fast-and-accurate-exhaled-breath-ammonia-measurement

Fast and Accurate Exhaled Breath Ammonia Measurement

This exhaled breath ammonia method uses a fast and highly sensitive spectroscopic method known as quartz enhanced photoacoustic spectroscopy (QEPAS) that ...

St. Luke's University Hospital

Non-alcoholic fatty liver disease: lumen-liver interactions and possible role for probiotics.

Gut flora-based therapy in liver disease? The liver cares about the gut.

Hepatic phosphorus magnetic resonance spectroscopy (31P MRS) offers the exciting potential of studying metabolic processes in the human liver in vivo. Many investigators have utilized 31P MRS to research a broad range of metabolic questions, and there is outstanding potential for this imaging modality in the future. However, at times it is difficult to appreciate this potential because most published series have been small, and comparisons between studies are difficult. Indeed, the published literature contains significant variation in data acquisition and data analysis techniques and, perhaps most importantly, the interpretation of the data itself. As MR technology continues to evolve and more studies are being performed, perhaps a greater consensus of study techniques and endpoints will emerge. This review summarizes the present literature on human hepatic 31P MRS.

Hepatic 31P magnetic resonance spectroscopy: a hepatologist's user guide.

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease in the United States and is prevalent in morbidly obese patients. While weight loss and treatment of risk factors are recommended, the reported effects of bariatric surgery on NAFLD are mixed.

Roux-en-Y gastric bypass improves liver histology in patients with non-alcoholic fatty liver disease.

Adult-to-adult living donor liver transplantation is an increasingly important option for 17000 patients awaiting liver transplantation in the United States. However, adult-to-adult living donor liver transplantation volumes peaked in 2001 (N = 518), and have gradually fallen in 2002 (N = 362), 2003 (N = 321), and 2004 (N = 323). Recent concerns about donor safety and ethical considerations have made careful analysis of donor availability and selection criteria critically important. We conducted a retrospective review of our active liver transplant recipient registry (N = 251) and compared it to our living donor registry (N = 231), which included all potential living donors before the selection process. Fifteen percent of recipients accounted for the majority (53%) of donor evaluations, whereas 42% of recipients did not have even a single donor evaluation. Recipient diagnosis appears to have a significant impact on donor availability, with donors rarely evaluated for patients with alcoholic cirrhosis. Careful and stringent selection criteria rule out 67% of potential donors.

Trends in adult-to-adult living donor liver transplant organ donation: the Johns Hopkins experience.

Nonalcoholic fatty liver disease (NAFLD) is a common and potentially serious form of chronic liver disease. Although NAFLD is known to be associated with obesity and some comorbid conditions, less is known about the severity of NAFLD among different racial groups.

Race and comorbid factors predict nonalcoholic fatty liver disease histopathology in severely obese patients.

Black cohosh, safety, and public awareness.

Magnetic resonance spectroscopy (MRS) measures hepatic fat and adenosine triphosphate (ATP), but magnetic resonance studies are challenging in obese subjects. We aimed to evaluate the inter- and intrarater reliability and stability of hepatic fat and ATP measurements in a cohort of overweight and obese adults.

Hepatic fat and adenosine triphosphate measurement in overweight and obese adults using 1H and 31P magnetic resonance spectroscopy.

The effect of a probiotic on hepatic steatosis.

Weight loss through lifestyle changes is recommended for nonalcoholic fatty liver disease (NAFLD). However, its efficacy in patients with type 2 diabetes is unproven.

Effect of a 12-month intensive lifestyle intervention on hepatic steatosis in adults with type 2 diabetes.

Amongst volatile compounds (VCs) present in exhaled breath, ammonia has held great promise and yet it has confounded researchers due to its inherent reactivity. Herein we have evaluated various factors in both breath instrumentation and the breath collection process in an effort to reduce variability. We found that the temperature of breath sampler and breath sensor, mouth rinse pH, and mode of breathing to be important factors. The influence of the rinses is heavily dependent upon the pH of the rinse. The basic rinse (pH 8.0) caused a mean increase of the ammonia concentration by 410 ± 221 ppb. The neutral rinse (pH 7.0), slightly acidic rinse (pH 5.8), and acidic rinse (pH 2.5) caused a mean decrease of the ammonia concentration by 498 ± 355 ppb, 527 ± 198 ppb, and 596 ± 385 ppb, respectively. Mode of breathing (mouth-open versus mouth-closed) demonstrated itself to have a large impact on the rate of recovery of breath ammonia after a water rinse. Within 30 min, breath ammonia returned to 98 ± 16% that of the baseline with mouth open breathing, while mouth closed breathing allowed breath ammonia to return to 53 ± 14% of baseline. These results contribute to a growing body of literature that will improve reproducibly in ammonia and other VCs.

Article	Year
Non-alcoholic fatty liver disease: lumen-liver interactions and possible role for probiotics. Journal of hepatology\| PubMed ID: 12713883	2003
Gut flora-based therapy in liver disease? The liver cares about the gut. Hepatology (Baltimore, Md.)\| PubMed ID: 15122746	2004
Hepatic 31P magnetic resonance spectroscopy: a hepatologist's user guide. Liver international : official journal of the International Association for the Study of the Liver\| PubMed ID: 15910484	2005
Roux-en-Y gastric bypass improves liver histology in patients with non-alcoholic fatty liver disease. Obesity research\| PubMed ID: 16076987	2005
Trends in adult-to-adult living donor liver transplant organ donation: the Johns Hopkins experience. Progress in transplantation (Aliso Viejo, Calif.)\| PubMed ID: 16676671	2006
Race and comorbid factors predict nonalcoholic fatty liver disease histopathology in severely obese patients. Surgery for obesity and related diseases : official journal of the American Society for Bariatric Surgery\| PubMed ID: 16925194	2005
Black cohosh, safety, and public awareness. Liver international : official journal of the International Association for the Study of the Liver\| PubMed ID: 17696943	2007
Hepatic fat and adenosine triphosphate measurement in overweight and obese adults using 1H and 31P magnetic resonance spectroscopy. Liver international : official journal of the International Association for the Study of the Liver\| PubMed ID: 18331237	2008
The effect of a probiotic on hepatic steatosis. Journal of clinical gastroenterology\| PubMed ID: 18936646	2008
Effect of a 12-month intensive lifestyle intervention on hepatic steatosis in adults with type 2 diabetes. Diabetes care\| PubMed ID: 20664019	2010
Factors influencing breath ammonia determination. Journal of breath research\| PubMed ID: 23774041	2013

Steven F. Solga

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