The Reorganization of Tissue Masses of Cordylophora Lacustris and the Effect of Oral Cone Grafts, with Supplementary Observations on Obelia Gelatinosa

1938 ◽  
Vol 15 (3) ◽  
pp. 303-326
Author(s):  
L. C. BEADLE ◽  
F. A. BOOTH
Keyword(s):  
Brackish Water ◽  
No Reduction ◽  
Sea Water ◽  
Magnesium Deficiency ◽  
Inhibitory Effect ◽  
Sodium Cyanide ◽  
Potassium Deficiency ◽  
Complete Suppression ◽  
Oral Cone ◽  
Similar Inhibitory Effect

1. A method is described for the preparation of reconstitution masses from the expressed coenosarc tissues of Cordylophora lacustris. This brackish water hydroid is more suitable for the purpose than others which have so far been used. 2. Under normal conditions (50% sea water at 16-17° C.) such masses produce one or more hydranths within about 2 days and often additional unorganized outgrowths. 3. The main histological features of the reconstitution masses as seen in sections are described. From these observations and from experiments with masses made from isolated ectoderm and endoderm it is concluded that there is no reduction of the cells to a pleuripotent condition. The cells of each original layer can form only the layer from which they were derived. 4. Masses made from endoderm cells only are incapable of holding together for long and soon disintegrate. Pure ectoderm masses, however, rapidly round up and form hollow vesicles but do not produce hydranths. 5. No signs of cell division during reconstitution were detected. 6. The "interstitial" cells observed in the coenosarc ectoderm are thus not able to differentiate into endoderm when this is absent and there is no indication that they perform any essential part in the process of reconstitution. 7. An oral cone when grafted into a mass will determine the position of the regenerated hydranth which develops in relation to the graft. 8. Evidence is given to prove that the action of the cone is one of pure induction and that it does not supply cells to the induced hydranth. 9. The action of the cone is independent of its orientation and it will produce its effect even after previous chopping up and reuniting. Attempts to graft killed oral cones have so far failed. 10. Grafts of distal halves of young gonophores do not induce hydranths. 11. Calcium or magnesium deficiency in the medium results in complete suppression of hydranth formation from masses but not always of unorganized outgrowths. Oral cone grafts, however, can overcome this inhibition and tentacles are formed. A similar inhibitory effect is produced by potassium deficiency, but is not overcome by an oral cone graft. 12. The quantity of calcium required to permit tentacle formation in plain masses is very small (c. 0.00006 M). 13. Sodium cyanide (c. M/30,000), phenyl urethane (c. M/3000) and low temperature (5.5-6.5° C.) can inhibit hydranth formation in plain masses, but oral cone grafts overcome this inhibition and induce the formation of tentacles. 14. Reconstitution masses which produced hydranths were also made from the coenosarc of another brackish water hydroid Obelia gelatinosa. Isolated ectoderm and endoderm were incapable of reorganization. 15. Mixed masses of Cordylophora and Obelia coenosarc separated into regions composed of tissue from one species only and each produced hydranths independently.

Investigational Studies on Quantity of Salinity in Netravati River Estuary Sand-Coastal Karnataka

2018 ◽  
Vol 6 (6) ◽  
pp. 46
Author(s):  
Raveesha P ◽  
K. E. Prakash ◽  
B. T. Suresh Babu
Keyword(s):  
Brackish Water ◽  
Sea Water ◽  
Salt Water ◽  
Construction Material ◽  
Salt Content ◽  
River Estuary ◽  
Sand Sample ◽  
River Sand ◽  
Natural Aggregates

The salt water mixes with fresh water and forms brackish water. The brackish water contains some quantity of salt, but not equal to sea water. Salinity determines the geographic distribution of the number of marshes found in estuary. Hence salinity is a very important environmental factor in estuary system. Sand is one major natural aggregate, required in construction industry mainly for the manufacture of concrete. The availability of good river sand is reduced due to salinity. The quality of sand available from estuarine regions is adversely affected due to this reason. It is the responsibility of engineers to check the quality of sand and its strength parameters before using it for any construction purpose. Presence of salt content in natural aggregates or manufactured aggregates is the cause for corrosion in steel. In this study the amount of salinity present in estuary sand was determined. Three different methods were used to determine the salinity in different seasonal variations. The sand sample collected nearer to the sea was found to be high in salinity in all methods.  It can be concluded that care should be taken before we use estuary sand as a construction material due to the presence of salinity.

