The effect of ACTH stimulation on plasma steroids in two patients with congenital hypoaldosteronism and in their relatives

1982 ◽  
Vol 99 (2) ◽  
pp. 245-250 ◽  
Author(s):  
S. L. S. Drop ◽  
I. M. E. Frohn-Mulder ◽  
H. K. A. Visser ◽  
W. G. Sippell ◽  
H. G. Dörr ◽  
...  

Abstract. In two children with isolated congential hyperreninaemic hypoaldosteronism, as well as in their relatives, plasma levels of aldosterone (Aldo), corticosterone (B), deoxycorticosterone (DOC), 18-OH-B and 18-OH-DOC were measured before and after an iv bolus of 0.25 mg Synacthen® (Ciba). A corticosterone methyl oxidase deficiency type II was demonstrated in one child. Her normoreninaemic parents (no consanguinity) had plasma values consistent with heterozygosity. The results in the other child and one asymptomatic sib were compatible with a partial corticosterone methyl oxidase deficiency type I. His parents were consanguine but had normal Aldo levels. Overnight dexamethasone administration did not suppress any of the steroids measured except cortisol, suggesting synthesis of these steroids by the zona glomerulosa.

2001 ◽  
Vol 38 (02) ◽  
pp. 542-553 ◽  
Author(s):  
Ji Hwan Cha

In this paper two burn-in procedures for a general failure model are considered. There are two types of failure in the general failure model. One is Type I failure (minor failure) which can be removed by a minimal repair or a complete repair and the other is Type II failure (catastrophic failure) which can be removed only by a complete repair. During a burn-in process, with burn-in Procedure I, the failed component is repaired completely regardless of the type of failure, whereas, with burn-in Procedure II, only minimal repair is done for the Type I failure and a complete repair is performed for the Type II failure. In field use, the component is replaced by a new burned-in component at the ‘field use age’ T or at the time of the first Type II failure, whichever occurs first. Under the model, the problems of determining optimal burn-in time and optimal replacement policy are considered. The two burn-in procedures are compared in cases when both the procedures are applicable.


2021 ◽  
Vol 34 (1) ◽  
pp. 79-88
Author(s):  
Dean Radin ◽  
Helané Wahbeh ◽  
Leena Michel ◽  
Arnaud Delorme

An experiment we conducted from 2012 to 2013, which had not been previously reported, was designed to explore possible psychophysical effects resulting from the interaction of a human mind with a quantum system. Participants focused their attention toward or away from the slits in a double-slit optical system to see if the interference pattern would be affected. Data were collected from 25 people in individual half-hour sessions; each person repeated the test ten times for a total of 250 planned sessions. “Sham” sessions designed to mimic the experimental sessions without observers present were run immediately before and after as controls. Based on the planned analysis, no evidence for a psychophysical effect was found. Because this experiment differed in two essential ways from similar, previously reported double-slit experiments, two exploratory analyses were developed, one based on a simple spectral analysis of the interference pattern and the other based on fringe visibility. For the experimental data, the outcome supported a pattern of results predicted by a causal psychophysical effect, with the spectral metric resulting in a 3.4 sigma effect (p = 0.0003), and the fringe visibility metric resulting in 7 of 22 fringes tested above 2.3 sigma after adjustment for type I error inflation, with one of those fringes at 4.3 sigma above chance (p = 0.00001). The same analyses applied to the sham data showed uniformly null outcomes. Other analyses exploring the potential that these results were due to mundane artifacts, such as fluctuations in temperature or vibration, showed no evidence of such influences. Future studies using the same protocols and analytical methods will be required to determine if these exploratory results are idiosyncratic or reflect a genuine psychophysical influence.


1998 ◽  
Vol 80 (2) ◽  
pp. 914-923 ◽  
Author(s):  
Michinori Kubota ◽  
Ikuo Taniguchi

