Detecting and Understanding the Roles of Nitric Oxide in biology

We are pursuing a dual strategy for investigating the chemistry of nitric oxide as a biological signaling agent. In one approach, metal-based fluorescent sensors for the detection of NO in living cells are evaluated, and a sensor based on a copper fluorescein complex has proved to be a valuable lead compound. Sensors of this class permit identification of NO from both inducible and constitutive forms of nitric oxide synthase and facilitate investigation of different NO functions in response to external stimuli. In the other approach, we employ synthetic model complexes of iron−sulfur clusters to probe their reactivity toward nitric oxide as biomimics of the active sites of iron−sulfur proteins. Our studies reveal that NO disassembles the Fe−S clusters to form dinitrosyl iron complexes.National Science Foundation (U.S.) (CHE-0907905)National Institute of General Medical Sciences (U.S.) (Grant F32 GM082031-03

A new portable monitor for measuring odorous compounds in oral, exhaled and nasal air

<p>Abstract</p> <p>Background</p> <p>The B/B Checker^®, a new portable device for detecting odorous compounds in oral, exhaled, and nasal air, is now available. As a single unit, this device is capable of detecting several kinds of gases mixed with volatile sulfur compounds (VSC) in addition to other odorous gasses. The purpose of the present study was to evaluate the effectiveness of the B/B Checker^®for detecting the malodor level of oral, exhaled, and nasal air.</p> <p>Methods</p> <p>A total of 30 healthy, non-smoking volunteers (16 males and 14 females) participated in this study. The malodor levels in oral, exhaled, and nasal air were measured using the B/B Checker^®and by organoleptic test (OT) scores. The VSCs in each air were also measured by gas chromatography (GC). Associations among B/B Checker^®measurements, OT scores and VSC levels were analyzed using Spearman correlation coefficients. In order to determine the appropriate B/B Checker^®level for screening subjects with malodor, sensitivity and specificity were calculated using OT scores as an identifier for diagnosing oral malodor.</p> <p>Results</p> <p>In oral and nasal air, the total VSC levels measured by GC significantly correlated to that measured by the B/B Checker^®. Significant correlation was observed between the results of OT scores and the B/B Checker^®measurements in oral (r = 0.892, p < 0.001), exhaled (r = 0.748, p < 0.001) and nasal air (r = 0.534, p < 0.001). The correlation between the OT scores and VSC levels was significant only for oral air (r = 0.790, p < 0.001) and nasal air (r = 0.431, p = 0.002); not for exhaled air (r = 0.310, p = 0.096). When the screening level of the B/B Checker^®was set to 50.0 for oral air, the sensitivity and specificity were 1.00 and 0.90, respectively. On the other hand, the screening level of the B/B Checker^®was set to 60.0 for exhaled air, the sensitivity and specificity were 0.82 and 1.00, respectively.</p> <p>Conclusion</p> <p>The B/B Checker^®is useful for objective evaluation of malodor in oral, exhaled and nasal air and for screening subjects with halitosis.</p> <p>Trial registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01139073">NCT01139073</a></p

Associations among hair loss, oral sulfur-containing gases, and gastrointestinal and metabolic linked diseases in Japanese elderly men: pilot study

<p>Abstract</p> <p>Background</p> <p>Male pattern baldness (MPB), an observable trait, has been reported to be associated with various diseases, such as prostate cancer and cardiovascular disease. Oral sulfur-containing gases have also been suggested to be useful as markers of systemic health condition. However, there are no known reports regarding the associations among MPB, and oral sulfur-containing gases, and systemic health conditions in males.</p> <p>Methods</p> <p>We studied 170 male subjects aged either 60 or 65 years old. The degree of MPB was assessed using the Norwood-Hamilton Baldness scale. Oral sulfur-containing gases were measured using a compact-designed device. All subjects completed physical and laboratory blood examinations, a face-to-face medical questionnaire, and an oral examination.</p> <p>Results</p> <p>There were significant differences between the levels of CH₃SCH₃and baldness patterns, independent of age. When we analyzed whether the association was linked to systemic health condition, a strong significant association was observed between the level of CH₃SCH₃and severe MPB in subjects with gastrointestinal diseases, hypertension, and hypercholesterolemia.</p> <p>Conclusion</p> <p>These results suggest that MPB is associated with the level of CH₃SCH₃, a sulfur-containing gas that causes oral malodor, in elderly Japanese males. Further, the association was intensified by the existence of gastrointestinal tract and metabolic disorders.</p

Methanotrophy, Methylotrophy, the Human Body and Disease

Methylotrophic Bacteria use one-carbon (C1) compounds as their carbon source. They have been known to be associated to the human body for almost 20 years as part of the normal flora and were identified as pathogens in the early 1990s in end-stage HIV patients and chemotherapy patients. In this chapter, I look at C1 compounds in the human body and exposure from the environment and then consider Methylobacterium spp. and Methylorubrum spp. in terms of infections, its role in breast and bowel cancers; Methylococcus capsulatus and its role in inflammatory bowel disease, and Brevibacterium casei and Hyphomicrobium sulfonivorans as part of the normal human flora. I also consider the abundance of methylotrophs from the Actinobacteria being identified in human studies and the potential bias of the ionic strength of culture media and the needs for future work. Within the scope of future work, I consider the need for the urgent assessment of the pathogenic, oncogenic, mutagenic and teratogenic potential of Methylobacterium spp. and Methylorubrum spp. and the need to handle them at higher containment levels until more data are available

Organic Light Emitting Diodes: Developing Chemicals to Light the Future

Advisor: Richard Eisenberg, Ph.D. Department of Chemistr