of Earth Observation (EO) and forest inventory data show markedly divergent estimates, even after accounting for reported uncertainties. To address this, a network of high-quality reference data is needed to calibrate and validate mapping algorithms. This study aims to generate reference AGB datasets using field inventory plots and airborne LiDAR data for eight sites in Central Africa and five sites in South Asia, two regions largely underrepresented in global reference AGB datasets. The study provides access to these reference AGB maps, including uncertainty maps, at 100 m and 40 m spatial resolutions covering a total LiDAR footprint of 1,11,650 ha [ranging from 150 to 40,000 ha at site level]. These maps serve as calibration/validation datasets to improve the accuracy and reliability of AGB mapping for current and upcoming EO missions (viz., GEDI, BIOMASS, and NISAR).

Exposure to the COVID-19 pandemic environment and generosity

We report data from an online experiment which allows us to study how generosity changed over a 6-day period during the initial explosive growth of the COVID-19 pandemic in Andalusia, Spain, while the country was under a strict lockdown. Participants (n = 969) could donate a fraction of a €100 prize to an unknown charity. Our data are particularly rich in the age distribution and we complement them with daily public information about COVID-19-related deaths, infections and hospital admissions. We find correlational evidence that donations decreased in the period under study, particularly among older individuals. Our analysis of the mechanisms behind the detected decrease in generosity suggests that expectations about others' behaviour, perceived mortality risk and (alarming) information play a key-but independent-role for behavioural adaptation. These results indicate that social behaviour is quickly adjusted in response to the pandemic environment, possibly reflecting some form of selective prosociality.

Increase of serum cyclophilin C levels in the follow-up of coronary artery disease: a biomarker and possible clinical predictor

Background

Traditional cardiovascular risk factors and a large number of biomarkers are well known in their association with the diagnosis and prognosis of coronary artery disease (CAD). Cyclophilin C (CypC) is a subfamily of immunophilins that modulates macrophage activation and redox homeostasis.

Purpose

This study is aimed at investigating the changes in serum CypC levels and their relationship with cardiovascular events at 12 months of follow-up in CAD patients.

Methods

The study included a total of 125 subjects (40 patients with acute CAD, 40 patients with chronic CAD and 45 control volunteers). We analyzed plasma CypC levels from baseline to 6 and 12 months for a better understanding of its behaviour in atherosclerosis.

Results

Serum CypC levels were shown to be gradually increased in CAD patients [(30.63 pg/mL ± 3.77 at baseline, 38.70 pg/mL ± 6.41 at 6 months (p=0.25) and 47.27 pg/mL ± 5.65 at 12 months (p=0.007)]. In addition, serum CypC levels during the follow-up were a significant predictor of CAD (c- statistic 0.76 at 6 months and 0.89 at 12 months; p<0.001). Despite it, there was no significant association between CypC and cardiovascular events, but serum CypC levels tended to be higher in patients suffering cardiovascular events during the follow-up (29.02 pg/mL ± 6.39 vs 79.96 pg/mL ± 22.18; p=0.029). In this regard, plasma levels of hsCRP >2.3 mg/L plus NT-proBNP >300pg/mL together were significant predictors of cardiovascular events during the follow-up in CAD patients with CypC levels >17.5 pg/mL (p=0.048).

Conclusions

Taken together, our results suggest that serum CypC levels increase during the follow-up in CAD patients and could be a novel biomarker with a possible prognostic value in combination with hsCRP and NT-proBNP.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III. Spain

It's not just an ileus: disparities associated with ileus following ventral hernia repair

PURPOSE

We sought to identify risk factors associated with postoperative ileus following ventral hernia repair.

METHODS

Utilizing the Nationwide Inpatient Sample (NIS) from 2008 to 2012, we identified adult patients that underwent either open or laparoscopic hernia repair for umbilical and ventral hernias with a diagnosis of umbilical/ventral hernia. We excluded cases with diagnosis of obstruction and bowel gangrene that underwent bowel resection, or with missing data. Risk variables of interest were age, sex, race, income status, insurance status, elective admission, comorbidity status (using the validated van Walraven Score), complications (mechanical, respiratory, postoperative infection, cardiovascular, intraoperative), morbid obesity, procedure type, conversion to open, mesh use, hospital type (rural, urban non-teaching, urban teaching), bed size, and region (northeast, midwest, south, west). Univariate analysis comparing patients with ileus vs control was performed. We then performed multivariable analysis using logistic regression, adjusting for all the risk variables, with ileus as the dependent variable.

RESULTS

30,912 patients were identified that met criteria. Of these, 2660 (8.61%) had postoperative ileus during their stay at the hospital. Univariate analysis showed all risk variables were associated with development of ileus with the exception of income status (p = 0.2903), elective admission (p = 0.7989), mesh use (p = 0.3620), and hospital bed size (p = 0.08351). Median length of stay was 7 days in the ileus cohort vs 3 days in control (p < 0.0001). Median total charges (adjusted to 2012 dollars) was $54,819 vs $35,058 (p < 0.0001). We then performed logistic regression adjusting for all risk variables and found that age (OR 1.66, p < 0.0001), male sex (OR 1.51, p < 0.0001), Black race (OR 1.49, p < 0.0001), comorbidity status (OR 1.12, p < 0.0001), laparoscopic cases converted to open (OR 1.55, p < 0.0001), postoperative complications (mechanical: OR 2.32, p < 0.0001, respiratory: OR 1.54, p < 0.0001, postoperative infection: OR 2.12, p < 0.0001, cardiovascular: OR 1.57, p = 0.0006, intraoperative: OR 1.29, p = 0.0200) were independently associated with increased risk of ileus. However, laparoscopic vs open (OR 0.76, p < 0.0001), elective admission (OR 0.91, p = 0.0378), and northeast vs south hospital region (OR 0.74, p < 0.0001) were independently associated with decreased risk of ileus.

CONCLUSION

We performed a large observational study looking for risk factors associated with ileus following ventral hernia repair. Race and region of treatment are independent risk factors associated with ileus following ventral hernia repair, and a potential source of disparities in care and increased admission length and higher cost of care. Further prospective studies are warranted.

