232 research outputs found
Blue rubber-bleb naevus syndrome: report of a case with consumption coagulopathy complicated by manifest thrombosis
Abstract
Blue rubber-bleb naevus (BRBN) syndrome is a rare disorder characterized by subcutaneous and gastrointestinal haemangiomas. The latter may lead to bleeding complications. A case is reported in which a process of chronic intravascular coagulation resulted in serious thrombotic complications. In the presence of a chronic consumption coagulopathy, it remains uncertain whether antiplatelet drugs are of prophylactic antithrombotic value
The cystic fibrosis defect approached from different angles - New perspectives on the gene, the chloride channel, diagnosis and therapy
Abstract
The search for the basic defect in cystic fibrosis (CF) has reached a decisive stage since the recent identification of the responsible gene. Electrophysiological and biochemical research had defined the CF defect as a dysregulation of epithelial chloride channels. The putative protein product of the now identified gene shares properties with other known transport proteins, but it is not necessarily itself a chloride channel protein. Elucidation of the primary cellular defect will certainly have important aetiological and hopefully therapeutic implications. The identification of the major gene mutation already has significant consequences for genetic counselling and prenatal diagnosis. Heterozygote detection at the population level awaits identification of the probably heterogenous mutations on about 30% of the CF chromosomes. At present, about 50% of CF patients are homozygous for the recently identified major CF mutation
Bile Acid Malabsorption in Cystic Fibrosis; Membrane Vesicles, a Tool for Revealing the Role of the Ileal Brush Border Membrane
ABSTRACT. Increased fecal bile acid loss in cystic fibrosis (CF) may result from ileal dysfunction. A method to quantitate in vitro Na+âdependent taurocholate uptake into brush border membrane vesicles prepared from frozen ileum and ileal biopsy specimen is described. This transport across the ileal brush border membrane can be measured selectively, in contrast to in vivo measurements which represent a complex overall process. Preliminary results obtained with ileal specimen of 2 CF patients, suggest that in vitro bile acid uptake is low but not abnormal. Copyrigh
Multicentre quantitative Ga-68 PET/CT performance harmonisation
Purpose Performance standards for quantitative F-18-FDG PET/CT studies are provided by the EANM Research Ltd. (EARL) to enable comparability of quantitative PET in multicentre studies. Yet, such specifications are not available for Ga-68. Therefore, our aim was to evaluate Ga-68-PET/CT quantification variability in a multicentre setting. Methods A survey across Dutch hospitals was performed to evaluate differences in clinical Ga-68 PET/CT study protocols. Ga-68 and F-18 phantom acquisitions were performed by 8 centres with 13 different PET/CT systems according to EARL protocol. The cylindrical phantom and NEMA image quality (IQ) phantom were used to assess image noise and to identify recovery coefficients (RCs) for quantitative analysis. Both phantoms were used to evaluate cross-calibration between the PET/CT system and local dose calibrator. Results The survey across Dutch hospitals showed a large variation in clinical Ga-68 PET/CT acquisition and reconstruction protocols. Ga-68 PET/CT image noise was below 10%. Cross-calibration was within 10% deviation, except for one system to overestimate F-18 and two systems to underestimate the Ga-68 activity concentration. RC-curves for F-18 and Ga-68 were within and on the lower limit of current EARL standards, respectively. After correction for local Ga-68/F-18 cross-calibration, mean Ga-68 performance was 5% below mean EARL performance specifications. Conclusions Ga-68 PET/CT quantification performs on the lower limits of the current EARL RC standards for F-18. Correction for local Ga-68/F-18 cross-calibration mismatch is advised, while maintaining the EARL reconstruction protocol thereby avoiding multiple EARL protocols
Changes in globus pallidus with (pre)term kernicterus
OBJECTIVE: We report serial magnetic resonance (MR) and sonographic
behavior of globus pallidus in 5 preterm and 3 term infants with
kernicterus and describe the clinical context in very low birth weight
preterm infants. On the basis of this information, we suggest means of
diagnosis and prevention. METHODS: Charts and MR and ultrasound images of
5 preterm infants and 3 term infants with suspected bilirubin-associated
brain damage were reviewed. Included were preterm infants with severe
hearing loss, quadriplegic hypertonia, and abnormal hypersignal of globus
pallidus on T2-weighted MR imaging (MRI). In 1 infant who died on day 150,
the diagnosis was confirmed during the neonatal period. The others were
picked up as outpatients and scanned at 12 or 22 months' corrected age.
