scholarly journals Magnesium Regulation in Mosquito Larvae (Aedes Campestris) Living in Waters of High MgSO4 Content

1974 ◽  
Vol 61 (3) ◽  
pp. 749-760 ◽  
Author(s):  
J. KICENIUK ◽  
J. E. PHILLIPS
Keyword(s):  
Body Weight ◽  
Body Surface ◽  
Natural Waters ◽  
Magnesium Content ◽  
Malpighian Tubules ◽  
Urinary Concentration ◽  
Mosquito Larvae ◽  
Magnesium Ions ◽  
General Body ◽  
Magnesium Regulation

1. Although larvae of A. campestris can live in natural waters in which the magnesium content may vary seasonally from extremes of 1 to more than 100 mM, the haemolymph levels of magnesium vary only from 1·5 to 4 mM. 2. Larvae survive in water containing 90 mM-Mg and drink their own body weight every few hours, the ingested fluid and the magnesium ions being largely absorbed into the haemolymph via the midgut. 3. The urinary concentration of Mg2+ ions was always substantially higher than that of the external media and up to 23 times that of the haemolymph. 4. It is suggested that magnesium is not excreted across the general body surface, the Malpighian tubules and hindgut being largely responsible for removing magnesium from the haemolymph. 5. These physiological observations are discussed in relation to the environmental conditions under which larvae are naturally found.

Active Transport of Magnesium by the Malpighian Tubules of the Larvae of the Mosquito, Aedes Campestris

1974 ◽  
Vol 61 (3) ◽  
pp. 761-771
Author(s):  
J. E. PHILLIPS ◽  
S. H. P. MADDRELL
Keyword(s):  
Active Transport ◽  
Concentration Gradient ◽  
Fluid Transport ◽  
Electrical Potential ◽  
Malpighian Tubules ◽  
Mosquito Larvae ◽  
Electrical Potential Difference ◽  
Maximal Rate ◽  
Magnesium Ions ◽  
Saturation Kinetics

1. Larvae of Aedes campestris can survive in water containing up to 100 mM Mg even though they ingest and absorb into the haemolymph considerable amounts of magnesium-rich fluid. 2. Isolated Malpighian tubules, unlike those of Rhodnius and Carausius secreted fluid containing elevated concentrations of magnesium. This transport displayed saturation kinetics, the half-maximal rate being at approximately 2·5 mM Mg. 3. Active transport of magnesium was demonstrated by the secretion of this cation against a tenfold concentration gradient and an electrical potential difference of 15 mV. 4. Magnesium ions are not required for fluid transport, which proceeds independently of magnesium transport. As a result fluid which is secreted slowly contains higher concentrations of magnesium than that which is secreted more rapidly. 5. Magnesium is transported by isolated Malpighian tubules fast enough to account for the observed excretion of magnesium in living mosquito larvae.

Sodium Regulation and Adaptation to Fresh Water in Gammarid Crustaceans

1968 ◽  
Vol 48 (2) ◽  
pp. 359-380
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Body Weight ◽  
Fresh Water ◽  
Body Surface ◽  
Sea Water ◽  
Sodium Concentration ◽  
The Body ◽  
Outward Diffusion ◽  
Gammarus Zaddachi ◽  
Freshwater Habitats ◽  
Sodium Regulation

1. Sodium uptake and loss rates are given for three gammarids acclimatized to media ranging from fresh water to undiluted sea water. 2. In Gammarus zaddachi and G. tigrinus the sodium transporting system at the body surface is half-saturated at an external concentration of about 1 mM/l. and fully saturated at about 10 mM/l. sodium. In Marinogammarus finmarchicus the respective concentrations are six to ten times higher. 3. M. finmarchicus is more permeable to water and salts than G. zaddachi and G. tigrinus. Estimated urine flow rates were equivalent to 6.5% body weight/hr./ osmole gradient at 10°C. in M. finmarchicus and 2.8% body weight/hr./osmole gradient in G. zaddachi. The permeability of the body surface to outward diffusion of sodium was four times higher in M. finmarchicus, but sodium losses across the body surface represent at least 50% of the total losses in both M. finmarchicus and G. zaddachi. 4. Calculations suggest that G. zaddachi produces urine slightly hypotonic to the blood when acclimatized to the range 20% down to 2% sea water. In fresh water the urine sodium concentration is reduced to a very low level. 5. The process of adaptation to fresh water in gammarid crustaceans is illustrated with reference to a series of species from marine, brackish and freshwater habitats.

