Effect of the pelleting process on diet formulations with varying levels of crystalline amino acids and reducing sugars on digestibility in growing pigs

The objective of this experiment was to determine the effects of pelleting on the standardized ileal digestibility (SID) of amino acids (AA) and crude protein (CP) in diets with or without increased concentrations of free AA and reducing sugars (RS). Eight individually housed, ileal cannulated barrows (initially 31.4 kg) were allotted to an 8 × 8 Latin square with eight diets and eight 7-d periods with ileal digesta collected on days 6 and 7. Treatments were arranged in a 2 × 2 × 2 factorial with the main effects of diet form (mash or pellet), crystalline AA (low or high), or RS (low or high), provided by distillers dried grains with solubles and bakery meal. Diets were pelleted to achieve a hot pellet temperature of 85 to 88 °C. Data were analyzed as a Latin square design using the GLIMMIX procedure of SAS 9.4. A feed form × RS interaction (P < 0.026) for SID of tryptophan was observed. Feeding pelleted low RS diets increased SID of tryptophan compared with mash high and low RS diets, and pelleted high RS diets. For the main effects of feed form, the SID of total AA, CP, and indispensable AA was greater (P < 0.042) in pelleted diets compared with mash diets. For the main effects of crystalline AA, pigs fed high crystalline AA had increased (P = 0.007) SID of tryptophan and decreased (P = 0.050) SID of histidine compared with those fed low crystalline AA diets. For the main effects of RS, high RS diets had decreased (P < 0.05) SID of total AA, CP, and indispensable AA compared with low RS diets. In conclusion, pelleting diets increased AA digestibility, and pelleting diets with increased crystalline AA or RS did not affect the improvement in AA digestibility from pelleting. Diets formulated with high crystalline AA had increased SID of tryptophan. Formulating diets with high RS resulted in decreased AA digestibility compared with corn-soybean meal-based diets.

B-1 plasma cells require non-cognate CD4 T cell help to generate a unique repertoire of natural IgM

Evolutionarily conserved, "natural" (n)IgM is broadly reactive to both self and foreign antigens. Its selective deficiency leads to increases in autoimmune diseases and infections. In mice, nIgM is secreted independent of microbial exposure to bone marrow (BM) and spleen B-1 cell-derived plasma cells (B-1PC), generating the majority of nIgM, or by B-1 cells that remain non-terminally differentiated (B-1sec). Thus, it has been assumed that the nIgM repertoire is broadly reflective of the repertoire of body cavity B-1 cells. Studies here reveal, however, that B-1PC generate a distinct, oligoclonal nIgM repertoire, characterized by short CDR3 variable immunoglobulin heavy chain regions, 7-8 amino acids in length, some public, many arising from convergent rearrangements, while specificities previously associated with nIgM were generated by a population of IgM-secreting B-1 (B-1sec). BM, but not spleen B-1PC, or B-1sec also required the presence of TCRαβ CD4 T cells for their development from fetal precursors. Together, the studies identify important previously unknown characteristics of the nIgM pool.

- Invited Review - Mineral composition and phosphorus digestibility in feed phosphates fed to pigs and poultry

Phosphorus (P) is a macro mineral needed for bone mineralization and cell membrane structure and P is also involved in several fundamental pathways of metabolism in the body. Because of the low concentration and digestibility of P in plant ingredients that are the main components of diets for poultry and pigs, feed phosphates are usually included in diets in addition to the P contributed by plant ingredients. The most widely used feed phosphates in poultry and swine diets are dicalcium phosphate (DCP) and monocalcium phosphate (MCP), but tricalcium phosphate (TCP), monosodium phosphate (MSP), and magnesium phosphate (MgP) may be used as well. Because feed phosphates are mostly produced from rock phosphate, feed phosphates have impurities that contain minerals other than P. Concentrations of P in feed phosphates range from 14.8% (MgP) to 25.7% (MSP). The standardized total tract digestibility (STTD) of P in pigs ranges from 71% (TCP) to 95% (MSP). The STTD of Ca and the standardized ileal digestibility (SID) of P and Ca in feed phosphates fed to pigs and poultry have been determined only in a few experiments. Available data indicate that the STTD of Ca and SID of P in MCP are greater than in DCP in both poultry and pigs, but the SID of Ca is similar between DCP and MCP fed to broilers. Information on mineral concentrations and digestibility values in feed phosphates is needed in diet formulation for pigs and poultry, but if diets are formulated to contain equal concentrations of digestible P and Ca, it is unlikely that animal performance will be impacted by the source of feed phosphates used in the diet.