Kubota, Michinori and Ikuo Taniguchi. Electrophysiological characteristics of classes of neuron in the HVc of the zebra finch. J. Neurophysiol. 80: 914–923, 1998. Whole cell recordings were made from zebra finch HVc neurons in slice preparations. Four distinct classes of neuron were found on the basis of their electrophysiological properties. The morphological characteristics of some of these neurons were also examined by intracellular injection of Lucifer yellow. Type I neurons (21 of 65 cells) had longer time-to-peak of an afterhyperpolarization following an action potential than the other classes. They exhibited both fast and time-dependent inward rectification and an initial high-frequency firing followed by a slower constant firing. Type I neurons had large somata and thick dendrites with many spines. The axons of some of the neurons in this class projected in the direction of area X of the parolfactory lobe. Type II neurons (30 of 65 cells) had a more negative resting membrane potential than the other classes. They exhibited fast inward rectification. Type II neurons could be divided into two subclasses by the absence (IIa; 22 cells) and the presence (IIb; 8 cells) of a low-threshold transient depolarization. Type IIa neurons had relatively small somata and thin, spiny dendrites. The axons of some of the neurons in this class projected in the direction of the robust nucleus of the archistriatum (RA). Type IIb neurons had relatively large somata and thick dendrites with many spines. Type III neurons (6 of 65 cells) had a shorter action-potential duration than the other classes. They exhibited prominent time-dependent inward rectification and a regular tonic firing with little or no accommodation. Type III neurons had beaded, aspiny dendrites. Type IV neurons (8 of 65 cells) had a longer action-potential duration, a much larger input resistance, and longer membrane time constant than the other classes. Type IV neurons had small somata and thin, short, sparsely spiny dendrites. The axons of some of the neurons in this class projected in the direction of the RA. These classes of neuron may play distinct roles in song production and representation in the HVc.


1989 ◽  
Vol 257 (1) ◽  
pp. R87-R95 ◽  
Author(s):  
A. Gnionsahe ◽  
M. Claire ◽  
N. Koechlin ◽  
J. P. Bonvalet ◽  
N. Farman

Distal segment of several amphibians exhibits aldosterone-modulated ion transport properties. On the other hand, A6 cells, derived from Xenopus laevis (XL) kidney, are aldosterone sensitive. We examined the distribution of aldosterone binding sites in isolated tubules of XL compared with rabbit. After incubation with 2 nM [3H]aldosterone, microdissected tubular segments from proximal (PT), distal straight segment (DST), and flask cell collecting (CT) tubules from XL and from rabbit cortical thick ascending limb (CTAL), connecting (CNT), and collecting (CCD) tubules were processed for dry film autoradiography. In XL, specific nuclear labeling of type I (mineralocorticoid) sites was restricted to DST. Labeling of type II (glucocorticoid) sites was present all along the tubule. No specific cytoplasmic labeling was observed, except for type II sites in PT. In the rabbit, aldosterone binds to both type I and type II sites in the three tubular segments studied. In these segments, the binding was about fourfold higher than in DST of XL. These results bring direct evidence in designating the distal tubule of amphibians as a target epithelium for aldosterone. In addition, they suggest that A6 cell line may derive from DST of the Xenopus nephron.


Toxins ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 262 ◽  
Author(s):  
Sabine Brantl ◽  
Peter Müller

Toxin–antitoxin (TA) systems were originally discovered as plasmid maintenance systems in a multitude of free-living bacteria, but were afterwards found to also be widespread in bacterial chromosomes. TA loci comprise two genes, one coding for a stable toxin whose overexpression kills the cell or causes growth stasis, and the other coding for an unstable antitoxin that counteracts toxin action. Of the currently known six types of TA systems, in Bacillus subtilis, so far only type I and type II TA systems were found, all encoded on the chromosome. Here, we review our present knowledge of these systems, the mechanisms of antitoxin and toxin action, and the regulation of their expression, and we discuss their evolution and possible physiological role.


2016 ◽  
Vol 29 (19) ◽  
pp. 6957-6971 ◽  
Author(s):  
Boqi Liu ◽  
Congwen Zhu ◽  
Yuan Yuan ◽  
Kang Xu

Abstract An advance in the timing of the onset of the South China Sea (SCS) summer monsoon (SCSSM) during the period 1980–2014 can be detected after 1993/94. In the present study, the interannual variability of the SCSSM onset is classified into two types for the periods before and after 1993/94, based on their different characteristics of vertical coupling between the upper- and lower-tropospheric circulation and the differences in their related sea surface temperature anomalies (SSTAs). On the interannual time scale, type-I SCSSM onset is characterized by anomalous low-level circulation over the northern SCS during 1980–93, whereas type-II SCSSM onset is associated with anomalies of upper-level circulation in the tropics during 1994–2014. The upper-tropospheric thermodynamic field and circulation structures over the SCS are distinct between the two types of SCSSM onset, and this investigation shows the importance of the role played by the spring SSTAs in the southern Indian Ocean (SIO) and that of ENSO events in type-I and type-II SCSSM onset, respectively. In the early episode, the warming SIO SSTAs can induce an anomalous low-level anticyclone over the northern SCS that affects local monsoonal convection and rainfall over land to its north, demonstrating a high sensitivity of subtropical systems in type-I SCSSM onset. However, in type-II SCSSM onset during the later episode, the winter warm ENSO events and subsequent warming in the tropical Indian Ocean can influence the SCSSM onset by modulating the spring tropical temperature and upper-level pumping effect over the SCS.


