The Physiology of Sea-Urchin Spermatozoa

1950 ◽  
Vol 26 (4) ◽  
pp. 396-409
Author(s):  
LORD ROTHSCHILD
Keyword(s):  
Sea Urchin ◽  
Seminal Plasma ◽  
Human Blood ◽  
Phosphate Buffer ◽  
Dry Weight ◽  
O2 Uptake ◽  
Low Concentrations ◽  
Initial Substrate ◽  
Rough Calculation ◽  
Initial Substrate Concentration

1. Spermatozoa and seminal plasma of Echinus esculentus contain catalase. 2. At 15° C., 4 ml. of a suspension of semen diluted with neutral phosphate buffer in the ratio 1:13 produced in 1 min. 90µl. O2 from an H2O2 solution containing 150 µl. O2. The dry weight of semen in the suspension was 45 mg. and the number of spermatozoa 8.55x109. Under the same conditions, seminal plasma obtained by centrifuging semen produced 50 µl. O2 in 1 min. The dry weight of seminal plasma in the suspension was 12 mg. Human blood, dry weight 229.3 mg./ml., must be diluted with phosphate buffer in the ratio 1:1700 to produce the same amount of O2 in 1 min. as the above suspension of semen. If catalatic activity is defined by the equation Ac = (gt)-1 In {a/(a-x)}, where g = weight in g./ml. of the catalase-containing material, t = 1 min., a = initial substrate concentration (H2O2), and x = amount of H2O2 decomposed in 1 min. at 15° C., Ac = 80-100, 150-200 and 6800 respectively for sea-urchin semen, sea-urchin seminal plasma and human blood. 3. The catalatic activity of semen and seminal plasma is strongly inhibited by hydroxylamine. 4. The O2 uptake and motility of sea-urchin spermatozoa is unaffected by M/5000 H2O2. Higher concentrations of H2O2, M/3000-5000, produce a pronounced ‘shock’ effect, from which the spermatozoa often completely recover. 5. Low concentrations of hydroxylamine, M/3000, reduce O2 uptake and motility. 6. Sea-urchin spermatozoa are almost instantly killed by combinations of hydroxylamine and H2O2, at concentrations which are relatively innocuous when the substances are added separately. 7. A rough calculation indicates that a single spermatozoon contains less than 500 molecules of catalase. 8. A new method of adding H2O2 to catalase-containing material in a manometer is described.

Effects of the Initial Rice Bran Concentration on the Production of Lactobacillus casei as Digestive Bio-regulator

2015 ◽  
Vol 74 (7) ◽  
Author(s):  
Siti Marsilawati Mohamed Esivan ◽  
Roslina Rashid ◽  
Nor Azrini Nadiha Azmi ◽  
Nor Athirah Zaharudin ◽  
Norasikin Othman
Keyword(s):  
Rice Bran ◽  
Substrate Concentration ◽  
Lactobacillus Casei ◽  
Dry Weight ◽  
Weight Measurement ◽  
Initial Substrate ◽  
The World ◽  
Live Bacteria ◽  
The Cost ◽  
Initial Substrate Concentration

Digestive bio-regulator or probiotic is defined as live bacteria with clinically documented health effects in humans and animals. Nowadays, there is increasing interest in probiotics from all over the world. However, the cost of producing probiotics products is still high. To reduce the cost, there is a need to study the usage of agro waste as an inexpensive substrate. The viability of the cell was counted in colony unit per mL (CFU/mL) and the growth was measured using dry weight measurement (g/mL). The sugar concentration was measured using glucose analyzer. At initial substrate concentration of 20% (w/v) and at incubation time of 10hr, the viability cell was 3 x 108 CFU/mL and cell dry weight was 0.0076 g/mL. From the results of this study, it is found that when the initial substrate concentration increased, the viability and growth of Lactobacillus casei increased.

