Selective Hypoaldosteronism: A Review

Objective: Selective hypoaldosteronism (SH) is a condition manifested by hyperkalemia due to low aldosterone secretion with normal cortisol. One of the obstacles in diagnosis is the awareness of the condition itself. The objective of this review is to highlight what is known about the epidemiology, pathophysiology, etiology, presentation, diagnosis, and treatment of SH.Methods: Literature search was performed on PubMed and Ovid Medline for articles which contained hypoaldosteronism as a major topic.Results: The recent literature on this topic is surprisingly limited. Few recent review articles were found, none of which were in English and less than 5 years old. Case reports and genetic literature were also included in this review, as they contain the most recent reports of SH in the literature.Conclusion: Awareness about SH will hopefully help physicians to identify patients at risk as well as decide on treatment if any therapy is required.Abbreviations:ACTH = adrenocorticotropic hormone AD = autosomal dominant AR = autosomal recessive ECF = extracellular fluid ICU = intensive care unit PHA II = pseudohypoaldosteronism type II PHA I = pseudohypoaldosteronism type I RTA = renal tubular acidosis SH = selective hypoaldosteronism ZG = zona glomerulosa     

Isolated chromosomes

Nucleoprotein threads isolated from mammalian tissues are interphase chromosomes rather than random fragments of stretched nuclei. Structures similar to the isolated threads are visible in intact nuclei. The isolated threads are often clearly microscopically double, consist of more or less tightly coiled chromonemata and show individuality in longitudinal differentiation. A nucleolus organizing chromosome with trabant and secondary constriction carrying the nucleolus can be recognized and is of identical structure in preparations from beef liver and pancreas.     

Population Studies of Isolated

Population size and structure of 52 isolated Nothofagus fusca stands were investigated in the lower Otira Valley, 3-6 km from a major population centre in the upper Taramakau catchment. The approximate age of N. fusca pioneer trees, estimated from partial increment cores and calculations based on diameter growth rates, indicated that nearly all isolated stands originated after 1600 AD, predominantly during the periods 1600-1760 AD and 1865-1910 AD. Age and location of pioneer trees from the latter time span suggest that their establishment was a result of human disturbance associated with European settlement of the region. Most of the sites occupied by the older N. fusca outliers are prone to intermittent natural disturbance, creating temporary gaps in the generally forested habitat. Reduced competition from both other tree species and ground cover in these habitats may have allowed establishment of N. fusca pioneer trees, but subsequent recruitment was limited except in floodplain stands. The comparatively abrupt regional geographical limit of N. fusca is discussed in relation to the local rainfall regime.     

Isolated wheat microspore culture

The use of doubled haploid plants in a wheat breeding program requires an efficient haploid production system. While the techniques for producing doubled haploids from anther culture are well established, those for isolated microspores are complicated and inefficient. Four methods of isolating microspores from anthers (blending, stirring, macerating, and floating) were compared. Isolated microspores were washed and cultured in liquid medium. The effects of pre-isolation mannitol conditioning, cell density, culture dilution, and sucrose centrifugation on microspore viability were evaluated. Isolation by blending gave the highest initial microspore viability (75%). Mannitol conditioning and purification by sucrose centrifugation had a detrimental effect on initial viability. An initial microspore density of 2 × 10⁵ microspores per ml was necessary for continued microspore viability. One hundred and nine haploid or spontancously doubled haploid plants were regenerated from microspores isolated without mannitol conditioning using the blending method. Based on this research, blender isolation with an initial density of 2 × 10⁵ microspores per ml is recommended for isolated microspore culture.Abbreviations LSmean least square mean - MES 2-N-morpholinoethane sulfonic acid - 2,4-d 2,4-dichlorophenoxyacetic acid - NAA -naphtaleneacetic acid     

Isolated persistent hypermethioninemia.

New information has been obtained on 30 patients with isolated persistent hypermethioninemia, most of them previously unreported. Biopsies to confirm the presumptive diagnosis of partially deficient activity of ATP: L-methionine S-adenosyltransferase (MAT; E.C.2.5.1.6) in liver were not performed on most of these patients. However, none showed the clinical findings or the extreme elevations of serum folate previously described in other patients with isolated hypermethioninemia considered not to have hepatic MAT deficiency. Patients ascertained on biochemical grounds had no neurological abnormalities, and 27/30 had IQs or Bayley development-index scores within normal limits or were judged to have normal mental development. Methionine transamination metabolites accumulated abnormally only when plasma methionine concentrations exceeded 300-350 microM and did so more markedly after 0.9 years of age. Data were obtained on urinary organic acids as well as plasma creatinine concentrations. Patterns of inheritance of isolated hypermethioninemia were variable. Considerations as to the optimal management of this group of patients are discussed.     