Association between heart rate, heart rate variability, cortisol, glucose and electrolytes in healthy newborn calves

ABSTRACT This study aims at evaluating the effects of electrolytes, glucose and cortisol levels over heart rate (HR) and heart rate variability (HRV) in healthy newborn calves. Seventeen healthy Holstein calves were evaluated during their first month of life, and the plasma concentrations of glucose, cortisol, calcium, magnesium, inorganic phosphorus, sodium and potassium were analyzed. HRV indexes were determined in the time and frequency domains through the analysis of neonatal electrocardiogram recordings. In the first day, low blood levels of phosphorus presented a strong correlation with the HR and the increased high-frequency components of HRV. The plasma concentrations of magnesium decreased significantly throughout the 35 days, revealing a positive association with a decreasing low-frequency components of HRV at day 28. There was a strong correlation between HR, HRV indexes, some plasma electrolytes, glucose and cortisol during the studied period. Variations in the concentrations and correlations observed may be attributed to the adaptive neonatal period in calves.

Retrospective study of allometric relationship between heart rate, electrocardiographic parameters and bodyweight in dogs

ABSTRACT The allometric relationship between bodyweight (BW) and heart rate (HR) has been described as inversely proportional in domestic species, but that has been refuted. The relationship between HR and electrocardiographic variables is described in literature. However, studies about the variation and influence of factors on the hemodynamic and electrocardiographic parameters in dogs are not abundant. As the metabolic rate is defined as the production and dissipation of heat by the body surface area (BSA) in m², it is essential to define that relationship. A retrospective study was conducted to analyze the correlation between HR, ECG parameters and BW in dogs. One thousand electrocardiographic tracings were analyzed in addition to the ECG parameters and clinical data such as gender, age and bodyweight. The determination of BSA was performed as follows: BSA (m2) = (10.1 x bodyweight 0.67) X 10-4. When the unified groups were analyzed, there was a negative but weak correlation (r= -0.14, P< 0.0001) between bodyweight and HR. There were differences between weight groups regarding electrocardiographic variables. There is no allometric relationship between BW and HR in dogs. Weight was associated with changes in ECG variables.

Improvement of appropriate pharmacological prophylaxis in hospitalised cancer patients with a multiscreen e-alert system: a single-centre experience

PURPOSE

Thromboprophylaxis use among medical inpatients, including cancer patients, is suboptimal. We aimed to evaluate the impact of a novel multiscreen version (v2.0) of an e-alert system for VTE prevention in hospitalised cancer medical patients compared to the original software.

METHODS

Prospective study including 989 consecutive adult cancer patients with high-risk of VTE. Patients were followed-up 30 days post-discharge. Two periods were defined, according to the operative software.

RESULTS

E-alert v2.0 was associated with an increase in the use of LMWH prophylaxis (65.5% vs. 72.0%); risk difference (95% CI) 0.064 (0.0043-0.12). Only 16% of patients in whom LMWH prophylaxis was not prescribed lacked a contraindication. No significant differences in the rates of VTE (2.9% vs. 3.2%) and major bleeding (2.7% vs. 4.0%) were observed.

CONCLUSIONS

E-alert v2.0 further increased the use of appropriate thromboprophylaxis in hospitalised cancer patients, although was not associated with a reduction in VTE incidence.

Early and late analysis of postpartum stress in newborn foals

ABSTRACT The aim of this study was to evaluate newborn foals stress in the first 48 hours of life. Heart rate (HR), heart rate variability (HRV) and serum cortisol concentrations, blood glucose, and lactate were determined in foals (n = 20, Paint Horse). Cortisol concentrations decreased significantly between four and 48 hours, with the highest concentration at 4 hours after birth. Positive correlations between cortisol and lactate occurred between 12 and 16 hours. And there was a negative correlation between cortisol and lactate 4 hours after birth. Among the values obtained for HR, there was significantly difference between the the value obtained at twelve hours of life moment and all the other moments measured, the highest values were at birth, 24 and 48 hours of life. Among HRV indexes, there were no statistical differences between the variables analysed. The cortisol, HR and HRV alterations were consistent to neonatal stress, but might be related to extrauterine environment adaptation associated to sympathoadrenal response, since those foals were healthy.

Implementation of a management protocol for massive bleeding reduces mortality in non-trauma patients: Results from a single centre audit

OBJECTIVE

To audit the impact upon mortality of a massive bleeding management protocol (MBP) implemented in our center since 2007.

DESIGN

A retrospective, single-center study was carried out. Patients transfused after MBP implementation (2007-2012, Group 2) were compared with a historical cohort (2005-2006, Group 1).

BACKGROUND

Massive bleeding is associated to high mortality rates. Available MBPs are designed for trauma patients, whereas specific recommendations in the medical/surgical settings are scarce.

PATIENTS

After excluding patients who died shortly (<6h) after MBP activation (n=20), a total of 304 were included in the data analysis (68% males, 87% surgical).

INTERVENTIONS

Our MBP featured goal-directed transfusion with early use of adjuvant hemostatic medications.

VARIABLES OF INTEREST

Primary endpoints were 24-h and 30-day mortality. Fresh frozen plasma-to-red blood cells (FFP:RBC) and platelet-to-RBC (PLT:RBC) transfusion ratios, time to first FFP unit and the proactive MBP triggering rate were secondary endpoints.

RESULTS

After MBP implementation (Group 2; n=222), RBC use remained stable, whereas FFP and hemostatic agents increased, when compared with Group 1 (n=82). Increased FFP:RBC ratio (p=0.053) and earlier administration of FFP (p=0.001) were also observed, especially with proactive MBP triggering. Group 2 patients presented lower rates of 24-h (0.5% vs. 7.3%; p=0.002) and 30-day mortality (15.9% vs. 30.2%; p=0.018) - the greatest reduction corresponding to non-surgical patients. Logistic regression showed an independent protective effect of MBP implementation upon 30-day mortality (OR=0.3; 95% CI 0.15-0.61).

