scholarly journals A NEW METHOD FOR THE INVESTIGATION OF THE CAPTURE REACTION IN PHOSPHATASE CYTOCHEMISTRY III. EFFECTS OF THE COMPOSITION OF THE INCUBATION MEDIUM ON THE TRAPPING OF PHOSPHATE IONS IN A MODEL SYSTEM

1974 ◽  
Vol 22 (2) ◽  
pp. 110-119 ◽  
Author(s):  
C. J. CORNELISSE ◽  
P. VAN DUIJN

A model system developed for the study of diffusion problems in lead salt enzyme cytochemistry served as a basis for the experiments reported in the present paper. Phosphate leakage, which was investigated in polyacrylamide films during incubation in media containing lead, could be expressed by a graphical parameter related to the average displacement of the phosphate ions prior to the onset of lead phosphate precipitation in the films. This parameter can be used as a measure for the efficiency of the capture reaction in cytochemical reactions in tissue sections. The concentration of lead ions, and to a lesser extent that of the phosphate ions, was found to be critical for the degree of phosphate diffusion in this system. Addition of 0.3% of β-glycerophosphate to the lead medium gave increased phosphate diffusion, and trapping was markedly improved by added chloride ions. Raising of the molarity of the acetate buffer resulted in impaired trapping efficiency. Similar findings were made in a parallel study on the kinetics of lead phosphate precipitation in supersaturated solutions with a nephelometric method. The results of the present investigation indicate that the film model system is highly suitable for the study of factors affecting the rapid immobilization of diffusible products of cytochemical reactions.

1978 ◽  
Vol 26 (5) ◽  
pp. 331-339 ◽  
Author(s):  
A S de Jong ◽  
T J Hak ◽  
P van Duijn ◽  
W T Daems

A model system is described for the investigation of the dynamics of precipitation processes in a matrix. In this system a solution containing the molecular species to be precipitated and the precipitating medium are pumped along opposite sides of a polyacrylamide film. The solutions flowing continuously along the film, interact and can form a precipitate inside the film. The applicability of the model was tested on the capture reaction for phosphate ions by the Gomori type medium for acid phosphatase. Precipitation of lead phosphate in the film occurred only at a phosphate concentration above a certain value. The dependence of this minimal phosphate concentration on various parameters was studied and the results were compared with values found in earlier model studies and calculations concerning phosphate concentrations that can be built up in lysosomes during the Gomori reaction. The system seems promising for obtaining fundamental data about other cytochemical enzyme trapping reactions as well as for the matrix facotrs involved in bone calcification and shell formation.


2019 ◽  
Author(s):  
Chem Int

The assessment of groundwater is essential for the estimation of suitability of water for safe use. An attempt has been made to study the groundwater of selected areas of Punjab (Sheikhupura & Sahiwal) and Sindh (Sindh, Jawar Dharki and Dharki), Pakistan. The results indicate that pH, color and odor were all within limits of WHO that is pH ranges 6.5–8.5, colorless and odorless, respectively. The high values of suspended solids were observed in the Sindh-1 and Dharki samples. Microbiologically only Sahiwal and Jawar Dharki were found fit for drinking purpose. Trace metals analysis of Sheikhupura-1 and Sindh-1 showed that values do not fall within limits of WHO for Iron. The ionic concentration analysis showed that high bicarbonate (HCO3-), ions are present in the samples of Sahiwal and Dharki; Sindh-1 and Jawar Dharki samples showed very high concentration for chloride ions, all samples were satisfactory level for sulphate (SO42-), sodium, magnesium and phosphate ions except samples of Sindh-1 and Jawar Dharki. High concentration of calcium and potassium ions was observed in samples of Sindh-1, while all other samples were found fit for drinking purposes in respect of nitrate, nitrite and ammonium ions. The high concentration of Fluoride was found only in Sheikhupura-2 samples.


1970 ◽  
Vol 117 (3) ◽  
pp. 615-621 ◽  
Author(s):  
M. C. Perry ◽  
C. N. Hales

1. The effluxes of 42K+ and 36Cl− from isolated fat-cells from the rat were studied under a variety of conditions known to affect the metabolism of the cells. 2. 42K+ efflux from isolated fat cells was increased in a Na+-free–high-K+ medium and decreased in a K+-free medium. The existence of K+ exchange diffusion across the fat-cell membrane is suggested. 3. 36Cl− efflux from isolated fat-cells was decreased when the Cl− component of the wash medium was replaced by acetate. The basal 36Cl− efflux is suggested to be partly by Cl− exchange diffusion and partly in company with a univalent cation. 4. A variety of lipolytic stimuli, adrenaline, adrenocorticotrophic hormone, N-6,O-2′-dibutyryladenosine cyclic 3′:5′-monophosphate and theophylline, increased 42K+ efflux from isolated fat-cells. The adrenaline stimulation was biphasic; an initial, rapid and transient increase in 42K+ loss from the fat-cells was followed by a slower, more prolonged, increase in 42K+ efflux. The initial phase was inhibited by phentolamine but not by propranolol. 5. Insulin increased 42K+ efflux only after preincubation with the cells.