The Respiration of Sea-Urchin Spermatozoa

1950 ◽  
Vol 27 (3) ◽  
pp. 420-436
Author(s):  
LORD ROTHSCHILD
Keyword(s):  
Oxygen Saturation ◽  
Sea Urchin ◽  
Seminal Plasma ◽  
Sea Water ◽  
Chelating Agent ◽  
Dilution Effect ◽  
O2 Uptake ◽  
Sperm Density ◽  
Dense Suspensions ◽  
Mammalian Spermatozoa

1. The O2 uptake of sea-urchin spermatozoa, Echinus esculentus, has been reexamined under varying conditions of sperm density, and in the presence of CuCl22H2O and sodium diethyldithiocarbamate (DDC). 2. The total O2 uptake of dilute sperm suspensions was previously thought to be higher than that of dense suspensions per unit quantity of spermatozoa (Dilution Effect I). This result is only obtained when the oxygen saturation of the dense suspension is inadequate, which may easily occur as the QOO2 of sea-urchin spermatozoa may reach 30 at 15.0° C. When oxygen saturation is satisfactory, the total O2 uptake of dense solutions is slightly greater than that of dilute ones. The experiment cannot be done in micro-respirometers of the normal Warburg type unless the density of spermatozoa per ml. suspension is less than about 109 corresponding to an initial semen dilution of 1:20 or 1:25. These figures apply to other manometric experiments on the O2 uptake of sea-urchin spermatozoa using normal amounts of material. 3. When movement ceases, there is a sharp increase in the O2 uptake of the suspension. 4. The addition of seminal plasma to dilute sperm suspensions does not inhibit the increased rate of O2 uptake, per unit quantity of spermatozoa, observed in these suspensions when compared with dense ones (Dilution Effect II). Dilution Effect II is therefore not caused by the dilution of an inhibitory substance in seminal plasma. 5. Sperm suspensions were prepared by diluting semen 1:50 with sea water and allowing them to respire for 45 mm. They were then centrifuged, the supernatant was discarded and the spermatozoa were re-suspended to different densities with sea water. This treatment has the following effects: (a) Centrifugation irreversibly damages the spermatozoa and reduces their O2 uptake. (b) Removal of the supernatant, which contains seminal plasma, and re-suspension in sea water also reduces O2 uptake. (c) The treatment markedly reduces Dilution Effect II. If the experiment is done in the same way but the suspensions are only allowed to respire for 10 min. before centrifugation, (a) and (b) are the same, but Dilution Effect II is normal. This shows that during metabolism, a regulatory substance is lost from dilute suspensions, as in mammalian spermatozoa; but this is not the cause of Dilution Effect II. 6. Dilution Effect II, considered as the reduced O2 uptake of dense suspensions, can be reversed by the addition of CuCl22H2O, 1 p.p.m., to the medium. 7. Dilution Effect II can be made to occur in sperm suspensions which do not normally exhibit it, by the addition of DDC, in concentrations as low as 3.64x10-5M (final concentration). The action of DDC is not greater when its concentration is increased to 10-3M, which suggests that in these conditions it acts as a chelating agent and not as a narcotic. For the same reasons its oxidation product, tetra ethyldithiocarbamyl disulphide, is unlikely to be responsible for DDC's inhibitory effect on sperm O2 uptake. 8. These results are consistent with the hypothesis that Dilution Effect II is due to the amounts of copper (or possibly zinc) in sea water being inadequate to satisfy the requirements of dense sea-urchin sperm suspensions. This situation is unlikely to arise during natural spawning as sperm densities are too low for the effect to occur in these conditions. Other interpretations of the stimulating action of copper and zinc are discussed. 9. The experiments remove several of the differences hitherto believed to exist between sea-urchin and mammalian spermatozoa.

