Effects of osmotic changes and neurosecretory extracts on kidney ultrastructure in the freshwater pulmonate Helisoma

1979 ◽  
Vol 57 (6) ◽  
pp. 1256-1270 ◽  
Author(s):  
Hamidur R. Khan ◽  
A. S. M. Saleuddin
Keyword(s):  
Basement Membrane ◽  
Basal Membrane ◽  
Distilled Water ◽  
Intercellular Spaces ◽  
Visceral Ganglion ◽  
Carbon Particles ◽  
Helisoma Duryi ◽  
Urine Formation ◽  
Effects Of Media

The ultrastructure of the heart and kidney, and the effects of media of different osmotic concentrations and of nervous tissue extracts, have been investigated in Helisoma duryi and H. trivolvis. The auricle and ventricle walls do not appear to be possible sites for urine formation. In the kidney sac, ferritin and carbon particles are retained by the basement membrane of the epithelium, whereas horseradish peroxidase passes through the basement membrane into the intercellular spaces 10 min after injection. Epithelial cells have deep basal membrane infoldings. Intercellular spaces and spaces in the infoldings are wide in snails kept in distilled water but narrow in snails kept in isosmotic saline. When kidney sacs from saline-acclimated snails were treated in vitro with visceral ganglion extract from snails kept in distilled water these spaces rapidly expanded. Visceral ganglion extract from snails kept in saline, or extracts of other ganglia, had no effect. It is suggested that urine formation occurs in the kidney sac, and that a factor (probably neurosecretory) from the visceral ganglion may act on kidney sac epithelium to alter the rate of filtration and fluid (prourine) transport.

The elevation of cAMP levels by a putative diuretic hormone in the osmoregulatory organs of the freshwater snail Helisoma duryi

1991 ◽  
Vol 69 (11) ◽  
pp. 2800-2804 ◽  
Author(s):  
Isaac Abraham ◽  
Hamid R. Khan ◽  
A. S. M. Saleuddin
Keyword(s):  
Hormonal Regulation ◽  
Kidney Tissue ◽  
Second Messenger ◽  
Freshwater Snail ◽  
Intracellular Camp ◽  
Experimental Conditions ◽  
Visceral Ganglion ◽  
Diuretic Hormone ◽  
Helisoma Duryi

In the freshwater snail Helisoma duryi, the kidney and mantle are major organs for osmoregulation and the visceral ganglion is the putative source of diuretic hormone. The role of cAMP as a second messenger in hormonal regulation of these organs has been studied. Hypo-osmotic treatment of snails raised the levels of intracellular cAMP in their kidney and mantle tissues. Forskolin, isobutylmethylxanthine, and theophylline also increased the levels of intracellular cAMP in these tissues. In addition, when these tissues from snails that were acclimated in isosmotic medium were treated in vitro with extracts of visceral ganglion of snails that were acclimated in hypo-osmotic medium, elevated levels of cAMP were observed, 12-fold for the kidney tissue and 4-fold for the mantle tissue. The stimulatory substance from the visceral ganglion was heat stable but labile to proteolytic digestion. In similar in vitro experimental conditions, hemolymph taken from hypo-osmotically treated snails also raised levels of cAMP. It is suggested that in H. duryi cAMP is involved as a second messenger for hormonal osmoregulation by kidney and mantle, and that the putative diuretic hormone is a neuropeptide.

Physical Properties of Isolated Perfused Renal Tubular Basement Membranes

1971 ◽  
Vol 29 ◽  
pp. 390-391
Author(s):  
Jared Grantham ◽  
Larry Welling
Keyword(s):  
Basement Membrane ◽  
Basement Membranes ◽  
Transport Mechanisms ◽  
Permeability Characteristics ◽  
Peritubular Capillaries ◽  
Strategic Location ◽  
Tubular Lumen ◽  
Glomerular Filtrate ◽  
Urine Formation ◽  
Renal Tubular

In the course of urine formation in mammalian kidneys over 90% of the glomerular filtrate moves from the tubular lumen into the peritubular capillaries by both active and passive transport mechanisms. In all of the morphologically distinct segments of the renal tubule, e.g. proximal tubule, loop of Henle and distal nephron, the tubular absorbate passes through a basement membrane which rests against the basilar surface of the epithelial cells. The basement membrane is in a strategic location to affect the geometry of the tubules and to influence the movement of tubular absorbate into the renal interstitium. In the present studies we have determined directly some of the mechanical and permeability characteristics of tubular basement membranes.

