Grain sorghum is a viable feedstock for ethanol production

Sorghum is a major cereal crop in the USA. However, sorghum has been underutilized as a renewable feedstock for bioenergy. The goal of this research was to improve the bioconversion efficiency for biofuels and biobased products from processed sorghum. The main focus was to understand the relationship among "genetics-structure-function-conversion" and the key factors impacting ethanol production, as well as to develop an energy life cycle analysis model (ELCAM) to quantify and prioritize the saving potential from factors identified in this research. Genetic lines with extremely high and low ethanol fermentation efficiency and some specific attributes that may be manipulated to improve the bioconversion rate of sorghum were identified. In general, ethanol yield increased as starch content increased. However, no linear relationship between starch content and fermentation efficiency was found. Key factors affecting the ethanol fermentation efficiency of sorghum include protein digestibility, level of extractable proteins, protein and starch interaction, mash viscosity, amount of phenolic compounds, ratio of amylose to amylopectin, and formation of amylose-lipid complexes in the mash. A platform ELCAM with a base case showed a positive net energy value (NEV) = 25,500 Btu/gal EtOH. ELCAM cases were used to identify factors that most impact sorghum use. For example, a yield increase of 40 bu/ac resulted in NEV increasing from 7 million to 12 million Btu/ac. An 8% increase in starch provided an incremental 1.2 million Btu/ac.

Yin Yang 1 is a critical regulator of B-cell development

The role of the transcription factor Yin Yang 1 (YY1) in development is largely unknown. Here we show that specific ablation of YY1 in mouse B cells caused a defect in somatic rearrangement in the immunoglobulin heavy-chain (IgH) locus and a block in the progenitor-B-to-precursor-B-cell transition, which was partially rescued by a prerearranged IgH transgene. Three-dimensional DNA fluorescence in situ hybridization analysis revealed an important function for YY1 in IgH locus contraction, a process indispensable for distal V(H) to D(H)J(H) recombination. We provide evidence that YY1 binds the intronic Ei mu enhancer within the IgH locus, consistent with a direct role for YY1 in V(H)D(H)J(H) recombination. These findings identified YY1 as a critical regulator of early B-cell development.

Cannabinoid 2 receptor induction by IL-12 and its potential as a therapeutic target for the treatment of anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma is the most aggressive type of thyroid malignancies. Previously, we demonstrated that tumorigenicity of anaplastic thyroid carcinoma cell line ARO was significantly reduced following interleukin (IL)-12 gene transfer. We suspected that tumor target structure in ARO/IL-12 cells might be changed and such a change may make them more susceptible to be killed through mechanisms apart from natural killer-dependent pathway. To identify genes involved, we examined gene expression profile of ARO and ARO/IL-12 by microarray analysis of 3757 genes. The most highly expressed gene was cannabinoid receptor 2 (CB2), which was expressed eightfold higher in ARO/IL-12 cells than ARO cells. CB2 agonist JWH133 and mixed CB1/CB2 agonist WIN-55,212-2 could induce significantly higher rate of apoptosis in ARO/IL-12 than ARO cells. Similar results were obtained when ARO cells were transfected with CB2 transgene (ARO/CB2). A considerable regression of thyroid tumors generated by inoculation of ARO/CB2 cells was observed in nude mice following local administration of JWH133. We also demonstrated significant increase in the induction of apoptosis in ARO/IL12 and ARO/CB2 cells following incubation with 15 nM paclitaxel, indicating that tumor cells were sensitized to chemotherapy. These data suggest that CB2 overexpression may contribute to the regression of human anaplastic thyroid tumor in nude mice following IL-12 gene transfer. Given that cannabinoids have shown antitumor effects in many types of cancer models, CB2 may be a viable therapeutic target for the treatment of anaplastic thyroid carcinoma.

Oxygen-derived free radicals mediate endothelium-dependent contractions in femoral arteries of rats with streptozotocin-induced diabetes

BACKGROUND AND PURPOSE

The present experiments were designed to study the contribution of oxygen-derived free radicals to endothelium-dependent contractions in femoral arteries of rats with streptozotocin-induced diabetes.

EXPERIMENTAL APPROACH

Rings with and without endothelium were suspended in organ chambers for isometric tension recording. The production of oxygen-derived free radicals in the endothelium was measured with 2',7'-dichlorodihydrofluorescein diacetate using confocal microscopy. The presence of protein was measured by western blotting.

