Pediatric reference intervals for endocrine markers in healthy children and adolescents on the Liaison XL (DiaSorin) immunoassay system

OBJECTIVES

Prominent physiological changes occurring throughout childhood and adolescence necessitate the consideration of age and sex in biomarker interpretation. Critical gaps exist in pediatric reference intervals (RIs) for specialized endocrine markers, despite expected influence of growth and development. The current study aimed to establish and/or verify RIs for six specialized endocrine markers on a specialized immunoassay system.

METHODS

Samples were collected from healthy children and adolescents (5 to <19 years) and apparently healthy outpatients (0 to <5 years) as part of the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER). Serum samples were analysed for aldosterone, renin (plasma), thyroglobulin, anti-thyroglobulin, growth hormone, and insulin-like growth factor-1 (IGF-1) on the Liaison XL (DiaSorin) immunoassay platform. RIs (2.5th and 97.5th percentiles) were established for aldosterone, renin, thyroglobulin, anti-thyroglobulin, and growth hormone. Manufacturer-recommended pediatric RIs for IGF-1 were verified.

RESULTS

Age-specific RIs were established for aldosterone, renin, and thyroglobulin, while no age-specific differences were observed for anti-thyroglobulin or growth hormone. IGF-1 was the only endocrine marker studied that demonstrated significant sex-specific differences. Manufacturer-recommended IGF-1 RIs were verified for children aged 6 to <19 years, while those for children aged 0 to <6 years did not verify.

CONCLUSIONS

This study marks the first time that pediatric RIs for aldosterone and renin were established in the CALIPER cohort and highlights the dynamic changes that occur in water and sodium homeostasis during the first years of life. Overall, these data will assist pediatric clinical laboratories in test result interpretation and improve clinical decision-making for patients tested using Liaison immunoassays.

Diabetic mitochondria are resistant to palmitoyl CoA inhibition of respiration, which is detrimental during ischemia

The bioactive lipid intermediate palmitoyl CoA (PCoA) can inhibit mitochondrial ADP/ATP transport, though the physiological relevance of this regulation remains unclear. We questioned whether myocardial ischemia provides a pathological setting in which PCoA regulation of ADP/ATP transport would be beneficial, and secondly, whether the chronically elevated lipid content within the diabetic heart could make mitochondria less sensitive to the effects of PCoA. PCoA acutely decreased ADP‐stimulated state 3 respiration and increased the apparent K_m for ADP twofold. The half maximal inhibitory concentration (IC₅₀) of PCoA in control mitochondria was 22 µM. This inhibitory effect of PCoA on respiration was blunted in diabetic mitochondria, with no significant difference in the K_m for ADP in the presence of PCoA, and an increase in the IC₅₀ to 32 µM PCoA. The competitive inhibition by PCoA was localised to the phosphorylation apparatus, particularly the ADP/ATP carrier (AAC). During ischemia, the AAC imports ATP into the mitochondria, where it is hydrolysed by reversal of the ATP synthase, regenerating the membrane potential. Addition of PCoA dose‐dependently prevented this wasteful ATP hydrolysis for membrane repolarisation during ischemia, however, this beneficial effect was blunted in diabetic mitochondria. Finally, using ³¹P‐magnetic resonance spectroscopy we demonstrated that diabetic hearts lose ATP more rapidly during ischemia, with a threefold higher ATP decay rate compared with control hearts. In conclusion, PCoA plays a role in protecting mitochondrial energetics during ischemia, by preventing wasteful ATP hydrolysis. However, this beneficial effect is blunted in diabetes, contributing to the impaired energy metabolism seen during myocardial ischemia in the diabetic heart.

Tissue plasminogen activator is a ligand of cation-independent mannose 6-phosphate receptor and consists of glycoforms that contain mannose 6-phosphate

Plasmin is the key enzyme in fibrinolysis. Upon interaction with plasminogen activators, the zymogen plasminogen is converted to active plasmin. Some studies indicate plasminogen activation is regulated by cation-independent mannose 6-phosphate receptor (CI-MPR), a protein that facilitates lysosomal enzyme trafficking and insulin-like growth factor 2 downregulation. Plasminogen regulation may be accomplished by CI-MPR binding to plasminogen or urokinase plasminogen activator receptor. We asked whether other members of the plasminogen activation system, such as tissue plasminogen activator (tPA), also interact with CI-MPR. Because tPA is a glycoprotein with three N-linked glycosylation sites, we hypothesized that tPA contains mannose 6-phosphate (M6P) and binds CI-MPR in a M6P-dependent manner. Using surface plasmon resonance, we found that two sources of tPA bound the extracellular region of human and bovine CI-MPR with low-mid nanomolar affinities. Binding was partially inhibited with phosphatase treatment or M6P. Subsequent studies revealed that the five N-terminal domains of CI-MPR were sufficient for tPA binding, and this interaction was also partially mediated by M6P. The three glycosylation sites of tPA were analyzed by mass spectrometry, and glycoforms containing M6P and M6P-N-acetylglucosamine were identified at position N448 of tPA. In summary, we found that tPA contains M6P and is a CI-MPR ligand.

Short-term legacy effects of feedlot manure application on soil mesofauna

Little research exists on short-term legacy effects of feedlot manure application on soil mesofauna. This long-term (since 1998) study was on an irrigated clay loam soil in southern Alberta cropped to barley (Hordeum vulgare L.). We sampled the soil 3-4 yr (2017-2018) into the legacy period following 17 annual manure applications (1998-2014). The selected treatments sampled were stockpiled feedlot manure containing straw bedding applied at 0, 13, 39, and 77 Mg ha^-1 (dry wt.). Intact soil cores were taken at three depth intervals (0-3, 3-6, and 6-9 cm) in the fall over 2 yr to determine the densities of Acari (mites) suborders and Collembola (springtails) families. Significant (P ≤ .05) application rate effects occurred on Oribatida and Astigmata after 3 yr (but not after 4 yr) into the legacy phase, whereas Prostigmata were unaffected. Densities of Astigmata after 3 yr were 3.2- to 4.1-fold greater at the 77 Mg ha^-1 rate compared with three lower rates. Significant application rate effects occurred on Entomobryidae, Isotomidae, and Onychiuridae after 4 yr (but not after 3 yr), with no treatment effects on Neelidae. Densities of mesofauna were generally greater at higher than at lower rates, except for Entomobryidae in 2018, where the reverse trend occurred. Significant application rate effects were attributed to lower soil bulk density and greater volumetric soil water content and soil organic carbon. Therefore, legacy effects of feedlot manure application generally persisted on soil mesofauna 3-4 yr into the legacy phase but depended on mesofauna type, year, and depth.