CONCLUSIONS

These data suggest that the implementation of a goal-directed MBP for prompt and aggressive management of non-trauma, massive bleeding patients is associated to reduced 24-h and 30-day mortality rates.

Toxin profile in samples collected in fresh and brackish water in Germany

The simultaneous detection of cyanotoxins is an important issue in order to prevent intoxications. In the present paper an Ultra Performance liquid Chromatography tandem mass spectrometry UPLC-MS/MS method was developed in order to simultaneously identify and quantify cylindrospermopsin (CYN), several microcystins (MC-LR, MC-RR, MC-YR) and some anatoxin-a (ATX-a) analogues. By using this new method all these toxins can be quickly separate. In addition the amino acid phenylalanine (Phe) can also be separate and therefore misidentifications with ATX-a can be avoided. By using this new method the presence of these toxins was studied in samples collected in several German localizations within the sampling program of the European Project μAqua (Universal microarrays for the evaluation of fresh-water quality based on detection of pathogens and their toxins). In these conditions, several ATX-a analogues, Phe, MC-LR and MC-RR were reported in samples collected.

Bromoalkaloids protect primary cortical neurons from induced oxidative stress

Bromoalkaloids are secondary metabolites with a demonstrated high activity in several therapeutic areas. In this research, we probe the neuroprotective and antioxidant activities of hymenialdisine and hymenin. Both structures were tested in an oxidative stress cellular model, consisting of cortical neurons that are incubated with the oxidative stress inducer hydrogen peroxide and the tested compound. Several oxidation biomarkers were analyzed, and the results of the oxidative stress induced neurons in the presence and absence of bromoalkaloids were compared. Both compounds demonstrated significant neuroprotective ability under stress conditions at low nanomolar concentrations, with hymenialdisine highlighted for demonstrating a more complete protection. Also, the activity of hymenialdisine and hymenin was studied in the nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway, and, for the first time, these halogenated metabolites are described as Nrf2 inducers, reinforcing the antioxidant capacity observed and therefore opening a new path of investigation. These results, added to the previously described effect of this compound family in negatively modulating several kinases and proinflammatory cytokines, position hymenialdisine and hymenin as good candidates for the development of new drugs for neurodegenerative diseases.

[Safety and efficacy of a prothrombin complex concentrate in patients with coagulopathy and hemorrhage]

BACKGROUND

Prothrombin complex concentrates (PCC) are approved for urgent reversal of vitamin K antagonists (VKA). Recently, PCC have been used in the management of massive bleeding-associated coagulopathy. The present work evaluates safety and efficacy of PCC in a case series of both VKA reversal and massive bleeding.

METHODS

Retrospective review of cases treated with CCP (January 2010 to February 2013). Safety endpoints were infusion reactions and incidence of thromboembolic events. Efficacy endpoints were: 1) VKA reversal efficacy and 2) Massive bleeding coagulopathy reversal and 24h mortality.

RESULTS

Thirty-one patients were included (22 male), median age 61 years (range 30-86). No infusion reactions were detected, and only 1 thrombotic episode was observed. VKA reversal was effective in 100% of patients (6/6), all of them with complete reversal of INR value. In massive bleeding, 24-hour survival was 64% (16/25). Invasive hemostatic procedures were required in 28% of patients (7/25). CCP use was correlated with bleeding control in 44% of cases (11/25), and also significantly associated with survival (p=0.01).

CONCLUSION

CCP are safe and effective for the novel indication of adjuvant treatment in massive bleeding patients, as well as for traditional urgent reversal of VKA.

Key role of phosphodiesterase 4A (PDE4A) in autophagy triggered by yessotoxin

Understanding the mechanism of action of the yessotoxin (YTX) is crucial since this drug has potential pharmacological effects in allergic processes, tumor proliferation and neurodegenerative diseases. It has been described that YTX activates apoptosis after 24h of treatment, while after 48 h of incubation with the toxin a decrease in cell viability corresponding to cellular differentiation or non-apoptotic cell death was observed. In this paper, these processes were extensively studied by using the erythroleukemia K-562 cell line. On one hand, events of K-562 cell differentiation into erythrocytes after YTX treatment were studied using hemin as positive control of cell differentiation. Cell differentiation was studied through the cyclic nucleotide response element binding (phospho-CREB) and the transferrin receptor (TfR) expression. On the other hand, using rapamycin as positive control, autophagic hallmarks, as non-apoptotic cell death, were studied after toxin exposure. In this case, the mechanistic target of rapamycin (mTOR) and light chain 3B (LC3B) levels were measured to check autophagy activation. The results showed that cell differentiation was not occurring after 48 h of toxin incubation while at this time the autophagy was triggered. Furthermore after 24h of toxin treatment none of these processes were activated. In addition, the role of the type 4A phosphodiesterase (PDE4A), the intracellular target of YTX, was checked. PDE4A-silencing experiments showed different regulation steps of PDE4A in the autophagic processes triggered either by traditional compounds or YTX. In summary, after 48 h YTX treatment PDE4A-dependent autophagy, as non-apoptotic programmed cell death, is activated.

Does pharmacological treatment of ADHD in adults enhance parenting performance? Results of a double-blind randomized trial

OBJECTIVE

This study examines the effects of parental lisdexamfetamine (LDX) treatment on parent-child interactions.

METHODS

Participants were 30 parents (27% were male) and their children aged 5-12 years, both diagnosed with DSM-IV attention-deficit/hyperactivity disorder (ADHD). Optimal LDX dose (30, 50, or 70 mg/day) was determined for parents during a 3-week open-label titration, followed by a within-subjects trial of the acute impact of LDX and placebo on observable parent-child interactions. Two laboratory-based, parent-child interactions simulating typical family tasks (e.g., homework, joint play) were conducted within 2 weeks, once with the adult on a blinded optimal dose of LDX and once on placebo (phase I). Parents were then randomly assigned to continue blinded treatment with LDX or placebo for another month followed by a third interaction task (phase II) to assess the ongoing effects of LDX on parent-child interactions. The primary outcome was the change in rate of parenting behaviors coded during the parent-child interaction tasks. Secondary outcomes included observed rates of children's inappropriate behaviors during the laboratory tasks and changes in parental ADHD symptom severity (ADHD-Rating Scale).

