scholarly journals The Physiology Of Contractile Vacuoles

1938 ◽  
Vol 15 (1) ◽  
pp. 143-151
Author(s):  
J. A. KITCHING
Keyword(s):  
Body Surface ◽  
Sucrose Solution ◽  
Tap Water ◽  
The Body ◽  
Partial Recovery ◽  
A Value ◽  
Contractile Vacuoles ◽  
Cyanide Solutions ◽  
Initial Check ◽  
Normal Difference

1. The rate of output of fluid from the contractile vacuoles of fresh-water peritrich ciliates was reduced in solutions of sulphide of concentration not less than M/1000. This effect was reversible. 2. Cyanide depressed the rate of vacuolar output in a concentration of M/100,000, but was more effective in higher concentrations (M/1000). In cyanide solutions there was (a) either a severe initial check or a temporary stoppage of the vacuole, and then later (b) a partial recovery of the rate of output to a value which was still much below the normal. During the initial check the body swelled. 3. Return of the organism from cyanide solution to tap water was followed by a sharp increase in the rate of vacuolar output to an abnormally high value. The body then shrank gradually to its normal size, and the rate of output also fell slowly to normal. 4. The swelling of the body which followed treatment of the organism with cyanide could be exactly counteracted by the addition of sucrose to the outside medium in a 0.05 M concentration. 5. It is concluded that the normal difference of osmotic pressure across the body surface is equivalent to that of a 0.05 M sucrose solution, and that this difference is maintained by the contractile vacuole. 6. The permeability of the body surface to water is estimated as 0.125-0.25 cubic micra per square micron per atmosphere per minute.

The Physiology of Contractile Vacuoles

1960 ◽  
Vol 37 (1) ◽  
pp. 73-82
Author(s):  
J. A. KITCHING ◽  
J. E. PADFIELD ◽  
M. H. ROGERS
Keyword(s):  
Body Surface ◽  
Normal Activity ◽  
The Body ◽  
Contractile Vacuole ◽  
Diffusion Constants ◽  
Contractile Vacuoles

1. The suctorian Discophrya collini (Root) has been subjected to D2O-H2O mixtures containing up to 99.7% D2O. 2. In 25% D2O or over there is a rapid but temporary shrinkage of the body. This shrinkage is difficult to estimate owing to the wrinkling of the body surface, but amounts to at least 10% in the undiluted (99.7%)D2O. 3. During the period of temporary shrinkage the contractile vacuole ceases activity. Normal activity is resumed when the normal volume is regained. In concentrations of D2O too low to cause shrinkage there is a temporary fall in the rate of vacuolar output. 4. Return to H2O leads to a brief but often very considerable rise in vacuolar output. 5. It is concluded that D2O penetrates less rapidly than H2O. A difference of at least 10% in the diffusion constants in the membrane would be required to explain our results. We cannot exclude this as unreasonable from our data, although an explanation based on differences in the equilibrium properties of D2O and H2O might also be invoked.

scholarly journals The Physiology of Contractile Vacuoles

1934 ◽  
Vol 11 (4) ◽  
pp. 364-381
Author(s):  
J. A. KITCHING
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Tap Water ◽  
Marine Species ◽  
The Body ◽  
Contractile Vacuole ◽  
Body Volume ◽  
Water Value ◽  
Contractile Vacuoles ◽  
Sustained Increase

1. The rate of output of fluid from the contractile vacuole of a fresh-water Peritrich Ciliate was decreased to a new steady value immediately the organism was placed in a mixture of tap water and sea water. The rate of output returned to its original value immediately the organism was replaced in tap water. The contractile vacuole was stopped when the organism was treated with a mixture containing more than 12 per cent, of sea water. 2. Transference of various species of marine Peritricha from 100 per cent, sea water to mixtures of sea water and tap water led to an immediate increase of the body volume to a new and generally steady value. Return of the organism to 100 per cent, sea water led to an immediate decrease of the body volume to its original value or less. 3. Marine Peritricha showed little change in rate of output when treated with concentrations of sea water between 100 and 75 per cent. In more dilute mixtures the rate of output was immediately increased, and then generally fell off slightly to a new steady value which was still considerably above the original (100 per cent. sea water) value. The maximum sustained increase was approximately x 80. Return of the organism to 100 per cent, sea water led to an immediate return of the rate of output to approximately its original value. 4. When individuals of some marine species were placed in very dilute concentrations of sea water, the pellicle was frequently raised up in blisters by the formation of drops of fluid underneath it, and the contractile vacuole stopped. 5. Evidence is brought forward to suggest that in the lower concentrations of sea water marine forms lost salts. 6. The contractile vacuole probably acts as an osmotic controller in fresh-water Protozoa. Its function in those marine Protozoa in which it occurs remains obscure.