Nutritional value of a new source of cheese coproduct fed to weanling pigs

Three experiments were conducted to test the hypothesis that values for standardized ileal digestibility (SID) of amino acids (AA) and metabolizable energy (ME) in a the cheese coproduct are greater than in fish meal or enzyme-treated soybean meal (ESBM). The second objective was to test the hypothesis that pigs fed a diet containing cheese coproduct will have growth performance that is not different from that of pigs fed other sources of protein. In experiment 1, eight ileal-cannulated barrows (11.0 ± 0.4 kg) were allotted to a replicated 4 × 4 Latin square design with four diets and four periods and two pigs per diet in each period. The four diets included an N-free diet and three diets that contained ESBM, fish meal, or the cheese coproduct as the source of AA. Results indicated that the cheese coproduct had greater (P < 0.05) SID of most AA compared with ESBM and fish meal. In experiment 2, 32 weanling barrows (14.0 ± 1.1 kg) were housed individually in metabolism crates and randomly allotted to one of four diets. A corn-based diet and three diets that contained corn and ESBM, fish meal, or cheese coproduct were formulated. Feces and urine were collected quantitatively. The ME in cheese coproduct was greater (P < 0.05) than in ESBM and fish meal. In experiment 3, 128 weaned pigs (6.2 ± 0.6 kg) were allotted to a randomized complete block design with four treatments and 8 replicate pens per diet. Phase 1 diets that contained 0%, 6.65%, 7.35%, or 14% cheese coproduct were fed from days 1 to 14 and a common phase 2 diet without cheese coproduct was fed from days 15 to 28. Individual pig weights were recorded at the beginning of the experiment, on days 14 and 28, and daily feed allotments were also recorded. Two blood samples were collected from 1 pig per pen on day 14 to analyze for blood urea N, albumin, total plasma protein, peptide YY, immunoglobulin G, tumor necrosis factor-α, interleukin-6, and interleukin-10. No differences were observed in average daily gain among treatments, but there was a tendency (P < 0.10) for total protein on day 14 to increase as cheese coproduct increased in the diets. In conclusion, the cheese coproduct used in this experiment has a greater SID of AA and greater ME than ESBM and fish meal and the cheese coproduct may be included in prestarter diets for weanling pigs without negatively impacting growth performance or indicators of intestinal health.

Effects of microbial phytase on standardized total tract digestibility of phosphorus in feed phosphates fed to growing pigs

