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1.
JCI Insight ; 9(11)2024 May 16.
Article in English | MEDLINE | ID: mdl-38753465

ABSTRACT

Glycogen storage disease type III (GSDIII) is a rare metabolic disorder due to glycogen debranching enzyme (GDE) deficiency. Reduced GDE activity leads to pathological glycogen accumulation responsible for impaired hepatic metabolism and muscle weakness. To date, there is no curative treatment for GSDIII. We previously reported that 2 distinct dual AAV vectors encoding for GDE were needed to correct liver and muscle in a GSDIII mouse model. Here, we evaluated the efficacy of rapamycin in combination with AAV gene therapy. Simultaneous treatment with rapamycin and a potentially novel dual AAV vector expressing GDE in the liver and muscle resulted in a synergic effect demonstrated at biochemical and functional levels. Transcriptomic analysis confirmed synergy and suggested a putative mechanism based on the correction of lysosomal impairment. In GSDIII mice livers, dual AAV gene therapy combined with rapamycin reduced the effect of the immune response to AAV observed in this disease model. These data provide proof of concept of an approach exploiting the combination of gene therapy and rapamycin to improve efficacy and safety and to support clinical translation.


Subject(s)
Dependovirus , Disease Models, Animal , Genetic Therapy , Genetic Vectors , Liver , Sirolimus , Animals , Sirolimus/pharmacology , Sirolimus/therapeutic use , Dependovirus/genetics , Genetic Therapy/methods , Mice , Liver/metabolism , Genetic Vectors/genetics , Genetic Vectors/administration & dosage , Muscle, Skeletal/metabolism , Phenotype , Glycogen Debranching Enzyme System/genetics , Glycogen Debranching Enzyme System/metabolism , Humans , Male
2.
Mol Ther Methods Clin Dev ; 28: 396-411, 2023 Mar 09.
Article in English | MEDLINE | ID: mdl-36910588

ABSTRACT

Gene therapy of Usher syndrome type 1B (USH1B) due to mutations in the large Myosin VIIA (MYO7A) gene is limited by the packaging capacity of adeno-associated viral (AAV) vectors. To overcome this, we have previously developed dual AAV8 vectors which encode human MYO7A (dual AAV8.MYO7A). Here we show that subretinal administration of 1.37E+9 to 1.37E+10 genome copies of a good-manufacturing-practice-like lot of dual AAV8.MYO7A improves the retinal defects of a mouse model of USH1B. The same lot was used in non-human primates at doses 1.6× and 4.3× the highest dose proposed for the clinical trial which was based on mouse efficacy data. Long-lasting alterations in retinal function and morphology were observed following subretinal administration of dual AAV8.MYO7A at the high dose. These findings were modest and improved over time in the low-dose group, as also observed in other studies involving the use of AAV8 in non-human primates and humans. Biodistribution and shedding studies confirmed the presence of vector DNA mainly in the visual pathway. Accordingly, we detected human MYO7A mRNA expression predominantly in the retina. Overall, these studies pave the way for the clinical translation of subretinal administration of dual AAV vectors in USH1B subjects.

3.
JACS Au ; 2(11): 2417-2425, 2022 Nov 28.
Article in English | MEDLINE | ID: mdl-36465550

ABSTRACT

This Perspective accounts for recent progress in the directed control of interfacial fluid flows harnessed to assemble architected soft materials. We are focusing on the paradigmatic problem of free-surface flows in curable elastomers. These elastomers are initially liquid and cure into elastic solids whose shape is imparted by concomitant and competing phenomena: flow-induced deformations and curing. Particular attention is given to the role of capillary forces in these systems. Originating from the cohesive nature of liquids and thus favoring smooth interfaces, capillary forces can also promote the destabilization of interfaces, e.g., into droplets. In turn, such mechanical instabilities tend to grow into regular patterns, e.g., forming hexagonal lattices. We discuss how the universality, robustness, and ultimate regularity of these out-of-equilibrium processes could serve as a basis for new fabrication paradigms, where instabilities are directed to generate target architected solids obtained without each element laid in place by direct mechanized intervention.