Low risk of clinically important central nervous system dysraphism in a cohort study of 69 patients with isolated aplasia cutis congenita of the head

BACKGROUND

Aplasia cutis congenita of the head may be associated with underlying fusion defects in the skin, soft tissues, muscle, or bone. The risk of central nervous system dysraphism in patients with aplasia cutis congenita is not known; however, knowledge of underlying structural defects can inform management considerations.

METHODS

This retrospective review investigated the risk of cranial central nervous system dysraphism in children presenting with aplasia cutis congenita of the head, who presented between 1/1/2000 and 6/15/2016. Inclusion criteria were subjects with aplasia cutis congenita of the head who received CT or MR imaging of the head.

RESULTS

We identified a total of 69 subjects with aplasia cutis congenita affecting the head and who received imaging. The most common location of the aplasia cutis congenita lesion was the vertex scalp (49.3%). The hair collar sign was present in 27.5% of patients. Twelve of 69 patients (17.4%) demonstrated abnormalities of the bone, vasculature, or brain on head imaging. Only one patient had a diagnosis of encephalocele that required neurosurgical intervention. There was a statistical association between the hair collar sign and the presence of abnormal imaging findings (P = .029), with a negative predictive value of 89.4%.

CONCLUSIONS

The incidence of central nervous system dysraphism in patients with aplasia cutis congenita of the head appears to be low, and it may not be necessary to image the head of each child presenting with this skin lesion. The hair collar sign may be a marker of underlying defects.

Progress in the understanding and treatment of Fabry disease

BACKGROUND

Fabry disease is caused by α-galactosidase A deficiency. Substrates of this lysosomal enzyme accumulate, resulting in cellular dysfunction. Patients experience neuropathic pain, kidney failure, heart disease, and strokes.

SCOPE OF REVIEW

The clinical picture and molecular features of Fabry disease are described, along with updates on disease mechanisms, animal models, and therapies.

MAJOR CONCLUSIONS

How the accumulation of α-galactosidase A substrates, mainly glycosphingolipids, leads to organ damage is incompletely understood. Enzyme replacement and chaperone therapies are clinically available to patients, while substrate reduction, mRNA-based, and gene therapies are on the horizon. Animal models exist to optimize these therapies and elucidate disease mechanisms for novel treatments.

GENERAL SIGNIFICANCE

Recent newborn screening studies demonstrate that Fabry disease is the most common lysosomal storage disease. As many countries now include Fabry disease in their screening panels, the number of identified patients is expected to increase significantly. Better knowledge of disease pathogenesis is needed to improve treatment options.

α-Galactosidase A-deficient rats accumulate glycosphingolipids and develop cardiorenal phenotypes of Fabry disease

Fabry disease is an X-linked lysosomal storage disease caused by α-galactosidase A (α-Gal A) deficiency. Kidney and heart failure are frequent complications in adulthood and greatly contribute to patient morbidity and mortality. Because α-Gal A-deficient mouse models do not recapitulate cardiorenal findings observed in patients, a nonmouse model may be beneficial to our understanding of disease pathogenesis. In this study, we evaluated disease processes in a recently generated Fabry rat model. We found that male Fabry rats weighed significantly less than wild-type (WT) males, whereas female Fabry rats weighed significantly more than WT females. Whereas no difference in female survival was detected, we observed that male Fabry rats had a decreased lifespan. Skin histology revealed that inflammation and lipoatrophy may be chief disease mediators in patients. With respect to the kidney and heart, we found that both organs accumulate α-Gal A substrates, including the established biomarkers, globotriaosylceramide and globotriaosylsphingosine. Longitudinal serum and urine chemistry panels demonstrated pronounced renal tubule dysfunction, which was confirmed histologically. Mitral valve thickening was observed in Fabry rats using echocardiography. We conclude that Fabry rats recapitulate important kidney and heart phenotypes experienced by patients and can be further used to study disease mechanisms and test therapies.-Miller, J. J., Aoki, K., Mascari, C. A., Beltrame, A. K., Sokumbi, O., North, P. E., Tiemeyer, M., Kriegel, A. J., Dahms, N. M., α-Galactosidase A-deficient rats accumulate glycosphingolipids and develop cardiorenal phenotypes of Fabry disease.

Neuropathic pain in a Fabry disease rat model

Fabry disease, the most common lysosomal storage disease, affects multiple organs and results in a shortened life span. This disease is caused by a deficiency of the lysosomal enzyme α-galactosidase A, which leads to glycosphingolipid accumulation in many cell types. Neuropathic pain is an early and severely debilitating symptom in patients with Fabry disease, but the cellular and molecular mechanisms that cause the pain are unknown. We generated a rat model of Fabry disease, the first nonmouse model to our knowledge. Fabry rats had substantial serum and tissue accumulation of α-galactosyl glycosphingolipids and had pronounced mechanical pain behavior. Additionally, Fabry rat dorsal root ganglia displayed global N-glycan alterations, sensory neurons were laden with inclusions, and sensory neuron somata exhibited prominent sensitization to mechanical force. We found that the cation channel transient receptor potential ankyrin 1 (TRPA1) is sensitized in Fabry rat sensory neurons and that TRPA1 antagonism reversed the behavioral mechanical sensitization. This study points toward TRPA1 as a potentially novel target to treat the pain experienced by patients with Fabry disease.

Salivary cytokine response in the aftermath of stress: An emotion regulation perspective

Elevated inflammation in the context of stress has been implicated in mental and physical health. Approaching this from an emotion regulation perspective, we tested whether the salivary cytokine response to stress is dampened by using distraction to minimize opportunity for poststressor rumination. Healthy young adults were randomized to an acute stressor: modified Trier Social Stress Test (TSST, Study 1) or angry memory retrieval (Study 2). Within each study, participants were randomized to poststressor condition-rest or distraction-at a 3:1 ratio. Saliva, collected before and 40 min after the end of each stressor, was assayed for proinflammatory cytokines (PICs): interleukin-1β (IL-1β), TNF-α, and IL-6. Both stressors increased all PICs, and both provoked negative emotion. At 40 min post-TSST, salivary PIC increases did not differ between distraction and rest, but correlated positively with emotional reactivity to stress. At 40 min after memory retrieval, IL-1β increases and intrusive rumination were lower during distraction than rest, but did not correlate with emotional reactivity. Trait rumination and interference control mechanisms, also measured, played little role in PIC increases. Overall, after some stressors, some salivary cytokine responses are lower during distraction than rest. The roles of specific emotions, emotional intensity, and poststressor timing of saliva collection in this finding require clarification. Furthermore, the possibility of two affective paths to inflammation in the context of stress-one sensitive to opportunities for early occurring emotion regulation (as reflected in emotional reactivity), and one sensitive to late-occurring emotion regulation (as reflected in distraction after stress)-deserves attention. (PsycINFO Database Record

Sheltering for Safety in Community Women With Divorce Histories

This cross-sectional study compared the prevalence of formal and informal sheltering (i.e., staying in an agency shelter, or with friends/family, respectively) and evaluated associations with abuse severity. Community women ( N = 197) with divorce histories reported on lifetime intimate partner abuse, including sheltering for safety. Prevalence of informal sheltering (43%) exceeded that of formal sheltering (11%). Rates/levels of coercive control, severe violence, injury, and police involvement were comparable for women who sheltered formally or informally, and exceeded those of women who never sheltered. Sheltering histories can be identified in community samples of women with divorce histories. Informal sheltering is prevalent, and comparable to formal sheltering in terms of correlations with abuse severity.

