General anaesthetics and bacterial luminescence I. The effect of diethyl ether on the in vivo light emission of Vibrio fischeri

1976 ◽  
Vol 193 (1111) ◽  
pp. 159-171 ◽  
Keyword(s):  
Diethyl Ether ◽  
Light Emission ◽  
Vibrio Fischeri ◽  
Early Period ◽  
Potassium Cyanide ◽  
Growth Cycle ◽  
Lag Phase ◽  
General Anaesthetic ◽  
Bacterial Luminescence

The factors which determine the sensitivity of bacterial luminescence to inhibition by the general anaesthetic, diethyl ether, have been investigated. The in vivo luminescent reaction of Vibrio fischeri displays a change in sensitivity to this agent during the bacterial growth cycle. This variation is particularly marked during the lag phase of growth and detailed investigations of the effect of potassium cyanide and n -decanal on the potency of ether during this early period are described. The results suggest that fluctuations in the substrate levels available to the light-producing enzyme are responsible for the variation in sensitivity to ether.

General anaesthetics and bacterial luminescence II. The effect of diethyl ether on the in vivo light emission of Vibrio fischeri

1976 ◽  
Vol 193 (1111) ◽  
pp. 173-190 ◽  
Keyword(s):  
Diethyl Ether ◽  
Light Emission ◽  
Vibrio Fischeri ◽  
General Anaesthetic ◽  
Bacterial Luminescence

The factors which determine the response of the in vitro luminescent reaction of Vibrio fischeri ,to the general anaesthetic diethyl ether, have been determined. The investigations show that, as was indicated by a study of the in vivo reaction, the levels of substrates available to the enzyme luciferase modify its response to ether. The results indicate that ether inhibits the binding of the aldehyde factor necessary for luminescence. There is evidence that it also acts as a second site where its presence appears to stimulate the binding of reduced flavin to the enzyme.

Effects of mycotoxins, aflatoxin B1 and deoxynivalenol, on the bioluminescence of Vibrio fischeri

2008 ◽  
Vol 1 (2) ◽  
pp. 189-193 ◽  
Author(s):  
S. Sarter ◽  
I. Metayer ◽  
N. Zakhia
Keyword(s):  
Aflatoxin B1 ◽  
Light Emission ◽  
Vibrio Fischeri ◽  
Exponential Phase ◽  
Lag Phase ◽  
Bioluminescence Inhibition ◽  
Aflatoxin B

The effects of aflatoxin B1 and deoxynivalenol on the luminescence of Vibrio fischeri were investigated to determine the conditions of using the bioluminescence as an indirect means for mycotoxin detection. The culture of Vibrio fischeri showed that bioluminescence reached a peak after 12 hours of incubation at 25 °C and then decreased drastically. During the lag phase which lasted 6 hours, light emission decreased drastically for both the mycotoxin assays – aflatoxin B1 10 µg/ml and deoxynivalenol 20 µg/ml – and the corresponding controls. Distinct bioluminescence inhibition appeared after this period of minimal bioluminescence of the controls and started with the exponential phase of growth. The percentage of bioluminescence inhibition for both mycotoxins was determined after 3.5, 10, 15 and 25 hours of incubation. The bioluminescence of Vibrio fischeri was inhibited with aflatoxin B1 and enhanced with deoxynivalenol. Both effects were delayed and required a long-term incubation over 10 hours, which may help to investigate bioassays for mycotoxin detection.

Oxygen Triggering Reversible Modulation of Vibrio fischeri Strain Y1 Bioluminescence In Vivo¶

2004 ◽  
Vol 79 (1) ◽  
pp. 120 ◽  
Author(s):  
Hajime Karatani ◽  
Susumu Yoshizawa ◽  
Satoshi Hirayama
Keyword(s):  
Vibrio Fischeri

Development and Evaluation of Floating Pulsatile Drug Delivery System Using Meloxicam

2017 ◽  
Vol 7 (04) ◽  
Author(s):  
ShirishaG. Suddala ◽  
S. K. Sahoo ◽  
M. R. Yamsani
Keyword(s):  
Rheumatoid Arthritis ◽  
Drug Delivery ◽  
Drug Release ◽  
Drug Delivery System ◽  
Delivery System ◽  
Lag Time ◽  
Oral Dosage ◽  
Lag Phase ◽  
Pulsatile Drug Delivery

