Evidence of depot-specific regulation of all-trans-retinoic acid biosynthesis in human adipose tissue.

The prevalence of obesity continues to rise, underscoring the need to better understand the pathways mediating adipose tissue (AT) expansion. All-trans-retinoic acid (atRA), a bioactive vitamin A metabolite, regulates adipogenesis and energy metabolism, and, in rodent studies, aberrant vitamin A metabolism appears a key facet of metabolic dysregulation. The relevance of these findings to human disease is unknown, as are the specific enzymes implicated in vitamin A metabolism within human AT. We hypothesized that in human AT, family 1A aldehyde dehydrogenase (ALDH1A) enzymes contribute to atRA biosynthesis in a depot-specific manner. To test this hypothesis, parallel samples of subcutaneous and omental AT from participants (n = 15) were collected during elective abdominal surgeries to quantify atRA biosynthesis and key atRA synthesizing enzymes. ALDH1A1 was the most abundant ALDH1A isoform in both AT depots with expression approximately twofold higher in omental than subcutaneous AT. ALDH1A2 was detected only in omental AT. Formation velocity of atRA was approximately threefold higher (p = 0.0001) in omental AT (9.8 [7.6, 11.2]) pmol/min/mg) than subcutaneous AT (3.2 [2.1, 4.0] pmol/min/mg) and correlated with ALDH1A2 expression in omental AT (ß-coefficient = 3.07, p = 0.0007) and with ALDH1A1 expression in subcutaneous AT (ß-coefficient = 0.13, p = 0.003). Despite a positive correlation between body mass index (BMI) and omental ALDH1A1 protein expression (Spearman r = 0.65, p = 0.01), BMI did not correlate with atRA formation. Our findings suggest that ALDH1A2 is the primary mediator of atRA formation in omental AT, whereas ALDH1A1 is the principal atRA-synthesizing enzyme in subcutaneous AT. These data highlight AT depot as a critical variable for defining the roles of retinoids in human AT biology.

Single institution and statewide performance of ultrasound in diagnosing appendicitis in pregnancy.

OBJECTIVE: Assess the performance of ultrasound (US) in pregnant patients presenting with acute abdominal pain concerning for appendicitis. METHODS: Descriptive analysis of pregnant patients who underwent an US for acute abdominal pain over a 6-year period using data from a statewide quality improvement collaborative and a single center. RESULTS: Statewide, 131 pregnant patients underwent an appendectomy and 85% had an US. In our single-center case series, 49 pregnant patients underwent an US for acute abdominal pain and four patients had appendicitis (8%). Of those, three were definitively diagnosed with US. The appendix was visualized by US in five patients (3 appendicitis/2 normal). Mean gestational age was 11 weeks for visualization of the appendix versus 20 weeks for non-visualization (p < 0.001). Concordance between US and pathology was similar statewide and at our institution (43%). CONCLUSIONS: US appears to play a central role in the evaluation of appendicitis in pregnant women, especially in the first trimester, and often contributes to definitive disposition. US performed less well in excluding appendicitis; however, in certain clinical settings, providers appeared to trust US findings. From these results, we developed a multidisciplinary imaging pathway for pregnant patients who present with acute abdominal pain concerning for appendicitis.

Recurrent symptoms after fundoplication with a negative pH study--recurrent reflux or functional heartburn?

INTRODUCTION: A small cohort of patients present after antireflux surgery complaining of recurrent heartburn. Over two thirds of these patients will have a negative 24-h pH study. The aim of our study is to determine whether these patients have an associated functional disorder or abnormal cytokine activity and to examine the reproducibility of pH testing. METHODS: A prospective analysis was carried out on a cohort of patients who had undergone a fundoplication and postoperative pH testing for recurrent heartburn: group A--patients with recurrent heartburn and a negative 24-h pH study and group B (control group)--patients with recurrent heartburn and a positive pH study. Questionnaires, a blood sample, and repeat pH testing were completed. RESULTS: Sixty-nine patients were identified. Group A's depression score (8.6 +/- 4.1) was significantly higher than group B's (5.9 +/- 4.2; P = 0.03). Cytokine levels were similar in both groups. Forty-seven of 49 (96%) patients who underwent repeat pH testing had a negative study. Symptom-reflux correlation was highly significant (P < 0.001). CONCLUSION: Some patients with recurrent heartburn and a negative pH study have associated functional or psychiatric comorbidities such as depression. Reproducibility of 24-h pH testing in these patients is excellent.

The use of a gamma probe and radioactive technetium to identify obscure gastrointestinal bleeding.

Lower gastrointestinal bleeding is a common cause of hospital admission. This bleeding is most often secondary to diverticuli, malignancy, or colitis. Rarely, the location of lower gastrointestinal bleeding cannot be identified after exhaustive efforts with endoscopy, angiography, and other modalities. To address this unique clinical situation, we present a modification of the technique for sentinel lymph node biopsy in which a gamma probe is used to identify the source of hemorrhage. This is completed intraoperatively after preoperative radioactive technetium sulfur colloid is injected at the time of angiography. This approach involves minimal risk and provides the surgeon with an improved ability to localize bleeding, as well as potentially minimize the extent of bowel resection.

Pancreatic fistulae: are we making progress?

BACKGROUND/PURPOSE: Pancreatic fistulae constitute a morbid outcome of pancreatic surgery. Yet, a definition of a pancreatic fistula does not exist that can be reliably used to report on and study this outcome. We compare reported fistula, morbidity, and mortality rates with fistula parameters in order to identify high-risk fistulae predictive of morbid outcomes. METHODS: A systematic literature review was performed; of 1426 articles identified, 43 articles ultimately met inclusion and exclusion criteria and were reviewed. Fistula, morbidity, and mortality rates as well as fistula definitions were extracted and then compared and graphically reported. RESULTS: Thirty-two different definitions of pancreatic fistulae were found in 43 articles; only 24 articles defined fistulae according to all three parameters examined in this study. The data trends suggest that fistula, morbidity, and mortality rates have remained relatively stable since 1980. Further, drainage volumes, amylase levels, and length of drainage do not appear to correlate with reported morbidity or mortality rates. CONCLUSIONS: This study suggests that pancreatic fistulae may not correlate with morbidity and mortality. Further, the parameters historically used to define fistulae do not appear to correlate with morbidity and mortality. A different system is needed to identify this outcome and determine its clinical significance.