An experiment was conducted to test the hypothesis that the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P in feed phosphates are increased by microbial phytase when fed to growing pigs. Monocalcium phosphate (MCP), monosodium phosphate (MSP), and magnesium phosphate (MgP) from volcanic deposits were used in the experiment. Three corn-soybean meal based diets that contained 0, 500, or 4,000 units of microbial phytase (FTU), but no feed phosphates, were formulated. Nine additional diets were formulated by adding each of the three feed phosphates to the three basal diets. A P-free diet was also formulated to estimate the basal endogenous loss of P, and therefore, 13 diets were used in the experiment. A total of 117 growing barrows (initial body weight: 15.56 ± 1.68 kg) were allotted to the 13 diets with 9 pigs per diet. Pigs were housed individually in metabolism crates equipped with a feeder and a nipple drinker. Installation of a screen floor under the slatted floor allowed for collection of feces. Diets were fed for 10 d, with the initial 5 d being a period of adaptation to the diet followed by a collection period of 4 d. During the experiment, pigs were fed equal amounts of feed twice daily at 0800 and 1600 h. Results indicated that the ATTD and STTD of P in all diets increased with the inclusion of 500 or 4,000 FTU, but the ATTD and STTD of P in the feed phosphates were not affected by the inclusion of phytase. This indicates that the increases in ATTD and STTD of P that were observed in the mixed diets when phytase was used were due to the release of P from phytate in corn and soybean meal and not from an increase in digestibility of P in feed phosphates. However, MgP had a lower (P < 0.05) ATTD and STTD of P than MCP and MSP. In conclusion, microbial phytase does not increase the digestibility of P in MCP, MSP, or MGP, but the digestibility of P in MgP is less than in MCP and MSP.

Maternal immune activation (MIA) impairs neonatal lung ILC2 establishment, function, and airway hyperresponsiveness

We have recently shown that prenatal inflammation induced by maternal immune activation (MIA) imparts lasting changes to innate immunity by driving the inappropriate expansion and persistence of lymphoid-biased progenitors during fetal life. To test how perturbation during this critical window drives immune dysfunction, we examined underlying changes to lung type-2 innate lymphoid cells (ILC2s) and susceptibility to airway hyperresponsiveness following MIA. MIA induction via a single-low dose injection of poly (I:C) at mid-gestation altered the establishment of a fetal liver (FL) ILC-committed progenitor, increasing cell number and frequency both one- and three-days post MIA. MIA also enhanced lung ILC2 proliferation postnatally, resulting in a robustly expanded ILC2 compartment at postnatal day (P)14 that persisted into adulthood. Concomitant with a greater inflammatory profile, MIA-treated ILC2s were hyperactivated, producing more IL5 and IL13 in-vitro. Lung cytokine levels remained relatively static across early lung development in MIA or saline conditions, suggesting changes to ILC2 proliferation and hyperactivation are cell-intrinsic. Furthermore, hyperactivated ILC2s led to remodeling of the lung immune landscape as observed by expansion of B-, T-, NK-, NKT-cells, alveolar macrophages and eosinophils, but ILC2s were the first immune population to expand in cell number. Altogether, our data suggest MIA imparts lasting changes to lung immunity by perturbing the establishment of committed ILC progenitors in the FL, altering the production of neonatal lung ILC2s poised to hyperactively respond to secondary immune activation, potentially contributing to greater allergic airway hyperresponsiveness.

Supported by grants from NIH/NICHD (T32HD007491

199 Effect of the Pelleting Process on Diet Formulations with Varying Levels of Crystalline Amino Acids and Reducing Sugars on Digestibility in Growing Pigs

The objective of this study was to determine effects of pelleting on the standardized ileal digestibility (SID) of amino acids (AA) in diets with or without increased concentrations of free AA and reducing sugars (RS). Eight individually housed, ileal cannulated barrows (initially 69.2 kg) were allotted to a replicated 8×8 Latin square with 8 diets and eight 7-d periods with ileal digesta collected on d 6 and 7. Treatments were arranged in a 2×2×2 factorial with main effects of diet form (mash vs. pellet), crystalline AA (low vs. high), or reducing sugars (low vs. high) provided by dried distillers grains with solubles and bakery meal. Diets were pelleted to achieve a hot pellet temperature of 85 to 88°C. Data were analyzed as a completely randomized Latin square using the GLIMMIX procedure of SAS. A feed form×RS interaction (P &lt; 0.026) for SID of tryptophan was observed. Feeding pelleted low RS diets improved SID of tryptophan compared with mash high and low RS diets, and pelleted high RS diets. For main effects of feed form, the SID of total AA, CP, and indispensable AA increased (P &lt; 0.042) in pigs fed pelleted diets compared with mash diets. For main effects of crystalline AA, pigs fed high crystalline AA had increased (P = 0.007) SID of tryptophan and decreased (P = 0.050) SID of histidine compared with those fed low crystalline AA diets. For main effects of RS diets, pigs fed high RS diets had decreased (P &lt; 0.05) SID of total AA, CP and indispensable AA. In conclusion, pelleting diets with increased crystalline AA or RS did not affect the improvement in AA digestibility from pelleting. Pelleting diets improved AA digestibility. Diets formulated with high crystalline AA had increased SID of tryptophan. Formulating diets with high RS resulted in decreased AA digestibility compared with corn-soybean meal-based diets.