KEY RESULTS

In the presence of L-NAME, the calcium ionophore A23187 induced larger endothelium-dependent contractions in femoral arteries from diabetic rats. Tiron, catalase, deferoxamine and MnTMPyP, but not superoxide dismutase reduced the response, suggesting that oxygen-derived free radicals are involved in the endothelium-dependent contraction. In the presence of L-NAME, A23187 increased the fluorescence signal in femoral arteries from streptozotocin-treated, but not in those from control rats, confirming that the production of oxygen-derived free radicals contributes to the enhanced endothelium-dependent contractions in diabetes. Exogenous H2O2 caused contractions in femoral arterial rings without endothelium which were reduced by deferoxamine, indicating that hydroxyl radicals contract vascular smooth muscle and thus could be an endothelium-derived contracting factor in diabetes. The reduced presence of Mn-SOD and the decreased activity of catalase in femoral arteries from streptozotocin-treated rats demonstrated the presence of a redox abnormality in arteries from rats with diabetes.

CONCLUSIONS AND IMPLICATIONS

These findings suggest that the redox abnormality resulting from diabetes increases oxidative stress which facilitates and/or causes endothelium-dependent contractions.

Inhibition of malignant activities of nasopharyngeal carcinoma cells with high expression of CD44 by siRNA

Since CD44 was found to be significantly inhibited in the human nasopharyngeal carcinoma cell line CNE-2L2 with profound reduction of malignant activities caused by inhibition of alpha-mannosidase Man2c1 gene expression and CD44 has been observed to be involved in many tumor-supporting functions, we studied the association of CD44 expression with the malignant activities of CNE-2L2 cells. Suppression of CD44 gene expression by RNA silencing technique resulted in profound reduction of malignant potential of the cells, including growth in vitro, colony formation, tumorigenesis and metastasis of tumors in nude mice. Direct injection of the adenoviruses harboring and producing siRNA to CD44 into the tumor inoculated with CNE-2L2 cells in nude mice caused inhibition of tumor growth. The data indicate a positive association of CD44 expression with the malignant activities of CNE-2L2 cells and suggest a possible therapeutic effect of direct introduction of siRNA to CD44 into tumors in some human solid tumors with high expression of CD44 gene.

Chinese medicinal herbs for sore throat

BACKGROUND

Chinese herbal medicines are commonly used to treat sore throat in China and among Chinese people worldwide. Their efficacy in treating sore throat has not previously been systematically reviewed.

OBJECTIVES

To assess the efficacy and safety of Chinese herbal medicines for patients with sore throat.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 3, 2006) which contains the Acute Respiratory Infections Group's specialised register; MEDLINE (1966 to August 2006); EMBASE (1980 to August 2006); AMED (1985 to August 2006); the Chinese Biomedical Database (CBM) (1975 to August 2006), and China National Knowledge Infrastructure (CNKI) (1994 to August 2006).

SELECTION CRITERIA

We only included randomised controlled trials (RCTs) assessing Chinese herbal medicines for the treatment of sore throat with the outcomes of recovery, inefficacy, and adverse events.

DATA COLLECTION AND ANALYSIS

One review author contacted the trial authors of claimed RCTs. Three review authors extracted and analysed the data.

MAIN RESULTS

Seven trials involving 1253 participants were included. All trials were identified as being of methodologically poor quality (C category). All of the Chinese herbal preparations in this review were inadequately characterised and were assessed in one trial only. It is highly likely that there was selection bias or detection bias, or both, in all of the included trials. Conflict of interest may have been another factor in producing a positive result in three studies as the prepared drugs were made in the trial author's hospital. We did not perform a meta-analysis and the results of the studies are reported separately. Three formulations were shown to be superior to the control in improving recovery: Ertong Qingyan Jiere Koufuye was more effective than Fufang Shuanghua Koufuye for acute pharyngitis (OR 1.54, 95% Cl 1.11 to 5.74); Yanhouling mixture was more effective than the gentamicin atomised inhalation for acute pharyngitis (OR 5.39, 95% CI 2.69 to 10.81) for acute pharyngitis; and Qinganlan Liyan Hanpian was more effective than Fufang Caoshanhu Hanpian for chronic pharyngitis (OR 2.25, 95% CI 1.08 to 4.67). Four four formulations were shown to be equal in efficacy to the control.

