Arteries, brain

Husson, B., Rodesch, G., Lasjuanias, P., Tardieu, M., Sebire, G. Magnetic resonance angiography in childhood arterial brain infarcts a comparative study with contrast angiography. Stroke. 33, 1280-1285 (2002)... 

Cholesterol is the central compound m any discussion of steroids Its name is a combination of the Greek words for bile (chole) and solid (stereos) preceding the characteristic alcohol suffix ol It is the most abundant steroid present m humans and the most important one as well because all other steroids arise from it An average adult has over 200 g of cholesterol it is found m almost all body tissues with relatively large amounts present m the brain and spinal cord and m gallstones Cholesterol is the chief constituent of the plaque that builds up on the walls of arteries m atherosclerosis... 

P-Adrenoceptor Blockers. There is no satisfactory mechanism to explain the antihypertensive activity of P-adrenoceptor blockers (see Table 1) in humans particularly after chronic treatment (228,231—233). Reductions in heart rate correlate well with decreases in blood pressure and this may be an important mechanism. Other proposed mechanisms include reduction in PRA, reduction in cardiac output, and a central action. However, pindolol produces an antihypertensive effect without lowering PRA. In long-term treatment, the cardiac output is restored despite the decrease in arterial blood pressure and total peripheral resistance. Atenolol (Table 1), which does not penetrate into the brain is an efficacious antihypertensive agent. In short-term treatment, the blood flow to most organs (except the brain) is reduced and the total peripheral resistance may increase. 

Methyldopa, through its metaboHte, CX-methyInorepinephrine formed in the brain, acts on the postsynaptic tt2-adrenoceptor in the central nervous system. It reduces the adrenergic outflow to the cardiovascular system, thereby decreasing arterial blood pressure. If the conversion of methyldopa to CX-methyl norepinephrine in the brain is prevented by a dopamine -hydroxylase inhibitor capable of penetrating into the brain, it loses its antihypertensive effects. 

Body temperatures are primarily sensed by temperature sensors in the hypothalamus near the center of the brain. Arterial blood flowing over and near the hypothalamus gives it information about the average thermal condition of... 

Baroreceptor. Specialized pressure-sensitive tissue located in carotid arteries. Nerve impulses proportional to arterial blood pressure are conducted from this tissue to the brain which in turn exerts control over the blood pressure. 

Expression (Human) Tissues Leukocytes, thymus, spleen, liver, ovary Cells PBLs, neutrophils,T-cells, dendritic cells, mast cells, eosinophils, macrophages, leukocytes Tissues spleen, small intestine, placenta, lung smooth muscle, Cells bronchial smooth muscle, CD34+ hemapoietic progenitor cells, monocytes, macrophages, mast cells, eosinophils, neutrophils, PBLs, human umbilical vein endothelial cells Tissues, heart, skeletal muscle, spleen, brain, lymp node, adrenal medulla, lung, human pumonary/ saphenous vein Cells monocytes, macrophages, mast cells, eosinophils, cardiac muscle, coronary artery, PBLs... 

Development of MMP null mice carrying specific MMP deletions has provided an opportunity to explore the role of MMPs in normal development as well as in such diverse conditions and diseases as skeletal dysplasias, coronary artery and heart disease, arthritis, cancer, and brain disorders. 

Ethanol distributes rapidly, with concentrations in body water 10 times higher than in body fat. The tissues with the greatest blood supply equdibrate most rapidly with arterial blood circulation. Shortly after alcohol ingestion, the ethanol concentration in the brain is higher than the venous concentration. 

After initial experiments demonstrating that the antiserum was capable of completely inhibiting the binding of [ H]PbTx-3 to its receptor site in rat brain membranes (Figure 9), we began studies designed to evaluate potential of the antiserum for prophylaxis and treatment of brevetoxin intoxication (34). The tethered rat model was used, and surgical implantations were identical to those described above. Heart rate, core and peripheral body temperatures, lead VIO ECG, and arterial blood pressure were monitored continuously. Respiratory rate was recorded each 5 min for the first 3 hr, then each 15 min until 6 hr. 

Occasionally, the diagnosis of acute ischemia can be established by NCCT because embohc material can be visualized directly, usually in the MCA or its branches. Emboli are often more radiodense than normal brain tissue, and therefore an affected proximal MCA may appear as a linear hyperdensity ( hyperdense middle cerebral artery sign or HMCA sign, Fig. 2.1c). One study found that the HMCA sign was 100% specific for MCA occlusion, but only 27% sensitive, probably because the density of embohc material is often indistinguishable from that of the normal MCA. ... 

Some have questioned the specificity of DWI in delineating particular areas of the brain that are destined for infarction, noting that some DWI lesions resolve at least partially in follow-up studies. However, it appears that reversibility of DWI lesions is quite unusual and typically involves only a small portion of initially abnormal tissue. One study found that reversal of a DWI abnormality occurred in 33% of patients following intra-arterial thrombolysis. However, in this study, the areas of reversal nevertheless went on to infarction in the majority of patients. ... 

FIGURE 2.6 Dynamic susceptibility contrast imaging. Axial images of the brain are acquired repeatedly, in this case every 1.5 seconds. As a bolus of intravenously injected contrast material enters the brain, first arteries, then brain parenchyma, and finally veins demonstrate a transient loss of signal intensity. In this acute stroke patient, hypoperfusion of the left middle cerebral artery territory results in delayed arrival of the contrast bolus and prolonged stasis of contrast within the tissue. 

Decreased cerebral blood flow, resulting from acute arterial occlusion, reduces oxygen and glucose delivery to brain tissue with subsequent lactic acid production, blood-brain barrier breakdown, inflammation, sodium and calcium pump dysfunction, glutamate release, intracellular calcium influx, free-radical generation, and finally membrane and nucleic acid breakdown and cell death. The degree of cerebral blood flow reduction following arterial occlusion is not uniform. Tissue at the... 

The Combined Lysis of Thrombus in Brain Ischemia Using Transcranial Ultrasound and Systemic rt-PA (CLOTBUST) study was a phase II randomized trial which compared continuous transcranial Doppler ultrasound insonation, in subjects with ultrasound evidence of MCA occlusion being given IV rt-PA, to sham insona-tion. ° There was an increased rate of arterial recanalization with the continuous insonation (49% vs. 30%, p = 0.03) and no increased risk of sICH. 

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