The Regulation of Calcium and Magnesium in the Brackish Water Polychaete Nereis Diversicolor O.F.M

1970 ◽  
Vol 53 (2) ◽  
pp. 425-443
Author(s):  
C. R. FLETCHER
Keyword(s):  
Brackish Water ◽  
Calcium Concentration ◽  
Sea Water ◽  
Calcium Influx ◽  
Coelomic Fluid ◽  
Nereis Diversicolor ◽  
Active Uptake ◽  
Calcium And Magnesium ◽  
Electrochemical Potentials

1. Nereis diversicolor tolerates changes in the concentration of calcium and magnesium in its coelomic fluid proportional to the concentrations in the medium between chlorosities of 100-1000 mM/kg of water. 2. In lower salinities both ions are maintained relatively constant providing that the ratios of these ions to chloride in the medium are similar to the ratios in sea water. 3. The ratio of the concentration of calcium in the coelomic fluid to the concentration in the medium is a function of the salinity of the medium but not of the calcium concentration. 4. Both calcium and magnesium are at lower electrochemical potentials in the coelomic fluid than in the medium, indicating that it is not necessary to invoke active uptake. 5. The rate of calcium influx is substantial. 6. In salinities below to mM of chloride/kg of water the urine must contain less calcium than the coelomic fluid. 7. The significance of these results is discussed.

High environmental salinity induces memory enhancement and increases levels of brain angiotensin-like peptides in the crab Chasmagnathus granulatus

2000 ◽  
Vol 203 (22) ◽  
pp. 3369-3379 ◽  
Author(s):  
A. Delorenzi ◽  
B. Dimant ◽  
L. Frenkel ◽  
V.E. Nahmod ◽  
D.R. Nassel ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Brackish Water ◽  
Sea Water ◽  
Immunohistochemical Analysis ◽  
Facilitatory Effect ◽  
Long Term Memory ◽  
Stimulus Context ◽  
Memory Enhancement ◽  
Chasmagnathus Granulatus

Previous work on the brackish-water crab Chasmagnathus granulatus demonstrated that an endogenous peptide similar to angiotensin II plays a significant role in enhancing long-term memory that involves an association between context and an iterative danger stimulus (context-signal memory). The present results show that this memory enhancement could be produced by moving crabs from brackish water to sea water (33.0%) and keeping them there for at least 4 days. The possibility that such a facilitatory effect is due to osmotic stress is ruled out. Coincidentally, the level of angiotensin-II-like peptides in crab brain, measured by radioimmunoassay, increases with the length of exposure to sea water, reaching a significantly different level at the fourth day. The presence of angiotensin-II-like immunoreactive material in neural structures of the supraoesophageal and eyestalk ganglia was confirmed by immunohistochemical analysis. The results are interpreted as supporting the hypothesis that exposure to water of high salinity is an external cue triggering a process mediated by angiotensins that leads to enhanced memory in these crabs.

scholarly journals Cyclic GMP regulates activation of phosphoinositidase C by bradykinin in sensory neurons

1996 ◽  
Vol 316 (2) ◽  
pp. 539-544 ◽  
Author(s):  
Justine S. HARVEY ◽  
Gillian M. BURGESS
Keyword(s):  
Cyclic Gmp ◽  
Inhibitory Effect ◽  
Neonatal Rat ◽  
Drg Neurons ◽  
Rapid Phase ◽  
Surface Receptors ◽  
Similar Inhibitory Effect ◽  
Key Factor ◽  
The Right ◽  
Oxide Synthase