AUTHORS' CONCLUSIONS

Based on the existing evidence included in this review, the efficacy of Chinese herbal medicine for treating sore throat is controversial and questionable. We cannot recommend any kind of Chinese medical herbal formulation as an effective remedy for sore throat, due to the lack of high quality clinical trials.

A Mg2+-responding RNA that controls the expression of a Mg2+ transporter

Mg2+ is the most abundant divalent cation in biological systems. It is required for ATP-mediated enzymatic reactions and as a stabilizer of ribosomes and membranes. The enteric bacterium Salmonella enterica serovar Typhimurium harbors three Mg2+ transporters and a regulatory system-termed PhoP/PhoQ-whose activity is regulated by the extracytoplasmic levels of Mg2+. We have determined that expression of the PhoP-activated Mg2+ transporter MgtA is also controlled by its 5'-untranslated region (5'UTR). The 5'UTR of the mgtA gene can adopt different stem-loop structures depending on the Mg2+ levels, which determine whether transcription reads through into the mgtA-coding region or stops within the 5'UTR. This makes the mgtA 5'UTR the first example of a cation-responding riboswitch. The initiation of mgtA transcription responds to extracytoplasmic Mg2+, and its elongation into the coding region to cytoplasmic Mg2+, which provides a singular example where the same ligand is sensed in different cellular compartments to regulate disparate steps in gene transcription. The PhoP-activated Mg2+ transporter mgtB is also regulated by Mg2+ in a strain lacking the Mg2+ sensor PhoQ, suggesting the presence of additional Mg2+-responding devices.

Phase II clinical trial of XELOX as first line treatment for patients with unresectable or metastatic gastric cancer

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Background: The survival of advanced gastric cancer remains poor, while no chemotherapy regimen was recognized standard. Oxaliplatin and Capecitabine (Xeloda) have demonstrated promising antitumor efficacy in advanced colorectal cancer. The present study was conducted to further evaluate the efficacy and safety of XELOX (Oxaliplatin and Xeloda) regimen in gastric cancer. Methods: Patients with unresectable or metastatic gastric cancer were enrolled into this study. They all receive the XELOX regimens (Oxaliplatin 130mg/ m2 intravenously in 2 hours on day 1 followed by oral capecitabine 1000mg/ m2 twice daily for 14 days every 3 weeks).We evaluated the response every 2 cycles. Results: The median age of the total enrolled 45 patients was 55 years (range, 22–82 years), including 32 male and 13 female. They received a median of 5 cycles (range, 2–8 cycles) of XELOX. 21 of 45 patients (46.7%) achieved an objective response, 1 patient (2.2%) had completed response. 17 patients (37.8%) experienced stable disease. Median time to tumor progression (TTP) and median overall survival were not available yet due to the further follow-up needed. Most toxicity events were mild to moderate in XELOX regimen, with grade 3/4 neutropenia of 8.9 %, thrombocytopenia of 6.7%, anemia of 11.1%, hand-foot syndrome of 6.7 % and diarrhea of 6.7 %. Grade 3 neuropathy was 4.4%. The patients with advanced gastric cancer had a good tolerance to this chemotherapy. Conclusions: XELOX is a highly effective first-line treatment for unrsectable and metastatic gastric cancer. The response rates in this trial seems to be similar to those observed with FU/leucovorin/oxaliplatin combinations. XELOX is tolerable well in the treatment of advanced gastric cancer.

No significant financial relationships to disclose.

Multivisceral resections of gastrointestinal stromal tumors

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Background: Gastrointestinal stromal tumors (GISTs) with positive kit staining, although rare, are the most common mesenchymal neoplasms affecting the gastrointestinal tract. We present our experience in the treatment of disease involving adjacent organs with multivisceral resections. Methods: The clinicopathologic records of twenty-two patients with multivisceral resection, among 170 patients suffered from GISTs treated in our hospital from 1994 to 2005, were retrospectively reviewed. Nine primary tumors originated from the stomach, 4 from the small intestine, 6 from the colorectum, 1 from abdominal cavity, and 2 from the retroperitoneal area. Meanwhile complete follow-up records were available in 15 patients with median 5-year follow-up. Results: The patients included 9 men and 13 women, from 36 to 77 year old. The largest tumor diameter ranged from 2 to 20 cm. The types of multivisceral operation comprised splenectomy (n=8), coloectomy (n=6), nephrectomy (n=5), partial hepatectomy (n=1), duodenectomy (n=1), oophorectomy (n=1), pancreatectomy (n=1), and adrenalectomy (n=1). None of lymph node metastatsis was found in 7 patients with lymph node dissection with gastric GISTs (n=5) or small intestinal GISTs (n=2). The involved organs confirmed by the pathologic diagnosis included kidney (n=2), spleen (n=2), pancreas (n=2), mesentery (n=1), and omentum (n=1). There was no perioperative mortality in this series. Among follow up patients, 9 were alive and 5 were died from the tumor recurrence or metastasis. Among them, one person with gastrectomy, pancreatectomy, adrenalectomy is still alive under 2 year follow-up by imatinib mesylate therapy postoperatively. Conclusions: Complete surgical resection with a negative gross margin by en bloc resection of the involved organs remains the standard treatment for non-metastatic GISTs. Imatinib mesylate represents a major breakthrough in the treatment of advanced GISTs and is the first effective systemic therapy for the disease.

