Shock induces a long-lasting elevation of blood glucose in Aplysia.

Glucose, and not trehalose, was found to be the main blood sugar in Aplysia californica. Changes in blood glucose in response to stress produced by electric shock were measured in blood obtained both from animals dissected within ten minutes of shocking and from catheterized animals at various intervals, up to two and a half hours after the shock. Electric shock increased blood glucose levels. The rise in blood sugar continued as long as two and a half hours after shock.     

Increased melatonin levels after hemorrhagic shock in male and female C3H/HeN mice

Although hemorrhagic shock leads to significant alterations of several hormones, e.g. ACTH, corticosterone and -endorphin, it is not known whether plasma melatonin levels are affected under this condition and if so, whether the effects are comparable in males and females. Using a radioimmunoassay, it was found that plasma melatonin levels were significantly increased in male and proestrus female C3H/HeN mice immediately after hemorrhagic shock. However, in male mice, by two hours after hemorrhage and resuscitation, plasma melatonin returned to levels comparable to those seen in control and sham-operated animals. Proestrus female mice, on the other hand, showed significantly increased plasma melatonin levels at two hours after surgery when compared to unoperated control animals. Although the significance and biological role of the transient increased plasma melatonin levels after hemorrhagic shock remain to be determined, it appears that the pineal gland and/or an extrapineal source of melatonin, of both male and proestrus female mice responds to severe hypotension by increased release of melatonin.     

Studies on the effect of allicin (diallyl disulphide-oxide) on alloxan diabetes.

On oral administration to alloxan diabetic rabbits, allicin produces an increase in its hypoglycemic action with relation to dose. A short-term treatment with allicin, as well as with tolbutamide, significantly reduced the blood sugar levels and glucose nitrogen ratio of the above animals.     

Raffinose as reserve sugar inDysdercus koenigii—a biosynthesis confirmation by14C glucose

Summary Dysdercus koenigii, studied for its sugar spectrum, showed consistent absence of trehalose in its blood and body muscles. Instead of this known reserve sugar, raffinose has been shown to fulfil this need. The biosynthesis confirmation has been made by¹⁴C glucose.     

Neuroendocrine control of carbohydrate metabolism in the freshwater bivalve molluscLamellidens marginalis

Summary Blood sugars and foot muscle glycogen were measured in the mussel,L. marginalis after ablation of the cerebral ganglia, and in mussels injected with cerebral ganglionic extract 3 h after ablation. There is a rise in the blood sugar and decrease in foot muscle glycogen 3 h after operation, but no change in sham-operated controls. The effect of ablation is reversed by injecting brain extract into ablated mussels. No such effect could be seen in the controls. The results are suggestive of the presence, in the cerebral ganglia, of a hypoglycaemic factor similar to insulin.     

Heat shock response inDrosophila

Major alterations in genetic activity have been observed in every organism after exposure to abnormally high temperatures. This phenomenon, called the heat shock response, was discovered in the fruit flyDrosophila. Studies with this organism led to the discovery of the heat shock proteins, whose genes were among the first eukaryotic genes to be cloned. Several of the most important aspects of the regulation of the heat shock response and of the functions of the heat shock proteins have been unraveled inDrosophila.     

Fecundity of the blood-feeding insectRhodnius prolixus increases in successive periods of egg production

The fecundity of the blood-feeding insect,Rhodnius prolixus, was observed to increase in successive periods of egg production, each period being triggered by a single large blood meal. As previously published, the fecundity of mated animals was significantly higher than that of unmated animals for the first period of egg production. For a second period of egg production, fecundity increased significantly in both mated and unmated animals. By the fourth period, fecundity had returned to first-feed values for mated animals, but remained high for unmated animals, and the fecundity of mated and unmated animals was not significantly different. Thus, during successive periods of egg production, the processes which maintain fecundity of unmated animals below that of mated animals are overcome.     

Cryopreservation of parasites

Summary In this review, advances in cryopreservation of helminth parasites are reported. Our own studies demonstrate that metacestodes ofEchinococcus multilocularis can be maintained in a viable state for at least 1–2 years by appropriate deep-freezing and storage in liquid nitrogen. Infective larvae of the nematodeToxocara canis cryopreserved for 1 week in liquid nitrogen were maintained after thawing in vitro in a chemically defined medium for 35 weeks. Although motility of previously deep-frozen larvae was reduced they produced secretory/excretory antigens of similar immunodiagnostic quality as those from unfrozen larvae. Whereas infective larvae of several species of trichostrongylids can be easily cryopreserved, the infective larvae of the cattle lungworm,Dictyocaulus viviparus, and muscle larvae ofTrichinella spiralis are more sensitive to damage by subzero temperatures. Therefore, survival rates after cryopreservation are low, but improvement of the cooling schedules appears to be feasible. It is concluded that cryopreservation of certain stages of helminth and protozoan parasites is a useful technique for long-term storage of defined isolates, which can contribute considerably to reducing the number of experimental animals usually required for serial passages.     