Serum Cholinesterase Variants: Examination of Several Differential Inhibitors, Salts, and Buffers Used to Measure Enzyme Activity

1971 ◽  
Vol 17 (3) ◽  
pp. 183-191 ◽  
Author(s):  
Philip J Garry
Keyword(s):  
Enzyme Activity ◽  
Sodium Fluoride ◽  
Phosphate Buffer ◽  
Divalent Cations ◽  
Kinetic Studies ◽  
Competitive Inhibitor ◽  
Serum Cholinesterase ◽  
Low Concentrations

Abstract Dibucaine, used as a differential inhibitor with acetyl-, propionyl-, and butyrylthiocholine as substrate, clearly identified the "usual" and "atypical" serum cholinesterases. Succinylcholine was also used successfully as a differential inhibitor with butyrylthiocholine as substrate. Sodium fluoride, used as a differential inhibitor, gave conflicting results, depending on whether Tris or phosphate buffer was used in the assay. Mono- and divalent cations (NaCl, KCl, MgCl2, CaCl2, and BaCl2) activated the "usual" and inhibited the "atypical" enzyme at low concentrations. The "usual" enzyme had the same activity in 0.05 mol of Tris or phosphate buffer per liter, while the heterozygous and "atypical" enzymes showed 12 and 42% inhibition, respectively, when assayed in the phosphate buffer. Kinetic studies showed the phosphate acted as a competitive inhibitor of "atypical" enzyme. Km values, determined for "usual" and "atypical" enzymes, were 0.057 and 0.226 mmol/liter, respectively, with butyrylthiocholine as substrate.

scholarly journals ALLELOPATHIC INFLUENCE OF TRIANTHIMA PORTULACASTRUM L. ON GROWTH AND DEVELOPMENTAL RESPONSES OF SESAME (SESAMUM INDICUM L.)

2017 ◽  
Vol 4 (2) ◽  
pp. 183-186
Author(s):  
Prabhakaran J ◽  
Kavitha D
Keyword(s):  
Block Design ◽  
Dry Weight ◽  
Germination Percentage ◽  
Sesamum Indicum ◽  
Negative Effects ◽  
Chlorophyll Contents ◽  
Whole Plant ◽  
Low Concentrations ◽  
Seedling Length ◽  
Developmental Responses

An experiment was conducted in order to determine the allelopathic effects of the aqueous extract of Trianthima portulacastrum L.on the seed germination, seedling growth and chlorophyll content ofsesame (Sesamum indicum L.). Greenhouse experiment was carried out as RCBD (Randomized complete block design)with four replications. Treatments included 0, 1, 2, 3 and 4% (W/W) residues of whole plant of T.portulacastrum with normal field soil. Results showed that the low concentrations of T.portulacastrum had no significant effect on the germination percentage, seedling length, dry weight, total chlorophyll contents at lower concentration(1%) of weed residues. However, treatments with higher concentrations had negative effects on germination, growth and seedling dry weight of sesame.

Photodegradation of p-Nitrophenol Catalyzed by ZnO/MWCNTs Composite Catalyst in Water

2012 ◽  
Vol 455-456 ◽  
pp. 1339-1344 ◽  
Author(s):  
Zhe Qi Li ◽  
Jing Yu Liu
Keyword(s):  
Irradiation Time ◽  
Solar Irradiation ◽  
Composite Catalyst ◽  
Catalyst Loading ◽  
Optimal Conditions ◽  
Mass Ratio ◽  
Initial Substrate ◽  
Effects Of Ph ◽  
Potential Use ◽  
Initial Substrate Concentration

Photodegradation ofp-nitrophenol catalyzed by ZnO/MWCNTs composite in water was investigated. The effects of pH, irradiation time, catalyst loading, initial substrate concentration and MWCNTs content on the degradation were investigated. Experiment results revealed that the optimal conditions were ap-nitrophenol concentration of 60.0 mg/L at pH 5.0 with catalyst loading of 10.0 g/L under solar irradiation for the illumination of 180 min. The highest efficiency on photodegradation ofp-nitrophenol can be achieved with an optimal MWCNTs/ZnO mass ratio of 0.16%. Possible decomposing mechanisms were also discussed. The repeatability of photocatalytic activity was tested. The photocatalyst was used ten cycles with degradation efficiency still higher than 95%. The results of the study showed the feasible and potential use of ZnO/MWCNTs composite in degradation of toxic organic pollutants.

