The enhanced induction of metallothionein by zinc,its half-life in the marine fishPleuronectes platessa,and the influence of stress factors on metallothionein levels

Summary Intraperitoneal injection of zinc raised levels of a hepatic metallothionein-like species. Assuming that this species was metallothionein (MT) then levels were raised from approximately 20 g/g to 300 g/g in 7 days, and levels thereafter remained high for the next 4 weeks. The half-lives of the protein in liver and kidney from starved fish, measured using in vivo incorporation of³⁵S cysteine at 11°C, were approximately 27 days and 32 days respectively. The following agents failed to stimulate synthesis of MT in plaice: stress (due to catching), endotoxin, dexamethasone, cortisol and turpentine.     

Copper metabolism in the LEC rat: Involvement of induction of metallothionein and disposition of zinc and iron

The Cu concentration was about 40 times higher in the liver of LEC (Long-Evans with a cinnamon-like coat color) rats aged 77 days (227.5±21.6 g/g liver) than in Fischer rats (5.2±0.1 g/g liver). However, in the kidney and brain of the LEC rats, Cu concentrations were lower than in these organs of the Fischer rats. Cu concentration in the hepatic metallothionein fraction was about 130 times higher in the LEC rats than in the Fischer rats. The LEC rats showed markedly low concentrations of Cu in the serum and bile. It seems likely that excretion of Cu from the liver into the bile and blood (as ceruloplasmin) is inherently lacking in the LEC rat.     

Extraordinary levels of cadmium and zinc in a marine sponge,Tedania charcoti Topsent: inorganic chemical defense agents

The Antarctic marine spongeTedania charcoti has been shown to contain extraordinarily high natural concentrations of cadmium and zinc, which have in turn been correlated to the ability of the crude ethanol extract to modulate protein phosphorylation in chicken forebrain and to inhibit the growth of several test bacteria.     

The influence of different nutrients on plasma cholecystokinin levels in the rat

Isocaloric and isovolemic amounts of protein (casein), fat (intralipid) and carbohydrate (saccharose) and an isovolemic control solution of water were administered intragastrically to conscious rats. The plasma CCK levels, determined by a sensitive and specific radioimmunoassay, showed an increment of 6.3 +/- 0.6, 2.7 +/- 0.5, 1.7 +/- 0.4 and -0.9 +/- 0.4 pM, respectively (basal value 2.5 +/- 0.3 pM). The threshold increment of plasma CCK to stimulate pancreatic enzyme secretion by exogenous CCK was found to be 1.5 pM. It is therefore concluded that casein is a potent stimulus for CCK secretion and pancreatic secretion, but that fat and even carbohydrate, although less potent, also produce a CCK increment above the threshold for pancreatic secretion.     

The molecular mechanism of zinc and cadmium stress response in plants

When plants are subjected to high metal exposure, different plant species take different strategies in response to metal-induced stress. Largely, plants can be distinguished in four groups: metal-sensitive species, metal-resistant excluder species, metal-tolerant non-hyperaccumulator species, and metal-hypertolerant hyperaccumulator species, each having different molecular mechanisms to accomplish their resistance/tolerance to metal stress or reduce the negative consequences of metal toxicity. Plant responses to heavy metals are molecularly regulated in a process called metal homeostasis, which also includes regulation of the metal-induced reactive oxygen species (ROS) signaling pathway. ROS generation and signaling plays an important duel role in heavy metal detoxification and tolerance. In this review, we will compare the different molecular mechanisms of nutritional (Zn) and non-nutritional (Cd) metal homeostasis between metal-sensitive and metal-adapted species. We will also include the role of metal-induced ROS signal transduction in this comparison, with the aim to provide a comprehensive overview on how plants cope with Zn/Cd stress at the molecular level.     