SEM Evaluation of Fluoride Pretreatment Effects on Acid-Etching of Caries-Like Enamel Lesions In Vitro

1981 ◽  
Vol 39 ◽  
pp. 474-475
Author(s):  
M. John Hicks
Keyword(s):  
Dental Enamel ◽  
Preventive Measure ◽  
Acid Etching ◽  
Distilled Water ◽  
Adhesive Resin ◽  
Fluoride Treatment ◽  
Treatment Groups ◽  
Pretreatment Effects ◽  
Preparation Techniques

Acid-etching of enamel surfaces has been performed routinely to bond adhesive resin materials to sound dental enamel as a caries-preventive measure. The effect of fluoride pretreatment on acid-etching of enamel has been reported to produce inconsistent and unsatisfactory etching patterns. The failure to obtain an adequate etch has been postulated to be due to fluoride precipitation products deposited on the enamel surface. The purpose of this study was to evaluate the effects of fluoride pretreatment on acid-etching of carieslike lesions of human dental enamel.Caries-like lesions of enamel were created in vitro on human molar and premolar teeth. The teeth were divided into two fluoride treatment groups. The specimens were exposed for 4 minutes to either a 2% Sodium Fluoride (NaF) solution or a 10% Stannous Fluoride (SnF2) solution. The specimens were then washed in deionized-distilled water. Each tooth was sectioned into four test regions. This was carried out to compare the effects of various time exposures (0 to 2 minutes) and differing concentrations (10 to 60% w/w) of phosphoric acid (H3PO4) on etching of caries-like lesions. Standard preparation techniques for SEM were performed on the specimens.

Accumulation of Macromolecular Particles in the Reticuloendothelial System (RES) Mediated by Platelet Aggregation and Disaggregation

1969 ◽  
Vol 22 (03) ◽  
pp. 496-507 ◽  
Author(s):  
W.G van Aken ◽  
J Vreeken
Keyword(s):  
Platelet Aggregation ◽  
Degradation Products ◽  
Reticuloendothelial System ◽  
Caproic Acid ◽  
Carbon Particles ◽  
Carbon Clearance ◽  
Aggregation And Disaggregation ◽  
Platelet Aggregates

SummaryCarbon particles cause platelet aggregation in vitro and in vivo. Prior studies established that substances which modify thrombocyte aggregation also influence the rate at which carbon is cleared from the blood.This study was performed in order to elucidate the mechanism by which the carbon-platelet aggregates specifically accumulate in the RES.Activation of fibrinolysis by urokinase or streptokinase reduced the carbon clearance rate, probably due to generated fibrinogen degradation products (FDP). Isolated FDP decreased the carbon clearance and caused disaggregation of platelets and particles in vitro. Inhibition of fibrinolysis by epsilon-amino-caproic acid (EACA), initially accelerated the disappearance of carbon and caused particle accumulation outside the RES, predominantly in the lungs. It is supposed that platelet aggregation and locally activated fibrinolysis act together in the clearance of particles. In the normal situation the RES with its well known low fibrinolytic activity, becomes the receptor of the particles.

Seed-borne fungi of cowpea [Vigna unguiculata (L.) Walp] and their possible control in vitro using locally available fungicides in Botswana.

