A Catecholamine storage in the pancreatic A2-cells of owl monkey (Aotes trivirgatus)

Summary The fluorescence method ofFalck andHillarp was used to study the occurrence of biogenic monoamines in the islets of Langerhans of monkeys. A storage of a catecholamine was demonstrated in the A₂-cells of owl monkey, whereas no histochemically demonstrable amount of monoamines could be seen in the islet cells of marmoset,Rhesus monkey, squirrel monkey, andCebus monkey.Supported by grants from the Swedish Medical Research Council (No. B69-14x-712-04C) and by the National Institutes of Health (No. 06701-02).     

Familial Plasma Lecithin:Cholesterol Acyltransferase Deficiency

A woman with familial plasma lecithin: cholesterol acyltransferase (L.C.A.T.) deficiency showed, like the other reported cases, obvious corneal opacity, proteinuria, and moderate anaemia with a slight haemolytic component. In the plasma the concentrations of free cholesterol, triglycerides, and lecithin were high, and those of esterified cholesterol, lysolecithin, and alphalipoprotein were low. L.C.A.T. activity in plasma was 10% of normal. The heparin-induced lipolytic activity in plasma was reduced. The erythrocyte lipid pattern was abnormal and showed the same pattern as earlier described in L.C.A.T. deficiency.The patient''s brother also probably suffered from the disease and died in uraemia. These are the fourth and fifth known patients with L.C.A.T. deficiency, the first one reported in a male, and the first one with a fatal outcome.     

Recent developments in aldehyde-induced monoamine fluorescence: The aluminum-formaldehyde (ALFA) method applied to immature and adult central nervous tissue

Summary In this review, the new aluminum-formaldehyde (ALFA) histofluoresence method for the highly sensitive visualization of monoamine-containing neurones in adult and immature central nervous tissue is summarized. Animals are first perfused with a buffer containing high concentrations of aluminum ions and the brains are then freeze-dried, reacted with formaldehyde vapour and further processes according to the Falck-Hillarp fluorescence method.The ALFA technique applied to adult brains visualizes all known catecholamine neurone systems with a sensitivity comparable to, and for certain noradrenergic systems higher than, that of the previously published glyoxylic acid-Vibratome method. The catecholamine systems in immature brains are demonstrated with a sensitivity clearly superior to that of any other available method. If the ALFA method is combined with systemic injections of -methylnoradrenaline into young animals (less than one week old), there is a dramatic increase in the intensity and number of catecholaminergic fibres. Many catecholaminergic systems which have too low concentrations of transmitter to be visualized in the untreated animal even with the ALFA method, can be demonstrated after administration of -methylnoradrenaline.The use of freeze-dried, paraffin-embedded tissue in the ALFA method makes possible convenient storage and parallel processing of many specimens. This mode of processing also allowsen boc reaction, which is the only way by which consistent and reproducible fluorescence yields can be obtained throughout large series of sections and parallel-processed specimens. In animals pretreated withl-tryptophan and monoamine oxidase-inhibitor, the technique is also useful for studies on central indolamine-containing systems.     

Structural studies of the capsular polysaccharide of Klebsiella type 52

The structure of the capsular polysaccharide from Klebsiella Type 52 has been investigated. Methylation analysis, characterization by gas-liquid chromatography-mass spectrometry of oligosaccharide derivatives obtained on partial hydrolysis of the methylated polysaccharide with acid, and specific degradation of the methylated polysaccharide by successive treatments with base and acid followed by characterization of the product, were the principal methods used. The polysaccharide is composed of hexasaccharide repeating-units containing D-glucuronic acid, D-galactose, and L-rhamnose, in the ratios 1:3:2. A structure for these units, disregarding the anomeric natures of the sugar residues, is proposed.     

Histochemical tests on lipids in the oral and skin epithelia in the mouse

Summary The present study concerns the application of a new tissue transport medium, Histocon, in lipid histochemical analysis of biopsies. It was generally found that this medium visibly retained more lipids quantitatively than did a fixation of the tissues. The lipid preserving capacity of Histocon seemed to be superior even to the use of fresh frozen specimens. These beneficial effects may be due to membrane stabilizing factors in the transport medium.Two types of lipids were usually found when comparing oral mucosa with epidermis. The mucosa was characterized chiefly by phospholipids with an increasing concentration gradient towards the stratum granulosum. The skin showed, in addition to the similar phospholipid gradient, also the presence of unsaturated hydrophobic lipids in the stratum corneum and granulosum.Supported in part by the Swedish Medical Research Council, grant no. K 73-24 X-3340-02 B.     