Acute stress induces increases in salivary IL-10 levels

The purpose of this study was to investigate the stress-reactivity of the anti-inflammatory cytokine, IL-10, in saliva and to determine how salivary IL-10 levels change in relation to those of IL-1β, a pro-inflammatory cytokine, following stress. Healthy young adults were randomly assigned to retrieve a negative emotional memory (n = 46) or complete a modified version of the Trier Social Stress Test (n = 45). Saliva samples were taken 10 min before (baseline) and 50 min after (post-stressor) onset of a 10-min stressor, and were assayed using a high sensitivity multiplex assay for cytokines. Measurable IL-10 levels (above the minimum detectable concentration) were found in 96% of the baseline samples, and 98% of the post-stressor samples. Flow rate-adjusted salivary IL-10 levels as well as IL-1β/IL-10 ratios showed moderate but statistically significant increases in response to stress. Measurement of salivary IL-10 and pro-/anti-inflammatory cytokine ratios may be useful, noninvasive tools, in stress research.

Influence of Organic Amendment and Compaction on Nutrient Dynamics in a Saturated Saline-Sodic Soil from the Riparian Zone

Cattle grazing in wet riparian pastures may influence nutrient dynamics due to nutrient deposition in feces and urine, soil compaction, and vegetation loss. We conducted a lab incubation study with a saline-sodic riparian soil to study nutrient (N, P, S, Fe, Mn, Cu, and Zn) dynamics in soil pore water using Plant Root Simulator (PRS) probes and release of nutrients into the overlying ponded water during flooding. The treatment factors were organic amendment (manure, roots, and unamended control), compaction (compacted, uncompacted), and burial time (3, 7, and 14 d). Amendment treatment had the greatest impact on nutrient dynamics, followed by burial time, whereas compaction had little impact. The findings generally supported our hypothesis that organic amendments should first increase nitrate loss, then increase Mn mobility, then Fe mobility and associated release of P, and finally increase sulfate loss. Declines in nitrate due to amendment addition were small because nitrate was at low levels in all treatments due to high denitrification potential instead of being released to soil pore water or overlying water. Addition of organic amendment strongly increased Mn and Fe concentrations in overlying water and of adsorbed Fe on PRS probes but only increased Mn on PRS probes on Day 3 due to subsequent displacement from ion exchange membranes. Transport of P to overlying water was increased by organic amendment addition but less so for manure than roots despite higher P on PRS probes. The findings showed that saline-sodic soils in riparian zones are generally a nutrient source for P and are a nutrient sink for N as measured using PRS probes after 3 to 7 d of flooding.

Subjective Sleep Quality in Women With Divorce Histories: The Role of Intimate Partner Victimization

A marital status of divorced or separated, as opposed to married, predicts increased risk of health problems, but not for all persons. Focusing on one established health risk that has been linked with divorce--poor subjective sleep quality--the present cross-sectional study examined whether a history of physical intimate partner victimization (IPV) helps identify divorced women at potentially greater risk of health problems. Community midlife women with divorce histories, all of whom were free of current IPV, reported on their past month sleep quality and lifetime IPV. The predicted odds of poor sleep quality were significantly greater for women with, versus without, IPV histories. This held after adjusting for socioemotional, medical, or sociodemographic risks. A dose-response relationship between IPV chronicity and poor quality sleep was observed. IPV history may help identify divorced women at increased risk of poor quality sleep and, more broadly, poor health.

Tryptophan 415 Is Critical for the Cholesterol Transport Functions of Scavenger Receptor BI

High density lipoproteins (HDL) are anti-atherogenic particles, primarily due to their role in the reverse cholesterol transport pathway whereby HDL delivers cholesteryl esters (CE) to the liver for excretion upon interaction with its receptor, scavenger receptor BI (SR-BI). We designed experiments to test the hypothesis that one or more of the eight highly conserved tryptophan (Trp; W) residues in SR-BI are critical for mediating function. We created a series of Trp-to-phenylalanine (Phe, F) mutant receptors, as well as Trp-less SR-BI (ΔW-SR-BI), and assessed their ability to mediate cholesterol transport. Wild-type (WT) or mutant SR-BI receptors were transiently expressed in COS-7 cells, and cell surface expression was confirmed. Next, we showed that Trp-less- and W415F-SR-BI had significantly decreased abilities to bind HDL and promote selective uptake of HDL-CE, albeit with higher selective uptake efficiency as compared to WT-SR-BI. Interestingly, only Trp-less-, but not W415F-SR-BI, showed an impaired ability to mediate efflux of free cholesterol (FC). Furthermore, both W415F- and Trp-less-SR-BI were unable to reorganize plasma membrane pools of FC based on lack of sensitivity to exogenous cholesterol oxidase. Restoration of Trp 415 into the Trp-less-SR-BI background was unable to rescue Trp-less-SR-BI's impaired functions, suggesting that Trp 415 is critical, but not sufficient for full receptor function. Furthermore, with the exception of Trp 262, restoration of individual extracellular Trp residues, in combination with Trp 415, into the Trp-less-SR-BI background partially rescued SR-BI function, indicating that Trp 415 must be present in combination with other Trp residues for proper cholesterol transport functions.