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PSVI-8 Mineral composition of feed grade monocalcium phosphate

Feed phosphates are included in swine diets to meet the requirements of P. Two products are predominantly used for this purpose, commercial monocalcium phosphate (MCP) and dicalcium phosphate (DCP). Theoretically, pure MCP should contain 26.5% P but commercial sources of MCP contain around 21 % P. The reason there is less P in commercial sources is that these sources are contaminated with calcium carbonate and other minerals. In addition, feed grade phosphates called MCP in reality is a mixture of MCP and DCP, which also contributes to the reduced P. To determine the complete composition of commercial MCP, seven sources of MCP were procured. All sources were analyzed for most common minerals that may be present in feed phosphates (Table 1) Results indicate that the composition of minerals is relatively stable among the different sources of MCP, indicating that the process to produce feed grade phosphates does not result in much variability. However, none of the commercial feed grade phosphates contained close to 26.5% P, which would be expected in a pure source.

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A critical period of innate-immune development: Fetal origins of allergic asthma susceptibility

Our lab previously identified a developmentally-restricted hematopoietic stem cell (drHSC) that only exists during fetal development and specifically gives rise to innate-like lymphocytes that persist across the lifespan. The identification of a developmentally-limited cell of origin for innate-like immune cells defines a “critical window” for immune development, in which the phenotype of the developing immune system can be shaped via extrinsic inputs. To test how perturbation during this critical window drives immune dysfunction, we examined underlying changes to innate lymphoid cells (ILCs) in the lung. ILCs are a recently identified family of fetal-derived innate-like lymphocytes that mimic the adaptive T-helper arm of our immune system. In the lung, type-2 innate lymphoid cells (ILC2s) produce IL5 and IL13, cytokines important for eosinophil recruitment, activation and goblet cell hyperplasia during allergic airway inflammation. Surprisingly, a single low-dose injection of poly (i:c) at mid-gestation robustly increased proliferative capacity and cellularity of lung ILC2s in offspring at postnatal day (P)9 and P14, respectively, concomitant with drHSC and common-helper innate lymphoid progenitor (ChILP) cell expansion during fetal development. Additionally, in poly (i:c) perturbed offspring, lung ILC2s exhibited heightened IL5 and IL13 production upon in-vitro stimulation with PMA and ionomycin. Ongoing experiments will examine how perturbation of transient progenitors during fetal development may impact the ChILP cell immune trajectory, altering the establishment and function of neonatal lung ILC2s, and ultimately contributing to allergic asthma susceptibility into adulthood.

Characterizing a “critical window” of immune development: how perturbation of developmental hematopoiesis shapes immune function and susceptibility to disease in offspring