No significant financial relationships to disclose.

Initial results from a phase II trial of motesanib diphosphate (AMG 706) in patients with differentiated thyroid cancer (DTC)

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Background: This phase 2 study evaluated the safety and efficacy of AMG 706, an oral, investigational multikinase (MKI) inhibitor with antiangiogenic and direct antitumor activity achieved by selectively targeting VEGF, PDGF, and Kit receptors and RET, in pts with advanced DTC or medullary thyroid cancer (MTC). Presented here are results from the DTC stratum. Methods: This was a multicenter, phase 2, open-label, single-arm study of pts with advanced thyroid cancer stratified by DTC or MTC (planned n=80 each). The primary endpoint was objective tumor response per modified RECIST by independent central review. Secondary DTC endpoints were duration of response and progression-free survival (PFS). Pts = 18 yrs with progressive, 131I-resistant disease, ECOG 0–2, and no prior treatment with VEGFr MKIs received AMG 706 125mg QD until disease progression or unacceptable toxicity. Assessments included tumor response (q8w), pharmacokinetics (PK), and safety. Results: 93 pts with DTC were enrolled and received at least 1 dose of AMG 706. DTC subtypes were: papillary, 58%; Hürthle cell, 18%; follicular, 16%; other, 8%. Median (range) age was 62 (36–81) yrs. 20% of pts had prior chemotherapy; 96% had prior 131I therapy. With median follow-up of 32 wks, objective tumor response (CR or PR) rate (95% CI) was 12% (6.1, 20.2); SD, n=64 (69%; durable SD =24 wks, 24%); PD, n=7 (8%). Median (95% CI) time to response was 103 (53, 161) days; median PFS was 276 (221, not estimable) days. 85% of pts were alive >8 months after starting therapy. All pts (100%) had some treatment- emergent adverse events (AE): grade 3, 55%; grade 4, 10%; grade 5, 5% (all grade 5 were deemed unrelated to AMG 706). Common AEs included diarrhea (70%; 11% grade 3), fatigue (58%; 5% grade 3), hypertension (49%; 22% grade 3), headache (43%; 4% grade 3), nausea (40%; 2% grade 3), and hypothyroidism and/or increased TSH (17%; no grade 3); none of these were grade 4 or 5. 6% of pts had cholecystitis. PK results showed that AMG 706 PK at 125mg QD was comparable to data obtained in other monotherapy studies at the same dose level. Conclusions: In this study of pts with advanced 131I-resistant DTC, AMG 706 showed encouraging antitumor activity and had tolerable and manageable toxicities. Further investigation is warranted.

No significant financial relationships to disclose.

The prognostic analysis of gastrointestinal stromal tumor

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Objective: To investigate the prognostic factor of gastrointestinal stromal tumor. Methods: The clinicopathological data of 103 patients with gastrointestinal stromal tumors were analyzed restrospectively. Life table, kaplan-meier survival rate and cox regression model were used to evaluate the prognostic factors. Results: The 1 year ,3 years and 5 years total survival rate of these 103 gastrointestinal stromal tumors was 86.3%, 51.7%, 42.8%. Tumor size, mitotic rate, primary organ of tumor and radical surgical excision or not were analyzed respectively, the difference is statistical significance (P<0.05). No significiant difference between the group of sex, age, immunohistochemistry expression and multi-organ resection or not. Conclusion: Flechers’ classification is rational, scientific, simple and feasible. Radical surgical excision is the best therapy to the primary gastrointestinal stomal tumor.

No significant financial relationships to disclose.