Histochemical observations on endogenous lactoperoxidase activity of the bovine submandibular salivary gland

Synopsis Seromucous demilunar cells of glutaraldehyde-fixed bovine submandibular salivary glands are intensely stained when sections are incubated in a benzidine-or a 3,3-diaminobenzidine-hydrogen peroxide medium in the pH range 6.0–9.0 whereas mucous acinar cells are completely unreactive. The histochemical reaction is completely inhibited by 3-amino-1,2,4-triazole. In contrast 2,4-dichlorophenol or potassium cyanide has little or no effect on the staining of demilunar cells. Striated duct cells also display a positive reaction with the diaminobenzidine method; this staining reaction, however, is most intense at pH 6.0. Furthermore, this reaction is markedly affected by potassium cyanide. The positive histochemical benzidine and diaminobenzidine reactions of demilunar cells probably corresponds to endogenous lactoperoxidase activity. On the other hand, the positive reaction shown by striated ducts, with optimal staining at pH 6.0 and which is completely inhibited by potassium cyanide, seems to be due to cytochromal oxidation of diaminobenzidine.     

Serum Trimethylamine-N-Oxide Is Strongly Related to Renal Function and Predicts Outcome in Chronic Kidney Disease

Background

The microbial metabolite Trimethylamine-N-oxide (TMAO) has been linked to adverse cardiovascular outcome and mortality in the general population.

Objective

To assess the contribution of TMAO to inflammation and mortality in chronic kidney disease (CKD) patients ranging from mild-moderate to end-stage disease and 1) associations with glomerular filtration rate (GFR) 2) effect of dialysis and renal transplantation (Rtx) 3) association with inflammatory biomarkers and 4) its predictive value for all-cause mortality.

Methods

Levels of metabolites were quantified by a novel liquid chromatography/tandem mass spectrometry-based method in fasting plasma samples from 80 controls and 179 CKD 3–5 patients. Comorbidities, nutritional status, biomarkers of inflammation and GFR were assessed.

Results

GFR was the dominant variable affecting TMAO (β = -0.41; p<0.001), choline (β = -0.38; p<0.001), and betaine (β = 0.45; p<0.001) levels. A longitudinal study of 74 CKD 5 patients starting renal replacement therapy demonstrated that whereas dialysis treatment did not affect TMAO, Rtx reduced levels of TMAO to that of controls (p<0.001). Following Rtx choline and betaine levels continued to increase. In CKD 3–5, TMAO levels were associated with IL-6 (Rho = 0.42; p<0.0001), fibrinogen (Rho = 0.43; p<0.0001) and hsCRP (Rho = 0.17; p = 0.022). Higher TMAO levels were associated with an increased risk for all-cause mortality that remained significant after multivariate adjustment (HR 4.32, 95% CI 1.32–14.2; p = 0.016).

Conclusion

Elevated TMAO levels are strongly associated with degree of renal function in CKD and normalize after renal transplantation. TMAO levels correlates with increased systemic inflammation and is an independent predictor of mortality in CKD 3–5 patients.     

Evolutionary consequences of climate‐induced range shifts in insects

Range shifts can rapidly create new areas of geographic overlap between formerly allopatric taxa and evidence is accumulating that this can affect species persistence. We review the emerging literature on the short‐ and long‐term consequences of these geographic range shifts. Specifically, we focus on the evolutionary consequences of novel species interactions in newly created sympatric areas by describing the potential (i) short‐term processes acting on reproductive barriers between species and (ii) long‐term consequences of range shifts on the stability of hybrid zones, introgression and ultimately speciation and extinction rates. Subsequently, we (iii) review the empirical literature on insects to evaluate which processes have been studied, and (iv) outline some areas that deserve increased attention in the future, namely the genomics of hybridisation and introgression, our ability to forecast range shifts and the impending threat from insect vectors and pests on biodiversity, human health and crop production. Our review shows that species interactions in de novo sympatric areas can be manifold, sometimes increasing and sometimes decreasing species diversity. A key issue that emerges is that climate‐induced hybridisations in insects are much more widespread than anticipated and that rising temperatures and increased anthropogenic disturbances are accelerating the process of species mixing. The existing evidence only shows the tip of the iceberg and we are likely to see many more cases of species mixing following range shifts in the near future.     

Large-scale use of fish traps for monitoring sea trout (Salmo trutta) smolts and sea lice (Lepeophtheirus salmonis) infestations: efficiency and reliability

Lice-infected sea trout populations were monitored using fish traps in the Romsdalsfjord (Norway). The reliability and efficiency of this capture technique, which allows estimation of lice infestation rates without killing the fish, was evaluated through a mark–recapture study. A total of 2447 sea trout smolts were captured, tagged and released over a three-year period. There was a considerable variation in capture rates (range: 0.4–17.7 fish per day) and sea lice numbers (number of lice per fish: 2.8–30.3; number of lice per gram body weight: 0.02–0.69) among localities, sampling times and years. Recapture rates of tagged fish with traps, which were low (2% or 0.11 fish per day), showed that the risk for pseudoreplication was minor, in terms of counting lice on the same fish several times. Most of the tagged sea trout (90%) were recaptured within the first two months after release, and no significant variations in lice numbers were found between tagging and recapture. The lack of differences in lice levels between tagging and recapture during the first week after tagging indicated that the method most likely would not significantly underestimate the lice infestations due to loss of lice during handling. Therefore, our results confirm that the use of fish traps is a suitable method for estimation of lice numbers on wild salmonids.