Responses of the Heliozoon Actinophrys Sol to Prey, to Mechanical Stimulation, and to Solutions of Proteins and Certain Other Substances

1960 ◽  
Vol 37 (2) ◽  
pp. 407-416
Author(s):  
J. A. KITCHING
Keyword(s):  
Body Surface ◽  
Tap Water ◽  
The Body ◽  
Albumin Solution ◽  
Egg Albumin ◽  
Other Substances ◽  
Γ Globulins ◽  
Skin Formation ◽  
Actinophrys Sol

1. Various flagellates and small ciliates stick to the axopods of Actinophrys. Contact with the base of an axopod or with the body surface leads to the outgrowth of a food funnel, by which the prey is ultimately surrounded. 2. If a fine probe or micropipette touches the body surface or the base of an axopod, a small cup may grow out over it, investing it closely, but the instrument is soon released. A squirt of tap water from a micropipette may also provoke the outgrowth of a small lobe or cup, or local pinocytosis. 3. Contact with, or a squirt from, a micropipette containing a solution of egg albumin provokes a more extensive reaction. The micropipette usually becomes invested extensively. The micropipette is drawn into the body and held there for up to an hour. 4 Immersion in egg albumin solution leads to a temporary spreading and lobulation of the axopod bases, and later a ‘skin’ may separate from the body surface. Skin formation is more pronounced in serum albumin solution, and may also be induced by γ-globulins and gelatin. 5. On treatment in vivo with toluidine blue or thionine a violet layer in the body surface separates as a pinkish violet or violet skin, leaving the body surface unstained. 6. There is evidence that the skin-forming substance is associated directly or indirectly with the maintenance of cell shape.

Active Transport and Sodium Fluxes at Moult in the Amphipod, Gammarus Duebeni

1969 ◽  
Vol 51 (3) ◽  
pp. 591-605
Author(s):  
A. P. M. LOCKWOOD ◽  
W. R. H. ANDREWS
Keyword(s):  
Fresh Water ◽  
Body Surface ◽  
Major Part ◽  
Sea Water ◽  
Sucrose Solution ◽  
The Body ◽  
Active Sodium ◽  
Sodium Influx ◽  
Sodium Uptake ◽  
High Level

1. The sodium fluxes of individual Gammarus duebeni, which moulted in sea water, have been followed daily from the morning following moult for at least 6 days. 2. Sodium influx from sea water declined from 15.1µM/animal/hr. on the first morning after moult to 1.7µM/animal/hr. by the tenth day after moult. 3. Sodium influx from 10 mM/l. NaCl plus sucrose solution isotonic with sea water declines from 4.48µM/animal/hr. to 0.14µM/animal/hr. in inter-moult animals. 4. Thionine inhibits over 90% of the influx from 10 mM/l NaCl plus isotonic sucrose on the first day after moult, and this, together with other evidence, suggests that the major part of the influx from this medium is due to active sodium uptake. The rate of active uptake is comparable with, or faster than, the rate of uptake by animals acclimatized to fresh water. 5. The influx occurs primarily across the body surface. It is suggested that the high level of sodium uptake is associated with the water uptake which occurs at moult.

scholarly journals REACTIONS OF THE NASAL CAVITY AND POSTNASAL SPACE TO CHILLING OF THE BODY SURFACE

1921 ◽  
Vol 34 (1) ◽  
pp. 11-45 ◽  
Author(s):  
Stuart Mudd ◽  
Alfred Goldman ◽  
Samuel B. Grant
Keyword(s):  
Nasal Cavity ◽  
Blood Supply ◽  
Nasal Mucosa ◽  
Body Surface ◽  
Room Temperature ◽  
The Body ◽  
Surface Discharge ◽  
Partial Recovery ◽  
Mucous Membranes ◽  
Local Reflex