Prior exposure of cultured neonatal rat dorsal root ganglion (DRG) neurons to bradykinin resulted in marked attenuation of bradykinin-induced activation of phosphoinositidase C (PIC). The (logconcentration)–response curve for bradykinin-induced [3H]inositol trisphosphate ([3H]IP3) formation was shifted to the right and the maximum response was reduced. Bradykinin increases cyclic GMP (cGMP) in DRG neurons [Burgess, Mullaney, McNeill, Coote, Minhas and Wood (1989) J. Neurochem. 53, 1212–1218] and treatment of the neurons with dibutyryl cGMP (dbcGMP) had a similar, inhibitory, effect on bradykinin-induced [3H]IP3 formation. NG-Nitro-L-arginine (LNNA) blocked bradykinin-induced formation of cGMP. It prevented the functional uncoupling induced by pretreatment with bradykinin, but not the inhibitory effect of dbcGMP on [3H]IP3 formation. The ability of LNNA to prevent desensitization was reversed by excess L-arginine, indicating that its actions were mediated through inhibition of nitric oxide synthase. In addition to functional desensitization, exposure to bradykinin reduced the number of cell-surface receptors detected with [3H]bradykinin, without affecting its KD value for the remaining sites. In contrast to bradykinin, pretreatment with dbcGMP had no effect on either the KD or Bmax for [3H]bradykinin binding. This implies that the inhibitory effect of dbcGMP was downstream from the binding of bradykinin to its receptor and upstream of IP3 formation. The lack of effect of dbcGMP on [3H]bradykinin binding suggests that the decrease in receptor number induced by bradykinin was mediated by a different mechanism and was not a key factor in the rapid phase of desensitization in these cells.

scholarly journals Extracellular accumulation of proline, serine and trehalose in the haemolymph of osmoconforming brackish-water mosquitoes

1987 ◽  
Vol 129 (1) ◽  
pp. 231-238 ◽  
Author(s):  
M. A. Garrett ◽  
T. J. Bradley
Keyword(s):  
Organic Compounds ◽  
Brackish Water ◽  
Sea Water ◽  
Full Range ◽  
Culex Tarsalis ◽  
Osmotic Concentration

Larvae of Culex tarsalis, a mosquito, are capable of surviving and developing in dilutions of sea water ranging from 0 mosmol l-1 to 700 mosmol l-1. In waters more dilute than 400 mosmol l-1, the larvae osmoregulate, whereas in those more concentrated than 400 mosmol l-1, the osmotic strength of the haemolymph parallels that of the medium, i.e. the larvae osmoconform. Over the full range of external concentrations tested, the larvae regulate the levels of Na+, K+, Mg2+, Ca2+ and Cl- in the haemolymph. Analyses of haemolymph samples from larvae adapted to media of 50 mosmol l-1 or 600 mosmol l-1 indicate that the increase in haemolymph osmotic concentration observed in media above 400 mosmol l-1 is due to the accumulation of organic compounds, particularly proline, serine and trehalose.

The accumulation of 137Cs by brackish water invertebrates and its relation to the regulation of potassium and sodium

1963 ◽  
Vol 43 (2) ◽  
pp. 541-565 ◽  
Author(s):  
G. W. Bryan
Keyword(s):  
New Media ◽  
Brackish Water ◽  
Sea Water ◽  
Indirect Evidence ◽  
The Body ◽  
Limiting Factor ◽  
Wide Range ◽  
Concentration Factors ◽  
The Relationship ◽  
Potamopyrgus Jenkinsi

The relationship between the ability of brackish water invertebrates to regulate Na and K and the extent to which the radioactive fission product 137Cs can be accumulated has been studied.The brackish water isopod Sphaeroma hookeri and the gastropod Potamopyrgus jenkinsi have been acclimatised to a wide range of sea-water dilutions. Unfed Sphaeroma can survive in sea-water concentrations of 100–2·5%, while Potamopyrgus can live fairly indefinitely in concentrations of 50–0·1%. Measurements of Na and K in the whole animals of both species and in the blood of Sphaeroma have been made. Salt movements are quite rapid and acclimatization to new media is achieved by both species in less than 10 h. Concentration factors for inactive K in particular increase to high values in the more dilute media.Uptake of the isotopes 42K and 137Cs from solution has been examined in both species over a range of sea-water concentrations. All of the body K is exchangeable with 42K and in Sphaeroma exchange of 42K between the blood and tissues is so rapid that the body surface appears to be the limiting factor in the uptake of the isotope. Both species exchange 42K more rapidly in the higher concentrations of sea water and one reason for this may be the existence of an exchange diffusion component of exchange which increases as the salinity of the medium is raised. Indirect evidence suggests that the excretion of 42K in urine is probably not an important factor in exchange.

