514 research outputs found
Chemical speciation of organic matter in natural waters. Interaction of nucleotide 5' mono-, di- and triphosphates with major components of seawater
AbstractThe interactions of nucleotide 5' mono-, di- and triphosphates in a multicomponent ionic medium simulating the macro-composition of seawater (Na+, K+, Ca2+, Mg2+, Cl-, SO42-, Synthetic Sea Water, SSW) have been investigated at different ionic strengths and at T= 25°C. A chemical speciation model, according to which all the internal interactions between the components of the ionic medium are taken into account, was applied to determine the effective formation constants of species in the nucleotide-seawater system. The results were compared to protonation parameters calculated from single electrolyte systems. A simpler model (SSW considered as a single salt BA, with Bz+ and Az-), representative of the cation (Na+, K+, Ca2+, Mg2+) and anion (Cl-, SO42-) macro-components of seawater respectively, was also used to calculate the overall complexing ability of the seawater salt towards all the systems here investigated
speciation of poly amino carboxylic compounds in seawater
AbstractIn this work quantitative data on the interaction of EDTA and EGTA with the major inorganic components of seawater are reported. Protonation constants and alkali and alkaline earth metal complex formation constants are reported at different ionic strengths (0< l/mol L−1≤1). These formation data were obtained from potentiometric measurements in several single and mixed electrolyte media (such as artificial seawater). Potentiometric measurements in artificial seawater (containing Na+, K+, Mg2+, Ca2+, Cl−and SO42−) were analysed by using the single salt approximation (the artificial seawater being considered as a single salt BA whose ions have fractional charge -zanion = zcation = 1.117). Several species BpHrL (L = EDTA or EGTA) are formed and their formation constants are reported at different salinities. Present results, together with similar data on the complexing capability of NTA, DTPA and TTHA towards inorganic components of natural fluids, allowed to find general conclusions on the important c..
Clinical impact of routine angiographic follow-up after percutaneous coronary interventions on unprotected left main
Background: Patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stent (DES) on unprotected left main (ULM) represent a complex subset. The role of routine coronary angiography at follow up in this subset remains debated.
Methods: At the documented center, all patients undergoing successful PCI on ULM lesions performing angiographic follow-up is suggested, but adherence to such a recommendation is inhomogeneous. Consecutive patients undergoing DES PCI on ULM were enrolled and experienced no adverse events during the first 6 months. Patients were then allocated to two groups: those undergoing routine control angiography (CA) and those undergoing clinical follow-up (CF). Primary endpoint was major adverse cardiac events (MACE) defined as cardiac death, myocardial infarction and urgent repeat target vessel revascularization.
Results: A total of 190 patients underwent successful DES implantation on ULM and the study population was without early events. CA was performed at 6 months after the index procedure in 91 (48%) patients. After 35 ± 21 months, MACE rates were significantly more common in the CF group as compared with the CA group (16.2% vs. 4.3%, p = 0.009). At multivariable analysis, CA was associated with reduced MACE risk (HR 0.13, 95% CI 0.1–0.7, p = 0.028). Of note, this was mainly driven by higher cardiac death rate in those undergoing CF than in those undergoing CA (p = 0.01).