2016 ◽  
Vol 5 (11) ◽  
pp. 5016 ◽  
Author(s):  
K. B. Khare* ◽  
Loeto D. ◽  
Wale K. ◽  
Salani M.
Keyword(s):  
Seed Germination ◽  
Continuous Light ◽  
Sodium Hypochlorite Solution ◽  
Distilled Water ◽  
Percentage Germination ◽  
Department Of Agriculture ◽  
Hypochlorite Solution ◽  
Cowpea Cultivars ◽  
Petri Plate

Seeds of three cowpea cultivars namely Black eye, ER 7 and Tswana obtained from the Department of Agriculture Research, Gaborone were tested for the presence of seed-borne fungi, and their possible control in vitro using locally available fungicides. Four hundred fifty seeds of each cultivar of cowpea were disinfected with 2% sodium hypochlorite solution for 10 min and washed three times with sterile distilled water before placing them in PDA plates (5 seeds/9 cm Petri plate), incubated at 22±2o C for 12 hour each under continuous light and dark. A total of eight fungi were detected from seeds of cowpea. These were Aspergillus flavus, A. niger, Cylindrocarpon sp., Fusarium equisiti, F. oxyaporum, Penicillium chyrosogenum, Rhizopus oligosporus and R. stolonifer. Rhizopus spp. were dominant fungi recovered from seeds, followed by Penicillium, Aspergillus, Fusarium and Cylindrocarpon. The fungi detected resulted in decay and rotting of seeds, and thereby reducing percentage germination of seeds (22%, 37% and 63 % seed germination in Black eye, ER7 and Tswana varieties of cowpea respectively). Out of four fungicides tested, benlate, captan, dithane M 45 and chlorothalanil. Dithane M45 effectively controlled seed-borne fungi, and enhanced seed germination to an average of 86% (93% germination with no fungi detected in Tswana variety) as compared to chlorothalonile (79%), benlate and captan (77%) and un-treated seeds (45%). The fungal incidence was reduced to 2.3%, 4.3%, 5.3% and 5.3% when seeds were treated with dithane M-45, chlorothalonil, benlate and captan respectively as compared to 62% in non-treated seeds.

scholarly journals Biosynthesis of basement membrane collagen by rabbit corneal endothelium in vitro.

1976 ◽  
Vol 251 (3) ◽  
pp. 730-733 ◽  
Author(s):  
N A Kefalides ◽  
J D Cameron ◽  
E A Tomichek ◽  
M Yanoff
Keyword(s):  
Basement Membrane ◽  
Corneal Endothelium ◽  
Basement Membrane Collagen ◽  
Membrane Collagen

scholarly journals Comparison of the Cerumenolytic Activities of New and Currently Used Agents

2021 ◽  
pp. 014556132098606
Author(s):  
Nguyen Quynh Anh ◽  
Pawin Numthavaj ◽  
Thongchai Bhongmakapat
Keyword(s):  
Salicylic Acid ◽  
Sodium Bicarbonate ◽  
Potassium Hydroxide ◽  
Glycolic Acid ◽  
Statistical Significance ◽  
In Vitro Study ◽  
Distilled Water ◽  
Moderate Amount ◽  
All Solutions

Objectives: This study compared the cerumen dissolution activities of 7.5% sodium bicarbonate, 5% potassium hydroxide, 10% lactic acid, 3% salicylic acid, 10% glycolic acid, and distilled water. Methods: An in vitro study was conducted with 36 cerumen samples. The cerumenolytic activities of the 6 agents were assessed by recording the degree of cerumen disintegration using digital photography at 15 minutes, 30 minutes, 1 hour, 2 hours, and 12 hours. The undissolved cerumen that remained after 12 hours was removed from the solutions and weighed after drying. Results: Potassium hydroxide showed the fastest cerumenolytic activity, dissolving a moderate amount of cerumen at 30 minutes, while glycolic acid and salicylic acid caused no visible changes in the cerumen samples. Samples treated with potassium hydroxide and sodium bicarbonate exhibited higher degrees of disintegration compared to samples treated with distilled water (odds ratio and 95% CI: 273.237 [0.203-367 470.4] and 1.129 [0.002-850.341], respectively). The greatest reduction in cerumen weight was associated with the use of sodium bicarbonate; however, this result did not reach statistical significance. Conclusions: Among the solutions tested, 5% potassium hydroxide showed the fastest dissolution activity, yielding moderate disintegration within only 30 minutes. In terms of residual cerumen weight within 12 hours, all solutions exhibited equivalent effectiveness in the disintegration of cerumen.