4.
J Am Geriatr Soc ; 70(12): 3538-3548, 2022 12.
Article in English | MEDLINE | ID: mdl-35929177

ABSTRACT

BACKGROUND: Lumbar spinal stenosis (LSS) is a common reason for spine surgery in which ligamentum flavum is resected. Transthyretin (TTR) amyloid is an often unrecognized and potentially modifiable mechanism for LSS that can also cause TTR cardiac amyloidosis. Accordingly, older adult patients undergoing lumbar spine (LS) surgery were evaluated for amyloid and if present, the precursor protein, as well as comprehensive characterization of the clinical phenotype. METHODS: A prospective, cohort study in 2 academic medical centers enrolled 47 subjects (age 69 ± 7 years, 53% male) undergoing clinically indicated LS decompression. The presence of amyloid was evaluated by Congo Red staining and in those with amyloid, precursor protein was determined by laser capture microdissection coupled to mass spectrometry (LCM-MS). The phenotype was assessed by disease-specific questionnaires (Swiss Spinal Stenosis Questionnaire and Kansas City Cardiomyopathy Questionnaire) and the 36-question short-form health survey, as well as biochemical measures (TTR, retinol-binding protein, and TTR stability). Cardiac testing included technetium-99m-pyrophosphate scintigraphy, electrocardiograms, echocardiograms, and cardiac biomarkers as well as measures of functional capacity. RESULTS: Amyloid was detected in 16 samples (34% of participants) and was more common in those aged ≥ 75 years of age (66.7%) compared with those <75 years (22.3%, p < 0.05). LCM-MS demonstrated TTR as the precursor protein in 62.5% of participants with amyloid while 37.5% had an indeterminant type of amyloid. Demographic, clinical, quality-of-life measures, electrocardiographic, echocardiographic, and biochemical measures did not differ between those with and without amyloid. Among those with TTR amyloid (n = 10), one subject had cardiac involvement by scintigraphy. CONCLUSIONS: Amyloid is detected in more than a third of older adults undergoing LSS. Amyloid is more common with advancing age and is particularly common in those >75 years old. No demographic, clinical, biochemical, or cardiac parameter distinguished those with and without amyloid. In more than half of subjects with LS amyloid, the precursor protein was TTR indicating the importance of pathological assessment.


Subject(s)
Amyloidosis , Cardiomyopathies , Spinal Stenosis , Female , Humans , Male , Amyloid/analysis , Amyloidosis/complications , Amyloidosis/pathology , Cardiomyopathies/complications , Constriction, Pathologic/complications , Prealbumin/analysis , Prealbumin/genetics , Prealbumin/metabolism , Prospective Studies , Spinal Stenosis/diagnosis , Spinal Stenosis/surgery , Middle Aged , Aged
5.
Soins ; 67(870-871): 16-20, 2022.
Article in French | MEDLINE | ID: mdl-36681499

ABSTRACT

The prison population in France is mostly composed of young but aging men, in relatively good health but vulnerable. In order to ensure optimal health care for this population, several levels of health care organization - somatic and psychiatric - have been set up since 1994. The different structures created since then allow incarcerated patients to benefit from care adapted to their particular conditions.


Subject(s)
Prisoners , Prisons , Male , Humans , France/epidemiology , Delivery of Health Care , Aging
6.
Soins ; 67(870-871): 26-30, 2022.
Article in French | MEDLINE | ID: mdl-36681501

ABSTRACT

The mission of the inter-regional secure hospital units is to care for incarcerated prisoners. There are eight of them in metropolitan France, one in each prison region. They are jointly managed by the health establishments for care and by the prison administration for security. Each prisoner receives care equivalent to that provided to the rest of the population.


