Alberto Pieretti

Dual-modality fluorescence and full-field optical coherence microscopy for biomedical imaging applications

Full-field optical coherence microscopy (FFOCM) is a high-resolution interferometric technique that is particularly attractive for biomedical imaging. Here we show that combining it with structured illumination fluorescence microscopy on one platform can increase its versatility since it enables co-localized registration of optically sectioned reflectance and fluorescence images. To demonstrate the potential of this dual modality, a fixed and labeled mouse retina was imaged. Results showed that both techniques can provide complementary information and therefore the system could potentially be useful for biomedical imaging applications.

Nestin-expressing Cells in the Gut Give Rise to Enteric Neurons and Glial Cells

Background  Neuronal stem cells (NSCs) are promising for neurointestinal disease therapy. Although NSCs have been isolated from intestinal musclularis, their presence in mucosa has not been well described. Mucosa‐derived NSCs are accessible endoscopically and could be used autologously. Brain‐derived Nestin‐positive NSCs are important in endogenous repair and plasticity. The aim was to isolate and characterize mucosa‐derived NSCs, determine their relationship to Nestin‐expressing cells and to demonstrate their capacity to produce neuroglial networks in vitro and in vivo.

Altered Goblet Cell Differentiation and Surface Mucus Properties in Hirschsprung Disease

Hirschsprung disease-associated enterocolitis (HAEC) leads to significant mortality and morbidity, but its pathogenesis remains unknown. Changes in the colonic epithelium related to goblet cells and the luminal mucus layer have been postulated to play a key role. Here we show that the colonic epithelium of both aganglionic and ganglionic segments are altered in patients and in mice with Hirschsprung disease (HSCR). Structurally, goblet cells were altered with increased goblet cell number and reduced intracellular mucins in the distal colon of biopsies from patients with HSCR. Endothelin receptor B (Ednrb) mutant mice showed increased goblet cell number and size and increased cell proliferation compared to wild-type mice in aganglionic segments, and reduced goblet cell size and number in ganglionic segments. Functionally, compared to littermates, Ednrb−/− mice showed increased transepithelial resistance, reduced stool water content and similar chloride secretion in the distal colon. Transcript levels of goblet cell differentiation factors SPDEF and Math1 were increased in the distal colon of Ednrb−/− mice. Both distal colon from Ednrb mice and biopsies from HSCR patients showed reduced Muc4 expression as compared to controls, but similar expression of Muc2. Particle tracking studies showed that mucus from Ednrb−/− mice provided a more significant barrier to diffusion of 200 nm nanoparticles as compared to wild-type mice. These results suggest that aganglionosis is associated with increased goblet cell proliferation and differentiation and subsequent altered surface mucus properties, prior to the development of inflammation in the distal colon epithelium. Restoration of normal goblet cell function and mucus layer properties in the colonic epithelium may represent a therapeutic strategy for prevention of HAEC.

Effects of Intraoperative Fluid Management on Postoperative Outcomes: A Hospital Registry Study.

Objective:Evaluate the dose-response relationship between intraoperative fluid administration and postoperative outcomes in a large cohort of surgical patients. Background:Healthy humans may live in a state of fluid responsiveness without the need for fluid supplementation. Goal-directed protocols driven by such measures are limited in their ability to define the optimal fluid state during surgery. Methods:This analysis of data on file included 92,094 adult patients undergoing noncardiac surgery with endotracheal intubation between 2007 and 2014 at an academic tertiary care hospital and two affiliated community hospitals. The primary exposure variable was total intraoperative volume of crystalloid and colloid administered. The primary outcome was 30-day survival. Secondary outcomes were respiratory complications within three postoperative days (pulmonary edema, reintubation, pneumonia, or respiratory failure) and acute kidney injury. Exploratory outcomes were postoperative length of stay and total cost of care. Our models were adjusted for patient-, procedure-, and anesthesia-related factors. Results:A U-shaped association was observed between the volume of fluid administered intraoperatively and 30-day mortality, costs, and postoperative length of stay. Liberal fluid volumes (highest quintile of fluid administration practice) were significantly associated with respiratory complications whereas both liberal and restrictive (lowest quintile) volumes were significantly associated with acute kidney injury. Moderately restrictive volumes (second quintile) were consistently associated with optimal postoperative outcomes and were characterized by volumes approximately 40% less than traditional textbook estimates: infusion rates of approximately 6–7 mL/kg/hr or 1 L of fluid for a 3-hour case. Conclusions:Intraoperative fluid dosing at the liberal and restrictive margins of observed practice is associated with increased morbidity, mortality, cost, and length of stay.