Abstract 522: Scavenger Receptor-BI’s Cholesterol Transport Functions are Dependent on its Extracellular Tryptophan Residues

High density lipoprotein (HDL) functions as an anti-atherogenic particle, primarily due to its role in reverse cholesterol transport whereby HDL delivers cholesterol to the liver for excretion upon interaction with its receptor, scavenger receptor BI (SR-BI). The extracellular domain of SR-BI is required for its cholesterol transport functions, yet our understanding of the molecular and structural features of this domain remains limited. We designed experiments to test the hypothesis that one or more of the six highly conserved extracellular tryptophan (Trp; W) residues are critical for mediating receptor function. Towards this end, we created a series of Trp-to-Phe mutant receptors of SR-BI, as well as Trp-free SR-BI and assessed the ability of these mutant receptors to mediate cholesterol transport. Wild-type (WT) or mutant SR-BI receptors were transiently expressed in COS7 cells and proper cell surface expression was confirmed by immunoblotting, confocal microscopy and flow cytometry. Next, we showed that Trp-free- and W415F-SR-BI had a significantly decreased ability to bind HDL (12.7% and 31.3% of WT levels, respectively) and promote selective uptake of HDL-cholesteryl esters (35.2% and 70.1% of WT levels, respectively). Interestingly, only Trp-free-, but not W415F-SR-BI, showed an impaired ability to mediate efflux of free cholesterol (FC) (90.8% decrease vs. WT). Furthermore, both W415F- and Trp-free SR-BI were unable to reorganize plasma membrane pools of FC based on lack of sensitivity of FC to exogenous cholesterol oxidase. We then designed an additional set of mutant SR-BI receptors to determine whether restoration of Trp415 alone (or in combination with other Trp residues) could rescue SR-BI function. Restoration of Trp415 into Trp-free-SR-BI partially rescued cholesterol transport functions. Addition of any of the other 5 extracellular Trp residues was also not sufficient to restore WT cholesterol transport function in combination with Trp415. In summary, loss of all Trp residues in SR-BI impairs its cholesterol transport functions, mostly due to the loss of Trp415. Homology modeling of SR-BI based on the crystal structure of LIMP-2, a member of the same protein family, may help identify the importance of this residue in future studies.

Utilization of assay performance characteristics to estimate hemoglobin A1c result reliability

BACKGROUND

Allowable total error (TE(a)) goals for hemoglobin (Hb) A(1c) require minimal assay imprecision and bias and implementation of a robust QC monitoring program. Here, we compare the combined influence on the risk of reporting unreliable results of TE(a) goals, a routine QC practice, and assay performance characteristics of 6 Hb A(1c) instruments across 4 academic medical centers.

METHODS

The CLSI protocols EP-5 and EP-9 were applied to investigate Hb A(1c) result imprecision and bias on the Variant II Turbo and Variant II (Bio-Rad), G8 (Tosoh), Capillarys 2 Flex Piercing (Sebia), COBAS Integra 800 (Roche), and DCA Vantage (Siemens). Patient-weighted σ values and the risk of reporting unreliable Hb A(1c) results were determined for each assay at TE(a) specifications of 5%, 6%, and 7%.

RESULTS

A large range of patient-weighted σ values spanning 0.5 orders of magnitude at a 6% TE(a) was observed. Although imprecision for all instruments was <3%, bias impacted the majority of the σ changes observed. Estimates for reporting unreliable results varied almost 500-fold based on analytical performance alone.

CONCLUSIONS

Considerable differences in the probability of reporting unreliable Hb A(1c) results between different NGSP (formerly the National Glycohemoglobin Standardization Program)-certified platforms were observed. At a 6% TE(a), our study indicates all but the Capillarys 2 Flex Piercing requires that the maximum affordable QC be run. Risk estimates for individual laboratories' Hb A(1c) methods can be used to assess QC practices and residual risk of an unreliable Hb A(1c) result.

Interleukin-6 and soluble interleukin-6 receptor levels in posttraumatic stress disorder: associations with lifetime diagnostic status and psychological context

This study correlated lifetime PTSD diagnostic status with interleukin-6 (IL-6) and soluble IL-6 receptor (sIL-6R) levels, and tested whether these correlations are sensitive to psychological context. Midlife women attended two research visits where blood was drawn (beginning of visits) and saliva and oral mucosal transudate were collected (beginning and end of visits) to measure IL-6 and sIL-6R. Women were classified as PTSD-/- (past and current symptoms below subsyndromal levels), PTSD+/- (past symptoms at or above subsyndromal levels), or PTSD+/+ (past and current symptoms at or above subsyndromal levels). PTSD+/+ women, compared to the other women, showed more negative emotion at the beginning of the visits, higher salivary IL-6 levels at the beginning versus end of visits, and positive correlations between negative emotion, salivary IL-6, and plasma sIL-6R. Their plasma sIL-6R levels exceeded those of the PTSD+/- women. Overall, IL-6 sensitivity to anticipation and to negative emotions, and higher sIL-6R levels, differentiated persistent versus remitted PTSD.

Intimate partner stalking victimization and posttraumatic stress symptoms in post-abuse women

This study aimed to further understanding of intimate partner stalking victimization in post-abuse women, with particular attention to the definition of stalking (with or without fear and threat) most predictive of posttraumatic stress (PTS) symptoms. In community midlife women with histories of divorce (N = 192), a history of stalking victimization accompanied by fear and threat was positively correlated with PTS symptom severity, after accounting for other partner abuse. The presence, compared with absence, of fear-and-threat stalking history doubled the odds of symptomatic levels of hyperarousal. Greater physical assault and injury chronicity differentiated fear-and-threat stalked women from other stalked women. Stalking contributed to a fuller understanding of PTS symptoms in women, showing particular relevance for hyperarousal.

Transport of Residual Nitrogen and Carbon through Intact Soil Cores Amended with Stockpiled Feedlot Manure with Wood-Chip or Straw Bedding

The environmental impact of using wood chips instead of straw bedding with feedlot manure on transport and leaching potential from feedlot manure is unknown. Our main objective was to determine if transport of total N, total organic N, NO-N, and nonpurgeable organic C (NPOC) to subsurface soil was lower for soils amended with feedlot manure if combined with wood chips compared with straw. A secondary objective was to compare transport of N and NPOC with organic amendments versus inorganic fertilizer. Stockpiled feedlot manure (SM) with wood chip (SM-WD) or barley straw (SM-ST) bedding at 39 Mg (dry wt.) ha, and inorganic fertilizer (IN) at 100 kg N ha, was applied annually for 13 yr to a clay loam soil in a replicated field experiment in southern Alberta, Canada. Intact soil cores were taken in fall 2011 (0-30 cm depth) from the three treatments, and the residual N and NPOC were eluted from the soil cores. Total N, total organic N, and NPOC were determined on filtered (1.0 μm) effluent samples that are primarily dissolved fraction but may contain some small particulate N and C. Peak concentrations, flow-weighted mean concentrations, and mass loss of total N, total organic N, NO-N, and NPOC were significantly ( ≤ 0.05) lower by 35 to 86% for SM-WD compared with SM-ST. Mean recoveries were also significantly lower for SM-WD than SM-ST by 0.07 to 8% (absolute difference). The transport behavior was similar for SM-WD and IN treatment, but solute transport was greater for SM-ST than for IN. Application of stockpiled feedlot manure with wood chips instead of straw bedding may be a beneficial management practice to reduce transport and leaching potential of N fractions and NPOC.