Subject(s)
Prisoners , Humans , Prisons , Hospitals , France
7.
NEJM Evid ; 1(7): EVIDoa2200052, 2022 Jul.
Article in English | MEDLINE | ID: mdl-38319253

ABSTRACT

BACKGROUND: Mucopolysaccharidosis type VI (MPS VI) is an inherited multisystem lysosomal disorder due to arylsulfatase B (ARSB) deficiency that leads to widespread accumulation of glycosaminoglycans (GAG), which are excreted in increased amounts in urine. MPS VI is characterized by progressive dysostosis multiplex, connective tissue and cardiac involvement, and hepatosplenomegaly. Enzyme replacement therapy (ERT) is available but requires life-long and costly intravenous infusions; moreover, it has limited efficacy on diseased skeleton and cardiac valves, compromised pulmonary function, and corneal opacities. METHODS: We enrolled nine patients with MPS VI 4 years of age or older in a phase 1/2 open-label gene therapy study. After ERT was interrupted, patients each received a single intravenous infusion of an adeno-associated viral vector serotype 8 expressing ARSB. Participants were sequentially enrolled in one of three dose cohorts: low (three patients), intermediate (two patients), or high (four patients). The primary outcome was safety; biochemical and clinical end points were secondary outcomes. RESULTS: The infusions occurred without severe adverse events attributable to the vector, meeting the prespecified end point. Participants in the low and intermediate dose cohorts displayed stable serum ARSB of approximately 20% of the mean healthy value but returned to ERT by 14 months after gene therapy because of increased urinary GAG. Participants in the high-dose cohort had sustained serum ARSB of 30% to 100% of the mean healthy value and a modest urinary GAG increase that did not reach a concentration at which ERT reintroduction was needed. In the high-dose group, there was no clinical deterioration for up to 2 years after gene therapy. CONCLUSIONS: Liver-directed gene therapy for participants with MPS VI did not have a dose-limiting side-effect and adverse event profile; high-dose treatment resulted in ARSB expression over at least 24 months with preliminary evidence of disease stabilization. (Funded by the Telethon Foundation ETS, the European Commission Seventh Framework Programme, and the Isaac Foundation; ClinicalTrials.gov number, NCT03173521; EudraCT number, 2016-002328-10.)

8.
Mar Drugs ; 18(9)2020 Aug 29.
Article in English | MEDLINE | ID: mdl-32872415

ABSTRACT

Nephroselmis sp. was previously identified as a species of interest for its antioxidant properties owing to its high carotenoid content. In addition, nitrogen availability can impact biomass and specific metabolites' production of microalgae. To optimize parameters of antioxidant production, Nephroselmis sp. was cultivated in batch and continuous culture conditions in stirred closed photobioreactors under different nitrogen conditions (N-repletion, N-limitation, and N-starvation). The aim was to determine the influence of nitrogen availability on the peroxyl radical scavenging activity (oxygen radical absorbance capacity (ORAC) assay) and carotenoid content of Nephroselmis sp. Pigment analysis revealed a specific and unusual photosynthetic system with siphonaxanthin-type light harvesting complexes found in primitive green algae, but also high lutein content and xanthophyll cycle pigments (i.e., violaxanthin, antheraxanthin, and zeaxanthin), as observed in most advanced chlorophytes. The results indicated that N-replete conditions enhance carotenoid biosynthesis, which would correspond to a higher antioxidant capacity measured in Nephroselmis sp. Indeed, peroxyl radical scavenging activity and total carotenoids were higher under N-replete conditions and decreased sharply under N-limitation or starvation conditions. Considering individual carotenoids, siphonaxanthin, neoxanthin, xanthophyll cycle pigments, and lycopene followed the same trend as total carotenoids, while ß-carotene and lutein stayed stable regardless of the nitrogen availability. Carotenoid productivities were also higher under N-replete treatment. The peroxyl radical scavenging activity measured with ORAC assay (63.6 to 154.9 µmol TE g-1 DW) and the lutein content (5.22 to 7.97 mg g-1 DW) were within the upper ranges of values reported previously for other microalgae. Furthermore, contents of siphonaxanthin ere 6 to 20% higher than in previous identified sources (siphonous green algae). These results highlight the potential of Nephroselmis sp. as a source of natural antioxidant and as a pigment of interest.