During development, fetal hematopoietic stem cells (HSCs) are responsible for the production of “unconventional” innate-like immune cells that persist across the lifespan and contribute to adult immunity. Dysregulation of fetal-derived immune cells contributes to pathogenesis in a variety of immune tolerance disorders, including allergy and asthma; however, the cellular and molecular mechanisms driving pathogenesis are unknown. Using a fate-mapping approach, we have previously identified a developmentally-restricted HSC (drHSC) that is lymphoidbiased and specifically gives rise to innate-like lymphocytes. The drHSC exists during perinatal development but disappears postnatally and does not persist into adulthood under homeostatic conditions. Our discovery of a transient cell-of-origin for a specialized component of adult immunity defines a “critical window” of immune development, during which phenotype can be shaped by extrinsic inputs in early life. We have validated the existence of this critical window of immune development by demonstrating that maternal immune perturbation with a single low-dose injection of poly(I:C) at mid-gestation induces lasting changes to the both hematopoiesis and immunity in offspring. Specifically, maternal immune perturbation causes expansion of the drHSC population in offspring and its inappropriate persistence into adulthood. Furthermore, inappropriate expansion and persistence of the drHSC population consequently results in parallel expansion of innate-like lymphocytes, thereby altering immune landscape and function in offspring. Ongoing work investigates the consequences of developmental perturbation on susceptibility to immune dysfunction, including asthma.

Perturbation of Developmental Hematopoiesis Shapes Lung ILC2 Immune Memory

Our lab has previously identified a developmentally-restricted hematopoietic stem cell (drHSC) that only exists in the perinatal period and specifically gives rise to innate-like lymphocytes. The identification of a developmentally-limited cell of origin for innate-like immune cells that persist across the lifespan defines a “critical window” for immune development, in which the phenotype of the adult immune system can be shaped by extrinsic inputs. To test how developmental perturbation during this critical window drives immune dysfunction, we examined underlying changes to innate-like immune cells in the lung and susceptibility to airway dysfunction following maternal immune stimulation. Lung type-2 innate lymphoid cells (ILC2s) are recognized as potent producers of IL5 and IL13, cytokines important for eosinophil recruitment, activation and goblet cell hyperplasia during allergic airway inflammation. Surprisingly, maternal immune stimulation via a single low-dose injection of poly (i:c) at mid-gestation robustly increased the cellularity of lung ILC2s in offspring at postnatal day 14, concomitant with drHSC and ILC2 progenitor expansion during fetal development. Additionally, lung ILC2s exhibited heightened IL5 and IL13 production upon in-vitro stimulation with PMA and ionomycin in poly (i:c) perturbed offspring. Ongoing experiments examine how altered ILC2 functionality, as a result of developmental perturbation, underlie susceptibility to allergic asthma in response to secondary house-dust mite immune stimulation. Together, our data suggest perinatal immune perturbation may contribute to allergic asthma susceptibility by altering drHSC establishment and training lung ILC2 “innate immune memory”.

Evaluation of the Edman degradation product of vancomycin bonded to core-shell particles as a new HPLC chiral stationary phase

A modified macrocyclic glycopeptide-based chiral stationary phase (CSP), prepared via Edman degradation of vancomycin, was evaluated as a chiral selector for the first time. Its applicability was compared with other macrocyclic glycopeptide-based CSPs: TeicoShell and VancoShell. In addition, another modified macrocyclic glycopeptide-based CSP, NicoShell, was further examined. Initial evaluation was focused on the complementary behavior with these glycopeptides. A screening procedure was used based on previous work for the enantiomeric separation of 50 chiral compounds including amino acids, pesticides, stimulants, and a variety of pharmaceuticals. Fast and efficient chiral separations resulted by using superficially porous (core-shell) particle supports. Overall, the vancomycin Edman degradation product (EDP) resembled TeicoShell with high enantioselectivity for acidic compounds in the polar ionic mode. The simultaneous enantiomeric separation of 5 racemic profens using liquid chromatography-mass spectrometry with EDP was performed in approximately 3 minutes. Other highlights include simultaneous liquid chromatography separations of rac-amphetamine and rac-methamphetamine with VancoShell, rac-pseudoephedrine and rac-ephedrine with NicoShell, and rac-dichlorprop and rac-haloxyfop with TeicoShell.