RESULTS

Twenty parents (67%) completed the trial. In phase I, medication was associated with a significant reduction in negative talk by parents (p = 0.0066, d = -0.47). There was a Medication × Task interaction (p = 0.0235) with a reduction in children's negative behaviors in the homework phase only (p = 0.0154, d = -0.58). In phase II, LDX was associated with significant increases in praise by parents (d = 0.81) and reductions in parental commands (d = -0.88) and children's inappropriate behaviors (d = -0.84) (all p-values < 0.05). While not reaching statistical significance, LDX was also associated with large reductions in parental verbalizations (d = -0.82), moderate increases in parental responsiveness (d = 0.55), and large reductions in the ratio of commands to verbalizations during the non-homework task (d = -1.05) (all p-values < 0.10). Significant reductions in parental ADHD symptoms vs. placebo were observed (p < 0.005). Loss of appetite, dry mouth, headaches, and delayed sleep onset were the most common adverse events.

CONCLUSIONS

Improvements in parent-child interactions emerged over time with LDX treatment of parental ADHD. Results suggest that pharmacological treatment of parental ADHD may improve outcomes in parents and their children.

Role of AKAP 149-PKA-PDE4A complex in cell survival and cell differentiation processes

The cellular localization of A-kinase anchoring proteins (AKAPs), protein kinase A (PKAs) and phosphodiesterases (PDEs) is a key step to the spatiotemporal regulation of the second messenger adenosine 3',5'-cyclic monophosphate (cAMP). In this paper the cellular distribution of the mitochondrial AKAP 149-PKA-PDE4A complex and its implications in the cell death induced by YTX treatment, a known PDE modulator, was studied. K-562 cell line was incubated with YTX for 24 or 48 h. Under these conditions AKAP 149, PKA and type-4A PDE (PDE4A) levels were measured in the cytosol, in the plasma membrane and in the nucleus. Apoptotic hallmarks were also measured after the same conditions. In addition, YTX effect on cell viability was checked after AKAP 149 and PDE4A silencing. The results obtained show a decrease in AKAP 149-PKA-PDE4A levels in cytosol after YTX exposure. 24h after the toxin addition, the complex expression increased in the plasma membrane and after 48 h in the nucleus domain. Furthermore Bcl-2 levels were decreased and the expression of caspase 3 together with caspase 8 activity were increased after 24h of toxin incubation but not after 48 h. These results suggest apoptotic cell death at 24h and a non-apoptotic cell death after 48 h. When AKAP 149 and PDE4A were silenced YTX did not induce cellular death. In summary, AKAP 149-PKA-PDE4A complex localization is related with YTX effect in K-562 cell line. When this complex is mainly located in the plasma membrane apoptosis is activated while when the complex is in the nuclear domain non-apoptotic cellular death or cellular differentiation is activated. Therefore AKAP 149-PKA-PDE4A distribution and integrity have a key role in cellular survival.

Prolonged neurological burden in severe lithium intoxication

A 53-year-old woman was brought to the Emergency Department for a persistent state of stupor, tremors, fever and oliguria. The patient had been under treatment for depression. The electrocardiogram showed a wider QRS complex; laboratory tests were as follows: urea 110 mg/dL, creatinine 3 mg/dL, sodium 135 mEq/L, potassium 4.5 mEq/L, and lithium 8.0 mEq/L. Renal replacement was initiated to normalize plasma lithium levels; both stupor and speech impairment persisted for several days after dialysis. Complete recovery was achieved several days afterwards.

Study of the neuronal effects of ouabain and palytoxin and their binding to Na,K-ATPases using an optical biosensor

The phycotoxin palytoxin (PTX) binds to Na,K-ATPase, inhibiting its activity and converting the pump into a channel. These mechanisms are poorly understood. We examined the effect of PTX on membrane potential (E(m)), intracellular calcium concentration ([Ca2+]i) and intracellular pH (pH(i)) in primary cultures of cerebellar granule cells (CGC) and compared PTX and ouabain actions in the same cellular parameters. In this system, PTX caused depolarization, intracellular calcium increase and acidification. This is similar to the effect of ouabain. Preincubation of the cells with ouabain, before addition of PTX, altered E(m), [Ca2+]i, and pH(i) in a fashion similar to that of ouabain alone. This suggest a direct interaction of PTX with the Na,K-ATPase. Therefore, we used a resonant mirror biosensor to evaluate the binding of PTX and ouabain to immobilized Na,K-ATPase. Ouabain binding to immobilized Na,K-ATPase was concentration-dependent. No binding of PTX to Na,K-ATPase was observed with up to 10 microM, or with PTX addition in the presence of ATP. The fact that ouabain binds to the pump in an immobilized conformation whereas not binding of PTX was observed indicates that PTX and ouabain do not share the same binding site, and PTX binding may require the tridimensional pump structure.

Extraction and cleaning methods to detect yessotoxins in contaminated mussels

Yessotoxin (YTX) and its analogues are a newly recognized group of toxins with increased presence in shellfish in recent years. They can be quantified by various functional assays due to their interaction with phosphodiesterases (PDEs). One of these assays detects the binding between the YTX and the fluorescently labeled PDE I using fluorescence polarization, a spectroscopic technique based on exciting a fluorescent molecule with plane-polarized light and measuring the polarization degree of the emitted light. The aim of this study was to develop a YTX extraction procedure from mussels that does not interfere with this detection method. YTX concentrations were measured in spiked mussel extracts obtained through use of different extraction methods and cleaning procedures. The percentages of toxin recovery in various steps of the processes were calculated using these concentrations. Six extraction methods and two cleaning steps were used and no matrix effects and high toxin recoveries were obtained in two cases. One case used acetone as extraction solvent followed by three dichloromethane partitions and the other case used methanol. The cleaning procedure includes a silica cartridge and a 10,000 NMWL filter. Finally these two extraction-cleaning-detection methods were applied to a naturally contaminated mussel sample and results showed that not only YTX but also homoYTX and hydroxyYTX can be quantified with a 85-90% recovery.

