scholarly journals Kir4.1-mediated spatial buffering of K+: Experimental challenges in determination of its temporal and quantitative contribution to K+clearance in the brain

Channels ◽  
2014 ◽  
Vol 8 (6) ◽  
pp. 544-550 ◽  
Author(s):  
Brian Roland Larsen ◽  
Nanna MacAulay
Keyword(s):  
Spatial Buffering ◽  
Quantitative Contribution ◽  
The Brain

Simultaneous Determination of Imatinib and N-Desmethyl Imatinib in Rat Plasma and Tissues Using LC-MS/MS

2019 ◽  
Vol 15 (2) ◽  
pp. 121-129
Author(s):  
Zhi Rao ◽  
Bo-xia Li ◽  
Yong-Wen Jin ◽  
Wen-Kou ◽  
Yan-rong Ma ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Oral Administration ◽  
Parent Drug ◽  
Gradient Elution ◽  
Biological Tissues ◽  
Rat Plasma ◽  
Running Water ◽  
Liver And Kidney ◽  
The Brain

Background: Imatinib (IM) is a chemotherapy medication metabolized by CYP3A4 to Ndesmethyl imatinib (NDI), which shows similar pharmacologic activity to the parent drug. Although methods for determination of IM and/or NDI have been developed extensively, only few observations have been addressed to simultaneously determine IM and NDI in biological tissues such as liver, kidney, heart, brain and bone marrow. Methods: A validated LC-MS/MS method was developed for the quantitative determination of imatinib (IM) and N-desmethyl imatinib (NDI) from rat plasma, bone marrow, brain, heart, liver and kidney. The plasma samples were prepared by protein precipitation, and then the separation of the analytes was achieved using an Agilent Zorbax Eclipse Plus C18 column (4.6 × 100 mm, 3.5 µm) with gradient elution running water (A) and methanol (B). Mass spectrometric detection was achieved by a triplequadrupole mass spectrometer equipped with an electrospray source interface in positive ionization mode. Results: This method was used to investigate the pharmacokinetics and the tissue distributions in rats following oral administration of 25 mg/kg of IM. The pharmacokinetic profiles suggested that IM and NDI are disappeared faster in rats than human, and the tissue distribution results showed that IM and NDI had good tissue penetration and distribution, except for the brain. This is the first report about the large penetrations of IM and NDI in rat bone marrow. Conclusion: The method demonstrated good sensitivity, accuracy, precision and recovery in assays of IM and NDI in rats. The described assay was successfully applied for the evaluation of pharmacokinetics and distribution in the brain, heart, liver, kidney and bone marrow of IM and NDI after a single oral administration of IM to rats.

Application of selected ion monitoring technique for quantitative determination of picomole levels of pyrrolidine in the brain

1981 ◽  
Vol 115 (2) ◽  
pp. 254-259 ◽  
Author(s):  
Yoshiro Okano ◽  
Takeshi Miyata ◽  
Katsunori Iwasaki ◽  
Kazuo Takahama ◽  
Taizo Hitoshi ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Selected Ion Monitoring ◽  
Monitoring Technique ◽  
The Brain

scholarly journals Mathematical Modelling of Nitric Oxide Release Caused by Exocytosis and Determination of a Stellate Neuron Activity Function in Rat Brain

2007 ◽  
Vol 12 (3) ◽  
pp. 399-408 ◽  
Author(s):  
A. Oleinick ◽  
C. Amatore ◽  
O. Klymenko ◽  
I. Svir
Keyword(s):  
Mathematical Modelling ◽  
Neuron Activity ◽  
Nitric Oxide Release ◽  
Numerical Fitting ◽  
No Release ◽  
Initial Hypothesis ◽  
Gaussian Decomposition ◽  
The Brain ◽  
Theoretical Results

In this work we report the results of the mathematical modelling of NO◦ -release by neurons considering a series of Gaussian bursts, together with its transport in the brain by diffusion. Our analysis relies on the NO◦ -release from a neuron monitored before, during and after its patch-clamp stimulation as detected by an ultramicroelectrode introduced into a slice of living rat’s brain. The parameters of the neuron activity function have been obtained by numerical fitting of experimental data with simulated theoretical results. Within our initial hypothesis about the Gaussian decomposition of NO◦ -release that allowed drawing qualitative and quantitative conclusions about the considered neuron activity function. It is noted that since the activity function can be readily modified this signal processing may be adapted to the treatment of other and maybe more physiologically relevant hypotheses.

scholarly journals Pope John Paul II and the Neurological Standard for the Determination of Death: A Critical Analysis of his Address to the Transplantation Society