Calcium isolation from large-volume human urine samples for 41Ca analysis by accelerator mass spectrometry

Calcium oxalate precipitation is the first step in preparation of biological samples for (41)Ca analysis by accelerator mass spectrometry. A simplified protocol for large-volume human urine samples was characterized, with statistically significant increases in ion current and decreases in interference. This large-volume assay minimizes cost and effort and maximizes time after (41)Ca administration during which human samples, collected over a lifetime, provide (41)Ca:Ca ratios that are significantly above background.

Cadmium intake and systemic exposure in postmenopausal women and age-matched men who smoke cigarettes

Mean blood cadmium (B-Cd) concentrations are two- to threefold higher in smokers than in nonsmokers. The basis for this phenomenon is not well understood. We conducted a detailed, multifaceted study of cadmium exposure in smokers. Groups were older smokers (62±4 years, n = 25, 20% male) and nonsmokers (62±3 years, n = 16, 31% male). Each subject's cigarettes were machine smoked, generating individually paired measures of inhaled cadmium (I-Cd) versus B-Cd; I-Cd and B-Cd were each evaluated three times, at monthly intervals. Urine cadmium (U-Cd) was analyzed for comparison. In four smokers, a duplicate-diet study was conducted, along with a kinetic study of plasma cadmium versus B-Cd. Female smokers had a mean B-Cd of 1.21ng Cd/ml, with a nearly 10-fold range (0.29-2.74ng Cd/ml); nonsmokers had a lower mean B-Cd, 0.35ng Cd/ml (p < 0.05), and narrower range (0.20-0.61ng Cd/ml). Means and ranges for males were similar. Estimates of cadmium amounts inhaled daily for our subjects smoking ≥ 20 cigarettes/day were far less than the 15 µg Cd reported to be ingested daily via diet. This I-Cd amount was too low to alone explain the 3.5-fold elevation of B-Cd in our smokers, even assuming greater cadmium absorption via lungs than gastrointestinal tract; cadmium accumulated in smokers' lungs may provide the added cadmium. Finally, B-Cd appeared to be linearly related to I-Cd values in 75% of smokers, whereas 25% had far higher B-Cd, implying a possible heterogeneity among smokers regarding circulating cadmium concentrations and potentially cadmium toxicity.

A mathematical model of adult subventricular neurogenesis

Neurogenesis has been the subject of active research in recent years and many authors have explored the phenomenology of the process, its regulation and its purported purpose. Recent developments in bioluminescent imaging (BLI) allow direct in vivo imaging of neurogenesis, and in order to interpret the experimental results, mathematical models are necessary. This study proposes such a mathematical model that describes adult mammalian neurogenesis occurring in the subventricular zone and the subsequent migration of cells through the rostral migratory stream to the olfactory bulb (OB). This model assumes that a single chemoattractant is responsible for cell migration, secreted both by the OB and in an endocrine fashion by the cells involved in neurogenesis. The solutions to the system of partial differential equations are compared with the physiological rodent process, as previously documented in the literature and quantified through the use of BLI, and a parameter space is described, the corresponding solution to which matches that of the rodent model. A sensitivity analysis shows that this parameter space is stable to perturbation and furthermore that the system as a whole is sloppy. A large number of parameter sets are stochastically generated, and it is found that parameter spaces corresponding to physiologically plausible solutions generally obey constraints similar to the conditions reported in vivo. This further corroborates the model and its underlying assumptions based on the current understanding of the investigated phenomenon. Concomitantly, this leaves room for further quantitative predictions pertinent to the design of future proposed experiments.

Markers of inflammation in midlife women with intimate partner violence histories

BACKGROUND

Lifetime occurrence of intimate partner violence (IPV) in women has been associated with increased prevalence of aging-related chronic diseases, including those with a pathophysiology involving inflammation. To begin to identify potential biologic mediators of this relationship, this cross-sectional study examined associations between past IPV and circulating levels of C-reactive protein (CRP) and interleukin-6 (IL-6)-measures linked with emergence of aging-related diseases-along with in vitro IL-6 production by peripheral blood mononuclear cells (PBMC) stimulated with either phytohemagglutinin A (PHA) or lipopolysaccharide (LPS).

METHODS

Apparently healthy, midlife women with divorce histories were recruited from the community. Histories of intimate partner psychological aggression, physical assault, sexual coercion, and stalking were assessed, along with current depression, posttraumatic stress symptoms, and health-related characteristics. At two visits, blood was drawn for assessment of biologic measures; measures were averaged across visits.

RESULTS

In this sample (n=68), a history of being stalked was significantly positively correlated with CRP levels; in a multiple regression analysis that included body mass index (BMI) and current symptoms, this association was attenuated by adjusting for BMI. Physical assault history was significantly negatively correlated with PHA-stimulated IL-6 production. This was most apparent for severe assault and was not accounted for by BMI or symptoms.

CONCLUSIONS

IPV histories remitted for an average of 10 years were associated with biologic mediators of inflammation. The profile was not uniformly proinflammatory, suggesting that in situations of traumatic or chronic stress, different aspects of the inflammatory response are differentially regulated and subjected to diverse compensatory mechanisms.

Correlations among inflammatory markers in plasma, saliva and oral mucosal transudate in post-menopausal women with past intimate partner violence

The relationship between psychosocial factors and an increased risk for disease has been related to a heightened pro-inflammatory status reflected in increased circulating levels of pro-inflammatory cytokines and/or C-reactive protein (CRP). Routinely, epidemiological studies rely on measurements of inflammatory markers in serum or plasma, but the use of biological fluids such as saliva or oral mucosal transudate (OMT) may offer potential advantages. This study investigated correlations among plasma CRP and levels of IL-6 and soluble IL-6 receptor (sIL-6R) in plasma, saliva and OMT in a population of middle aged women with histories of past intimate partner violence (IPV). A total of 67 women without existing chronic diseases participated in the study, which included two visits each in which psychological tests were administered, and blood, saliva and OMT samples were collected. Although significantly higher plasma CRP levels were found in past IPV sufferers compared to controls, there were no significant differences in IL-6 or sIL-6R levels in plasma, saliva or OMT between the two groups. There were only relatively modest correlations between IL-6 levels in plasma and those in saliva or OMT and between plasma IL-6 and CRP levels. A significant correlation between IL-6 and sIL-6R levels in both saliva and OMT, but not in plasma, was also detected. No significant correlations were found between levels of IL-6 in saliva or OMT and periodontal health measures. Results indicate that IL-6 and sIL-6R levels in saliva or OMT do not closely reflect those in plasma, and therefore are not a good surrogate for systemic levels.