Association of body size estimation and age in African-American females

This cross-sectional research study tested the hypothesis that body image estimates of African-American females differ as a function of age. To test this hypothesis, body image estimates of 379 African-American females, ranging in age from 16 to 96 years, were contrasted as a function of age group, while statistically controlling body mass index. Three body size estimates, current body size, ideal body size, and reasonable body size were measured using the Body Image Assessment for Obesity. The discrepancies between current and ideal body size estimates and between current and reasonable body size estimates were also analyzed to assess for differences in body size dissatisfaction. The study found that younger African-American women (16 to 35 years) differed from older African-American women (>35 years) on measures of body size dissatisfaction. Women in the age range of 26 to 35 years reported higher estimates of current body size in comparison to women older than 35 years. The youngest age group (16 to 25 years) reported thinner ideal body size goals in comparison to women who were slightly older (26 to 35 years) and women who were older than 75 years. The pattern of body image estimates across a large age range suggests that younger African-American women, in comparison to older African-American women, may have body images that may make them more susceptible to eating disorders.

Percent body fat measured by BIA and DEXA in obese, African-American adolescent girls

OBJECTIVE

To compare the estimation of body fat between bioelectrical impedance analysis (BIA) and dual energy X-ray absorptiometry (DEXA) in overweight, African-American female adolescents.

SUBJECTS

In total, 54 African-American adolescent female subjects were recruited for Study 1. Each adolescent's body mass index was greater than the 85th percentile and their average body fat was 45% according to DEXA. A total of 26 African-American adolescent female subjects were available for Study 2, and had an average body fat of 26% according to DEXA.

MEASUREMENTS

Percent body fat was measured by DEXA and BIA. Seven different BIA equations were tested. Both sets of data were analyzed using Bland-Altman regression analyses, utilizing percent body fat measured by DEXA as the criterion.

RESULTS

The Kushner equation provided estimates that were unaffected by body fat in both studies. Estimates were unbiased when applied to the exclusively overweight sample and biased when utilized with the separate sample of normal weight and obese girls. The remaining equations were biased, provided inconsistent estimates across body weight, or were biased and provided inconsistent estimates. Ethnicity-specific and ethnicity-combined equations performed similarly in the obese sample, but became more disparate when applied to a sample encompassing a wider body weight range. The limits of agreement between all BIA equations and the DEXA estimates ranged from 6 to 9%.

CONCLUSION

The study suggests that the Kushner BIA equation is appropriate for use with African-American female adolescents across the weight spectrum, while the majority of BIA equations underestimated percent body fat as body fat increased.

Efficacy of an internet-based behavioral weight loss program for overweight adolescent African-American girls

OBJECTIVE

This randomized controlled trial tested the efficacy of an internet-based lifestyle behavior modification program for weight management in African-American girls.

DESIGN

African-American girls were randomly assigned to an interactive behavioral internet program or an internet health education program, the control condition. The behavioral intervention included internet counseling and was highly interactive. The control intervention was a passive (non-interactive) educational program. Parents were also participants in the study. Participants in both treatment groups met in face-to-face sessions on four occasions over the first 12 weeks of a 6-month intervention.

SUBJECTS

The study enrolled 57 African-American adolescent girls (ages 11 to 15 years) who were overweight or obese and had at least one biological parent who was obese [body mass index (BMI) >30 kg/m2]. Of the 57 participants, 50 (88%) completed the 6-month trial.

MEASUREMENTS

Outcome data, including BMI, body weight, body composition, dietary intake, and weight loss behaviors were collected at baseline and 6-months later. A computer server tracked utilization of the websites. Participation in the program was measured by number of "hits" on the website.

RESULTS

Compared to the control condition, adolescents in the behavioral treatment lost more body fat (group difference =1.6% body fat) and parents lost significantly more body weight (group difference =2.1 kg). Utilization of the behavioral website by adolescents and parents was associated with positive outcome. Dietary fat intake was lowered for adolescents and parents in the behavioral treatment group.

CONCLUSION

An internet-based behavioral intervention was superior to internet-based health education and yielded decreased body fat for adolescent girls and decreased body weight for parents.

Mast cell exocytosis can be triggered by ammonium chloride with just a cytosolic alkalinization and no calcium increase

A human mast cell line (HMC-1) has been used to study the effect of cytosolic alkaline pH in exocytosis. Compound 48/80, concanavalin A, and thapsigargin do not induce histamine release in HMC-1 cells. Although thapsigargin does not activate histamine release, it does show a large increase in cytosolic Ca(2+), and no change in cytosolic pH. However, when HMC-1 cells were activated with ionomycin, a significant histamine release takes place, and this effect is higher in the presence of thapsigargin. Both drugs show an additive effect on cytosolic Ca(2+) levels. Ammonium chloride (NH(4)Cl) does activate cytosolic alkalinization and histamine release, with no increase in cytosolic Ca(2+). NH(4)Cl does block the release of internal Ca(2+) by thapsigargin, not by ionomycin, and decreases Ca(2+) influx stimulated by these drugs. Under conditions in which the alkalinization induced by NH(4)Cl is blocked by acidification with sodium propionate, histamine release is inhibited. The release of histamine is also observed when NH(4)Cl is added after propionate addition, regardless of the final pH value attained. Our results show that a shift in pH alkaline values, even with final pH below 7.2 is enough to activate histamine release. A shift to less acidic values is a sufficient signal to activate the cells.