scholarly journals Method for maintenance of coffee leaves in vitro for mass rearing of Leucoptera coffeellum (Guérin-Méneville) (Lepidoptera: Lyonetiidae)

2000 ◽  
Vol 29 (4) ◽  
pp. 849-854 ◽  
Author(s):  
Ronaldo Reis Jr. ◽  
Lima ◽  
Evaldo F. Vilela ◽  
Raimundo S. Barros
Keyword(s):  
Plant Growth ◽  
Mass Rearing ◽  
Developmental Cycle ◽  
Plant Tissues ◽  
Distilled Water ◽  
Complete Development ◽  
Detached Leaves ◽  
Leaf Survival ◽  
The Ideal

To accomplish systematic studies with coffee leafminer, it is necessary to establish a mass rearing system under artificial conditions. It is possible to rear this species, from egg to adult, under laboratory conditions, without using coffee seedlings but detached leaves maintained in vitro. Synthetic cytokinins are routinely used for maintenance of plant cell and plant tissues in vitro. Two plant growth regulators, benzyladenin and kinetin, in concentrations 10-6 and 10-7 M were used to mantain the leaves. Green leaves collected in the field were maintained in the solution to be tested. Distilled water served as control. The experiment lasted 30 days, a period longer than the necessary for the complete development of the insect. Both artificial cytokinines indeed increased the lifetime of the coffee leaves, maintaining them green and healthy. Leaves placed in the cages for oviposition were attractive to the insect, with significant number of eggs per leaf. In most cases, eggs resulted in individuals that completed the whole developmental cycle. Tests with regulator in different concentrations with healthy leaves showed efficiency. However, we believe that hormone concentrations to be used with mined leaves should be larger, because these when maintained at 10-7 M leaves did not present a satisfactory lifetime. Therefore, tests with mined leaves with different hormone concentrations should be made to find out the ideal concentration for leaf survival. In our laboratory we are successfully using 10-6 M benzyladenin for the maintenance of mined leaves.

scholarly journals POLYMORPHONUCLEAR LEUKOCYTES IN IMMUNOLOGIC REACTIONS

1966 ◽  
Vol 124 (4) ◽  
pp. 733-752 ◽  
Author(s):  
Charles G. Cochrane ◽  
Barbara S. Aikin
Keyword(s):  
Basement Membrane ◽  
Polymorphonuclear Leukocytes ◽  
Electron Microscopic Observation ◽  
Severe Damage ◽  
Electron Microscopic ◽  
Cationic Proteins ◽  
Vascular Basement Membrane ◽  
Arthus Phenomenon ◽  
Immunologic Reactions

Vascular basement membrane was disrupted in the presence of polymorphonuclear leukocytes (PMN's) during two immunologic reactions: The Arthus phenomenon and the reaction to locally injected antibody to vascular basement membrane. This disruption was evidenced by (a) the inability of the basement membrane to retain circulating carbon, by (b) loss of antigenic constituents, and by (c) electron microscopic observation showing actual gaps in the structure of the vascular basement membrane. The factors within PMN's responsible for damage to isolated glomerular basement membrane in vitro were found by isolation procedures to be cathepsins D and E. Cationic proteins of PMN's were separable from the cathepsins. While inducing vascular permeability upon injection, these basic proteins failed to inflict the severe damage to the basement membrane observed in Arthus and antibasement membrane reactions. It is concluded that the full expression of these immunologic lesions requires destruction of the basement membrane possibly brought about by cathepsins D and E. Some of the physicochemical properties of these pathologically active leukocytic factors are given.

scholarly journals Heterologously overexpressed, affinity-purified human meprin α is functionally active and cleaves components of the basement membrane in vitro

FEBS Letters ◽  
1999 ◽  
Vol 465 (1) ◽  
pp. 2-7 ◽  
Author(s):  
Danny Köhler ◽  
Markus-N. Kruse ◽  
Walter Stöcker ◽  
Erwin E. Sterchi
Keyword(s):  
Basement Membrane
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