3D Neurovascular Unit Tissue Model to Assess Responses to Traumatic Brain Injury.

The neurovascular unit (NVU) is a critical interface in the central nervous system that links vascular interactions with glial and neural tissue. Disruption of the NVU has been linked to the onset and progression of neurodegenerative diseases. Despite its significance the NVU remains challenging to study in a physiologically relevant manner.

Microbes affect gut epithelial cell composition through immune-dependent regulation of intestinal stem cell differentiation.

Gut microbes play important roles in host physiology; however, the mechanisms underlying their impact remain poorly characterized. Here, we demonstrate that microbes not only influence gut physiology but also alter its epithelial composition. The microbiota and pathogens both influence intestinal stem cell (ISC) differentiation.

Multiscale analysis reveals that diet-dependent midgut plasticity emerges from alterations in both stem cell niche coupling and enterocyte size.

The gut is the primary interface between an animal and food, but how it adapts to qualitative dietary variation is poorly defined. We find that the midgut plastically resizes following changes in dietary composition. A panel of nutrients collectively promote gut growth, which sugar opposes.

A Rare Cohort of Two Rhnull Individuals.

Objective: A 77 year old female was admitted with a subdural hematoma requiring 1 unit of apheresis platelets. She was a study subject in the 1960s and was found to be Rhnull, along with another individual who previously served as a directed donor for her.

Methods: Serologic testing performed by the immunohematology reference laboratory (IRL) confirmed that the patient was Rhnull and expressed anti-Rh29 antibodies.

Hippo, TGF-β, and Src-MAPK pathways regulate transcription of the upd3 cytokine in Drosophila enterocytes upon bacterial infection.

Cytokine signaling is responsible for coordinating conserved epithelial regeneration and immune responses in the digestive tract. In the Drosophila midgut, Upd3 is a major cytokine, which is induced in enterocytes (EC) and enteroblasts (EB) upon oral infection, and initiates intestinal stem cell (ISC) dependent tissue repair. To date, the genetic network directing upd3 transcription remains largely uncharacterized.

Regional Cell-Specific Transcriptome Mapping Reveals Regulatory Complexity in the Adult Drosophila Midgut.

Deciphering contributions of specific cell types to organ function is experimentally challenging. The Drosophila midgut is a dynamic organ with five morphologically and functionally distinct regions (R1-R5), each composed of multipotent intestinal stem cells (ISCs), progenitor enteroblasts (EBs), enteroendocrine cells (EEs), enterocytes (ECs), and visceral muscle (VM). To characterize cellular specialization and regional function in this organ, we generated RNA-sequencing transcriptomes of all five cell types isolated by FACS from each of the five regions, R1-R5.

Methods to assess intestinal stem cell activity in response to microbes in Drosophila melanogaster.

Drosophila melanogaster presents itself as a powerful model for studying the somatic stem cells of the gut and how bacteria affect intestinal homeostasis. The Gal4/UAS/Gal80 (ts) system allows for temporally controlled expression of fluorescent proteins, RNAi knock-down, and other genetic constructs targeted to specific cell populations in the midgut. Similarly, FLP/FRT-mediated somatic recombinations in intestinal stem cells (ISCs) are utilized to visualize and analyze the clonal lineages of individual or populations of stem cells.

Airway constriction measured from tantalum bronchograms in conscious mice in response to methacholine.

A single-projection X-ray technique showed an increase in functional residual capacity (FRC) in conscious mice in response to aerosolized methacholine (MCh) with little change in airway resistance (Raw) measured using barometric plethysmography (Lai-Fook SJ, Houtz PK, Lai Y-L. J Appl Physiol 104: 521-533, 2008). The increase in FRC presumably prevented airway constriction by offsetting airway contractility.

End-expiratory and tidal volumes measured in conscious mice using single projection x-ray images.

The evaluation of airway resistance (R(aw)) in conscious mice requires both end-expiratory (V(e)) and tidal volumes (V(t)) (Lai-Fook SJ and Lai YL. J Appl Physiol 98: 2204-2218, 2005). In anesthetized BALB/c mice we measured lung area (A(L)) from ventral-to-dorsal x-ray images taken at FRC (V(e)) and after air inflation with 0.

Transdiaphragmatic transport of tracer albumin from peritoneal to pleural liquid measured in rats.