Regulation of carbohydrate metabolism by the optic tentacles of the garden snailCryptozona ligulata (Gastropoda-Stylommatophora)

Summary The presence of a hyperglycemic factor in the optic tentacles of the snailC. ligulata is reported here. A preliminary characterization based on crude extracts indicates the factor to be water-soluble, heat labile and to be an albumin. The ablation of optic tentacles and injection of optic tentacle extract into operated and normal snails caused a rise in blood sugar, total carbohydrate and glycogen in the foot muscle and mantle and a decrease in hepatopancreatic glycogen. The ablation also caused a fall in blood free amino acids and a rise in the tissues, which was reversed in the blood and foot muscle by injection of the extract. Possible conversion of amino acids to total carbohydrates and glycogen by gluconeogenesis is suggested.     

Causes of artificially high blood glucose values in experiments with diabetic rats and mice

Unusually high blood sugar values may be caused by the slightest contamination of the blood obtained after puncture of the tail vein by diabetic urine, that has dried onto the tails of the animals. This can be avoided by collecting blood that is allowed to drip from the severed tip of the tail or by carefully cleaning the tail before puncturing the tail vein.     

Comportamento dell allossanain vivo

Summary The author describes a microprocedure, based on the o-phenylenediamine reaction, for the determination of alloxan in blood and tissuesin vivo. With this method he has been able to determine alloxan in blood, liver, kidney, muscle, and pancreas of rats treated with diabetogenous doses of alloxan. This substance has been found in the blood and tissues during an hour and a half after the injection and in the urine collected directly from the ureter a quarter of an hour after the injection.     

Causes of artificially high blood glucose values in experiments with diabetic rats and mice

Summary Unusually high blood sugar values may be caused by the slightest contamination of the blood obtained after puncture of the tail vein by diabetic urine, that has dried onto the tails of the animals. This can be avoided by collecting blood that is allowed to drip from the severed tip of the tail or by carefully cleaning the tail before puncturing the tail vein.     

PCR jumping in clones of 30-million-year-old DNA fragments from amber preserved termites (Mastotermes electrodominicus)

DNA from 30-million-year-old amber preserved termites (Mastotermes electrodominicus) was PCR amplified with nuclear ribosomal RNA small subunit primers and cloned into the TA vector (INVITROGEN). We obtained several classes of recombinant clones as a result. AuthenticMastotermes electrodominicus clones were identified. The source of other classes of clones was identified as contaminants of the ancient DNA template. Several of the clones appeared to be chimeric in structure with half of the clone identical to the termite sequence and the other half identical to contaminant sequences. The phenomenon of PCR jumping was identified as a possible source for the chimeric clones.     

Investigations of receptor-mediated phagocytosis by hormone-induced (imprinted)Tetrahymena pyriformis

Receptor-mediated endocytosis byTetrahvmena pyriformis was studied using tetramethylrhodamine isothiocyanate-labeled concanavalin A (TRITC-Con A) with fluorescence and confocal microscopy. In the presence of insulin, or 24 h after insulin pretreatment (hormonal imprinting), the binding and uptake of TRITC-Con A increased when compared to controls, owing to the binding of TRITC-Con A to sugar oligomers of insulin recptors. Mannose inhibited the binding of Con A, thus demonstrating the specificity of binding. Histamine, a phagocytosis-promoting factor in mammals andTetrahymena, and galactose, did not influence the uptake of TRITC-Con A.     

Heat shock proteins in three relatedDrosophila species belonging to theobscura group

The effect of heat shock on protein synthesis in three relatedDrosophila species belonging to theobscura group was analyzed on SDS-acrylamide gels. Four major heat shock proteins (hsps) were found in these species, in which synthesis reaches a maximum at 34°C. Although the higher molecular weight proteins are conserved, differences in size were found for the small hsps in these species. By means of in situ hybridization usingD. melanogaster probes for the small hsp genes, it was inferred that the small hsp genes of theobscura group species are clustered at the 27A locus in all three species.     