Conclusions: CA after complex PCI, such as ULM PCI, is associated with reduced MACE. Such an observation calls for appropriately designed randomized trials
Clinical impact of routine angiographic follow-up after percutaneous coronary interventions on unprotected left main
Background: Patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stent (DES) on unprotected left main (ULM) represent a complex subset. The role of routine coronary angiography at follow up in this subset remains debated. Methods: At the documented center, all patients undergoing successful PCI on ULM lesions performing angiographic follow-up is suggested, but adherence to such a recommendation is inhomogeneous. Consecutive patients undergoing DES PCI on ULM were enrolled and experienced no adverse events during the first 6 months. Patients were then allocated to two groups: those undergoing routine control angiography (CA) and those undergoing clinical follow-up (CF). Primary endpoint was major adverse cardiac events (MACE) defined as cardiac death, myocardial infarction and urgent repeat target vessel revascularization. Results: A total of 190 patients underwent successful DES implantation on ULM and the study population was without early events. CA was performed at 6 months after the index procedure in 91 (48%) patients. After 35 \ub1 21 months, MACE rates were significantly more common in the CF group as compared with the CA group (16.2% vs. 4.3%, p = 0.009). At multivariable analysis, CA was associated with reduced MACE risk (HR 0.13, 95% CI 0.1\u20130.7, p = 0.028). Of note, this was mainly driven by higher cardiac death rate in those undergoing CF than in those undergoing CA (p = 0.01). Conclusions: CA after complex PCI, such as ULM PCI, is associated with reduced MACE. Such an observation calls for appropriately designed randomized trials
Anderson-Fabry’s Disease: A Rare but Treatable Case of Fever of Unknown Origin
Anderson-Fabry’s disease (AFD) is a rare, X-linked lysosomal storage disorder caused by the complete deficiency or attenuated activity of the enzyme α-galactosidase A, leading to progressive systemic intracellular accumulation of glycosphingolipids and subsequent cellular dysfunction, inflammation and fibrosis. Fever is a frequently misinterpreted symptom in the early stages of the disease, leading to diagnostic delay. We present the case of a 35-year-old man admitted to our Periodic Fever Research Centre for long-lasting recurrent episodes of fever of unknown origin. After extensive assessment, we diagnosed AFD associated with a novel GLA mutation. We started enzyme replacement therapy with clinical benefit and complete remission of fever
Relation Between Platelet Response to Exercise and Coronary Angiographic Findings in Patients With Effort Angina
Background—
Platelet reactivity is increased by exercise in patients with obstructive coronary artery disease (CAD) but not in patients with syndrome X. In this study, we prospectively investigated whether the platelet response to exercise might help distinguish, among patients with angina, those with obstructive CAD from those with normal coronary arteries (NCAs).
Methods and Results—
Venous blood samples were collected before and 5 minutes after exercise from 194 consecutive patients with stable angina. Platelet reactivity was measured by the platelet function analyzer (PFA)-100 system as the time for flowing whole blood to occlude a collagen-adenosine diphosphate ring (closure time). Coronary angiography showed CAD in 163 patients (84%) and NCA in 31 patients (16%). Baseline closure time was shorter in NCA patients (78.0±16 versus 95.5±23 seconds,
P
<0.0001). With exercise, closure time decreased in CAD patients (−15.5 seconds; 95% confidence limits [CL], −13.0 to −18.0 seconds;
P
<0.0001), but increased in NCA patients (12.5 seconds; 95% CL, 7.4 to 17.7 seconds;
P
=0.0004). An increase in closure time with exercise ≥10 seconds had 100% specificity and positive predictive value for NCAs. Similarly, a decrease ≥10 seconds had 100% specificity and positive predictive value for CAD. A closure time change (increase or decrease) ≥10 seconds allowed a correct classification of 55% of all patients.
Conclusions—
Among patients with stable angina, the response of platelet reactivity to exercise was predictive of normal or stenosed coronary arteries at angiography. Specifically, an increase in closure time with exercise ≥10 seconds was invariably associated with the presence of NCA
Fronto-orbito-ethmoidal intradiploic meningiomas: A case study with systematic review
Background: Primary intradiploic meningiomas, extra-axial tumors arising primarily in the skull, are rare. The authors reported a complex case of intradiploic intraosseous metaplastic meningioma of the left medial wall and orbital roof with the left frontal sinus invasion and left ethmoidal body bone substitution. The authors also conducted a systematic review concerning diagnosis and management of patients affected by purely calvarial intradiploic meningiomas along with a focus on fronto-orbito-ethmoidal ones. Methods: A literature search was conducted using PubMed and Scopus databases according to preferred reporting items for systematic reviews and meta-analysis statement and with the following Mesh terms: Intradiploic, intraosseous, calvarial, and meningioma. Eligibility criteria were limited by the nature of existing literature on intradiploic meningiomas, consisting of only case series, and case reports. Results: A total of 128 published studies were identified through our search. 41 studies were included in this systematic review, 59 patients with a female/male ratio of 1.2/1. The mean age of the patients is of 47.69 years (range 3-84 years). Only seven out of 59 patients (11.9%) presented a complex intradiploic meningioma located in fronto-orbito-ethmoidal region like our case. In almost all patients, a gross-total resection was performed (96.6%) and only in two patients (3.4%) a subtotal resection was achieved. Conclusion: The authors shared this successfully treated case to add to the overall clinical experience in the management of this rare subtype tumor, with the hope that more studies are conducted to further address the mechanism of intradiploic meningiomas development
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