Calcium-pH crosstalks in rat mast cells: modulation by transduction signals show non-essential role for calcium in alkaline-induced exocytosis

Alkalinization of cytosolic pH with ammonium chloride (NH4Cl) was reported to be a stimulus for mast cell degranulation. This paper studied the modulatory role of drugs that target protein kinase C (PKC), adenosine 3',5'-cyclic monophosphate (cAMP), tyrosine kinase (TyrK) and phosphatidylinositol 3-kinase (PI3K) on this effect. We used Go6976 (100 nM) and low concentrations of GF109203X (Gf) (50 nM) to inhibit calcium-dependent PKC isozymes. For calcium-independent isozymes, we used 500 nM Gf, and 10 microM rottlerin to specifically inhibit PKC delta, and chelerythrine as non-specific PKC inhibitor. Genistein (10 microM) and lavendustin A (1 microM) were used as unspecific TyrK inhibitors, and 10 nM wortmannin as a PI3K inhibitor. Chelerythrine and 50 nM Gf inhibit histamine release in the presence of external calcium. The inhibition caused by wortmannin was strictly internal calcium-dependent. cAMP-active drugs did not modify the response to NH4Cl. The effect of NH4Cl on histamine release was triggered by a transient elevation on cytosolic pH, which was simultaneous to an elevation on cytosolic calcium and followed by a probable Ca2+-H+ exchange after addition of external calcium. EGTA inhibit the response to suboptimal concentrations of NH4Cl, and BAPTA increased the effect of NH4Cl. There is a clear relationship between NH4Cl-mediated calcium release and histamine release, since those drugs that inhibit this release also inhibit NH4Cl-mediated histamine release; nevertheless, NH4Cl-mediated histamine release was possible in the absence of any calcium release, as shown with BAPTA. This data, in combination with the results with PKC inhibitors, suggest that calcium is not only unnecessary to trigger cell activation, but also that it may be a negative modulator of NH4Cl-mediated exocytosis.

Digital photography: a new method for estimating food intake in cafeteria settings

OBJECTIVE

The primary objective of this study was to test the comparability of digital photography and visual estimation procedures for estimating food intake.

RESEARCH METHODS AND PROCEDURES

The study sample included 71 breakfast meals and 59 lunch meals eaten in a university cafeteria during a single day. A total of 66 different foods were employed as test foods that could be selected by the students. Food selections and plate waste, as estimated by digital photography and visual estimation, were compared. For digital photography, three observers independently estimated portion sizes of each food item based upon digital photographs. One observer estimated portion sizes in the cafeteria setting, using visual estimation, a method that has been validated in other studies.

RESULTS

To test the accuracy of the two procedures for measuring food intake, the estimates of food weights derived from both procedures were compared using Bland-Altman regression. In comparison to visual estimation, the digital photography method yielded comparable estimates of food selections, plate waste, and total food intake for seven of nine comparisons. The two methods of estimating food portions yielded comparable results for most (78%) types of foods. The two methods also yielded similar variability.

DISCUSSION

These findings suggest that the digital photography method is an alternative to the traditional method of estimating food intake via direct observation.

Dimethylsphingosine increases cytosolic calcium and intracellular pH in human T lymphocytes

N,N-Dimethyl-D-erythro-sphingosine (DMS) is the N-methyl derivative of sphingosine; both are activators of sphingosine-dependent protein kinases. The aim of this work was to study the effect of DMS on cytosolic calcium and intracellular pH (pHi) in human T lymphocytes. The variations of calcium and pH were determined by fluorescence digital imaging using Fura-2-AM and BCECF-AM, respectively. DMS increased both pHi and Ca(2+)-cytoslic in human T lymphocytes. These effects were dose-dependent. This drug induced a fast increase in pHi and a release of calcium from different intracellular calcium pools than thapsigargin. DMS also induced a Ca(2+)-influx different from the store-operated calcium channels, since drug effect was not modified by 30 microM SKF 96365. The influx of calcium induced by DMS was completely blocked by preincubation in the presence of nickel, or lanthanum, while the increase in pHi was no affected. However, the presence of cadmium reduced but does not block Ca(2+)-influx. The inhibition of G-protein by 100 ng/mL pertussis toxin, and the inhibition of tyrosine kinases by genistein significantly reduced the cytosolic calcium increase induced by DMS by an inhibition of both, release of calcium from intracellular pools and influx from extracellular medium. The inhibition of pools emptiness by these drugs was related with the inhibition that they induce in the DMS cytosolic alcalinization. In summary, DMS increases pHi and as consequence releases calcium from intracellular pools, and it increases calcium-influx through a channel different from store-operated channel (SOC). Both cytosolic calcium and pHi increase are modulated by G-proteins and tyrosine kinases.

Prolactin induces calcium influx and release from intracellular pools in human T lymphocytes by activation of tyrosine kinases

The early events related to intracellular signals after prolactin (PRL) activation in T lymphocytes are not clearly established. The aim of this work was to study the effect of PRL in cytosolic calcium levels in human T lymphocytes. By using the dye FURA-2 AM, the variations in cytosolic Ca(2+) were studied in peripheral human T lymphocytes isolated from extracted blood from healthy donors. Fifty nanograms per milliliter PRL induces a small increase in cytosolic calcium. When the cells are preincubated overnight (16-20 h) in the presence of PRL, the increase in calcium is higher. This high increase is due to the release from intracellular pools and to the influx from the extracellular media. That is, after overnight incubation with PRL, calcium influx in T cells follows the capacitative model. Since PRL receptor (PRL-R) activation involves the tyrosine kinase pathway, we check calcium effect in the presence of genistein, a known inhibitor of tyrosine kinases. When cells are preincubated in the presence of 10 microM genistein, and PRL is immediately added, no increase in cytosolic calcium is observed. The presence of genistein also completely blocks the increase in cytosolic calcium stimulated by PRL after overnight incubation with PRL. In the presence of PRL and N,N-dimethyl-D-erythro-sphingosine (DMS), a stimulus that increases cytosolic calcium in T cells by tyrosine kinase stimulation, a high, even insignificant, calcium influx is induced. However, when the cells are incubated overnight in the presence of PRL, and then DMS is added, a significant increase in cytosolic calcium levels takes place. This increase is associated with an increase in calcium release from intracellular pools and an increase in calcium uptake. Genistein reduces the influx of external calcium induced by DMS after short incubation with PRL and significantly inhibits both, calcium pools empty, and calcium influx is induced by DMS after overnight incubation with PRL. In summary, PRL induces calcium influx in normal T lymphocytes. The influx is magnified after long PRL exposures, intracellular Ca(2+) pool-dependent, and activated through tyrosine kinases.