Devices are described by means of which the terminals of thermopiles may be held in stable apposition with the mucous membranes of the nasal cavity and postnasal space and local temperature variations thus followed. Chilling of the body surface has without exception caused depression of the temperature of the nasal mucosa surface, amounting in some instances to as much as 6°C., and indicating marked reflex vasoconstriction and diminution of blood supply. With rewrapping, partial recovery of blood supply promptly occurs, although recovery has been incomplete within the duration of the experiments in ten of twelve instances. Application of the wires within the nasal cavity has usually caused pain and discharge of clear mucus, sometimes also lacrimation and sneezing. The rhinorrhea has occurred both on the side directly irritated and on the opposite side, although on the former more abundantly, and has apparently been little if at all affected by the diminished blood supply and shrinkage of the mucous membrane incident to chilling the body surface. Discharge from the nose has been at most a rare occurrence in experiments in which the nasal mucosa was not directly irritated. The temperature of the nasopharyngeal mucosa surface has also been depressed, typically between 1° and 2°C., with chilling of the body surface. This depression has also been shown to have local reflex vasoconstriction and ischemia as its basis. With rewrapping, prompt return toward normal occurs, but here also recovery of blood supply has in the majority of instances not been complete within the duration of the experiments. The thresholds of the chilling vasoconstrictor reflex to the mucous membranes of the nasal cavity and postnasal space, tonsil, oropharynx, and palate and the threshold of the reflex to the skin of the trunk have been found to be lower than the threshold of the like reflex to the skin of the forehead. Disrobing 'the warmly wrapped subject in a room a little below ordinary room temperature has been found sufficient to cause marked vasoconstriction in the sites of the former group, but only slight or no vasoconstriction in the forehead. A number of instances of cold or sore throat occurred among the subjects of the experiments, in several instances correlated with somewhat interesting bacteriologic findings which will be described elsewhere.

scholarly journals The accumulation of radioactive caesium in crabs

1961 ◽  
Vol 41 (3) ◽  
pp. 551-575 ◽  
Author(s):  
G. W. Bryan
Keyword(s):  
Body Surface ◽  
Natural Environment ◽  
Sea Water ◽  
Carcinus Maenas ◽  
The Body ◽  
Limiting Factor ◽  
A Value ◽  
Cancer Pagurus ◽  
The Relationship ◽  
Accuracy Rates

SUMMARYThe accumulation of 134Cs and 42K from artificial sea water has been followed in crabs of the following species, viz. Carcinus maenas, Portunus puber, P. depurator, Polybius henslowi, Cancer pagurus and Corystes. cassivelaunm. In all cases 134Cs is taken up far more slowly than 42K but at equilibrium a higher concentration factor is attained by 134Cs. In Carcinus a value of about 8 is found for 134Cs and about 4 for 42K. Uptake of 134Cs in Carcinus is not affected by feeding on inactive food over a period of 1000 h. The relationship between the rates of uptake of the two isotopes is not the same in the different species and it is concluded that it would not be possible to predict with any accuracy rates of uptake for 134Cs in other species of crabs from the results of short 42K experiments.Uptake of 134Cs was followed in the blood and tissues of Carcinus and Cancer, and muscle is the principal limiting factor in the attainment of equilibrium by whole animals. Uptake of 42K by tissues has also been followed and in all species nearly all the inactive K appears to be readily exchangeable. At equilibrium in all species plasma/sea water and tissue/plasma 134Cs ratios nearly always exceed those for inactive K. The tissue/plasma 134Cs ratios in Carcinus are about twice those for K and the significance of this has been discussed.Loss of both isotopes in whole Carcinus is a slower process than uptake.Isotope accumulation takes place mainly across the body surface in unfed animals, but uptake of 134Cs from food is very rapid and complete and would considerably enhance the attainment of equilibrium in a natural environment.Selective excretion of 134Cs relative to K has been found in Carcinus, Cancer and Portunus puber.