1974 ◽  
Vol 61 (3) ◽  
pp. 737-747 ◽  
Author(s):  
TETSUYA HIRANO

1. Internal as well as external factors affecting water ingestion in the eel were analysed using oesophagus-cannulated eels. 2. Acute withdrawal of the blood induced an immediate drinking response in the freshwater eel, whereas infusion of a large amount of hypertonic saline interrupted the copious drinking observed in the seawater eel. 3. The freshwater eel responded to slow infusion of hypertonic NaCl solution by constant drinking. 4. Inhibition of drinking was observed in the seawater eel by distension of the stomach or intestine with isotonic mannitol solution. 5. The freshwater eel started drinking immediately after transfer to sea water, and stopped drinking immediately after return to fresh water. 6. Application of various salt solutions revealed that chloride ions are responsible for the induction of drinking in sea water. 7. Stimulation of drinking by chloride ions and inhibition by fresh water may be an anticipatory drinking behaviour, which facilitates adaptation of eels to both sea water and fresh water.


2014 ◽  
Vol 143 ◽  
pp. 392-397 ◽  
Author(s):  
Thippeswamy Sannaveerappa ◽  
He Cai ◽  
Mark P. Richards ◽  
Ingrid Undeland

1981 ◽  
Vol 29 (11) ◽  
pp. 1263-1272 ◽  
Author(s):  
H Shio ◽  
P B Lazarow

The theoretical advantages of electron microscopic cytochemistry were utilized to look for evidence of possible connections between peroxisomes and the endoplasmic reticulum in rat liver. Established cytochemical procedures for catalase (peroxisomes) and glucose-6-phosphatase (endoplasmic reticulum) were carried out, and evidence was sought of diffusion of reaction products between the organelles. No such diffusion was observed: lead phosphate was found in the endoplasmic reticulum and in the nuclear envelope but not in peroxisomes; oxidized diaminobenzidine (DAB) was seen only in peroxisomes. In addition, both types of cytochemistry were carried out on the same tissue. The two kinds of reaction product could be distinguished by virtue of their different electron opacities. No mixing of the two reaction products was observed. These results do not support the hypothesis that peroxisomes and endoplasmic reticulum may be connected; rather, they support the idea that the two organelles exist as separate cellular compartments.


PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1303 ◽  
Author(s):  
Gwili E.M. Gibbon ◽  
Markus Bindemann ◽  
David L. Roberts

The recognition of individuals forms the basis of many endangered species monitoring protocols. This process typically relies on manual recognition techniques. This study aimed to calculate a measure of the error rates inherent within the manual technique and also sought to identify visual traits that aid identification, using the critically endangered mountain bongo,Tragelaphus eurycerus isaaci, as a model system. Identification accuracy was assessed with a matching task that required same/different decisions to side-by-side pairings of individual bongos. Error rates were lowest when only the flanks of bongos were shown, suggesting that the inclusion of other visual traits confounded accuracy. Accuracy was also higher for photographs of captive animals than camera-trap images, and in observers experienced in working with mountain bongos, than those unfamiliar with the sub-species. These results suggest that the removal of non-essential morphological traits from photographs of bongos, the use of high-quality images, and relevant expertise all help increase identification accuracy. Finally, given the rise in automated identification and the use of citizen science, something our results would suggest is applicable within the context of the mountain bongo, this study provides a framework for assessing their accuracy in individual as well as species identification.


2021 ◽  
Vol 9 (1) ◽  
pp. 122
Author(s):  
Valérie Laroute ◽  
Roberto Mazzoli ◽  
Pascal Loubière ◽  
Enrica Pessione ◽  
Muriel Cocaign-Bousquet

GABA (γ-aminobutyric acid) production has been widely described as an adaptive response to abiotic stress, allowing bacteria to survive in harsh environments. This work aimed to clarify and understand the relationship between GABA production and bacterial growth conditions, with particular reference to osmolarity. For this purpose, Lactococcus lactis NCDO 2118, a GABA-producing strain, was grown in glucose-supplemented chemically defined medium containing 34 mM L-glutamic acid, and different concentrations of salts (chloride, sulfate or phosphate ions) or polyols (sorbitol, glycerol). Unexpectedly, our data demonstrated that GABA production was not directly related to osmolarity. Chloride ions were the most significant factor influencing GABA yield in response to acidic stress while sulfate ions did not enhance GABA production. We demonstrated that the addition of chloride ions increased the glutamic acid decarboxylase (GAD) synthesis and the expression of the gadBC genes. Finally, under fed-batch conditions in a complex medium supplemented with 0.3 M NaCl and after a pH shift to 4.6, L. lactis NCDO 2118 was able to produce up to 413 mM GABA from 441 mM L-glutamic acid after only 56 h of culture, revealing the potential of L. lactis strains for intensive production of this bioactive molecule.


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