Subject(s)
Antioxidants/metabolism , Carotenoids/metabolism , Chlorophyta/metabolism , Microalgae/metabolism , Nitrogen/metabolism , Antioxidants/pharmacology , Biomass , Carotenoids/pharmacology , Chlorophyta/growth & development , Microalgae/growth & development , Oxygen Radical Absorbance Capacity , Time Factors
9.
Crit Rev Biochem Mol Biol ; 55(2): 197-218, 2020 04.
Article in English | MEDLINE | ID: mdl-32466661

ABSTRACT

Retinol-binding protein 2 (RBP2; originally cellular retinol-binding protein, type II (CRBPII)) is a 16 kDa cytosolic protein that in the adult is localized predominantly to absorptive cells of the proximal small intestine. It is well established that RBP2 plays a central role in facilitating uptake of dietary retinoid, retinoid metabolism in enterocytes, and retinoid actions locally within the intestine. Studies of mice lacking Rbp2 establish that Rbp2 is not required in times of dietary retinoid-sufficiency. However, in times of dietary retinoid-insufficiency, the complete lack of Rbp2 gives rise to perinatal lethality owing to RBP2 absence in both placental (maternal) and neonatal tissues. Moreover, when maintained on a high-fat diet, Rbp2-knockout mice develop obesity, glucose intolerance and a fatty liver. Unexpectedly, recent investigations have demonstrated that RBP2 binds long-chain 2-monoacylglycerols (2-MAGs), including the canonical endocannabinoid 2-arachidonoylglycerol, with very high affinity, equivalent to that of retinol binding. Crystallographic studies establish that 2-MAGs bind to a site within RBP2 that fully overlaps with the retinol binding site. When challenged orally with fat, mucosal levels of 2-MAGs in Rbp2 null mice are significantly greater than those of matched controls establishing that RBP2 is a physiologically relevant MAG-binding protein. The rise in MAG levels is accompanied by elevations in circulating levels of the hormone glucose-dependent insulinotropic polypeptide (GIP). It is not understood how retinoid and/or MAG binding to RBP2 affects the functions of this protein, nor is it presently understood how these contribute to the metabolic and hormonal phenotypes observed for Rbp2-deficient mice.


Subject(s)
Retinol-Binding Proteins, Cellular/chemistry , Retinol-Binding Proteins, Cellular/metabolism , Adult , Animals , Embryonic Development/physiology , Female , Humans , Immunity, Innate , Intestine, Small/embryology , Intestine, Small/immunology , Intestine, Small/metabolism , Liver/embryology , Liver/metabolism , Male , Monoglycerides/metabolism , Obesity/metabolism , Pregnancy , Retinoids/metabolism , Retinol-Binding Proteins, Cellular/genetics , Vitamin A/metabolism
10.
Sci Adv ; 6(11): eaay8937, 2020 03.
Article in English | MEDLINE | ID: mdl-32195347

ABSTRACT

Expressed in the small intestine, retinol-binding protein 2 (RBP2) facilitates dietary retinoid absorption. Rbp2-deficient (Rbp2-/- ) mice fed a chow diet exhibit by 6-7 months-of-age higher body weights, impaired glucose metabolism, and greater hepatic triglyceride levels compared to controls. These phenotypes are also observed when young Rbp2-/- mice are fed a high fat diet. Retinoids do not account for the phenotypes. Rather, RBP2 is a previously unidentified monoacylglycerol (MAG)-binding protein, interacting with the endocannabinoid 2-arachidonoylglycerol (2-AG) and other MAGs with affinities comparable to retinol. X-ray crystallographic studies show that MAGs bind in the retinol binding pocket. When challenged with an oil gavage, Rbp2-/- mice show elevated mucosal levels of 2-MAGs. This is accompanied by significantly elevated blood levels of the gut hormone GIP (glucose-dependent insulinotropic polypeptide). Thus, RBP2, in addition to facilitating dietary retinoid absorption, modulates MAG metabolism and likely signaling, playing a heretofore unknown role in systemic energy balance.