Influence of streambank fencing on the environmental quality of cattle-excluded pastures

Limited information exists on the effect of streambank fencing on riparian zone pastures. The objective of this study was to test the hypothesis that 4 to 6 yr of streambank fencing would improve the environmental quality of the cattle-excluded pasture compared with the grazed pasture and cause the fenced pasture to act as a buffer or filter strip. Rangeland health, vegetative and soil properties, and rainfall simulation runoff were measured in the cattle-excluded and adjacent grazed native pastures along the fenced reach of the Lower Little Bow River in southern Alberta, Canada, for 3 yr (2005-2007). Rangeland health was improved (health score increase from 55 to 72%); vegetation cover (13-21%) and standing litter (38-742%) were increased; and bare soil (72-93%) and soil bulk density (6-8%) were decreased under cattle exclusion, indicating an improvement in environmental quality from streambank fencing. In contrast, other vegetation (total and live basal area, fallen litter) and soil properties (soil water and soil C, N, and P) were not improved by cattle exclusion. Cattle exclusion significantly (P </= 0.10) reduced surface runoff depth of water (21-32%) and mass loads of total N fractions (21-52%) in 2 of 3 yr compared with the grazed pasture, suggesting that this fenced pasture may act as a buffer for certain runoff variables. In contrast, other runoff variables (turbidity, electrical conductivity, pH, concentrations and loads of total suspended solids, and certain N and P fractions) in the cattle-excluded pasture were generally not improved by streambank fencing. Overall, streambank fencing improved the quality of certain environmental variables within the cattle-excluded pasture.

Fibrinogen is a co-antioxidant that supplements the vitamin E analog trolox in a model system

OBJECTIVE

It appears that the atherosclerotic plaque is a prooxidant environment where some molecules that are normally antioxidants, including vitamins C and E, may act as prooxidants that contribute to atherosclerosis by oxidizing LDL. Some molecules can act as co-antioxidants to eliminate this prooxidant effect by recycling or other mechanisms of supplementation. Fibrinogen and other acute phase proteins found in the plaque are antioxidants. We hypothesized that fibrinogen can act as a co-antioxidant to supplement vitamin E thereby eliminating its oxidative effect under prooxidant conditions. We tested a model system for this hypothesis using the vitamin E analogue Trolox in a cell free system.

METHODS

LDL was oxidized using 5 umol/l copper. Antioxidant conditions were achieved by adding the antioxidants immediately with LDL, while prooxidant conditions were created by adding antioxidants after a 40 min delay. Oxidation was monitored as the lag phase at 234 nm.

RESULTS

Under antioxidant conditions, the protective effect of fibrinogen and Trolox combined together were about equal to the sum of the anitioxidant effects of each alone (additive), while under prooxidant conditions the combined protection was 54-200% greater (synergistic). These effects were different than those of vitamin C with Trolox in that under antioxidant conditions fibrinogen and Trolox were additive while vitamin C and Trolox showed strong synergistic effects, and in that unlike vitamin C and Trolox fibrinogen showed no prooxidant tendencies under prooxidant reaction conditions.

CONCLUSIONS

The data indicated that fibrinogen did act as a co-antioxidant to supplement Trolox and eliminate its prooxidant effect, most probably, by directly quenching the phenoxyl radical, because unlike vitamin C, fibrinogen did not appear to recycle vitamin E. But fibrinogen may act as a universal antioxidant, since unlike Trolox and vitamin C, it showed little tendency toward becoming a prooxidant.

Influence of obesity on vitamin D-binding protein and 25-hydroxy vitamin D levels in African American and white women

25-Hydroxy vitamin D (25OHD) is lipophilic and highly bound to vitamin D-binding protein (VDBP) in plasma. In the present study, we examined VDBP and 25OHD levels by race and body mass index (BMI) in young adult women to determine whether circulating VDBP plays a role in the low levels of 25OHD with obesity and among African Americans. In agreement with previous studies, mean 25OHD levels were lower in African American women than in whites (P < .01). In a hierarchical multiple regression model, BMI was associated with 25OHD after adjustment for age in white women (P = .02, R(2) = .10) but not in African American women. The VDBP levels, by contrast, were similar in African Americans and whites, and were unrelated to BMI in either racial group. Furthermore, VDBP was unrelated to the plasma level of 25OHD. These data confirm an interaction between race and obesity in vitamin D metabolism, and imply that the carrier protein is not an important determinant of circulating 25OHD in women, nor is it affected by race or adiposity.

Computed tomographic emphysema distribution: relationship to clinical features in a cohort of smokers

Computed tomography (CT) scanning allows precise assessment of both the extent and distribution of emphysema. There has been little work on the relationship between the distribution of emphysema and clinical features of the disease. The current study investigated the association between clinical features and distribution of emphysema. A total of 129 patients with smoking-related chronic obstructive pulmonary disease underwent CT assessment of the extent and distribution of their emphysema (core/rind and upper/lower zone predominance). Emphysema was found predominantly in the upper/core zone and this distribution was related to the extent of disease. Core predominance was associated with lower forced expiratory volume in one second (FEV(1)), FEV(1)/forced vital capacity ratio and body mass index (BMI); and with higher BODE (BMI, airflow obstruction, dyspnoea and exercise capacity) index and Medical Research Council dyspnoea score. Upper-zone predominance was associated with female sex and an increased total St George's Respiratory Questionnaire score. Using multiple linear regression age, sex and whole lung emphysema severity were independently associated with core/rind distribution, while sex and whole lung emphysema severity were independently related to upper/lower distribution. Distribution of emphysema related best to clinical features when divided into core/rind predominance. However, the effects were not independent of the extent of emphysema. Increased age and female sex were related to disease distribution independent of emphysema severity. These findings may be related to differences in development of emphysema.