Objective: The objective of this research work was to develop and evaluate the floating– pulsatile drug delivery system (FPDDS) of meloxicam intended for Chrono pharmacotherapy of rheumatoid arthritis. Methods: The system consisting of drug containing core, coated with hydrophilic erodible polymer, which is responsible for a lag phase for pulsatile release, top cover buoyant layer was prepared with HPMC K4M and sodium bicarbonate, provides buoyancy to increase retention of the oral dosage form in the stomach. Meloxicam is a COX-2 inhibitor used to treat joint diseases such as osteoarthritis and rheumatoid arthritis. For rheumatoid arthritis Chrono pharmacotherapy has been recommended to ensure that the highest blood levels of the drug coincide with peak pain and stiffness. Result and discussion: The prepared tablets were characterized and found to exhibit satisfactory physico-chemical characteristics. Hence, the main objective of present work is to formulate FPDDS of meloxicam in order to achieve drug release after pre-determined lag phase. Developed formulations were evaluated for in vitro drug release studies, water uptake and erosion studies, floating behaviour and in vivo radiology studies. Results showed that a certain lag time before drug release which was due to the erosion of the hydrophilic erodible polymer. The lag time clearly depends on the type and amount of hydrophilic polymer which was applied on the inner cores. Floating time and floating lag time was controlled by quantity and composition of buoyant layer. In vivo radiology studies point out the capability of the system of longer residence time of the tablets in the gastric region and releasing the drug after a programmed lag time. Conclusion: The optimized formulation of the developed system provided a lag phase while showing the gastroretension followed by pulsatile drug release that would be beneficial for chronotherapy of rheumatoid arthritis and osteoarthritis.

scholarly journals Nociceptive Sensitization by Activation of Protease-Activated Receptor 2 in a Rat Model of Incisional Pain

2021 ◽  
Vol 11 (2) ◽  
pp. 144
Author(s):  
Kanta Kido ◽  
Norika Katagiri ◽  
Hiromasa Kawana ◽  
Shigekazu Sugino ◽  
Masanori Yamauchi ◽  
...  
Keyword(s):  
Postoperative Pain ◽  
Inflammatory Responses ◽  
Early Period ◽  
Intraplantar Injection ◽  
C Fibers ◽  
Nociceptive Responses ◽  
Incisional Pain ◽  
Protease Activated Receptor 2

Postoperative pain and consequent inflammatory responses after tissue incision adversely affects many surgical patients due to complicated mechanisms. In this study, we examined whether activation of protease-activated receptor 2 (PAR-2), which is stimulated by tryptase from mast cells, elicits nociception and whether the PAR-2 antagonist could reduce incisional nociceptive responses in vivo and in vitro. The effects of a selective PAR-2 antagonist, N3-methylbutyryl-N-6-aminohexanoyl-piperazine (ENMD-1068), pretreatment on pain behaviors were assessed after plantar incision in rats. The effects of a PAR-2 agonist, SLIGRL-NH2, on nociception was assessed after the injection into the hind paw. Furthermore, the responses of C-mechanosensitive nociceptors to the PAR-2 agonist were observed using an in vitro skin–nerve preparation as well. Intraplantar injection of SLIGRL-NH2 elicited spontaneous nociceptive behavior and hyperalgesia. Local administration of ENMD-1068 suppressed guarding behaviors, mechanical and heat hyperalgesia only within the first few hours after incision. SLIGRL-NH2 caused ongoing activity in 47% of C-mechanonociceptors in vitro. This study suggests that PAR-2 may support early nociception after incision by direct or indirect sensitization of C-fibers in rats. Moreover, PAR-2 may play a regulatory role in the early period of postoperative pain together with other co-factors to that contribute to postoperative pain.

scholarly journals Anticancer Compounds Derived from Marine Diatoms

Marine Drugs ◽  
2020 ◽  
Vol 18 (7) ◽  
pp. 356 ◽  
Author(s):  
Hanaa Ali Hussein ◽  
Mohd Azmuddin Abdullah
Keyword(s):  
Unsaturated Fatty Acids ◽  
High Surface ◽  
High Surface Area ◽  
Drug Carriers ◽  
Growth Cycle ◽  
In Vivo Studies ◽  
High Yield ◽  
Anti Cancer ◽  
Nano Medicine