Subject(s)
Body Weight , Gastric Inhibitory Polypeptide/metabolism , Intestinal Mucosa/metabolism , Monoglycerides/metabolism , Retinol-Binding Proteins, Cellular/metabolism , Signal Transduction , Animals , Diet, High-Fat , Gastric Inhibitory Polypeptide/genetics , Mice , Mice, Knockout , Retinol-Binding Proteins, Cellular/genetics
11.
Phys Rev Lett ; 122(20): 201801, 2019 May 24.
Article in English | MEDLINE | ID: mdl-31172764

ABSTRACT

Hidden photons are dark matter candidates motivated by theories beyond the standard model of particle physics. They mix with conventional photons, and they can be detected through the very weak electromagnetic radiation they induce at the interface between a metal and the air. SHUKET [search for U(1) dark matter with an electromagnetic telescope] is a dedicated experiment sensitive to the hidden photon-induced signal. The results from a hidden photon search campaign are reported, with no significant detection of a dark matter signal. Exclusion limits are derived from the observed noise fluctuations in a 5-6.8 GHz frequency range, corresponding to a hidden photon mass region ranging from 20.8 to 28.3 µeV. SHUKET is currently the most sensitive instrument in this mass range, and the obtained limits on the kinetic mixing term constrain significantly dark matter models inspired from string theory.

12.
Biochem Biophys Res Commun ; 514(4): 1231-1237, 2019 07 05.
Article in English | MEDLINE | ID: mdl-31109648

ABSTRACT

All-trans-retinoic acid (ATRA) has been well described as a positive regulator for early stage of adipocyte differentiation and lipid metabolism and also linked to an in vivo fat-lowering effect in mice. However, not all studies support this association. Our objective was to characterize the action of ATRA in mature adipocytes of mice by ablating RAR signaling through overexpression of a well-characterized dominant negative RARα mutant (RARdn) form specifically in adipocytes. Altered RAR signaling in adipocytes resulted in a significant decrease in ATRA levels in visceral and brown adipose tissues as well as liver tissue. This was linked to significant impairments in glucose clearance and elevated hepatic lipid accumulation for chow diet fed mice, indicating the development of metabolic disease, including hepatic steatosis. In addition, we found that adipose RARdn expression in mice fed a chow diet decreased thermogenesis. We conclude that altered RAR signaling and ATRA levels in adipocytes impacts glucose and lipid metabolism in mice.


Subject(s)
Adipocytes/metabolism , Fatty Liver/metabolism , Glucose Intolerance/metabolism , Retinoic Acid Receptor alpha/genetics , Animals , Mice , Mice, Transgenic , Retinoic Acid Receptor alpha/metabolism , Signal Transduction
13.
Langmuir ; 35(24): 7659-7671, 2019 Jun 18.
Article in English | MEDLINE | ID: mdl-31013102

ABSTRACT

Printing of ultrathin layers of polymeric and colloidal inks is critical for the manufacturing of electronics on nonconventional substrates such as paper and polymer films. Recently, we found that nanoporous stamps overcome key limitations of traditional polymer stamps in flexographic printing, namely, enabling the printing of ultrathin nanoparticle films with micron-scale lateral precision. Here, we study the dynamics of liquid transfer between nanoporous stamps and solid substrates. The stamps comprise forests of polymer-coated carbon nanotubes, and the surface mechanics and wettability of the stamps are engineered to imbibe colloidal inks and transfer the ink upon contact with the target substrate. By high-speed imaging during printing, we observe the dynamics of liquid spreading, which is mediated by progressing contact between the nanostructured stamp surface and by the substrate and imbibition within the stamp-substrate gap. From the final contact area, the volume of ink transfer is mediated by rupture of a capillary bridge; and, after rupture, liquid spreads to fill the area defined by a precursor film matching the stamp geometry with high precision. Via modeling of the liquid dynamics, and comparison with data, we elucidate the scale- and rate-limiting aspects of the process. Specifically, we find that the printed ink volume and resulting layer thickness are independent of contact pressure; and that printed layer thickness decreases with retraction speed. Under these conditions, nanoparticle films with controlled thickness in the <100 nm regime can be printed using nanoporous stamp flexography, at speeds commensurate with industrial printing equipment.