The influence of different nutrients on plasma cholecystokinin levels in the rat

Summary Isocaloric and isovolemic amounts of protein (casein), fat (intralipid) and carbohydrate (saccharose) and an isovolemic control solution of water were administered intragastrically to conscious rats. The plasma CCK levels, determined by a sensitive and specific radioimmunoassay, showed an increment of 6.3±0.6, 2.7±0.5, 1.7±0.4 and –0.9±0.4 pM, respectively (basal value 2.5±0.3 pM). The threshold increment of plasma CCK to stimulate pancreatic enzyme secretion by exogenous CCK was found to be 1.5 pM. It is therefore concluded that casein is a potent stimulus for CCK secretion and pancreatic secretion, but that fat and even carbohydrate, although less potent, also produce a CCK increment above the threshold for pancreatic secretion.Supported by Grant IKW 86-16 from the Netherlands Cancer Foundation KWF.     

Inhibitory effect of halocyamine,an antimicrobial substance from ascidian hemocytes,on the growth of fish viruses and marine bacteria

Summary Halocyamine A, an antimicrobial substance isolated from hemocytes of the solitary ascidianHalocynthia roretzi, inhibited in vitro the growth of fish RNA viruses (infectious hematopoietic necrosis virus and infectious pancreatic necrosis virus). Pretreatment of RNA virus with halocyamine A reduced the infectivity of the virus toward host cells. The growth of marine bacteria,Achromobacter aquamarinus andPseudomonas perfectomarinus, was also inhibited by halocyamine A but that ofAlteromonas putrefaciens andVibrio anguillarum was not. These results suggest that halocyamine may have a role in the defense mechanisms ofH. roretzi against marine viruses and bacteria.     

The effect of chronic heat stress on cortisol levels in the antarctic fishPagothenia borchgrevinki

Radioimmunoassay was used to determine levels of the stress-inducible glucocorticoid, cortisol, circulating in the plasma of the extremely stenothermal Antarctic fishPagothenia borchgrevinki at rest and after heat stress. Fish sampled immediately after capture (–1.9°C) had low cortisol levels (10.4±1.4 ng ml^–1, mean±SEM) as did fish which were laboratory rested for 3 days. Sudden exposure to 5°C (48h) resulted in a peak cortisol value after 3 h (69.9±6.8 ng ml^–1) whereas exposure to 8°C (6h) resulted in a peak value after 1 h (73.5±8.0 ng ml^–1). At both temperatures levels remained significantly elevated (p<0.05) for the entire period of exposure. Increased temperature also resulted in a significant change in haemoglobin, haematocrit and mean cell haemoglobin concentration (MCHC) (p<0.05). Plasma lactate was significantly elevated only after exposure to 8°C (p<0.05). Plasma cortisol levels fromP. borchgrevinki are reported here for the first time and show this cryopelagic Antarctic species to have an unusual hormonal stress profile.     

Relationship between the molecular weights of pesticides and their bioconcentration factors by fish

Summary A significant positve correlation was found between the molecular weights (187–412) of 19 pesticides and their bioconcentration factors (4–37,800) in 2 fresh-water fishes; topmouth gudgeon and fathead minnows.     

The influence of electrical stimulation of the rat brain on serum prolactin levels

Zusammenfassung Prolaktin wurde mittels Radio-immunbestimmung in Seren gemessen, die 30 und 60 min nach elektrischer Stimulation des Gehirns abgenommen wurden. Ähnliche Ergebnisse wurden in Kontrolltieren und elektrisch stimulierten Tieren erhalten. Die Serumprolaktinspiegel sanken, wenn die Elektroden in der präoptischen Region lagen. Ein vorübergehender Abfall wurde gemessen, wenn die Elektroden im ventralen, medialen Hypothalamus lagen. Keine Änderung im Prolaktinspiegel wurde gefunden, wenn die Elektroden im Neocortex lagen.

---

---

Acknowledgment. This work was supported by an NSF Research Grant, No. GB 27359. The authors appreciate receiving as a gift the rat prolactin RP-1-1 used for radioiodination and the rat prolactin RP-1 used as the standard from the NIAMD Rat Prolactin Hormone Distribution Program.     

