61 research outputs found
Aquaporin-6 is expressed along the rat gastrointestinal tract and upregulated by feeding in the small intestine
Background: Several aquaporins (a family of integral membrane proteins) have been recently
identified in the mammalian gastrointestinal tract, and their involvement in the movement of fluid
and small solutes has been suggested. In this direction we investigated, in some regions of the rat
gastrointestinal tract, the presence and localization of aquaporin-6, given its peculiar function as an
ion selective channel.
Results: RT-PCR and immunoblotting experiments showed that aquaporin-6 was expressed in all
the investigated portions of the rat gastrointestinal tract. The RT-PCR experiments showed that
aquaporin-6 transcript was highly expressed in small intestine and rectum, and less in stomach,
caecum and colon. In addition, jejunal mRNA expression was specifically stimulated by feeding.
Immunoblotting analysis showed a major band with a molecular weight of about 55 kDa
corresponding to the aquaporin-6 protein dimer; this band was stronger in the stomach and large
intestine than in the small intestine. Immunoblotting analysis of brush border membrane vesicle
preparations showed an intense signal for aquaporin-6 protein.
The results of in situ hybridization experiments demonstrate that aquaporin-6 transcript is present
in the isthmus, neck and basal regions of the stomach lining, and throughout the crypt-villus axis in
both small and large intestine. In the latter regions, immunohistochemistry revealed strong
aquaporin-6 labelling in the apical membrane of the surface epithelial cells, while weak or no
labelling was observed in the crypt cells. In the stomach, an intense staining was observed in mucous
neck cells and lower signal in principal cells and some parietal cells.
Conclusion: The results indicate that aquaporin-6 is distributed throughout the gastrointestinal
tract. Aquaporin-6 localization at the apical pole of the superficial epithelial cells and its
upregulation by feeding suggest that it may be involved in movements of water and anions through
the epithelium of the villi
Variation in Structure and Process of Care in Traumatic Brain Injury: Provider Profiles of European Neurotrauma Centers Participating in the CENTER-TBI Study.
INTRODUCTION: The strength of evidence underpinning care and treatment recommendations in traumatic brain injury (TBI) is low. Comparative effectiveness research (CER) has been proposed as a framework to provide evidence for optimal care for TBI patients. The first step in CER is to map the existing variation. The aim of current study is to quantify variation in general structural and process characteristics among centers participating in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. METHODS: We designed a set of 11 provider profiling questionnaires with 321 questions about various aspects of TBI care, chosen based on literature and expert opinion. After pilot testing, questionnaires were disseminated to 71 centers from 20 countries participating in the CENTER-TBI study. Reliability of questionnaires was estimated by calculating a concordance rate among 5% duplicate questions. RESULTS: All 71 centers completed the questionnaires. Median concordance rate among duplicate questions was 0.85. The majority of centers were academic hospitals (n = 65, 92%), designated as a level I trauma center (n = 48, 68%) and situated in an urban location (n = 70, 99%). The availability of facilities for neuro-trauma care varied across centers; e.g. 40 (57%) had a dedicated neuro-intensive care unit (ICU), 36 (51%) had an in-hospital rehabilitation unit and the organization of the ICU was closed in 64% (n = 45) of the centers. In addition, we found wide variation in processes of care, such as the ICU admission policy and intracranial pressure monitoring policy among centers. CONCLUSION: Even among high-volume, specialized neurotrauma centers there is substantial variation in structures and processes of TBI care. This variation provides an opportunity to study effectiveness of specific aspects of TBI care and to identify best practices with CER approaches
Variation in neurosurgical management of traumatic brain injury: A survey in 68 centers participating in the CENTER-TBI study
Background Neurosurgical management of traumatic brain injury (TBI) is challenging, with only low-quality evidence. We aimed to explore differences in neurosurgical strategies for TBI across Europe. Methods A survey was sent to 68 centers participating in the Collaborative European Neurotrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. The questionnaire contained 21 questions, including the decision when to operate (or not) on traumatic acute subdural hematoma (ASDH) and intracerebral hematoma (ICH), and when to perform a decompressive craniectomy (DC) in raised intracranial pressure (ICP). Results The survey was completed by 68 centers (100%). On average, 10 neurosurgeons work in each trauma center. In all centers, a neurosurgeon was available within 30 min. Forty percent of responders reported a thickness or volume threshold for evacuation of an ASDH. Most responders (78%) decide on a primary DC in evacuating an ASDH during the