Type I epithelial cells are the main target of whole-body hypoxic preconditioning in the lung

Whole-body hypoxic preconditioning (WHPC) prolongs survival of mice exposed to severe hypoxia by attenuating pulmonary edema and preserving gas exchange. However, the cellular and molecular mechanism(s) of this protection remains unclear. The objective of this study was to identify the cellular target(s) of WHPC in the lung. Conscious mice were exposed to hypoxia (7% O(2)) for 6 hours with or without pretreatment of WHPC ([8% O(2)] x 10 min/[21% O(2)] x 10 min; 6 cycles). Hypoxia caused severe lung injury, as shown by the development of high-permeability-type pulmonary edema and the release of lactate dehydrogenase and creatine kinase into the airspace and the circulation. All these signs of hypoxic lung injury were significantly attenuated by WHPC. Hypoxia also caused a remarkable release of type I cell markers (caveolin-2 and receptor for advanced glycation end products) in lung lavage that was almost completely abolished by WHPC. Conversely, hypoxia-induced release of type II cell markers (surfactant-associated proteins A and D) was only marginal, and was unaffected by WHPC. Electron microscopic analysis demonstrated considerable hypoxic damage in alveolar type I cells and vascular endothelial cells. Notably, WHPC completely eliminated hypoxic damage in the former and alleviated it in the latter. Type II cells appeared normal. Furthermore, WHPC up-regulated protein expression of cytoprotective genes in the lung, such as heat shock proteins and manganese superoxide dismutase. Thus, WHPC attenuates hypoxic lung injury through protection of cells constituting the respiratory membrane, especially hypoxia-vulnerable type I epithelial cells. This beneficial effect may involve up-regulation of cytoprotective genes.

Metabolic rate and vascular function are reduced in women with a family history of type 2 diabetes mellitus

Metabolic and vascular abnormalities have been found in individuals with type 2 diabetes mellitus (T2D). Family history is often associated with increased risk of the development of T2D. We sought to determine if young, sedentary, insulin-sensitive individuals with a family history of T2D (FH+) have a reduced resting energy expenditure (REE) and vascular endothelial function compared with individuals who have no family history of T2D (FH-). The REE was determined in 18 FH+ individuals and 15 FH- individuals using indirect open-circuit calorimetry. Vascular endothelial function was measured via flow-mediated dilation (FMD) of the brachial artery. C-reactive protein and interleukin-6 were also measured to look at vascular inflammation. Body composition was measured via bioelectrical impedance analysis to determine fat-free mass and fat mass for each individual. Insulin resistance was calculated using the homeostasis model assessment equation and fasting insulin and glucose concentrations. Subjects (n = 42) were approximately 26 years old and had normal fasting serum insulin or glucose concentrations. The REE normalized for body weight (kilocalories per day per kilogram body weight) was significantly reduced in the FH+ women compared with FH- women (P < .001) but not in the men. The FMD was significantly reduced (34.3%) in the FH+ group compared with the FH- in women (P = .002). However, no between-group difference in FMD was present in male subjects (P = .376). Young, healthy, insulin-sensitive women with a family history of T2D have reduced whole-body metabolic rate and vascular endothelial function compared with those with no family history of disease. These differences in whole-body metabolic rate and vascular endothelial function were not present in male subjects.

Ischemia modified albumin, a marker of acute ischemic events: a pilot study

Ischemia modified albumin (IMA) is a relatively new marker for evaluating patients with cardiac ischemia. Data are emerging on its potential role in non-cardiac ischemic events. In this pilot study we evaluated the utility of IMA in diagnosing acute coronary syndromes (ACS), assessed its role in the diagnosis of non-cardiac ischemia, and correlated its efficacy with troponin T (TnT). Serum levels of IMA were measured in 89 sequential patients who presented to the emergency room with chest pain for which serum TnT was ordered. The patients were classified into 4 groups based on their IMA and TnT results and discharge diagnoses. The data were analyzed with Fischer's exact test. Multivariate logistic regression analysis relating acute coronary syndrome (ACS) to the combination of TnT and IMA was also performed. The results showed that IMA was a useful marker for the diagnosis of ACS. There was a significant relationship between TnT and IMA (p = 0.032), suggesting that both these biomarkers added significant information about the presence of ACS (p = 0.028) and may be useful for triage of patients who present to the emergency room with chest pain. Serum IMA was also increased in a small proportion of patients with symptoms of stroke, suggesting that it should be considered a marker of acute ischemic events and not specific for cardiac ischemia.

Thyroxine ameliorates oxidative stress by inducing lipid compositional changes in human lens epithelial cells

PURPOSE

Lipid saturation and sphingolipids make model membranes less susceptible to oxidation. A human lens epithelial cell line, HLE B-3, was treated with thyroxine to determine whether this treatment increases lipid saturation and membrane sphingolipids, as it does in other tissues, and if so, to see whether the treatment ameliorates the affects of lipid oxidation.

METHODS

One group of HLE B-3 cells was treated with thyroxine, and another group was not. Cells were then grown in a normoxic (20% O(2)), or hyperoxic (80% O(2)), atmosphere. Phospholipid composition was determined by matrix-assisted laser desorption ionization time-of-flight mass spectrometry and (31)P nuclear magnetic resonance spectroscopy. Cell viability was determined with a trypan blue dye assay. A chromogenic reagent was used to measure the secondary products of lipid oxidation.

RESULTS

After 6 days of growth in a hyperoxic atmosphere, the thyroxine-treated cells were 20 times more viable than were the untreated cells. As a result of thyroxine treatment, the phosphatidylcholine (PC)-to-sphingolipid molar ratio decreased significantly (by 52%), and the PCs were eight times more unsaturated than were the sphingomyelins. The decrease in the amount of PCs coupled with a 33% decrease in the average unsaturation of the sphingolipids resulted in a phospholipid membrane with fewer double bonds. Products of lipid oxidation were three times higher in untreated cells after growth in a hyperoxic atmosphere than in untreated cells grown in a normoxic atmosphere. Thyroxine treatment reduced the amount of lipid oxidation products by approximately 60% compared with that in untreated cells. A 100% increase in cardiolipin with thyroxine treatment may contribute to a decrease in reactive oxygen species generated by the mitochondria. The total antioxidant power was not affected by thyroxine. Therefore, thyroxine-induced fluctuations in antioxidant levels are unlikely to influence increased cell viability and a concomitant decrease in the amount of lipid oxidation products in thyroxine-treated cells.

CONCLUSIONS

The results support the idea that membranes containing more cardiolipin and more sphingolipids and having higher levels of saturation are more resistant to oxidation and protect cells from oxidative stress. Development of a therapy to increase sphingomyelins and lipid saturation in the lens may delay the onset of cataract.

Clone-specific anti-CD45 blocking factor in patient plasma

We observed inhibition of anti-CD45, but not anti-CD3, -CD4, or -CD8 staining in the whole blood of an individual clinical specimen. Subsequent experiments demonstrated the presence of a plasma factor, which likewise blocked CD45 staining of third party lymphocytes. The blocking activity was anti-CD45 clone (2D1) specific. Experiments utilizing immunoabsorption, immunofluorescence, and commercial blocking reagents failed to provide evidence for identifying blocking factor as heterophilic antibody. Biochemical identification of blocking factor was not accomplished.

