scholarly journals Levothyroxine Therapy in Gastric Malabsorptive Disorders

2021 ◽  
Vol 11 ◽  
Author(s):  
Camilla Virili ◽  
Nunzia Brusca ◽  
Silvia Capriello ◽  
Marco Centanni

Oral levothyroxine sodium is absorbed in the small intestine, mainly in the jejunum and the ileum being lower the absorption rate at duodenal level. The time interval between the ingestion of oral thyroxine and its appearance in the plasma renders unlike a gastric absorption of the hormone. However, several evidence confirm the key role of the stomach as a prerequisite for an efficient absorption of oral levothyroxine. In the stomach, in fact, occur key steps leading to the dissolution of thyroxine from the solid form, the process bringing the active ingredient from the pharmaceutical preparation to the aqueous solution. In particular, gastric juice pH, volume, viscosity, as well as gastric emptying time seem to be the most important limiting factors. These hypotheses are confirmed by the detection of an increased need for levothyroxine in patients with Helicobacter pylori infection, chronic atrophic gastritis, gastroparesis, or in simultaneous treatment with drugs interfering with gastric acidic output. The aim of the present article is to focus on the knowledge of pathophysiologic events that determine the absorptive fate of traditional (tablet) and alternative thyroxine preparations (softgel capsule and liquid solution) in patients bearing gastric disorders.

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Hiroshi Kaneko ◽  
Tetsuo Hatanaka ◽  
Aki Nagase ◽  
Seishiro Marukawa ◽  
Tetsuya Sakamoto

Introduction: In Japan, the number of automated external defibrillators (AEDs) placed in public areas has climbed up to the estimated 530,000. We reported previously that a half of out-of-hospital cardiac arrests occurred within 100 m from a public AED in urban areas. However, shocks for defibrillation were given to less than 15% of those patients. The objectives of this study was to identify the limiting factors against the use of AEDs by bystanders. Methods: A prospective survey on out-of-hospital cardiac arrest was conducted in the city of Osaka (Dec 2016 through Mar 2017) and the city of Nagoya (Dec 2016 through Nov 2017) searching for patient demographics and AED settings including; absence/presence of a public AED on the scene, attachment of AED pads, delivery of shocks before the time of EMS arrival. Results: Of 558 cases of cardiac arrest registered during the survey period, an AED had already been delivered at the patient side by the time of EMS arrival in 92 case (16.5%). Of those, pads had been attached in 89 cased (96.7%). Shocks had been advised in 35 cases (39.3%) and to all but one of those cases at least 1 shock had been given by the bystanders. There were no statistically significant differences between the groups of cases with and without AEDs at the patient side regarding the patient age (65 years [IQR: 48-74] vs 63 years [IQR49-75], p=0.84), gender (p=0.68) and the time from call to EMS arrival (7 min [IQR: 6-9] vs 7 min [IQR: 6-9], p=0.74). Cases occurring indoors had more chances of AEDs being delivered on the patient side than cases occurring outdoors (24.0% vs 7.8%, p<0.001). Conclusions: Our study indicates that once an AED is delivered at the patient side, pads are successfully attached and shocks are given if indicated in almost all cases. This suggests that finding and delivering an AED onto the patient side are the limiting factors against the use of AEDs by bystanders. In order to popularize the use of AEDs by bystanders, informing people with AED placement and clear direction to the AED location seem to be the key steps.


2018 ◽  
Vol 16 (3) ◽  
pp. E78-E78
Author(s):  
Sorin Aldea ◽  
Stephan Gaillard

Abstract The eyebrow approach is a versatile technique that may apply to various vascular and tumoral pathologies of the anterior skull base. We present a case of multiple aneurysms clipping through the eyebrow approach and we discuss the nuances of this technique. A 44-yr-old patient presented with incidentally found aneurysms. Angiography showed 2 4.5-mm aneurysms on the left middle cerebral artery (MCA) and internal carotid artery (ICA) bifurcations. At surgery, the patient is positioned supine with the head elevated, slightly rotated, and extended in order to obtain good access and gravity retraction of the brain. A 3-cm incision is placed in the eyebrow and a small supraorbital bone flap is raised. The floor of the orbit and the edges of the craniotomy are thoroughly drilled in order to maximize the working space. After dural opening, the sylvian fissure was widely dissected and the MCA aneurysm was identified. A large opening of the sylvian and carotid cistern allows retractor free surgery. The ICA bifurcation aneurysm is then dissected and clipped. The MCA aneurysm is treated last in order to avoid a conflict between instruments especially during clipping. Aneurysms occlusion and vessel permeability is verified by Doppler ultrasonography and indocyanine green (ICG) angiography. After achieving hemostasis, the dura is closed and a subcuticular continuous suture is used at the skin. The postoperative course was uneventful. The eyebrow approach allows simultaneous treatment of multiple aneurysms of the anterior circle of Willis in selected cases. Proper positioning, drilling of the orbital floor and extensive arachnoid dissection are the key steps of this procedure.