Three instances of term kernicterus were included for comparison of serial
MRI in the neonatal period and early infancy: they were caused by
glucose-6-phosphate dehydrogenase deficiency, urosepsis, and dehydration
plus fructose 1-6 biphosphatase deficiency. RESULTS: Five preterm infants
of 25 to 29 weeks' gestational age presented with total serum bilirubin
(TSB) levels below exchange transfusion thresholds commonly advised. Mixed
acidosis was present in 3 infants around the TSB peak. The
bilirubin/albumin molar ratio was >0.5 in all, in the absence of
displacing drugs. All failed to pass bedside hearing screen tests and had
severe hearing loss on auditory brain response testing. Symmetrical
homogeneous hyperechogenicity of globus pallidus was the alerting feature
in 1 infant. Globus pallidus was hyperintense on T1-weighted MR images in
this child. The other infants presented with severe developmental delay as
a result of dyskinetic quadriplegia and hearing loss. Globus pallidus was
normal on T1- but hyperintense on T2-weighted MR images at 12
Regulation of chloride transport in cultured normal and cystic fibrobis keratinocytes
Abstract
Cultured normal (N) and cystic fibrosis (CF) keratinocytes were evaluated for their Clâ-transport properties by patch-clamp-, Ussing chamber- and isotopic efflux-measurements. Special attention was paid to a 32 pS outwardly rectifying Clâ channel which has been reported to be activated upon activation of cAMP-dependent pathways in N, but not in CF cells. This depolarization-induced Clâ channel was found with a similar incidence in N and CF apical keratininocyte membranes. However, activation of this channel in excised patches by protein kinase (PK)-A or PK-C was not successfull in either N or CF keratinocytes. Forskolin was not able to activate Clâ channels in N and CF cell-attached patches. The Ca2+-ionophore A23187 activated in cell-attached patches a linear 17 pS Clâ channel in both N and CF cells. This channel inactivated upon excision. No relationship between the cell-attached 17 pS and the excised 32 pS channel could be demonstrated. Returning to the measurement of Clâ transport at the macroscopic level, we found that a drastic rise in intracellular cAMP induced by forskolin did in N as well as CF cells not result in a change in the short-circuit current (Isc) or the fractional efflux rates of 36Clâ and 125Iâ. In contrast, addition of A23187 resulted in an increase of the Isc and in the isotopic anion efflux rates in N and CF cells. We conclude that Clâ-transport in cultured human keratinocytes can be activated by Ca2+, but not by cAMP-dependent pathways
Endotracheal temperature and humidity measurements in laryngectomized patients: intra- and inter-patient variability
This study assesses intra- and inter-patient variability in endotracheal climate (temperature and humidity) and effects of heat and moister exchangers (HME) in 16 laryngectomized individuals, measured repeatedly (N = 47). Inhalation Breath Length (IBL) was 1.35 s without HME and 1.05 s with HME (P < 0.0001). With HME, end-inspiratory (minimum) humidity values increased 5.8 mg H2O/L (P < 0.0001) and minimum temperature values decreased 1.6°C (P < 0.0001). For the temperature and humidity minimums, the inter-patient variability was much smaller than the short- and long-term intra-patient variability. For exhalation breath length and full breath length, the opposite was the case. Conclusions: (1) Because inter-patient variability is smaller than intra-patient variability, investigating endotracheal climate in a limited number of laryngectomized subjects is justified, provided repeated measurements per patient are accomplished; (2) main contributor to intra-patient variability is the positioning of the catheter tip in the trachea; (3) an HME leads to a shortened IBL which enhances the HME effect
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