<Emphasis Type="Italic">Drosophila melanogaster</Emphasis> innate immunity: an emerging role for peptidoglycan recognition proteins in bacteria detection

Over the past years, parallel studies conducted in mammals and flies have emphasized the existence of common mechanisms regulating the vertebrate and invertebrate innate immune systems. This culminated in the discovery of the central role of the Toll pathway in Drosophila immunity and in the implication of Toll-like receptors (TLRs)/interleukin-1(IL-1) in the mammalian innate immune response. In spite of clear similarities, such as shared intracellular pathway components, important divergences are expected between the two groups, whose last common ancestor lived more than half a billion years ago. The most obvious discrepancies lie in the mode of activation of the signalling receptors by microorganisms. In mammals, TLRs are part of protein complexes which directly recognize microbe-associated patterns, whereas Drosophila Toll functions like a classical cytokine receptor rather than a pattern recognition receptor. Recent studies demonstrate that members of the evolutionarily conserved peptidoglycan recognition protein family play an essential role in microbial sensing during immune response of Drosophila.Received 26 June 2003; received after revision 29 July 2003; accepted 25 August 2003     

New evidence on the robust identification of news shocks: Role of revisions in utilization‐adjusted TFP series and term structure data

Data revisions and selections of appropriate forwarding‐looking variables have a major impact on true identification of news shocks and quality of research findings derived from structural vector autoregression (SVAR) estimation. This paper revisits news shocks to identify the role of different vintages of total factor productivity (TFP) series and term structure of interest rates as major prognosticators of future economic growth. There is a growing strand of literature regarding the use of utilization‐adjusted TFP series, provided by Fernald (Federal Reserve Bank of San Francisco, Working Paper Series, 2014) for identification of news shocks. We reestimate Barsky and Sims' (Journal of Monetary Economics, 2011, 58, 273–289) empirical analysis by employing 2007 and 2015 vintages of TFP data. We find substantial quantitative as well as qualitative differences among impulse response functions when using 2007 and 2015 vintages of TFP data. Output and hours initially decline, followed by quick reversal of both variables. In sharp contrast to results achieved by the 2007 vintage of TFP data, results achieved by the 2015 vintage of TFP data depict that output and hours will increase in response to positive TFP shock. By including term structure data in our VAR specification, total surprise technology shock and news shock account for 97% and 92% of the forecast error variance in total TFP and total output respectively. We find that revisions in TFP series over time ultimately impact the conclusion regarding news shocks on business cycles. Our results support the notion that term structure data help in better identification of news shock as compared to other forward‐looking variables.     

Natural selection for resistance to mercury pollution

Summary The survival under conditions of mercury pollution of two natural populations of the marine gastropodCerithium rupestre, derived from mercury-polluted and mercury-free sites, was tested in the laboratory. The results indicate a significantly higher survival rate for animals derived from the mercury-polluted site, in each of six repetitive experiments. We conclude that mercury resistance in marine organisms is reinforced in mercury polluted sites, presumably by natural selection for increased resistance. The evolution of metal tolerance in marine organisms may be as fast as that of metal tolerance in plants and the evolution of industrial melanisms in moths.     

Molecular mechanisms of nitrosative stress-mediated protein misfolding in neurodegenerative diseases

Nitrosative and oxidative stress, associated with the generation of excessive reactive oxygen or nitrogen species, are thought to contribute to neurodegenerative disorders. Many such diseases are characterized by conformational changes in proteins that result in their misfolding and aggregation. Accumulating evidence implies that at least two pathways affect protein folding: the ubiquitin-proteasome system (UPS) and molecular chaperones. Normal protein degradation by the UPS can prevent accumulation of aberrantly folded proteins. Molecular chaperones – such as protein-disulfide isomerase, glucose-regulated protein 78, and heat shock proteins – can provide neuroprotection from aberrant proteins by facilitating proper folding and thus preventing their aggregation. Our recent studies have linked nitrosative stress to protein misfolding and neuronal cell death. Here, we present evidence for the hypothesis that nitric oxide contributes to degenerative conditions by S-nitrosylating specific chaperones or UPS proteins that would otherwise prevent accumulation of misfolded proteins. Received 5 December 2006; received after revision 7 February 2007; accepted 15 March 2007     

Die Rolle von Glukose im Erholungsprozess des Muskels

Summary It is well known that after exhausting muscle work glucose (or saccharose) leads to quick recovery in man. Experiments on rats have shown that in adult animals 50% of all creatine is present as creatine-phosphate (CP). In old animals above 22 months, only about 25% is present as CP. Diets with a 50% glucose content lead in old animals, in rest, to 50% CP in the muscle. Also after exhausting work on glucose diet the restitution is so complete that about 50% CP is present. The main reservoir of energy for the restitution of muscle, ADP ATP, comes from the breakdown of CP. The problem may be discussed whether high glucose diet may be damaging insulin production by exhaustion.