Author(s):  
S. Serge Barold

The diagnosis of first-degree and third-degree atrioventricular (AV) block is straightforward but that of second-degree AV block is more involved. Type I block and type II second-degree AV block are electrocardiographic patterns that refer to the behaviour of the PR intervals (in sinus rhythm) in sequences (with at least two consecutive conducted PR intervals) where a single P wave fails to conduct to the ventricles. Type I second-degree AV block describes visible, differing, and generally decremental AV conduction. Type II second-degree AV block describes what appears to be an all-or-none conduction without visible changes in the AV conduction time before and after the blocked impulse. The diagnosis of type II block requires a stable sinus rate, an important criterion because a vagal surge (generally benign) can cause simultaneous sinus slowing and AV nodal block, which can resemble type II block. The diagnosis of type II block cannot be established if the first post-block P wave is followed by a shortened PR interval or by an undiscernible P wave. A narrow QRS type I block is almost always AV nodal, whereas a type I block with bundle branch block barring acute myocardial infarction is infranodal in 60–70% of cases. All correctly defined type II blocks are infranodal. A 2:1 AV block cannot be classified in terms of type I or type II block, but it can be AV nodal or infranodal. Concealed His bundle or ventricular extrasystoles may mimic both type I or type II block (pseudo-AV block), or both


1991 ◽  
Vol 260 (5) ◽  
pp. E713-E718 ◽  
Author(s):  
P. L. Greenhaff ◽  
J. M. Ren ◽  
K. Soderlund ◽  
E. Hultman

The concentrations of glycogen, ATP, and phosphocreatine were analyzed in types I and II muscle fibers separated from biopsy samples of the quadriceps femoris muscle in five healthy volunteers. Muscle samples were obtained before and after 64 s of intermittent electrical stimulation. The experiment was carried out without and with epinephrine (Epi) infusion. Before stimulation the glycogen concentration was 11% higher in type II than in type I fibers (P less than 0.05). During electrical stimulation, rapid glycogenolysis occurred in type II fibers with hardly any detectable glycogenolysis in type I fibers. The calculated rates of glycogenolysis were 0.18 +/- 0.14 and 3.54 +/- 0.53 mmol glucose.kg dry muscle-1.s-1 in types I and II fibers, respectively. Epi infusion increased the rate of glycogenolysis during electrical stimulation in type I fibers (10-fold) but did not enhance the rate in type II fibers (P greater than 0.05). It is considered that, during short-term maximal muscle contraction, rapid muscle glycogenolysis occurs predominantly in type II fibers even though types I and II fibers are recruited and that, when Epi stimulation of glycogenolysis occurs, this is predominantly limited to type I fibers.


2020 ◽  
Vol 28 (2) ◽  
pp. 479-487 ◽  
Author(s):  
Navid Neyshaburinezhad ◽  
Maryam Seidabadi ◽  
Mohammadreza Rouini ◽  
Hoda Lavasani ◽  
Alireza Foroumadi ◽  
...  

2008 ◽  
Vol 5 (suppl_1) ◽  
Author(s):  
Emery Conrad ◽  
Avraham E Mayo ◽  
Alexander J Ninfa ◽  
Daniel B Forger

Many biological systems contain both positive and negative feedbacks. These are often classified as resonators or integrators. Resonators respond preferentially to oscillating signals of a particular frequency. Integrators, on the other hand, accumulate a response to signals. Computational neuroscientists often refer to neurons showing integrator properties as type I neurons and those showing resonator properties as type II neurons. Guantes & Poyatos have shown that type I or type II behaviour can be seen in genetic clocks. They argue that when negative feedback occurs through transcription regulation and post-translationally, genetic clocks act as integrators and resonators, respectively. Here we show that either behaviour can be seen with either design and in a wide range of genetic clocks. This highlights the importance of parameters rather than biochemical mechanism in determining the system behaviour.


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