Confocal microscopy study of the different patterns of 2-NBDG uptake in rabbit enterocytes in the apical and basal zone

D-Glucose uptake in isolated rabbit enterocytes was studied using confocal microscopy and 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-D-glucose (2-NDBG), a D-glucose fluorescent analogue, by analysing the fluorescence of apical and basal enterocyte zones. Under normal conditions, apical fluorescence was always higher than basal, presumably due to the location of the Na+-D-glucose cotransporter in the brush-border membrane. After blocking this transporter with phlorizin, apical and basal fluorescence values were similar. This suggests that both brush-border and basolateral membranes participate in phlorizin-insensitive D-glucose transport, since transport across only one membrane cannot explain the uniform overall fluorescence observed. Similarly, after inhibiting the Na+-D-glucose cotransporter by incubating the enterocytes in a medium containing 0.5 mM Na+, neither apical nor basal fluorescence predominated. In contrast, with 130.5 mM extracellular Na+, apical fluorescence was clearly higher than basal fluorescence. These results suggest that phlorizin-insensitive, Na+-independent 2-NDBG uptake occurred through both brush-border and basolateral membranes, probably via the glucose uniporters GLUT2 and GLUT5, suggesting that the latter is a D-glucose transporter.

Maitotoxin-induced calcium entry in human lymphocytes: modulation by yessotoxin, Ca(2+) channel blockers and kinases

We have studied the effect of the ciguatera-related toxin maitotoxin (MTX) on the cytosolic free calcium concentration ([Ca(2+)]i) of human peripheral blood lymphocytes loaded with the fluorescent probe Fura2 and the regulation of MTX action by different drugs known to interfere in cellular Ca(2+) signalling mechanisms and by the marine phycotoxin yessotoxin (YTX). MTX produced a concentration-dependent elevation of [Ca(2+)]i in a Ca(2+)-containing medium. This effect was stimulated by pretreatment with YTX 1 microM and NiCl(2) 15 microM. The voltage-independent Ca(2+) channel antagonist 1-[beta-[3-(4-methoxyphenyl)propoxyl]-4-methoxyphenyl]-1H-imidazole hydrochloride (SKF96365) blocked the MTX-induced [Ca(2+)]i elevation, while the L-type channel blocker nifedipine had no effect. Pretreatment with NiCl(2) or nifedipine did not modify YTX-induced potentiation of MTX effect, and SKF96365-induced inhibition was reduced in the presence of YTX, which suggest different pathways to act on [Ca(2+)]i. Preincubation with N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide.2HCl (H-89) or genistein (10 microM) also had no effect on the MTX-induced [Ca(2+)]i increment. In contrast, the PKC inhibitor bisindolilmaleimide I (GF109203X 1 microM) potentiated the MTX effect, whereas phosphatidylinositol (PI) 3-kinase inhibition with wortmannin (10 nM) reduced the MTX-elicited Ca(2+) entry. In summary, MTX produced Ca(2+) influx into human lymphocytes through a SKF96365-sensitive, nifedipine-insensitive pathway. The MTX-induced [Ca(2+)]i elevation was stimulated by the marine toxin YTX through a mechanism insensitive to SKF96365, nifedipine or NiCl(2). It was also stimulated by the divalent cation Ni(2+) and PKC inhibition and was partially inhibited by PI 3-kinase inhibition.

Ouabain-induced enhancement of rat mast cells response. Modulation by protein phosphorylation and intracellular pH

The digitalic glicoside ouabain induces potentiation of rat mast cell histamine release in response to several stimuli, which is mediated by Na+/Ca2+ exchanger. In this work, we studied the effect of ouabain on cytosolic calcium, intracellular pH and histamine release with Ca2+ ionophore A23187 in conditions designed to maximize ouabain-induced potentiation of rat mast cells response. The effect of protein kinase C (PKC), cAMP and phosphatase inhibition was also tested. Ouabain induced an enhancement in histamine release, cytosolic calcium and intracellular pH. The adenylate cyclase activator forskolin reduced the effect of ouabain on histamine release and intracellular pH, but enhanced the effect on cytosolic calcium. PKC activator PMA enhanced the effect of ouabain on histamine release and cytosolic calcium, without affecting intracellular pH. A PKC inhibitor, GF-109203X, reduced ouabain-induced enhancement of histamine release and intracellular pH, but increased the enhancement on cytosolic calcium. Finally, inhibition of protein phosphatases 1 and 2A with okadaic acid, increased the effect of ouabain on histamine release and intracellular pH, but reduced cytosolic calcium in presence of ouabain. This result suggest that ouabain-induced potentiation of rat mast cell histamine release with A23187 is modulated by kinases, and this modulation may be carried out by changes in intracellular alkalinization. However, the mechanism underlying cellular alkalinization remains to be elucidated.

Modulation of cytosolic calcium levels of human lymphocytes by yessotoxin, a novel marine phycotoxin

Yessotoxin (YTX) is a polyether toxin of marine origin that has been classified among the diarrheic shellfish poisoning (DSP) toxins group due to its lipophilic nature. However, unlike other DSP toxins, YTX does not produce diarrhea and its mechanisms of action are unknown. We studied the effect of YTX on the cytosolic calcium levels of freshly isolated human lymphocytes by means of fluorescence imaging microscopy. We showed that YTX produced a calcium influx through nifedipine and SKF 96365 (1-[beta-[3-(4-methoxyphenyl)propoxyl]-4-methoxyphenyl]-1H-imidazole hydrochloride)-sensitive channels. This Ca2+ entry was not affected by the DSP toxin okadaic acid, which inhibits protein phosphatases. In addition, YTX also produced an inhibition of capacitative calcium entry activated by thapsigargin or by preincubation in a Ca2+-free medium. This capacitative calcium entry was not sensitive to nifedipine. Furthermore, the inhibitory effect of YTX was dependent on the time of addition of the toxin. We suggest that YTX may interact with calcium channels in a way similar to that described for other polyether marine compounds such as brevetoxins and maitotoxin, although an involvement of other second messengers is also likely.