14.
Rev Infirm ; 67(246): 24-25, 2018 Dec.
Article in French | MEDLINE | ID: mdl-30591128

ABSTRACT

Inter-regional secure hospital units have noted an increase in the complex pathologies and care load of detained patients they receive for somatic care in a short-stay scheduled hospitalisation. Communication between health care providers and prison staff is essential for the proper functioning of these closed units. Transmissions with level 1 health units are essential to ensure continuity of care upon the patient's return to custody.


Subject(s)
Delivery of Health Care , Medically Unexplained Symptoms , Prisoners , Hospitalization , Humans , Prisons
15.
Front Zool ; 14: 54, 2017.
Article in English | MEDLINE | ID: mdl-29225659

ABSTRACT

BACKGROUND: Many legged animals change gaits when increasing speed. In insects, only one gait change has been documented so far, from slow walking to fast running, which is characterised by an alternating tripod. Studies on some fast-running insects suggested a further gait change at higher running speeds. Apart from speed, insect gaits and leg co-ordination have been shown to be influenced by substrate properties, but the detailed effects of speed and substrate on gait changes are still unclear. Here we investigate high-speed locomotion and gait changes of the cockroach Nauphoeta cinerea, on two substrates of different slipperiness. RESULTS: Analyses of leg co-ordination and body oscillations for straight and steady escape runs revealed that at high speeds, blaberid cockroaches changed from an alternating tripod to a rather metachronal gait, which to our knowledge, has not been described before for terrestrial arthropods. Despite low duty factors, this new gait is characterised by low vertical amplitudes of the centre of mass (COM), low vertical accelerations and presumably reduced total vertical peak forces. However, lateral amplitudes and accelerations were higher in the faster gait with reduced leg synchronisation than in the tripod gait with distinct leg synchronisation. CONCLUSIONS: Temporally distributed leg force application as resulting from metachronal leg coordination at high running speeds may be particularly useful in animals with limited capabilities for elastic energy storage within the legs, as energy efficiency can be increased without the need for elasticity in the legs. It may also facilitate locomotion on slippery surfaces, which usually reduce leg force transmission to the ground. Moreover, increased temporal overlap of the stance phases of the legs likely improves locomotion control, which might result in a higher dynamic stability.

16.
Int Marit Health ; 68(1): 46-51, 2017.
Article in English | MEDLINE | ID: mdl-28357836

ABSTRACT

BACKGROUND: To evaluate the epidemiology of patients who require mechanical ventilation during hyperbaric oxygen therapy. MATERIALS AND METHODS: One-hundred-fifty patients who required mechanical ventilation during hyperbaric oxygen therapy were prospectively studied during a 6-year period in a French university hyperbaric centre. We analysed the indication of hyperbaric oxygen therapy, agent used for sedation, presence of a chest tube, need for vasopressor agents and tolerance and appearance of side effects. Finally, we compared the outcomes of patients according to the presence or absence of acute respiratory distress syndrome (ARDS). RESULTS: Eleven children and 139 adult patients were included (n = 150) in the study. In both populations, carbon monoxide poisoning (51%) and iatrogenic gas embolism (33%) were the two main causes of intubation and mechanical ventilation. The combination of midazolam and sufentanil was used in 85 (67%) patients. All of the patients were given a bolus of a neuromuscular blocker during the hyperbaric session, despite the presence of ARDS in 35 patients. Patient-ventilator asynchrony was the most frequent side effect in 6 (5%) patients and was often the consequence of suboptimal sedation. Mortality was higher in the group with ARDS (23%). CONCLUSIONS: Carbon monoxide poisoning and iatrogenic gas embolism are the two main diseases of the patients who required mechanical ventilation during hyperbaric oxygen therapy in this study. Mechanical ventilation is a safe method for patients during hyperbaric oxygen therapy. Sedation needs to be perfected to avoid patient-ventilator asynchrony.