The rise of geology and its influence on contemporary thought

Sous la Révolution, la conjoncture politique et militaire et l'échec de la poudre de muriate (chlorate) devaient conduire la France à privilégier la rationalisation des procédés de fabrication pour tenter d'accroître la portée des armes. En 1796, la poudre ronde de J. P. Champy (1744–1816), successeur de Lavoisier à la tête du service des Poudres et salpêtres, parut approcher de la poudre idéale: pour un prix de revient réduit, elle offrait une puissance suffisante et une sécurité optimale de fabrication et d'emploi. Malgré l'avis des experts scientifiques et militaires, sa production cessa pourtant à la suite d'un blocage politico-administratif. A la fin de l'Empire, J. S. Champy (1778–1845), perfectionna le procédé de son père pour en faire le premier système de production mécanisé, dont l'introduction devait modifier l'organisation du travail et la configuration des poudreries créées sous la Restauration. Le succès du système conduisit paradoxalement à son échec après une décennie de production qui resta toujours expérimentale: la poudre ronde remettait en cause les techniques métallurgiques en faisant éclater les canons. La publication inédite du premier rapport d'expertise de ce procédé (1813) fournit l'occasion de suivre les origines et l'évolution d'un système qui annonce la mécanisation de l'industrie poudrière au XIXe siècle, tout en se présentant clairement comme l'aboutissement des procédés révolutionnaires de l'an II. Elle permet aussi de s'interroger sur les critères et le statut de l'expertise, au moment même où l'analyse chimique de la poudre commence avec Proust, Gay-Lussac et Brianchon.     

The influence of chlorothiazide and tolbutamide upon intestinal serotonin levels in the sprague-dawley rat

Zusammenfassung Der Serotoningehalt der Schleimhaut im obern Duodenumteil, im mittleren Jejunum, im Ileumendteil und im Appendix von Sprague-Dawley Charles River Rattenmännchen wurde ohne Vorbehandlung und mit Chlorothiazid- und Tolbutamidvorbehandlung spektrophotofluorimetrisch bestimmt. Die Serotoningehalte für die 3 Gruppen vergleichbarer Gewebe waren ähnlich, was zeigt, dass die früher beschriebene Erhöhung des Serotoningehaltes der Schleimhaut nach Sulfamerazinvorbehandlung wahrscheinlich nicht mit einer unspezifischen Wirkung des Sulfonamidteils verbunden ist.

---

---

This study was supported in part by an award from the National Science Foundation toJ. H. Thompson, M.D., M.R.C.P.I., Department of Pharmacology, U.C.L.A. School of Medicine, Los Angeles, California 90024.     

The effect of stress factors on the spontaneous photon emission from microorganisms

The results of recent work on the photon emission from three yeasts and a bacterium is presented. Both visible region and ultraviolet photon emission is observed; however, no luminescence is observed in the absence of oxygen. The visible region emission is attributed to excited carbonyl groups and excited singlet oxygen dimers formed during the decomposition of lipid hydroperoxides. Possible sources of the ultraviolet photon emission are also examined. The use of microorganisms in the study of ultraweak photon emission and its relation to oxidative, temperature and chemical stress is reviewed and the applications and (or) functions of this photon emission are also discussed.     

The influence of long term estrogen treatment on plasma prolactin levels induced by ether anesthesia in ovariectomized rats

Summary 2 methods of continuous estrogen delivery, polyestradiol phosphate injection and implantation of Silastic capsules of estradiol-17 , in ovariectomized rats induced increases in plasma prolactin in the afternoon (15.00–17.00) beginning at 1 week and continuing for 4–8 weeks. In addition these methods of estrogen treatment potentiated the ether-induced increase in plasma prolactin in the morning (9.00–11.00) beginning on week 2 and continuing for 3–8 weeks. These results indicate that estrogen activates the mechanisms that cause an afternoon surge in prolactin before potentiating a morning elevation induced by ether anesthesia.Acknowledgment. This work was supported by NIH General Research Support, grant No. RR05384-14 to Wayne State University School of Medicine. The authors also with to express their appreciation to Mrs C. Van De Walle for her expert technical assistance in the prolactin radioimmunoassay, to Dr Richard R. Gala for his advice and support of this project and to the Rat Pituitary Hormone Distribution Program of NIAMDD for the generous gift of Rat Prolactin.     

The influence of furosemide on the renal excretion of chloramphenicol and its metabolites.

Simultaneous administration of chloramphenicol and furosemide (10 mg i.v.) decreased urinary excretion of chloramphenicol but increased the excretion of its metabolites as aryl amines and total nitro compounds. These latter increases were directly related to Na excretion.