operation, when swelling is present. For ICH, 3% would perform an evacuation directly to prevent secondary deterioration and 66% only in case of clinical deterioration. Most respondents (91%) reported to consider a DC for refractory high ICP. The reported cut-off ICP for DC in refractory high ICP, however, differed: 60% uses 25 mmHg, 18% 30 mmHg, and 17% 20 mmHg. Treatment strategies varied substantially between regions, specifically for the threshold for ASDH surgery and DC for refractory raised ICP. Also within center variation was present: 31% reported variation within the hospital for inserting an ICP monitor and 43% for evacuating mass lesions. Conclusion Despite a homogeneous organization, considerable practice variation exists of neurosurgical strategies for TBI in Europe. These results provide an incentive for comparative effectiveness research to determine elements of effective neurosurgical care
Variation in neurosurgical management of traumatic brain injury
Background: Neurosurgical management of traumatic brain injury (TBI) is challenging, with only low-quality evidence. We aimed to explore differences in neurosurgical strategies for TBI across Europe. Methods: A survey was sent to 68 centers participating in the Collaborative European Neurotrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. The questionnaire contained 21 questions, including the decision when to operate (or not) on traumatic acute subdural hematoma (ASDH) and intracerebral hematoma (ICH), and when to perform a decompressive craniectomy (DC) in raised intracranial pressure (ICP). Results: The survey was completed by 68 centers (100%). On average, 10 neurosurgeons work in each trauma center. In all centers, a neurosurgeon was available within 30 min. Forty percent of responders reported a thickness or volume threshold for evacuation of an ASDH. Most responders (78%) decide on a primary DC in evacuating an ASDH during the operation, when swelling is present. For ICH, 3% would perform an evacuation directly to prevent secondary deterioration and 66% only in case of clinical deterioration. Most respondents (91%) reported to consider a DC for refractory high ICP. The reported cut-off ICP for DC in refractory high ICP, however, differed: 60% uses 25 mmHg, 18% 30 mmHg, and 17% 20 mmHg. Treatment strategies varied substantially between regions, specifically for the threshold for ASDH surgery and DC for refractory raised ICP. Also within center variation was present: 31% reported variation within the hospital for inserting an ICP monitor and 43% for evacuating mass lesions. Conclusion: Despite a homogeneous organization, considerable practice variation exists of neurosurgical strategies for TBI in Europe. These results provide an incentive for comparative effectiveness research to determine elements of effective neurosurgical care
Effects of tracheal intubation on ventilation with LMA Classic (TM) for percutaneous dilation tracheostomy
Aim. The classic laryngeal mask airway (cLMATM) can be used in place of an endotracheal tube (ETT) as the ventilatory device during percutaneous dilational tracheostomy (PDT). We aimed to investigate the possible loss of effica- cy of cLMATM after tracheal intubation.
Methods. Severity of laryngeal lesions and efficacy of cLMATM were determined in two groups of thirty patients each who were switched from ETT ventilation to cLMA ventilation for PDT after a short (12 days) tracheal intubation.
Results. cLMATM allowed us to carry out PDT in all patients. Short tracheal intubations resulted in mild lesions of the larynx and mild gas leaks during cLMATM ventilation. Longer intubations caused moderate-to-severe (P<0.05) lesions of the larynx and larger gas leaks. A single complication occurred in one patient post-procedurally and in no patient at 6-month follow-up.
Conclusion. Efficacy of cLMATM was maintained after short tracheal intubation and decreased after long intubation
Synthesis, characterization and electrochemical studies on technetium(V) and rhenium(V) oxo-complexes with N,N\u2032-2-hydroxypropane-1,3-bis(salicylideneimine)
Ligand-exchange reactions of potential quinquedentate Schiff base ligands derived from salicylaldehyde and 1,3-diamino-2-hydroxypropane (H3L) with [MOCl4] 12 (M = Tc and Re) have been investigated. The complexes [MOCl2(R-OH)(H2L\ub7HCl)] (I) (R = Me, Et), [ReOCl(HL)] (II) and \u3bc-O[MO(HL)]2 (III) were synthesized and characterized by the usual physicochemical measurements. Cyclic voltammetries for both III complexes reveal two separate and single-electron redox processes. The crystal structure of \u3bc-O[TcO(HL)]2 was determined by single-crystal X-ray diffraction methods. Crystals are monoclinic, space group P21/c, with a = 9.423(6), b = 19.666(9), c = 22.785(11) \uc5, \u3b2 = 99.41(4)\ub0 and Z = 4. X-ray diffraction provides 2842 observed reflections (up to \u3b8 = 40\ub0) and the structure has been refined by full-matrix least-squares methods to R = 0.10. The \u2018dimeric\u2019 structure of \u3bc-O[TcO(HL)]2 consists of two distorted octahedral TcO(HL) moieties bridged by an oxygen atom which occupies the sixth coordination site of each moiety with the Tc-O-Tc angle nearly linear (173\ub0)
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