Subject(s)
Hyperbaric Oxygenation/adverse effects , Hypnotics and Sedatives/administration & dosage , Respiration, Artificial/adverse effects , Adult , Carbon Monoxide Poisoning/therapy , Chest Tubes , Child , Embolism, Air/therapy , Female , France , Humans , Hyperbaric Oxygenation/methods , Iatrogenic Disease , Male , Respiratory Distress Syndrome/mortality , Respiratory Distress Syndrome/therapy , Vasoconstrictor Agents/therapeutic use , Ventilators, Mechanical/adverse effects
17.
Subcell Biochem ; 81: 95-125, 2016.
Article in English | MEDLINE | ID: mdl-27830502

ABSTRACT

It is well established that chylomicron remnant (dietary) vitamin A is taken up from the circulation by hepatocytes, but more than 80 % of the vitamin A in the liver is stored in hepatic stellate cells (HSC). It presently is not known how vitamin A is transferred from hepatocytes to HSCs for storage. Since retinol-binding protein 4 (RBP4), a protein that is required for mobilizing stored vitamin A, is synthesized solely by hepatocytes and not HSCs, it similarly is not known how vitamin A is transferred from HSCs to hepatocytes. Although it has long been thought that RBP4 is absolutely essential for delivering vitamin A to tissues, recent research has proven that this notion is incorrect since total RBP4-deficiency is not lethal. In addition to RBP4, vitamin A is also found in the circulation bound to lipoproteins and as retinoic acid bound to albumin. It is not known how these different circulating pools of vitamin A contribute to the vitamin A needs of different tissues. In our view, better insight into these three issues is required to better understand vitamin A absorption, storage and mobilization. Here, we provide an up to date synthesis of current knowledge regarding the intestinal uptake of dietary vitamin A, the storage of vitamin A within the liver, and the mobilization of hepatic vitamin A stores, and summarize areas where our understanding of these processes is incomplete.


Subject(s)
Liver/metabolism , Vitamin A/metabolism , Adipose Tissue/metabolism , Animals , Biological Transport , Carotenoids/metabolism , Chylomicrons/metabolism , Forecasting , Hepatic Stellate Cells/metabolism , Hepatocytes/metabolism , Humans , Intestinal Absorption , Lipoproteins/metabolism , Models, Biological , Retinol-Binding Proteins, Plasma/metabolism , Serum Albumin/metabolism , Vitamin A Deficiency/metabolism
18.
J Extra Corpor Technol ; 48(3): 113-121, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27729704

ABSTRACT

Competitive flows syndrome result in severe regional hypoxemia when the deoxygenated flow from the native left ventricle (LV) competes with oxygenated flow from extracorporeal life support (ECLS) pump with potentially severe consequences for the cerebral and coronary circulations. Fast correction of hypoxemia could be obtained by decreasing native LV flow by infusion of a short-acting beta-blocker (esmolol). Our purpose was to retrospectively review the efficacy of esmolol in this situation and hypothesize on the potential mechanisms of action and the associated risks. This is a retrospective analysis of five clinical cases, who underwent lung transplantation and a femoro-femoral venoarterial (VA) ECLS. The patients presented severe hypoxemia (SpO2 < 85%) measured through photoplethysmography on a right hand finger. From the patients' medical records and anesthesia flowcharts, hemodynamic, right heart catheterization, echocardiography variables, and arterial blood gas results were noted before and after injection of esmolol. Mechanical ventilation and VA ECLS function variables were optimized and unchanged before and after esmolol injection. All patients had terminal respiratory failure with pulmonary hypertension and conserved LV systolic function. Immediately following esmolol injection (1.3 ± .7 mg/kg; mean ± 1 SD), SpO2 increased from 73% ± 12 to 95% ± 6; blood to arterial partial pressure in CO2 (PaCO2) decreased from 52 ± 18 to 35 ± 7 mmHg systolic pulmonary artery pressure decreased from 61 ± 8 to 50 ± 12 mmHg; the pulmonary artery oxygen saturation (SvO2); increased from 51% ± 24 to 77% ± 12; systemic arterial pressure or catecholamine requirements were unchanged. In conclusion, these results suggest that injection of esmolol allowed rapid correction of regional hypoxemia occurring during lung transplantation despite femoro-femoral VA ECLS. The mechanism is probably a decreased cardiac output of the native LV due to esmolol-induced negative inotropic and chronotropic effects without significant adverse effects on systemic tissue perfusion.