2015 ◽  
Vol 87 (6) ◽  
pp. 557-567 ◽  
Author(s):  
Marta I. Litter

AbstractThis article is an overview of recent work performed in our laboratory on TiO2 heterogeneous photocatalysis of aqueous systems containing toxic forms of chromium, arsenic, lead, uranium and mercury. The cases of chromium and arsenic are treated in profundity. Photocatalytic treatments can convert the ionic species into their metallic solid form and deposit them over the semiconductor surface, or transform them into less toxic soluble species. When a transformation to the zerovalent state is possible, this allows the recovery of the metal from the waters, with an important economical return. Three types of mechanisms can be considered, all of them taking place through successive thermodynamically allowed monoelectronic electron transfer steps: (a) direct reduction by photogenerated electrons; (b) indirect reduction by intermediates generated by hole or hydroxyl radical oxidation of electron donors (reducing radicals); (c) oxidative removal by holes or hydroxyl radicals. Fundamentals of oxidative or reductive heterogeneous photocatalysis are described, with special emphasis on the role of organic donors present in the medium acting as synergists. This indicates the possibility of simultaneous treatment of pollutants of different chemical structure and properties present in the same medium.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Virginia Rubio ◽  
Ana I. García-Pérez ◽  
M. Cristina Tejedor ◽  
Angel Herráez ◽  
José C. Diez

The coumarin esculetin shows antioxidant action on some cell types, both by scavenging ROS and by decreasing ROS production. We have previously demonstrated the induction of apoptosis by esculetin on NB4 human leukaemia cells by an ill-defined mechanism related to ROS levels. In this work, we analyze the effect of the simultaneous treatment with esculetin and two oxidants to observe the early events in the mechanism of esculetin-induced apoptosis. Our results show that, from the early time of 15 min, esculetin acts synergistically with H2O2to decrease cell viability and metabolic activity and to increase apoptosis in NB4 cells. In contrast, the early oxidative effects oft-BHP are neutralised by esculetin, protecting human leukaemia NB4 cells from apoptosis. Esculetin seems to restrict the increase in peroxides caused by H2O2ort-BHP in the time interval analyzed. These results contribute to a better understanding of the cytotoxic effect caused by esculetin on NB4 cells. At the same time, the early neutralisation of exogenous oxidants could be of interest to prevent diseases related to oxidative stress imbalance.


Author(s):  
K. Cowden ◽  
B. Giammara ◽  
T. Devine ◽  
J. Hanker

Plaster of Paris (calcium sulfate hemihydrate, CaSO4. ½ H2O) has been used as a biomedical implant material since 1892. One of the primary limiting factors of these implants is their mechanical properties. These materials have low compressive and tensile strengths when compared to normal bone. These are important limiting factors where large biomechanical forces exist. Previous work has suggested that sterilization techniques could affect the implant’s strength. A study of plaster of Paris implant mechanical and physical properties to find optimum sterilization techniques therefore, could lead to a significant increase in their application and promise for future use as hard tissue prosthetic materials.USG Medical Grade Calcium Sulfate Hemihydrate Types A, A-1 and B, were sterilized by dry heat and by gamma radiation. Types A and B were additionally sterilized with and without the setting agent potassium sulfate (K2SO4). The plaster mixtures were then moistened with a minimum amount of water and formed into disks (.339 in. diameter x .053 in. deep) in polyethylene molds with a microspatula. After drying, the disks were fractured with a Stokes Hardness Tester. The compressive strengths of the disks were obtained directly from the hardness tester. Values for the maximum tensile strengths σo were then calculated: where (P = applied compression, D = disk diameter, and t = disk thickness). Plaster disks (types A and B) that contained no setting agent showed a significant loss in strength with either dry heat or gamma radiation sterilization. Those that contained potassium sulfate (K2SO4) did not show a significant loss in strength with either sterilization technique. In all comparisons (with and without K2SO4 and with either dry heat or gamma radiation sterilization) the type B plaster had higher compressive and tensile strengths than that of the type A plaster. The type A-1 plaster however, which is specially modified for accelerated setting, was comparable to that of type B with K2SO4 in both compressive and tensile strength (Table 1).