In conscious Wistar-Kyoto rats, we studied the uptake of radioactive tracer (125)I-albumin into the pleural space and circulation after intraperitoneal (IP) injections with 1 or 5 ml of Ringer solution (3 g/dl albumin). Postmortem, we sampled pleural liquid, peritoneal liquid, and blood plasma 2-48 h after IP injection and measured their radioactivity and protein concentration. Tracer concentration was greater in pleural liquid than in plasma approximately 3 h after injection with both IP injection volumes.

Effect of pancreatic and leukocyte elastase on hydraulic conductivity in lung interstitial segments.

Elastase-induced changes in flow were used to quantify the degradation of lung interstitial elastin. Degassed rabbit lungs were inflated with silicon rubber via airways and vessels. The lungs were cut into 1-cm-thick sections.

Effect of concentration and hyaluronidase on restriction of hetastarch flux through lung interstitial segments.

The transport properties of lung interstitium were studied by measuring the flow of hetastarch solution (2 and 6%) through 1-cm perivascular interstitial segments of rabbit lungs. Hetastarch (10(4)-10(7) Da) solution has a colloid osmotic pressure similar to that of albumin solution. Driving pressure was 5 cm H(2)O and mean interstitial pressure was 0 cm H(2)O.

Dexamethasone-induced changes in lung function are not prevented by concomitant treatment with retinoic acid.

Alveolarization is impaired in rats treated with dexamethasone (Dex) on postnatal days 4-13, but concomitant treatment with all-trans retinoic acid (RA) increases alveolar number. To determine whether morphological changes induced by Dex and/or RA predict changes in lung function at 1 mo, we assessed resting breathing parameters, dynamic compliance, ventilation required to maintain O(2) saturation at > or = 90%, and pressure-volume curves of air-filled lungs. During resting breathing, mean tidal volume per gram was greater in Dex + RA-treated rats than in controls (P < 0.

Effect of frequency and tidal volume on pleural pressure in rabbits during high frequency ventilation.

Regional effects of the chest wall on airway pressure transmission were studied during high frequency ventilation in anesthetized rabbits. We measured airway pressure (Paw), esophageal pressure (Pes), and costal pleural pressure (Ppl) by a rib capsule and flow and volume with a calibrated pneumotachograph. Using a closed circuit, pressures and flow were measured at varying frequencies (2-80 Hz) and tidal volumes (2-20 ml).

Effect of blood flow on capillary transit time and oxygenation in excised rabbit lung.

We used an isolated perfused lung preparation of the rabbit to study the effect of increasing blood flow on pulmonary capillary transit time by two methods. In one method, capillary transit time was measured from fluorescent dye dilution curves from arterioles and venules of the subpleural microcirculation. Values of transit time were similar to those for the whole lung determined by dividing capillary blood volume by blood flow.

Immunoassay detection of drugs in racing horses. IX. Detection of detomidine in equine blood and urine by radioimmunoassay.

Detomidine is a potent non-narcotic sedative agent which is currently in the process of being approved for veterinary clinical use in the United States. Since no effective screening method in horses is available for detomidine, we have developed an 125I radioimmunoassay for detomidine in equine blood and urine as part of a panel of tests for illegal drugs in performance horses. Our 125I radioimmunoassay has an I-50 for detomidine of approximately 2 ng/ml.

Immunoassay detection of drugs in racing horses. VI. Detection of furosemide (Lasix) in equine blood by a one step ELISA and PCFIA.

A one step enzyme-linked immunosorbent assay (ELISA) and a particle concentration fluorescent immunoassay (PCFIA) test for furosemide were evaluated as part of a panel of pre- and post-race tests for illegal medication of racing horses. These tests are very sensitive to furosemide with an I-50 for furosemide of about 20 ng/ml. The test is also rapid; an average pre-race complement of 10 samples can be analyzed in 90 minutes or less.

Immunoassay detection of drugs in racing horses. IV. Detection of fentanyl and its congeners in equine blood and urine by a one step ELISA assay.

We have developed and evaluated a one step enzyme-linked immunosorbent assay (ELISA) test for fentanyl as part of a panel of pre- and post-race tests for narcotic analgesics in racing horses. This ELISA test detects fentanyl with an I-50 of about 100 pg/ml. The test is economical in that it can be read with an inexpensive spectrophotometer, or even by eye.