Subject(s)
Extracorporeal Membrane Oxygenation/adverse effects , Hypoxia/drug therapy , Hypoxia/etiology , Lung Transplantation/adverse effects , Premedication/methods , Propanolamines/administration & dosage , Adrenergic beta-1 Receptor Antagonists/administration & dosage , Adult , Anastomosis, Surgical/methods , Female , Femoral Artery/surgery , Femoral Vein/surgery , Humans , Hypoxia/prevention & control , Lung Transplantation/rehabilitation , Male , Middle Aged , Treatment Outcome
19.
Hepatobiliary Surg Nutr ; 5(1): 1-14, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26904552

ABSTRACT

Retinoids (vitamin A and its natural and synthetic analogs) are required by most tissues for maintaining the normal health of the tissue. This is certainly true for the pancreas. The recent literature is convincing that retinoids are needed by the adult to assure normal pancreatic endocrine functions, especially those of the α- and ß-cells. It is also well established that retinoids are required to insure normal pancreas development in utero, including the development of the endocrine pancreas. The actions of retinoids for maintaining normal pancreatic islet functions has drawn considerable research interest from investigators interested in understanding and treating metabolic disease. Pancreatic retinoids are also of interest to investigators studying the origins of pancreatic disease, including the development of pancreatic fibrosis and its sequelae. This research interest is focused on pancreatic stellate cells (PSCs) which store retinoids and possess the metabolic machinery needed to metabolize retinoids. The literature on pancreatic disease and retinoids suggests that there is an association between impairments in pancreatic retinoid storage and metabolism and the development of pancreatic disease. These topics will be considered in this review.

20.
J Crit Care ; 32: 56-62, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26689743

ABSTRACT

PURPOSE: Circulatory failure (CF) influences management of out-of-hospital cardiac arrest (OHCA) patients and the decision of circulatory assistance. We performed a study to identify on hospital admission patients at risk for CF-related death. MATERIALS AND METHODS: This is a single-center study including OHCA patients without obvious extracardiac cause and sustained return of spontaneous circulation, in a retrospective derivation (RC) and prospective validation cohort (PC). Univariate/multivariate logistic regression was used in the RC to determine a score predicting CF-related death (due to rearrest or persistent shock despite adequate fluid and catecholamine treatment). The score was validated in the PC. RESULTS: We included 207 patients in the RC and 96 in the PC. Circulatory failure occurred in 59% of RC and 63% of PC patients (P = .70); 35% in both cohorts died of CF. In multivariate regression, correlates of CF-related death making up the logistic score were arterial pH (P < .0001) and shock requiring catecholamines on admission (P = .0045). In the PC, for a logistic score cut-off of 0.5, sensitivity for CF-related death was 50%; specificity, 92%. Patients with shock and arterial pH less than or equal to 7.11 had a CF-related death probability greater than 0.5. CONCLUSION: A logistic score based on arterial pH and shock requiring catecholamines on admission can predict CF-related death in OHCA patients.


Subject(s)
Coma/mortality , Out-of-Hospital Cardiac Arrest/mortality , Shock/mortality , Aged , Epidemiologic Methods , Female , France/epidemiology , Humans , Male , Middle Aged , Myocardial Infarction/mortality , Out-of-Hospital Cardiac Arrest/etiology , Patient Admission , Prognosis , Shock/diagnosis
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