Author(s):  
J.D. Geller ◽  
C.R. Herrington

The minimum magnification for which an image can be acquired is determined by the design and implementation of the electron optical column and the scanning and display electronics. It is also a function of the working distance and, possibly, the accelerating voltage. For secondary and backscattered electron images there are usually no other limiting factors. However, for x-ray maps there are further considerations. The energy-dispersive x-ray spectrometers (EDS) have a much larger solid angle of detection that for WDS. They also do not suffer from Bragg’s Law focusing effects which limit the angular range and focusing distance from the diffracting crystal. In practical terms EDS maps can be acquired at the lowest magnification of the SEM, assuming the collimator does not cutoff the x-ray signal. For WDS the focusing properties of the crystal limits the angular range of acceptance of the incident x-radiation. The range is dependent upon the 2d spacing of the crystal, with the acceptance angle increasing with 2d spacing. The natural line width of the x-ray also plays a role. For the metal layered crystals used to diffract soft x-rays, such as Be - O, the minimum magnification is approximately 100X. In the worst case, for the LEF crystal which diffracts Ti - Zn, ˜1000X is the minimum.


2001 ◽  
Vol 15 (4) ◽  
pp. 256-274 ◽  
Author(s):  
Caterina Pesce ◽  
Rainer Bösel

Abstract In the present study we explored the focusing of visuospatial attention in subjects practicing and not practicing activities with high attentional demands. Similar to the studies of Castiello and Umiltà (e. g., 1990) , our experimental procedure was a variation of Posner's (1980) basic paradigm for exploring covert orienting of visuospatial attention. In a simple RT-task, a peripheral cue of varying size was presented unilaterally or bilaterally from a central fixation point and followed by a target at different stimulus-onset-asynchronies (SOAs). The target could occur validly inside the cue or invalidly outside the cue with varying spatial relation to its boundary. Event-related brain potentials (ERPs) and reaction times (RTs) were recorded to target stimuli under the different task conditions. RT and ERP findings showed converging aspects as well as dissociations. Electrophysiological results revealed an amplitude modulation of the ERPs in the early and late Nd time interval at both anterior and posterior scalp sites, which seems to be related to the effects of peripheral informative cues as well as to the attentional expertise. Results were: (1) shorter latency effects confirm the positive-going amplitude enhancement elicited by unilateral peripheral cues and strengthen the criticism against the neutrality of spatially nonpredictive peripheral cueing of all possible target locations which is often presumed in behavioral studies. (2) Longer latency effects show that subjects with attentional expertise modulate the distribution of the attentional resources in the visual space differently than nonexperienced subjects. Skilled practice may lead to minimizing attentional costs by automatizing the use of a span of attention that is adapted to the most frequent task demands and endogenously increases the allocation of resources to cope with less usual attending conditions.


2001 ◽  
Vol 17 (1) ◽  
pp. 25-35 ◽  
Author(s):  
G. Leonard Burns ◽  
James A. Walsh ◽  
David R. Patterson ◽  
Carol S. Holte ◽  
Rita Sommers-Flanagan ◽  
...  

Summary: Rating scales are commonly used to measure the symptoms of attention deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD). While these scales have positive psychometric properties, the scales share a potential weakness - the use of vague or subjective rating procedures to measure symptom occurrence (e. g., never, occasionally, often, and very often). Rating procedures based on frequency counts for a specific time interval (e. g., never, once, twice, once per month, once per week, once per day, more than once per day) are less subjective and provide a conceptually better assessment procedure for these symptoms. Such a frequency count procedure was used to obtain parent ratings on the ADHD, ODD, and CD symptoms in a normative (nonclinical) sample of 3,500 children and adolescents. Although the current study does not provide a direct comparison of the two types of rating procedures, the results suggest that the frequency count procedure provides a potentially more useful way to measure these symptoms. The implications of the results are noted for the construction of rating scales to measure the ADHD, ODD, and CD symptoms.


Methodology ◽  
2013 ◽  
Vol 9 (3) ◽  
pp. 123-128 ◽  
Author(s):  
Gordon Willis ◽  
Hennie Boeije

Based on the experiences of three research groups using and evaluating the Cognitive Interviewing Reporting Framework (CIRF), we draw conclusions about the utility of the CIRF as a guide to creating cognitive testing reports. Authors generally found the CIRF checklist to be usable, and that it led to a more complete description of key steps involved. However, despite the explicit direction by the CIRF to include a full explanation of major steps and features (e.g., research objectives and research design), the three cognitive testing reports tended to simply state what was done, without further justification. Authors varied in their judgments concerning whether the CIRF requires the appropriate level of detail. Overall, we believe that current cognitive interviewing practice will benefit from including, within cognitive testing reports, the 10 categories of information specified by the CIRF. Future use of the CIRF may serve to direct the overall research project from the start, and to further the goal of evaluation of specific cognitive interviewing procedures.


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