Adaptations to a terrestrial existence in the robber crab Birgus latro L. IX. Hormonal control of post-renal urine reprocessing and salt balance in the branchial chamber

2000 ◽  
Vol 203 (2) ◽  
pp. 389-396 ◽  
Author(s):  
S. Morris ◽  
P. Greenaway ◽  
A.M. Adamczewska ◽  
M.D. Ahern
Keyword(s):  
Cyclic Amp ◽  
Ion Transport ◽  
Fresh Water ◽  
Sea Water ◽  
Inhibitory Effect ◽  
Hormonal Control ◽  
Uptake System ◽  
Dietary Salt ◽  
Artificial Urine ◽  
Brachyuran Crabs

The terrestrial robber crab Birgus latro L. regulates the composition of its final excretory product (termed P) depending on the availability of dietary salt by reabsorbing ions from urine passed over the gills. Laboratory and field-based studies investigated the nature of the mechanisms of control of this branchial ion uptake. B. latro were prepared such that their branchial chambers could be perfused with artificial urine, and the rate of ion transport from the artificial urine was determined. For B. latro acclimated to drinking fresh water, the rates of Na(+) and Cl(−) uptake were more than four times those of crabs drinking 70 % sea water. Crabs were injected with either saline carrier or the same solution containing either dopamine or dibutyryl cyclic AMP (db-cAMP) (final concentration 8.7×10(−)(7)mol l(−)(1)haemolymph). Dopamine and db-cAMP inhibited Na(+) and Cl(−) uptake in animals acclimated to fresh water and markedly reduced their gill Na(+)/K(+)-ATPase activity. Dopamine stimulated the production of cyclic AMP within the branchial epithelial cells. Dopamine, released from the pericardial organs, acts as a primary messenger, and cyclic AMP acts as a second messenger most likely promoting phosphorylation of membrane proteins. In contrast to aquatic brachyuran crabs, ion transport in B. latro, an anomuran, is controlled via an inhibitory effect. Terrestrial crabs normally have access to fresh water and must salvage salt from their urine, and a mechanism to down-regulate a normally active uptake system seems more appropriate to their ecology. Whether the control is stimulatory or inhibitory in the various air-breathing crabs may depend on the osmoregulatory abilities of their aquatic ancestors, but in either case has significant implications for the evolution of crustaceans to life on land. Further work must establish whether terrestrial brachyuran crabs are similar to B. latro and whether this crab is unique amongst the anomuran crabs.

Oxidative phosphorylation in magnesium and potassium deficiency in the rat

1961 ◽  
Vol 201 (6) ◽  
pp. 1120-1122 ◽  
Author(s):  
R. B. Beechey ◽  
N. W. Alcock ◽  
I. MacIntyre
Keyword(s):  
Oxygen Consumption ◽  
Oxidative Phosphorylation ◽  
Normal Control ◽  
Magnesium Deficiency ◽  
Potassium Deficiency ◽  
Satisfactory Explanation ◽  
Methods Of Isolation

Heart sarcosomes were isolated from magnesium-deficient, potassium-deficient, and normal control rats. Two methods of isolation were used. P/O ratios were determined after measuring the oxygen consumption polarometrically in some cases and mano-metrically in others. No matter which method of isolation was used, or which method of determining the oxygen consumption, no difference could be demonstrated between the ratios obtained using sarcosomes isolated from the control rats and those isolated from the magnesium-deficient or the potassium-deficient rats. The results obtained in magnesium deficiency are not in agreement with those reported in 1957 by Vitale, Nakamura, and Hegsted ( J. Biol. Chem. 228: 573, 1957), who found lowered P/O ratios were associated with magnesium deficiency. While no satisfactory explanation can be found for the differences reported, it is suggested that they can only be ascribed to differences in technique.

