The role of beta 2-adrenoceptor on the pathogenesis of insulin resistance in essential hypertension

The role of beta 2-adrenoceptor on the pathogenesis of insulin resistance in essential hypertension (EH) was explored. After the measurement of blood pressure in 15 EH patients and 8 control subjects, EH patients were divided into two groups by the elevation of plasma NE (delta NE) 5 min after standing: 7 normoadrenergic EH (delta NE < 140 pg/ml) and 8 hyperadrenergic EH (delta NE > or = 140 pg/ml). On the morning after a 12-h overnight fast, regular insulin (0.1 U/kg) was injected intravenously, and glucose disappearance rate (GDR) was measured and used as an index of insulin sensitivity. On the following day, the test was reinvestigated following the administration of mabuterol, a beta 2 agonist. Plasma growth hormone (GH), cortisol, norepinephrine (NE) and epinephrine (Epi) were measured before and after the mabuterol administration. Although there were no significant differences of basal GDR among these three groups, mabuterol induced a considerable decrease in GDR in EH patients but not in control subjects. There was no significant difference in the decrease of GDR between normo- and hyperadrenergic EH. The decrease in GDR tended to correlate with the mean blood pressure at rest in EH but not in normal subjects. Plasma glucose and serum insulin in EH patients were increased more than in normal subjects. Plasma GH, cortisol and Epi were not elevated by mabuterol, but plasma NE increased in each group, significantly in hyperadrenergic EH. There was no correlationship between the increase in plasma NE and the decrease in GDR after mabuterol.(ABSTRACT TRUNCATED AT 250 WORDS)     

Switching characteristics of LD transceivers for optical TCMtransmission

LD transceivers for a TCM (time-compression multiplexing) scheme are promising for bidirectional transmission and economical optical subscriber networks. This paper describes LD switching characteristics when cycling between transmitter and receiver states. An LD equivalent circuit model is discussed based on detailed observations of the LD discharge properties during switching operations. It Is confirmed that the LD current-blocking layers significantly affect switching characteristics. In addition, a “reverse-bias method” for high-speed switching is proposed     

Integrin signaling

Integrins provide dynamic links between cells and extracellular matrix molecules. Although integrins were originally viewed as relatively simple adhesion molecules, it soon became clear that intracellular signal transduction initiated by integrins is centrally involved in many cellular processes. In fact, a remarkable number of classical signaling pathways are now known to be activated or modified by the interactions of cells with matrix proteins via integrins. These integrin signaling responses can also involve many other extracellular and intracellular molecules. The following mini-reviews were solicited from some of the future leaders in the field of integrin signaling. They examine selected important portions of this field, provide conceptual syntheses from a large and confusing literature, and then propose novel testable ideas. These ideas should encourage dialogue and open new avenues of research in this rapidly expanding, exciting field.     

Local polarization phenomena in In-doped CdTe X-ray detector arrays

Local polarization phenomena have been studied in detector arrays with the detector element size of 500 μm×500 μm, which are fabricated from high-resistivity In-doped CdTe crystals grown by the vertical Bridgman technique. It has been found for the first time that a polarization effect, which is characterized by a progressive decrease of the pulse counting rate with increasing photon fluence, strongly depends on the detector elements, that is, the portion of crystals used. The influence of several parameters, such as the applied electric field strength, time, and temperature, on this local polarization effect is also investigated. From the photoluminescence measurements of the inhomogeneity of In dopant, it is concluded that the local polarization effect observed here originates from an deep level associated with In dopant in CdTe crystals     

Atherosclerosis regression in the elderly--correlation between centrally depressed lesions and risk factors

Atherosclerotic plaque with central depression (depressed lesion) may indicate regression of atherosclerosis in the aorta. Aortic depressed lesions have a solitary elevated area of plaque with a sharply-bordered roung depression in its center and no area ulceration. This may be interpretable as a sign of regression of atherosclerosis. To clarify the pathogenesis of depressed lesion, we studied clinical risk factors such as hypercholesterolemia in patients with depressed lesions that were confirmed at autopsy. The patients were divided into 3 groups according to their total cholesterol level at autopsy: a high-risk group (> or = 220 mg/dl), a moderate-risk group (180-220 mg/dl), and a low-risk group (< or = 180 mg/dl). Depressed lesions were found in 16.4% of those in the high-risk group, in 14.6% of those in the moderate-risk group and in 69.0% of those in the low-risk group. Severe aortic atherosclerosis was found in 69.8% of the patients; 50.9% of those with severe disease were in the-low risk group. Depressed lesions were also found in those with low levels of low-density lipoprotein cholesterol (< or = 140 mg/dl), 58.8% of whom were found to have severe atherosclerosis. There was no relationship between total cholesterol level and the presence of depressed lesions. However, a clinical prevention trial may result in sufficient control of ahterosclerosis among those in the high-risk group and may also lead to regression of aortic lesions.     

Antigen-induced airway hyperresponsiveness is associated with infiltration of eosinophils in lung tissue, but not with bronchoalveolar lavage eosinophilia or neutrophilia

Hemimicropsia is a rare disorder of visual perception characterized by an apparent reduction of the size of objects when presented in one hemifield. We report two cases of hemimicropsia resulting from focal brain lesions. The first patient was an art teacher and could accurately depict his abnormal visual perception. He subsequently died and his brain was examined post mortem. In the second patient, micropsia was assessed by a quantified size comparison task. The size of a given object is normally perceived as constant across any spatial position. Hemimicropsia may thus be considered a limited violation of the size constancy principle. Behavioural and anatomical data are discussed in relation to the neural basis of visual object perception in humans.     

Effect of Cold-Rolling on Precipitation Phenomena in Sensitized Type 316L and 340L Austenitic Stainless Steels

Precipitation phenomena in Type 316L and 304L stainless steels were studied mainly by transmission electron microscopic (TEM) observations after cold-rolling ranging from 0% (as solution annealed) to 80% reduction in thickness,and then by sensitization treatment. Precipitates were identified by electron diffraction analysis and EDS analysis.Precipitates observed in sensitized 316L stainless steel were sigma and chi phases, whereas carbide and sigma were observed in sensitized 304L stainless steel. Recrystallized grains were formed in 30% cold-rolled and sensitized 304L.However, the tendency toward recrystallization in sensitized 316L was much lower than in 304L. Precipitation of sigma and chi phases was accelerated by cold-rolling and they were observed at grain boundaries in lower cold-rolling; they were also seen, in grain interiors in higher cold-rolling. Higher deformation induced partially recrystallization combined with precipitation, resulting in the formation of heterogeneous microstructures.     

Association of alpha1-antichymotrypsin polymorphism with cerebral amyloid angiopathy

Hemodialysis permits a long term survival to patients with End Stage Renal Disease (E.S.R.D.). However the patients ongoing hemodialysis presented a immunodeficiency and a important modification of drugs biodisponibility. Tuberculosis is an endemic disease in our countries. Extrapulmonary tuberculosis is reported from these two cases among 13 patients treated in C.H.U.A. Le Dantec hemodialysis center. Clinical symptoms are not specific bacteria is not found. Diagnosis is obtained by a bundle of arguments. Antituberculosis treatment need to be adjusted in this field. Even if Rifampicine can be administrated at normal dose. The others drugs must be adapted on their clearance and the underlying disease. The two patients presented psychiatrical symptoms motivating a reduction of isoniazide dose witch threshold toxicity is lowered by renal failure state. These observations must increase watchfulness on nephrologist of undeveloping countries, confronted with tuberculosis renewed out break.