Nomenclature for Isolated Chloroplasts

THE nomenclature used to describe the “intactness” or degree of breakage of isolated chloioplasts has been most confusing in the past few years. This resulted chiefly from reports that chloroplasts should be isolated carefully and rapidly to obtain high rates of CO₂ fixation (50–250 µmol/mg chlorophyll/h). This type of chloroplast cannot translocate NADP, ferricyanide or ADP through its intact limiting membrane or envelope. “Class I” chloroplasts, as seen by phase contrast microscopy, had previously been considered to be similar to the in vivo situation. Unfortunately, in vitro they showed only low rates of CO₂ a fixation and easily transported NADP, ferricyanide and ADP into the chloroplast.     

Mycoplasma Suipneumoniae Isolated in Denmark

Though several agents may be involved in the etiology of enzootic pneumonia of pigs, recent investigations seem to indicate that the great majority of cases are caused by a Mycoplasma species — called M. suipneumoniae in Britain (Goodwin et al 1965) and M. hyopneumoniae in the U.S.A. (Maré & Switzer 1965).     

Isolated water in desiccated microorganisms

The presence of isolated mobile water in dehydrated eukaryotic microorganisms established earlier by NMR has been confirmed by direct chemical registration of this water in the yeast Cryptococcus albidus. This water constitutes several per cent of the dry biomass weight. Apparently, its preservation should be attributed to changes in the permeability of intracellular membranes upon dehydration. The water is released by the cells when they are heated to 150--200 degrees C and the cellular structures containing water are destroyed.     

Electrical Impedance of Isolated Amnion

The electrical impedance of the guinea pig amniotic membrane was measured, under standardized conditions, over the frequency range of 20 to 7000 cycles/second. This impedance can be represented analytically by a simple frequency-dependent function which is precisely of the form of the Debye relaxation equation. The observed data exhibit a broad dispersion centered at a frequency of 1050 cycles/second and a narrow distribution of time constants centered about 152 microseconds, both effects being due to the polydisperse nature of amniotic tissue. If the narrow time-constant distribution is approximated by a single time constant, amnion impedance can be simulated by a simple electrical circuit of frequency-independent elements. The Maxwell-Wagner interfacial treatment, although successfully adapted for cell suspensions, is shown to lose its quantitative significance in the case of the tightly structured amnion. In addition, determinations were made on the chemical composition of amniotic fluid, fetal blood and urine, and maternal blood and urine; the DC potential across the amniotic membrane was also measured.     

Mycobacterium malmoense Isolated from Soil

Mycobacterium malmoense was isolated from a soil sample, and biological, biochemical, antigenic, and genetic characteristics of the isolate were described. This is the first report of isolation of this organism in Japan.     

Biomechanics of Isolated Plant Cuticles

The mechanical properties of isolated cuticles of leaves (Yucca aloifolia, Clusia fluminensis, Nerium oleander, Hedera helix) and one fruit (Lycopersicon esculentum) were investigated by means of a tensile test. Samples of the leaves and the fruit were cut to identical size (12.5 × 50 mm) and the cuticles were enzymatically isolated, cleaned, and air dried. The morphology of the isolated cuticular membranes (CM) was investigated by scanning electron microscopy (SEM) and showed considerable differences. The thickness of the CM was determined by a digital image analysis system and ranged between 2.4 and 13.4 μm. The CM were subjected to a tensile test and the results are presented as stress-strain diagrams. From the latter, Young's moduli were calculated, a measure for the stiffness which allows the direct comparison of different materials. The obtained values ranged between 0.1 and 1.3 CPa. Hydration of CM caused a decrease of Young's moduli of about 35–50%. A possible role of the cuticle as a factor for the stabilization of plant organs is discussed.     

蓝锭果(Lonicera caerulea)中的花青素色素的研究

本研究从蓝果忍冬（LoniceraCaerulea）的果实中分离出红色素纯组分,通过层林、水解、光谱、高效液相色谱、核磁共振等方法的研究,鉴定红色素花青素的主要组分是花青定-3-葡萄糖,其他少量成份是花青定-3,5-双葡萄糖、花青定-3-芸香糖、花青定-3-龙胆二糖、芍药定-3-葡萄糖。     

Shigella sonnei Isolated from Well Water

A method is described which led to the isolation of Shigella sonnei from well water suspected of being the primary foci in a school-associated shigellosis outbreak.     

Electron-Microprobe Analysis of Isolated Plant Cells

A technique is described for the study of the intracellularlocalization of minerals in a single isolated plant cell byElectron Microprobe X-ray Analyser. Tissue-culture cells weremicro-analysed for zinc, calcium, potassium, and phosphorus.The X-ray oscillograms showed accumulation of zinc, potassium,and phosphorus in the nuclei. Microprobe analysis is a non-destructivemethod and allows for multiple element analysis in the sametissue, thereby having a wide application in the study of biologicalmaterials at cellular and subcellular levels.