Glycerol incorporation in certain oral streptococci

1980 ◽  
Vol 30 (3) ◽  
pp. 759-765
Author(s):  
T A Kral ◽  
L Daneo-Moore
Keyword(s):  
Dry Weight ◽  
Defined Medium ◽  
Oral Streptococci ◽  
Chemically Defined Medium ◽  
Low Concentrations ◽  
Saturation Kinetics ◽  
Wild Rats ◽  
Different Strains ◽  
Streptococcus Rattus ◽  
Type Strains

Cells of 30 different strains of oral streptococci were grown in a chemically defined medium supplemented with [14C]glycerol to determine their ability to incorporate the labeled glycerol. Of the five species tested, only two, the rat-type strains (Streptococcus rattus) and strains isolated from wild rats (Streptococcus ferus), were able to incorporate the nonfermentable substrate, glycerol. For those strains capable of incorporating glycerol, the amount incorporated ranged from 0.15 to 0.43% of the cellular dry weight and followed simple saturation kinetics. The amount of glycerol incorporated depended solely on the concentration of glycerol in the growth medium. As a result, cultures exposed to low concentrations of glycerol ceased incorporation of the labeled glycerol before cessation of exponential growth.

The Physiology of Sea-Urchin Spermatozoa

1948 ◽  
Vol 25 (4) ◽  
pp. 344-352
Author(s):  
LORD ROTHSCHILD
Keyword(s):  
Sea Urchin ◽  
Seminal Plasma ◽  
Sea Water ◽  
O2 Activation ◽  
Residual Tension ◽  
K Concentration

1. Echinus esculentus spermatozoa are normally motionless in undiluted semen. They become active when the semen is diluted with sea water or seminal plasma obtained by gentle centrifugation (1500 r.p.m., 12 cm. radius, for 15 min.). 2. A sperm-immobilizing substance can, however, be obtained in seminal plasma by more prolonged centrifugation of semen. 3. Spermatozoa can be made motile in undiluted semen by increasing the O2 tension in the atmosphere surrounding the semen. 4. This O2 activation is completely inhibited by N2; the N2 effect is reversible. 5. Measurements of seminal O2 tension were made with an O2 electrode. The O2 tension of semen is low, being at most 15 mm. Hg. It was not possible to decide whether this residual tension was due to O2 or some other substance reacting at the electrode. 6. The K content of seminal plasma is about 1·55 mg./ml., which is four times higher than that of perivisceral fluid or sea water. 7. The pH of semen is lower than that of sea water, being approx. 7·5. 8. Neither K concentration nor pH is responsible for the inactivity of sperm in semen. 9. A hormone, Androgamone I, is often considered to be responsible for the inactivity of spermatozoa in non-mammalian semen. No support has been found for this view and it is concluded that in E. esculentus semen the spermatozoa are motionless through lack of O2.

scholarly journals An Elution Procedure for Visualization of Adult Hemoglobins in Human Blood Smears

Blood ◽  
1974 ◽  
Vol 43 (2) ◽  
pp. 239-242 ◽  
Author(s):  
David Kabat
Keyword(s):  
Cord Blood ◽  
Human Blood ◽  
Phosphate Buffer ◽  
Newborn Infants ◽  
Potassium Phosphate ◽  
Fetal Hemoglobin ◽  
Potassium Phosphate Buffer ◽  
Blood Smears

Abstract A procedure is described for visualization of normal and mutant adult hemoglobins in human blood smears. After extraction of blood smears with a concentrated potassium phosphate buffer (2.76 M, pH 7.2), erythrocytes that had adult hemoglobins stained bright red with erythrosin, whereas cells that had only fetal hemoglobin appeared as clear ghosts. Analyses of cord blood from newborn infants indicate that, although most erythrocytes contain only Hb F and a few contain only Hb A, many contain both hemoglobins A and F.

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