A comprehensive methodology for the chiral separation of 40 tobacco alkaloids and their carcinogenic E/Z-(R,S)-tobacco-specific nitrosamine metabolites

The predominant enantiomer of nicotine found in nature is (S)-nicotine and its pharmacology has been widely established. However, pharmacologic information concerning individual enantiomers of nicotine-related compounds is limited. Recently, a modified macrocyclic glycopeptide chiral selector was found to be highly stereoselective for most tobacco alkaloids and metabolites. This study examines the semi-synthetic and native known macrocyclic glycopeptides for chiral recognition, separation, and characterization of the largest group of nicotine-related compounds ever reported (tobacco alkaloids, nicotine metabolites and derivatives, and tobacco-specific nitrosamines). The enantioseparation of nicotine is accomplished in less than 20s for example. All liquid chromatography separations are mass spectrometry compatible for the tobacco alkaloids, as well as their metabolites. Ring-closed, cyclized structures were identified and separated from their ring-open, straight chain equilibrium structures. Also, E/Z-tobacco-specific nitrosamines and their enantiomers were directly separated. E/Z isomers also are known to have different physical and chemical properties and biological activities. This study provides optimal separation conditions for the analysis of nicotine-related isomers, which in the past have been reported to be ineffectively separated which can result in inaccurate results. The methodology of this study could be applied to cancer studies, and lead to more information about the role of these isomers in other diseases and as treatment for diseases.

Effective methodologies for enantiomeric separations of 150 pharmacology and toxicology related 1°, 2°, and 3° amines with core-shell chiral stationary phases

Core-shell particles (superficially porous particles, SPPs) have been proven to provide high-throughput and effective separations of a variety of chiral molecules. However, due to their limited commercialization, many separations have not been reported with these stationary phases. In this study, four SPP chiral stationary phases (CSPs) were utilized for the enantiomeric separation of 150 chiral amines. These amines encompass a variety of structural and drug classes, which are particularly important to the pharmaceutical industry and in forensics. This comprehensive evaluation demonstrates the power of these CSPs and the ease of method development and optimization. The CSPs used in this study included the macrocyclic glycopeptide-based CSPs (VancoShell and NicoShell), the cyclodextrin-based CSP (CDShell-RSP), and the cyclofructan-based CSP (LarihcShell-P). These CSPs offered versatility for a variety of applications and worked in a complementary fashion to baseline separate all 150 amines. The LarihcShell-P was highly effective for separating primary amines. VancoShell, NicoShell, and CDShell-RSP were useful for separating all types of amines. These CSPs are multi-modal and can be utilized with mass spectrometry compatible solvents. Eighteen racemic controlled substances were simultaneously baseline separated in a single liquid chromatography-mass spectrometry (LC-MS) analysis. Details in high-performance liquid chromatography (HPLC) parameters will be discussed as well as the improved chromatographic performance afforded by the SPP CSPs.

Macrocyclic glycopeptide chiral selectors bonded to core-shell particles enables enantiopurity analysis of the entire verubecestat synthetic route

Verubecestat is an inhibitor of β-site amyloid precursor protein cleaving enzyme 1 (BACE1) being evaluated in clinical trials for the treatment of Alzheimer's disease. Synthetic route development involves diastereoselective transformations with a need for enantiomeric excess (ee) determination of each intermediate and final active pharmaceutical ingredient (API). The analytical technical package of validated methods relies on enantioselective SFC and RPLC separations using multiple 3 and 5 μm coated polysaccharide-based chiral stationary phases (CSPs) and mobile phases combinations. Evaluation of recently developed chiral columns revealed a single chiral selector (Teicoplanin) bonded to 2.7 μm core-shell particles using H₃PO₄ in H₂O/ACN and triethylammonium acetate: methanol based eluents at different isocratic compositions allowed good enatioseparation of all verubecestat intermediates. EE determination of verubecestat is easily performed on NicoShell, another macrocyclic glycopeptide chiral selector bonded to 2.7 μm superficially porous particles. This approach enables fast and reliable enantiopurity analysis of the entire verubecestat synthetic route using only two chiral columns and mobile phases on a conventional HPLC system, simplifying technical package preparation, method validation and transfer to manufacturing facilities.