Cancer is the main cause of death worldwide, so the discovery of new and effective therapeutic agents must be urgently addressed. Diatoms are rich in minerals and secondary metabolites such as saturated and unsaturated fatty acids, esters, acyl lipids, sterols, proteins, and flavonoids. These bioactive compounds have been reported as potent anti-cancer, anti-oxidant and anti-bacterial agents. Diatoms are unicellular photosynthetic organisms, which are important in the biogeochemical circulation of silica, nitrogen, and carbon, attributable to their short growth-cycle and high yield. The biosilica of diatoms is potentially effective as a carrier for targeted drug delivery in cancer therapy due to its high surface area, nano-porosity, bio-compatibility, and bio-degradability. In vivo studies have shown no significant symptoms of tissue damage in animal models, suggesting the suitability of a diatoms-based system as a safe nanocarrier in nano-medicine applications. This review presents an overview of diatoms’ microalgae possessing anti-cancer activities and the potential role of the diatoms and biosilica in the delivery of anticancer drugs. Diatoms-based antibodies and vitamin B12 as drug carriers are also elaborated.

scholarly journals INFLUENCE OF ANESTHESIA ON EXPERIMENTAL NEUROTROPIC VIRUS INFECTIONS

1946 ◽  
Vol 84 (4) ◽  
pp. 277-292 ◽  
Author(s):  
S. Edward Sulkin ◽  
Christine Zarafonetis ◽  
Andres Goth
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Diethyl Ether ◽  
Cervical Region ◽  
Virus Infections ◽  
Ether Anesthesia ◽  
Neurotropic Virus ◽  
Experimental Infections

Anesthesia with diethyl ether significantly alters the course and outcome of experimental infections with the equine encephalomyelitis virus (Eastern or Western type) or with the St. Louis encephalitis virus. No comparable effect is observed in experimental infections produced with rabies or poliomyelitis (Lansing) viruses. The neurotropic virus infections altered by ether anesthesia are those caused by viruses which are destroyed in vitro by this anesthetic, and those infections not affected by ether anesthesia are caused by viruses which apparently are not destroyed by ether in vitro. Another striking difference between these two groups of viruses is their pathogenesis in the animal host; those which are inhibited in vivo by ether anesthesia tend to infect cells of the cortex, basal ganglia, and only occasionally the cervical region of the cord. On the other hand, those which are not inhibited in vivo by ether anesthesia tend to involve cells of the lower central nervous system and in the case of rabies, peripheral nerves. This difference is of considerable importance in view of the fact that anesthetics affect cells of the lower central nervous system only in very high concentrations. It is obvious from the complexity of the problem that no clear-cut statement can be made at this point as to the mechanism of the observed effect of ether anesthesia in reducing the mortality rate in certain of the experimental neurotropic virus infections. Important possibilities include a direct specific effect of diethyl ether upon the virus and a less direct effect of the anesthetic upon the virus through its alteration of the metabolism of the host cell.

Synthesis and turnover of proteins and mRNA in germinating wheat embryos

1982 ◽  
Vol 60 (3) ◽  
pp. 389-397 ◽  
Author(s):  
Zbyszko F. Grzelczak ◽  
Mark H. Sattolo ◽  
Linda K. Hanley-Bowdoin ◽  
Theresa D. Kennedy ◽  
Byron G. Lane
Keyword(s):  
Growth Phase ◽  
Time Course ◽  
Phase 1 ◽  
Major Product ◽  
Lag Phase ◽  
Wheat Embryo ◽  
Phase Development ◽  
Wheat Embryos

The most prominent methionine-labeled protein made when cell-free systems are programmed with bulk mRNA from dry wheat embryos has been identified with what may be the most abundant protein in dry wheat embryos. The protein has been brought to purity and has a distinctive amino acid composition, Gly and Glx accounting for almost 40% of the total amino acids. Designated E because of its conspicuous association with early imbibition of dry wheat embryos, the protein and its mRNA are abundant during the "early" phase (0–1 h) of postimbibition development, and easily detected during "lag" phase (1–5 h), but they are almost totally degraded soon after entry into the "growth" phase of development, by about 10 h postimbibition.The most prominent methionine-labeled protein peculiar to the cell-free translational capacity of bulk mRNA from "growth" phase embryos is not detected as a product of in vivo synthesis. Its electrophoretic properties and its time course of emergence, after 5 h postimbibition development, suggest that this major product of cell-free synthesis may be an in vitro counterpart to a prominent methionine-labeled protein made only in vivo, by "growth" phase embryos. Designated G because of its conspicuous association with "growth" phase development, the cell-free product does not comigrate with any prominent dye-stained band in electrophoretic distributions of wheat proteins. The suspected cellular counterpart to G, also, does not comigrate with a prominent dye-stained wheat protein during electrophoresis, and although found in particulate as well as soluble fractions of wheat embryo homogenates it is not concentrated in either nuclei or mitochondria, as isolated.

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