Pyrazolopyrimidines: synthesis, effect on histamine release from rat peritoneal mast cells and cytotoxic activity

A series of 1H-pyrazolo[3,4-d]pyrimidines (3--6) substituted at positions 1 (R(1)=Ph, H, tert-butyl and ribosetribenzoate), 4 (R(2)=chlorine, nitrogen and oxygen nucleophiles), and 6 (dimethylamino) have been synthesized and their effect on the release of histamine from rat peritoneal mast cells measured. After chemical stimulation, (polymer 48/80), several compounds (i.e. 3b, 4a, 4b, 4d, 4g, 5a), produce inhibition two to three times higher (40--60%) than DSCG but this action is lower after preincubation. 4b (R(1)=Ph, R(2)=NHCH(2)Ph; 50--70% inhibition) and 5a (R(1)=H, R(2)=OMe; 50--55% inhibition) are the most active ones in both experiments. With ovoalbumin as stimulus, several pyrazolopyrimidines show inhibition similar to DSCG, the most active compounds being 6a--d (IC(50)=12--16 microM; R(1)=ribosetribenzoate, R(2)=methoxy and amino). Compounds 4e (R(1)=t-butyl, R(2)=OMe) and 4g (R(1)=t-butyl, R(2)=piperidino) are inducers of the release of histamine (60 and 150% increase). Compounds 4b and 4c showed cytotoxic activity (IC(50)=1 microg/mL) to HT-29 human colon cancer cells.

Severe necrotizing mastopathy caused by calciphylaxis alleviated by total parathyroidectomy

Calciphylaxis is a complication caused by secondary hyperparathyroidism in patients with chronic renal failure. These patients may present with clinical findings of ischemic necrosis involving the skin and muscle resulting in subsequent gangrene and vascular calcifications. We report a rare case of necrotizing mastopathy caused by calciphylaxis in a 70-year-old female with end-stage renal disease whose symptoms resolved with a total parathyroidectomy.

Hypertonicity-induced intracellular pH changes in rat mast cells

In a non-isotonic environment, cells can shrink or swell and return to their normal shape by activating ion transport pathways. Changes in intracellular pH (pHi) after osmotic stress have been identified in several cells. In order to study the mechanisms that regulate cytosolic pH of rat mast cells in a hypertonic medium, we used the pH sensitive dye, BCECF. Under these hypertonic conditions, pHi undergoes an alkalinization following an initial acidification. The alkalinization is mediated by a Na+/H+ exchanger, since it is inhibited by amiloride and lack of extracellular sodium. Under these conditions, the alkalinization is increased with the PKC activators, TPA and OAG, and partially blocked with trifluoperazine, an unspecific protein kinase C (PKC) and Ca2+ calmodulin-dependent protein kinases (Ca2+/CaM K) inhibitor. There is also an anion exchanger, blocked with DIDS but not activated by PKC, that participates in the observed alkalinization. However, Na+/H+ exchanger is the main mechanism involved in the alkalinization of pHi of mast cells in a hyperosmotic environment.

Construction of a whole-genome radiation hybrid panel for high-resolution gene mapping in pigs

We have developed a panel of 152 whole-genome radiation hybrids by fusing irradiated diploid pig lymphocytes or fibroblasts with recipient hamster permanent cells. The number and size of the porcine chromosome fragments retained in each hybrid clone were checked by fluorescence in situ hybridization with a SINE probe or by primed in situ labeling (PRINS) with SINE-specific primers. A strategy based on the interspersed repetitive sequence polymerase chain reaction (IRS-PCR) was developed for selected clones to determine if the large fragments painted by the SINE probe corresponded to one pig chromosome or to different fragments of several chromosomes. This strategy was buttressed by a double PRINS approach using primers specific for alpha-satellite sequences of two different groups of swine chromosomes. Genome retention frequency was estimated for each clone by PCR with 32 markers localized on different porcine chromosomes. Of the 152 hybrids produced, 126 were selected on the basis of cytogenetic content and chromosome retention frequency to construct a radiation hybrid map of swine chromosome 8. Our initial results for this chromosome indicate that the resolution of the radiation hybrid map is 18 times higher than that obtained by linkage analysis.

Sodium, PMA and calcium play an important role on intracellular pH modulation in rat mast cells

In a series of experiments aimed to understand the signaling pathways that regulate intracellular pH (pHi) in rat mast cells, the effect of different intracellular mechanisms on the activity of the Na+/H+ exchanger was studied. After promoting an artificial acidification with sodium propionate we determined the variations on pHi rate recovery. pHi was measured with the dye 2, 7-bis(carboxyethyl)-5(6)-carboxyfluorescein acetoxymethyl ester. We studied the effect that the inhibition of some cellular exchangers with different drugs induced on pHi. When the Na+/H+ exchanger was inhibited in the presence of amiloride, the recovery rate constant was twofold smaller than the control value. After the recovery, the final pH was lower than the initial value when the cells were treated either with amiloride or with 4, 4'-diisothiocyanatostilbene-2,2'-disulfonic acid (an anionic antiport inhibitor). No effect was observed when the Na+/K+-ATPase or the Na+/Ca2+ exchanger were inhibited. The suppression of intracellular and extracellular calcium did not induced any change in pHi. The addition of thapsigargin, an activator of capacitative calcium influx, or the phorbol esther 12-O-tetradecanoylphorbol-13-acetate (PMA), a protein kinase C (PKC) activator, increased the activity of the antiporter. Both effects were abrogated by inhibition of the Na+/K+-ATPase with ouabain. The increase in cAMP levels did not affect the effect of PMA on pHi recovery, but it blocked the effect of thapsigargin. Our results indicate that rat mast cells regulate pHi by the combination of some anionic exchanger and the Na+/H+ antiporter. And also that the modulation of this exchanger is the consequence of the connection between different intracellular mechanisms, Na+/K+-ATPase-PKC-calcium, among which cAMP seems not to have a direct role.