2017 ◽  
Vol 84 (2) ◽  
pp. 155-186 ◽  
Author(s):  
Doyen Nguyen
Keyword(s):  
Brain Death ◽  
Catholic Church ◽  
The Body ◽  
Human Organism ◽  
Determination Of Death ◽  
Pope John Paul Ii ◽  
John Paul Ii ◽  
The Brain ◽  
The Catholic Church

The introduction of the “brain death” criterion constitutes a significant paradigm shift in the determination of death. The perception of the public at large is that the Catholic Church has formally endorsed this neurological standard. However, a critical reading of the only magisterial document on this subject, Pope John Paul II's 2000 address, shows that the pope's acceptance of the neurological criterion is conditional in that it entails a twofold requirement. It requires that certain medical presuppositions of the neurological standard are fulfilled, and that its philosophical premise coheres with the Church's teaching on the body-soul union. This article demonstrates that the medical presuppositions are not fulfilled, and that the doctrine of the brain as the central somatic integrator of the body does not cohere either with the current holistic understanding of the human organism or with the Church's Thomistic doctrine of the soul as the form of the body. Summary The concept of “brain death” (the neurological basis for legally declaring a person dead) has caused much controversy since its inception. In this regard, it has been generally perceived that the Catholic Church has officially affirmed the “brain death” criterion. The address of Pope John Paul II in 2000 shows, however, that he only gave it a conditional acceptance, one which requires that several medical and philosophical presuppositions of the “brain death” standard be fulfilled. This article demonstrates, taking into consideration both the empirical evidence and the Church's Thomistic anthropology, that the presuppositions have not been fulfilled.

Microsphere Determination of Cochlear Blood Flow in Chickens

1987 ◽  
Vol 96 (4) ◽  
pp. 341-348 ◽  
Author(s):  
Daniel Zaluzec ◽  
Joseph Ramzy ◽  
Robert Wotring ◽  
Lincoln Gray
Keyword(s):  
Blood Flow ◽  
Inverse Relationship ◽  
External Auditory Meatus ◽  
Blood Gas ◽  
Radioactive Microspheres ◽  
Cochlear Blood Flow ◽  
Camera Lucida ◽  
Micron Diameter ◽  
The Brain

Chickens were injected with 9-micron-diameter radioactive microspheres. Cochleas were removed through the external auditory meatus, and the positions of all embedded microspheres were drawn under camera-lucida. Constant measurements of arterial pressures and postinjection blood-gas determinations confirmed that injections were made into normal circulatory systems. The averaged estimate of cochlear blood flow in chickens is 0.75 μl/min. Variability in these data from chickens is similar to that reported from mammals. A potentially important but puzzling observation is an inverse relationship between blood flow to the cochlea and to the brain. The ease of cochlear extraction makes chickens ideal models for study of cochlear blood flow.

Focal Ischemic Cerebral Injury in the Newborn: Diagnosis by Ultrasound and Correlation with Computed Tomographic Scan

PEDIATRICS ◽  
1983 ◽  
Vol 71 (5) ◽  
pp. 790-793
Author(s):  
Alan Hill ◽  
David J. Martin ◽  
Alan Daneman ◽  
Charles R. Fitz
Keyword(s):  
Term Infant ◽  
Cerebral Injury ◽  
Ultrasound Scanning ◽  
Older Children ◽  
Cerebral Lesions ◽  
Ischemic Brain ◽  
Computed Tomographic ◽  
Cerebral Ischemic ◽  
The Brain

Ischemic brain injury in the newborn is a common cause of subsequent neurologic deficits seen in older children. Clearly, determination of severity and location of such injury is important for management and prognosis. Although ultrasound scanning of the brain has been used extensively in the premature infant for diagnosis of hemorrhagic lesions, its use in the term infant for recognition of isehemic cerebral lesions has not been reported. Four cases are described in which focal echodense areas were identified on ultrasound scan of the brain. These echodense areas on ultrasound corresponded to the appearance on computed tomographic (CT) scan of areas of decreased density which are known to represent ischemic cerebral injury. In three of the four cases there were focal neurologic findings and/or focal abnormalities on EEG. In two cases, real-time ultrasound scanning demonstrated changes in arterial pulsations in cerebral vessels in the area of the lesions. Thus in both, there was diminution in pulsations within the echodense areas and in one case, an increase in pulsations was observed at the periphery of the echodense lesion. Our data demonstrate the value of ultrasound scanning for assessment of the extent and location of focal cerebral ischemic lesions in the newborn. Such assessment permite assessment of prognosis.

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