Tumor-promoting phorbol esters inhibit monocyte adherence to endothelial cells

1989 ◽  
Vol 66 (1) ◽  
pp. 437-442 ◽  
Author(s):  
D. W. Kamp ◽  
K. D. Bauer ◽  
D. B. Rubin ◽  
M. M. Dunn
Keyword(s):  
Endothelial Cells ◽  
Phorbol Esters ◽  
Kinetic Studies ◽  
Inhibitory Effect ◽  
Adhesive Interaction ◽  
Kinase C ◽  
Inflammatory Stimuli ◽  
Similar Inhibitory Effect ◽  
Monocyte Adherence ◽  
Activate Protein Kinase

Monocyte adherence to endothelial cells (EC) is an important event in the development of a monocytic inflammatory response, yet the effects of inflammatory mediators on monocyte adherence to EC are not well described. We compared the effects of phorbol esters known to activate protein kinase C, including phorbol myristate acetate (PMA) and phorbol 12,13-dibutyrate (PDA), on monocyte adherence to bovine aortic EC. Human monocytes (purity 90 +/- 1% SE) were isolated by centrifugal elutriation to obtain monocytes not previously exposed to a surface. Kinetic studies revealed that 51Cr-labeled monocyte adherence to EC reached a plateau after a 45-min incubation. Concentrations of PMA between 10 and 1,000 ng/ml significantly decreased monocyte adherence to EC (26 +/- 10 and 35 +/- 8% decrease compared with control, respectively). Concentrations of PDA of 100 and 1,000 ng/ml had a similar inhibitory effect. In contrast, the chemotactic stimulus, zymosan-activated serum, significantly increased monocyte adherence (40 +/- 14% increase compared with control). Thus inflammatory stimuli have different effects on the adhesive interaction of monocytes to EC. This may provide a mechanism to selectively modulate monocyte egress from the circulation into extravascular inflammatory sites.

scholarly journals Resveratrol Inhibits Propagation ofChlamydia trachomatisin McCoy Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Ivan M. Petyaev ◽  
Nayilia A. Zigangirova ◽  
Elena Y. Morgunova ◽  
Nigel H. Kyle ◽  
Elena D. Fedina ◽  
...  
Keyword(s):  
Inhibitory Effect ◽  
Potential Effect ◽  
Nucleic Acid Amplification ◽  
Eukaryotic Cells ◽  
Developmental Cycle ◽  
Antifungal Compound ◽  
Future Studies ◽  
Amplification Protocol ◽  
Similar Inhibitory Effect ◽  
Dose Dependent

Resveratrol (RESV), an antifungal compound from grapes and other plants, has a distinct ability to inhibit theChlamydia (C.) trachomatisdevelopmental cycle in McCoy cells, a classic cell line used for chlamydial research. Inoculation ofC. trachomatiswith increasing amounts of RESV (from 12.5 to 100 μM) gave a dose-dependent reduction in the number of infected McCoy cells visualized by using monoclonal antibodies against chlamydial lipopolysaccharide. A similar trend has been observed with immunoassay for major outer membrane protein (MOMP). Furthermore, there was a step-wise reduction in the number ofC. trachomatisinfective progenies caused by the increasing concentrations of RESV. The ability of RESV to arrestC. trachomatisgrowth in McCoy cells was confirmed by a nucleic acid amplification protocol which revealed dose-dependent changes in mRNAs for different genes of chlamydial developmental cycle (euo,incA, andomcB). Although the precise nature of the antichlamydial activity of RESV is yet to be determined and evaluated in future studies, the observed effect of RESV onC. trachomatisinfection was not related to its potential effect on attachment/entry of the pathogen into eukaryotic cells or RESV toxicity to McCoy cells. Similar inhibitory effect was shown forC. pneumoniaeandC. muridarum.

Sign in / Sign up

Export Citation Format

Share Document