The p53--Mdm2--HAUSP complex is involved in p53 stabilization by HAUSP

The ubiquitin-specific protease HAUSP is a critical component of the p53-Mdm2 pathway by acting as a specific deubiquitinase for both p53 and Mdm2. Recent structural studies have indicated that p53 and Mdm2 bind to the N-terminal TRAF-like domain of HAUSP in a mutually exclusive manner. To understand the mechanism of HAUSP-mediated effects, we have created a p53 mutant that lacks HAUSP binding based on the crystal structure analysis. Indeed, this mutant p53 protein can be degraded by Mdm2 but fails to interact with HAUSP both in vitro and in vivo. Surprisingly, however, we have found that direct interaction between HAUSP and p53 is not absolutely required for it to antagonize efficiently Mdm2-mediated ubiquitination of p53 and that HAUSP is capable of enzymatically functioning in trans on p53 by using Mdm2 as a bridge. Further, we show that a trimeric protein complex containing p53, Mdm2 and HAUSP can exist in vivo, despite mutually exclusive binding, with Mdm2 serving as a binding mediator for p53 and HAUSP. These findings reveal the complication of HAUSP-mediated effects in the p53-Mdm2 interplay. It also has important implications for the development of novel chemotherapeutic compounds aimed at blocking this protein-protein interaction.

The histone H3K4 demethylase SMCX links REST target genes to X-linked mental retardation

Gene transcription is critically influenced by chromatin structure and the modification status of histone tails. Methylation of lysine residues in histone tails is dynamically regulated by the opposing activities of histone methyltransferases and histone demethylases. Here we show that JARID1C/SMCX, a JmjC-domain-containing protein implicated in X-linked mental retardation and epilepsy, possesses H3K4 tri-demethylase activity and functions as a transcriptional repressor. An SMCX complex isolated from HeLa cells contains additional chromatin modifiers (the histone deacetylases HDAC1 and HDAC2, and the histone H3K9 methyltransferase G9a) and the transcriptional repressor REST, suggesting a direct role for SMCX in chromatin dynamics and REST-mediated repression. Chromatin immunoprecipitation reveals that SMCX and REST co-occupy the neuron-restrictive silencing elements in the promoters of a subset of REST target genes. RNA-interference-mediated depletion of SMCX derepresses several of these targets and simultaneously increases H3K4 trimethylation at the sodium channel type 2A (SCN2A) and synapsin I (SYN1) promoters. We propose that loss of SMCX activity impairs REST-mediated neuronal gene regulation, thereby contributing to SMCX-associated X-linked mental retardation.

S. pombe LSD1 Homologs Regulate Heterochromatin Propagation and Euchromatic Gene Transcription

LSD1 represses and activates transcription by demethylating histone H3K4me and H3K9me, respectively. Genetic ablation of the S. pombe homologs, splsd1 and splsd2, resulted in slow growth and lethality, respectively, underscoring their physiological importance. spLsd1 and spLsd2 form a stable protein complex, which exhibits demethylase activity toward methylated H3K9 in vitro. Both proteins were associated with the heterochromatin boundary regions and euchromatic gene promoters. Loss of spLsd1 resulted in increased H3K9 methylation accompanied by reduced euchromatic gene transcription and heterochromatin propagation. Removal of the H3K9 methylase Clr4 partially suppressed the slow growth phenotype of splsd1Delta. Conversely, catalytically inactivating point mutations in the splsd1 and splsd2 genes partially mimicked the growth and heterochromatin propagation phenotypes. Taken together, these findings suggest the importance of both enzymatic and nonenzymatic roles of spLsd1 in regulating heterochromatin propagation and euchromatic transcription and also suggest that misregulation of spLsd1/2 is likely to impact the epigenetic state of the cell.

Determination of the natural frequency of a cantilevered ZnO nanowire resonantly excited by a sinusoidal electric field

The electric-field-induced mechanical resonance of an individual nanotube (NT) or nanowire (NW) has been utilized as a versatile technique for in situ measurement of the Young's modulus of the NT/NW in electron microscopes. The key step of this technique is to determine the fundamental natural frequency of the NT/NW. However, the emergence of super- and/or sub-harmonic resonances might make the determination uncertain. This paper investigates the resonance behaviour of ZnO NWs in a nanotip-nanowire system in order to clarify this obscurity. It is found that forced and parametric resonance are two basic modes of the observed multi-frequency resonances and that each mode exhibits a distinct characteristic. By controlling the driving force exerted on the NW to be either lateral or axial, the two otherwise entangled modes are clearly separated. Based on this resonance mode separation, a criterion for identifying the natural frequency of ZnO NWs is proposed.