A positive pregnancy test in the post-menopausal psychiatric patient-: what to think?

Assaying the serum β-hCG is the pregnancy test employed to verify an early pregnancy. It becomes positive at approximately 10 days after conception. Knowing whether or not a patient is pregnant is critical to avoid exposure to medications or procedures that might be teratogenic. Psychiatric patients are sometimes suboptimal historians, so such β-hCG testing is especially worthwhile to assure recognition of an active, early-stage pregnancy.In normal pregnancy, the serum β-hCG level doubles every 2 to 3 days for the first eight weeks or so. Minimally raised, non-escalating β-hCG concentrations are documented in non-pregnant, post-menopausal women. Repeating the assay in 12 to 36 hours would help to clarify a non-pregnant status, because there is no rapid escalation in the post-menopausal β-hCG level. In normal pregnancy, expect at least a 30-percent increase in β-hCG concentration over this time period. Ectopic pregnancies, some neoplasia, and other conditions may also elevate the β-hCG, but again, not in the escalating patterns of normal pregnancy. In those cases, further workup may be needed. The very rapid, accurate detection of an early pregnancy is an important part of safe medical practice and better patient care.

Positive pregnancy tests in a nongravid, premenopausal woman due to hCG beta-chain production by multiple myeloma

Positive pregnancy test results occurred in a nongravid, premenopausal woman while she was receiving chemotherapy for multiple myeloma. We tested 2 hypotheses to account for this finding: (1) Heterophil antibodies caused positive interference in the immunoassays. (2) Genuine human chorionic gonadotropin (hCG) originated from a nonsyncytiotrophoblastic source. Paraprotein was eliminated as a source of positive interference because 3 different instruments with unique capture and signal antibodies gave similar results (83, 90, and 97 mIU/mL [83, 90, and 97 IU/L]). Human antimouse antibodies (HAMAs) were unlikely to cause positive interference because immunoreactivity was maintained after serum was treated to neutralize heterophil antibodies. Immunoassays performed after gel filtration of serum indicated that immunoreactivity was due to genuine hCG. The high-molecular-weight fraction (heterophil antibody) had 6 mIU/mL (6 IU/L) of hCG. The low-molecular-weight fraction (hCG) had 86 mIU/mL (86 IU/L) of hCG. Immunohistochemical stains revealed that myeloma cells expressed immunoreactive hCG. Hence, multiple myeloma caused positive pregnancy test results in a nongravid woman.

Vitamins in human arteriosclerosis with emphasis on vitamin C and vitamin E

INTRODUCTION

This review focuses on the process of arteriosclerosis arising from oxidative stress on lipoproteins and the general failure of randomized human trials using vitamins to retard this process.

REVIEW

As well as clinical trials, the paper reviews the mechanisms by which a variety of oxidants act. Antioxidants are discussed, emphasizing interactions of vitamins C and E with transition metals that can lead to prooxidation. There is a focus on interactions between supplemental or co-antioxidants that counterbalance prooxidant effects of one another.

CONCLUSIONS

It is concluded that normal cellular supplementation mechanisms are poorly accessible in the arteriosclerotic plaque leading to a prooxidant environment in which the haphazard introduction of vitamins could potentially be hazardous. Continued investigations into basic and clinical redox interactions of the kind discussed in this review using new measuring techniques may lead to approaches whereby antioxidants can be introduced into tissue in controlled ways for reducing arteriosclerosis.

Whole-body hypoxic preconditioning protects mice against acute hypoxia by improving lung function

Survival in severe hypoxia such as occurs in high altitude requires previous acclimatization, which is acquired over a period of days to weeks. It was unknown whether intrinsic mechanisms existed that could be rapidly induced and could exert immediate protection on unacclimatized individuals against acute hypoxia. We found that mice pretreated with whole-body hypoxic preconditioning (WHPC, 6 cycles of 10-min hypoxia-10-min normoxia) survived significantly longer than control animals when exposed to lethal hypoxia (5% O2, survival time of 33.2 ± 6.1 min vs. controls at 13.8 ± 1.2 min, n = 10, P < 0.005). This protective mechanism became operative shortly after WHPC and remained effective for at least 8 h. Accordingly, mice subjected to WHPC demonstrated improved gas exchange when exposed to sublethal hypoxia (7% O2, arterial blood Po2 of 49.9 ± 4.2 vs. controls at 39.7 ± 3.6 Torr, n = 6, P < 0.05), reduced formation of pulmonary edema (increase in lung water of 0.491 ± 0.111 vs. controls at 0.894 ± 0.113 mg/mg dry tissue, n = 10, P < 0.02), and decreased pulmonary vascular permeability (lung lavage albumin of 7.63 ± 0.63 vs. controls at 18.24 ± 3.39 mg/dl, n = 6–10, P < 0.025). In addition, the severity of cerebral edema caused by exposure to sublethal hypoxia was also reduced after WHPC (increase in brain water of 0.254 ± 0.052 vs. controls at 0.491 ± 0.034 mg/mg dry tissue, n = 10, P < 0.01). Thus WHPC protects unacclimatized mice against acute and otherwise lethal hypoxia, and this protection involves preservation of vital organ functions.

Fate of coliform bacteria in composted beef cattle feedlot manure

The link between livestock production, manure management, and human health has received much public attention in recent years. Composting is often promoted as a means of sanitizing manure to ensure that pathogenic bacteria are not spread to a wider environment during land application. In a two-year study (1998 and 1999) in southern Alberta, we examined the fate of coliform bacteria during windrow composting of cattle (Bos taurus) manure from feedlot pens bedded with cereal straw or wood chips. Numbers of total coliforms (TC) and Escherichia coli declined as the composting period progressed. In 1998, TC levels (mean of both bedding types) were log10 7.86 cells g(-1) dry wt. for raw manure on Day 0, log10 3.38 cells g(-1) by Day 7, and log10 1.69 cells g(-1) by Day 14. More than 99.9% of TC and E. coli was eliminated in the first 7 d when average windrow temperatures ranged from 33.5 to 41.5 degrees C. The type of bedding did not influence the numbers of TC or E. coli. Dessication probably played a minor role in coliform elimination, since water loss was low (< 0.07 kg kg(-1)) in the first 7 d of composting. However, total aerobic heterotroph populations remained high (> 7.0 log10 CFU g(-1) dry wt., where CFU is colony forming units) throughout the composting period, possibly causing an antagonistic effect. Land application of compost, with its nondetectable levels of E. coli compared with raw manure, should minimize environmental risk in areas of intensive livestock production.