The Role of Computer Modeling in Electrocardiography

1990 ◽  
Vol 29 (04) ◽  
pp. 282-288 ◽  
Author(s):  
A. van Oosterom
Keyword(s):  
Electrical Activity ◽  
Computer Modeling ◽  
Body Surface ◽  
Electrical Current ◽  
The Body ◽  
Volume Conductor ◽  
Current Generator ◽  
Cardiac Electrical Activity ◽  
Source Models

AbstractThis paper introduces some levels at which the computer has been incorporated in the research into the basis of electrocardiography. The emphasis lies on the modeling of the heart as an electrical current generator and of the properties of the body as a volume conductor, both playing a major role in the shaping of the electrocardiographic waveforms recorded at the body surface. It is claimed that the Forward-Problem of electrocardiography is no longer a problem. Several source models of cardiac electrical activity are considered, one of which can be directly interpreted in terms of the underlying electrophysiology (the depolarization sequence of the ventricles). The importance of using tailored rather than textbook geometry in inverse procedures is stressed.

The use of Body Surface Index as a Better Clinical Health indicators Compare to Body Mass Index and Body Surface Area for Clinical Application

2018 ◽  
pp. 131-136
Author(s):  
Shirazu I. ◽  
Theophilus. A. Sackey ◽  
Elvis K. Tiburu ◽  
Mensah Y. B. ◽  
Forson A.
Keyword(s):  
Surface Area ◽  
Body Surface Area ◽  
Clinical Application ◽  
Body Surface ◽  
Body Height ◽  
Health Indicators ◽  
The Body ◽  
Body Parameters ◽  
The Relationship ◽  
Individual Body

The relationship between body height and body weight has been described by using various terms. Notable among them is the body mass index, body surface area, body shape index and body surface index. In clinical setting the first descriptive parameter is the BMI scale, which provides information about whether an individual body weight is proportionate to the body height. Since the development of BMI, two other body parameters have been developed in an attempt to determine the relationship between body height and weight. These are the body surface area (BSA) and body surface index (BSI). Generally, these body parameters are described as clinical health indicators that described how healthy an individual body response to the other internal organs. The aim of the study is to discuss the use of BSI as a better clinical health indicator for preclinical assessment of body-organ/tissue relationship. Hence organ health condition as against other body composition. In addition the study is `also to determine the best body parameter the best predict other parameters for clinical application. The model parameters are presented as; modeled height and weight; modelled BSI and BSA, BSI and BMI and modeled BSA and BMI. The models are presented as clinical application software for comfortable working process and designed as GUI and CAD for use in clinical application.

STUDIES IN THE SUPPOSED GOITROGENOUS EFFECT OF TAP WATER IN HELSINKI

1960 ◽  
Vol XXXIII (IV) ◽  
pp. 630-636
Author(s):  
F.-E. Krusius ◽  
P. Peltola
Keyword(s):  
Tap Water ◽  
Physiological Saline ◽  
Normal Weight ◽  
The Body ◽  
Iodine Uptake ◽  
Redistilled Water ◽  
Detectable Difference ◽  
Term Administration ◽  
Long Term Experiment

ABSTRACT The study reported here was performed in order to examine the tap water of Helsinki for its alleged goitrogenous effect. In a short-term, 24-hour experiment with rats, kept on an iodine-poor diet, we noticed no inhibition of the 4-hour 131I uptake, as compared with that of animals receiving physiological saline instead of tap water. Two similar groups of rats receiving 1 and 2 mg of mercazole in redistilled water showed a distinct blockage of the 4-hour uptake, which proved the effect of this substance. In a long-term experiment of 5 weeks' duration there was no detectable difference in the body weight, thyroid weight and the 4-hour 131I uptake when the rats receiving tap water or distilled water to which 0.45 per cent of sodium chloride was added were compared with each other. Replacement of tap water by a 10 mg per cent solution of mercazole in redistilled water enlarged the thyroid to double its normal weight and increased the 131I uptake to approximately five times that of the controls. Thus our experiments failed to demonstrate any goitrogenous effect in the tap water of Helsinki. Changes similar to those produced by a long-term administration of mercazole, i. e. an enlargement of the thyroid and an increased thyroidal iodine uptake, have been shown to be due to milk collected from goitrous areas. The observations here reported confirm the importance of milk in the genesis of the goitre endemia of Helsinki. Attention is further called to the fact that a thyroidal enlargement combined with an increased thyroidal iodine uptake cannot always be taken as a sign of iodine deficiency because similar changes may be produced by the administration of goitrogens.

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