Novel magnetic rings for rapid vascular reconstruction in canine liver transplantation model

OBJECTIVE

Magnetic rings were used for rapid vascular reconstruction in a canine liver transplantation model.

MATERIALS AND METHODS

Thirty-two adult mongrel dogs weighing 13 to 16 kg were randomly selected as donors or recipients of transplantations. The recipients were randomly divided into two groups: group A (n = 10) had magnetic rings used for vascular reconstruction without venovenous bypass; group B (n = 6) had vascular reconstruction performed by continuous suturing with splenojugular venovenous bypass.

RESULTS

In group A, the entire operative period was 3.24 +/- 0.49 hours, the durations of clamping the portal vein and the infrahepatic vena cava of the recipient were 5.89 +/- 2.27 minutes and 3.89 +/- 0.73 minutes, respectively. In group B, the entire operative period was 4.12 +/- 0.51 hours with the duration of clamping portal vein and infrahepatic vena cava, 28.33 +/- 6.04 minutes and 12.16 +/- 3.72 minutes (P < .01 vs group A). In group A, mean arterial pressure dropped during the anhepatic phase but recovered quickly after reperfusion. The fluid infusion was about 730.56 +/- 50.56 mL in the group A and a pressor agent was unnecessary. In group B, blood pressure dropped during the anhepatic phase and slowly recovered. The fluid infusion was about 2241.67 +/- 390.78 mL and a pressor agent was used to maintain the blood pressure of the recipient. No twist or thrombus was discovered in the anastomoses group A and the endothelium at the site of anastomosis was entire. In group B, errhysis was common in the anastomotic stomas. Nine of 10 dogs in group A survived more than 3 days, the longest being 8 days, whereas four of the six dogs in group B survived less than 3 days.

CONCLUSION

The results showed that the anhepatic time was significantly shortened (about 5.89 +/- 2.27 minutes) in group A compared with group B and venovenous bypass was unnecessary. Magnetic rings could be used for rapid vascular reconstruction in canine liver transplantation model. The long-term results of this procedure should be clarified before it is applied in clinical practice in the future.

Progress in developing a composite tissue-engineered aortic valve

This paper reviews the rationale for developing a tissue-engineered aortic valve by building up the complex microstructure from its basic components, and presents recent progress towards that goal. Over the past 4 years, we have been working on engineering the functional components of the composite valve the collagen fiber bundles, the elastin sheets, and the hyaluronan matrix that keeps the tissue hydrated. Most recently, we have been working on optimizing the geometry and material properties of the collagen constructs, by varying their size and aspect ratio, and the types of loading protocols the constructs experience during the culture process.

Combustion-generated nanoparticulates in the El Paso, TX, USA / Juarez, Mexico Metroplex: their comparative characterization and potential for adverse health effects

In this paper we report on the collection of fine (PM₁) and ultrafine (PM_0.1), or nanoparticulate, carbonaceous materials using thermophoretic precipitation onto silicon monoxide/formvar-coated 3 mm grids which were examined in the transmission electron microscope (TEM). We characterize and compare diesel particulate matter (DPM), tire particulate matter (TPM), wood burning particulate matter, and other soot (or black carbons (BC)) along with carbon nanotube and related fullerene nanoparticle aggregates in the outdoor air, as well as carbon nanotube aggregates in the indoor air; and with reference to specific gas combustion sources. These TEM investigations include detailed microstructural and microdiffraction observations and comparisons as they relate to the aggregate morphologies as well as their component (primary) nanoparticles. We have also conducted both clinical surveys regarding asthma incidence and the use of gas cooking stoves as well as random surveys by zip code throughout the city of El Paso. In addition, we report on short term (2 day) and longer term (2 week) in vitro assays for black carbon and a commercial multiwall carbon nanotube aggregate sample using a murine macrophage cell line, which demonstrate significant cytotoxicity; comparable to a chrysotile asbestos nanoparticulate reference. The multi-wall carbon nanotube aggregate material is identical to those collected in the indoor and outdoor air, and may serve as a surrogate. Taken together with the plethora of toxic responses reported for DPM, these findings prompt concerns for airborne carbonaceous nanoparticulates in general. The implications of these preliminary findings and their potential health effects, as well as directions for related studies addressing these complex issues, will also be examined.