A Novel In Vitro Model to Study Alveologenesis

Many pediatric pulmonary diseases are associated with significant morbidity and mortality due to impairment of alveolar development. The lack of an appropriate in vitro model system limits the identification of therapies aimed at improving alveolarization. Herein, we characterize an ex vivo lung culture model that facilitates investigation of signaling pathways that influence alveolar septation. Postnatal Day 4 (P4) mouse pup lungs were inflated with 0.4% agarose, sliced, and cultured within a collagen matrix in medium that was optimized to support cell proliferation and promote septation. Lung slices were grown with and without 1D11, an active transforming growth factor-β-neutralizing antibody. After 4 days, the lung sections (designated P4 + 4) and noncultured lung sections were examined using quantitative morphometry to assess alveolar septation and immunohistochemistry to evaluate cell proliferation and differentiation. We observed that the P4 + 4 lung sections exhibited ex vivo alveolarization, as evidenced by an increase in septal density, thinning of septal walls, and a decrease in mean linear intercept comparable to P8, age-matched, uncultured lungs. Moreover, immunostaining showed ongoing cell proliferation and differentiation in cultured lungs that were similar to P8 controls. Cultured lungs exposed to 1D11 had a distinct phenotype of decreased septal density when compared with untreated P4 + 4 lungs, indicating the utility of investigating signaling in these lung slices. These results indicate that this novel lung culture system is optimized to permit the investigation of pathways involved in septation, and potentially the identification of therapeutic targets that enhance alveolarization.

Full-field optical coherence microscopy is a novel technique for imaging enteric ganglia in the gastrointestinal tract

Background  Noninvasive methods are needed to improve the diagnosis of enteric neuropathies. Full‐field optical coherence microscopy (FFOCM) is a novel optical microscopy modality that can acquire 1 μm resolution images of tissue. The objective of this research was to demonstrate FFOCM imaging for the characterization of the enteric nervous system (ENS).

Renal Abscess in Previously Healthy Girl

We describe the case of a previously healthy 11-year-old girl with a Staphylococcal aureus renal abscess. The diagnosis was confirmed by renal ultrasonography and abdominal computed tomography. We emphasize the need to obtain an abdominal ultrasound scan and computed tomography scan in patients with abdominal or flank pain, and laboratory evidences of infection to avoid diagnostic and therapeutic delays.

Megacalycosis: a rare condition

Megacalycosis is an extremely rare condition. We report our experience with two cases and discuss its pathogenesis, diagnosis and management in children. Our two patients had presented a prior diagnosis of congenital hydronephrosis. An increased number of calyces with a significant disproportion between the degree of calyceal dilatation and a mildly dilated renal pelvis were found in each case. Megacalycosis must be considered in the differential diagnosis of congenital hydronephrosis, polycalycosis, and infundibular stenosis. The diagnosis is suggested by ultrasound and confirmed by diuretic renography, intravenous pyelography or magnetic resonance urography. Voiding cystourethrography should be performed to rule out vesicoureteral reflux. A high index of suspicion is needed for the diagnosis of this condition.

Bladder Hamartoma in a Fetus: Case Report

We present the case of the youngest reported patient with a bladder hamartoma detected prenatally by ultrasonography. Bladder tumors in newborns are rare, but a hamartoma should not be discarded among the diagnostic possibilities when evaluating a fetus or a newborn with a polypoid bladder lesion.

Sa1817 Intestinal Mucosa-Derived Neural Stem Cells Give Rise to Neurons and Glia

identical to those formed by brain NSCs. 5) NSCs from both brain and gut gave rise to neurons In Vivo when transplanted into aganglionic chicken hindgut. Nestin expression was lost by the neuronal lineage, but retained by the glial lineage. 6) Addition of glial-derived neurotrophic factor (GDNF) significantly increased the number of neurons in culture. Conclusions: Brainand gut-derived NSCs share many similarities. Both arise from Nestin+ cells. As neurospheres, they maintain Nestin expression. Nestin is downregulated as NSC differentiate to neurons, but preserved in newly formed glia. Both can be successfully transplanted into aganglionic chicken, where they give rise to neurons and glial cells.