Evaluation of nicotine in tobacco-free-nicotine commercial products

Recently, a variety of new tobacco-free-nicotine, TFN, products have been commercialized as e-liquids. Tobacco-derived nicotine contains predominantly (S)-(-)-nicotine, whereas TFN products may not. The TFN products are said to be cleaner, purer substances, devoid of toxic components that come from the tobacco extraction process. A variety of commercial tobacco and TFN products were analyzed to identify the presence and composition of each nicotine enantiomer. A rapid and effective enantiomeric separation of nicotine has been developed using a modified macrocyclic glycopeptide bonded to superficially porous particles. The enantiomeric assay can be completed in <2 min with high resolution and accuracy using high performance liquid chromatography with electrospray ionization mass spectrometry. The results of this study suggest the need for pharmacological studies of (R)-(+)-nicotine, which is present in much greater quantities in commercial TFN products compared to commercial tobacco-derived products. Such studies are required by the FDA for new enantiomeric pharmacological products. Copyright © 2016 John Wiley & Sons, Ltd.

Cytotoxicity assessment of some carbon nanotubes and related carbon nanoparticle aggregates and the implications for anthropogenic carbon nanotube aggregates in the environment

Nanotechnology and nanomaterials have become the new frontier world-wide over the past few years and prospects for the production and novel uses of large quantities of carbon nanotubes in particular are becoming an increasing reality. Correspondingly, the potential health risks for these and other nanoparticulate materials have been of considerable concern. Toxicological studies, while sparse, have been concerned with virtually uncharacterized, single wall carbon nanotubes, and the conclusions have been conflicting and uncertain. In this research we performed viability assays on a murine lung macrophage cell line to assess the comparative cytotoxicity of commercial, single wall carbon nanotubes (ropes) and two different multiwall carbon nanotube samples; utilizing chrysotile asbestos nanotubes and black carbon nanoaggregates as toxicity standards. These nanotube materials were completely characterized by transmission electron microscopy and observed to be aggregates ranging from 1 to 2 microm in mean diameter, with closed ends. The cytotoxicity data indicated a strong concentration relationship and toxicity for all the carbon nanotube materials relative to the asbestos nanotubes and black carbon. A commercial multiwall carbon nanotube aggregate exhibiting this significant cell response was observed to be identical in structure to multiwall carbon nanotube aggregates demonstrated to be ubiquitous in the environment, and especially in indoor environments, where natural gas or propane cooking stoves exist. Correspondingly, preliminary epidemiological data, although sparse, indicate a correlation between asthma incidence or classification, and exposure to gas stoves. These results suggest a number of novel epidemiological and etiological avenues for asthma triggers and related respiratory or other environmental health effects, especially since indoor number concentrations for multiwall carbon nanotube aggregates is at least 10 times the outdoor concentration, and virtually all gas combustion processes are variously effective sources. These results also raise concerns for manufactured carbon nanotube aggregates, and related fullerene nanoparticles.

Carbon nanotubes and other fullerene nanocrystals in domestic propane and natural gas combustion streams

Carbon nanotubes and other aggregated fullerene-related multi-layer shell structures have been collected in propane and natural gas flame emissions from domestic cooking stoves and observed by transmission electron microscopy. Some aggregated nanoparticles collected on 3 mm electron microscope grids by thermal precipitation were mostly multi-walled nanotubes; many tangled and distorted, and aggregated with other closed-concentric, multi-shell forms. Such clean-burning regimes may be major contributors to complex particulate matter in indoor and outdoor air.

The Shulman syndrome

The Shulman syndrome is a symptom complex recently described in the rheumatology literature that is characterized by eosinophilia, hypergammaglobulinemia, and a diffuse scleroderma-like process of the extremities. The onset of illness has been associated with a period of unusual physical exertion. The condition seems to respond to corticosteroid therapy for systemic effect.