Regulation of rectal secretion in saline-water mosquito larvae living in waters of diverse ionic composition

1977 ◽  
Vol 66 (1) ◽  
pp. 83-96 ◽  
Author(s):  
T. J. Bradley ◽  
J. E. Philips
Keyword(s):  
Chemical Composition ◽  
External Medium ◽  
Saline Water ◽  
Ionic Composition ◽  
Malpighian Tubules ◽  
Fluid Composition ◽  
Mosquito Larvae ◽  
Major Site ◽  
Osmotic Concentration ◽  
Anal Papillae

1. Larvae of the saline-water mosquito Aedes campestris were adapted to three waters, all having an osmotic concentration of 700 mOsm, but differing in ionic rations. The (Na+Mg) SO4 medium was much moretoxic than the NAHCO3 or the NaCl media. 2. Ionic and osmotic concentrations of haemolymph and rectal secretion were measured in larvae adapted to all three media. The ratio of ionic concentrations in the rectal secretion reflected those in the external medium to which the larvae had been adapted, with the exception of SO42-, which was possibly replaced by HCO3-in the secretion. These differences in rectal fluid composition persisted even though all ligated recta were bathed in the same artificial haemolymph. 3. The Malpighian tubules were found to be the major site of SO42- excretion. In media containing high levels of NA+, Mg2+, K+, Cl- and HCO3-, the rectum secreted a hyperosmotic fluid containing these ions at concentrations several times greater than those found in the haemolymph. 4. These data provide the basis for speculation on the functioning of anal papillae in waters of diverse chemical composition.

Developmental pattern of hypercapnic and hypoxic ventilatory responses from childhood to adulthood

1994 ◽  
Vol 76 (1) ◽  
pp. 314-320 ◽  
Author(s):  
C. L. Marcus ◽  
W. B. Glomb ◽  
D. J. Basinski ◽  
S. L. Davidson ◽  
T. G. Keens
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Body Size ◽  
Respiratory Rate ◽  
Body Surface ◽  
Vital Capacity ◽  
Developmental Pattern ◽  
Ventilatory Responses ◽  
End Tidal ◽  
Arterial O2 Saturation

The developmental pattern of ventilatory responses, through childhood and puberty into adulthood, is not known. Therefore we studied hypercapnic (HCVR) and hypoxic ventilatory responses (HOVR) in 59 subjects (29 males and 30 females) 4–49 yr of age, of whom 35 were children ( < 18 yr old). There was a significant correlation between HCVR and weight (r = 0.33, P < 0.02), vital capacity (r = 0.30, P < 0.05), and body surface area (r = 0.30, P < 0.05) but not height (r = 0.22, NS). There was no correlation between HOVR and any of the correcting factors. To account for disparities in body size, volume-related results were scaled for body weight. The HCVR corrected for weight (HCVR/WT) decreased with age (r = -0.57, P < 0.001). HCVR/WT was significantly higher in children than in adults (0.056 +/- 0.024 vs. 0.032 +/- 0.015 l.kg-1 x min-1. Torr end-tidal PCO2-1, P < 0.001). The (tidal volume/inspiratory duration)/weight, respiratory rate, and heart rate responses to hypercapnia were increased in the children, and the CO2 threshold was lower (36 +/- 5 vs. 40 +/- 6 Torr, P < 0.05). Similarly, the HOVR corrected for weight (HOVR/WT) decreased with age (r = 0.34, P < 0.05), and HOVR/WT was significantly higher in children than in adults (-0.035 +/- 0.017 vs. -0.024 +/- 0.016 l.kg-1 x min-1.% arterial O2 saturation-1, P < 0.02). The respiratory rate and heart rate responses to hypoxia were increased in the children. We conclude that rebreathing HCVR and HOVR are higher during childhood than during adulthood.

scholarly journals CONTENTS OF MAGNESIUM IN THE ENVIRONMENT AND POPULATION MORBIDITY RATE OF ARTERIAL HYPERTENSION

2019 ◽  
Vol 98 (5) ◽  
pp. 494-497 ◽  
Author(s):  
M. A. Yahyaev ◽  
Shamil K. Salikhov ◽  
S. O. Abdulkadyrova ◽  
A. Sh. Aselderova ◽  
Z. Z. Surkhayeva ◽  
...  
Keyword(s):  
Arterial Hypertension ◽  
Natural Waters ◽  
Medical Information ◽  
Magnesium Deficiency ◽  
Magnesium Content ◽  
Magnesium Concentration ◽  
Morbidity Rate ◽  
Photometric Method ◽  
Number Of Patients ◽  
Water Plants

Introduction. Study of the interrelation between magnesium content in biosphere objects (soil, natural water, plants) with arterial hypertension (AH) incidence among the population living in the territory of the plain Dagestan (Babayurtovsky, Kizlyar, Tarumovsky and Nogai districts of the Republic). material and Methods. To assess the development of hypertension, the data were obtained from the medical information center of the Ministry of Health of Dagestan. Samples of soil, water, plants with the determination of the magnesium content in them were processed by the photometric method in the biogeochemical laboratory of the Prikaspiyskiy Institute of Biology Resources of Daghestan Scientific Centre of the Russian Academy of Sciences. For analyzes, the material was selected in the summer months. The correlation coefficients are calculated by Pearson. Results. When comparing the incidence rates of AH for 2005-2007 with the magnesium content in soils, natural waters, plants, a negative average correlation of magnesium concentration in the study sites with the incidence of AH population was established in the study area. A number of patients in the studied years was also noted to be changing, but the dependence of the incidence of AH of the population on the magnesium content in the biosphere objects is preserved. Conclusions. One of the factors of occurrence and course of hypertension is the magnesium status of the population, which depends on the geochemical features of the territory. As a result of the study, it was found that the higher the magnesium content in biosphere objects, the lower the incidence of AH population. In order to reduce the AH values among the population, it is necessary to correct the lack of magnesium in the human body with magnesium additives, which contribute to the regulation of blood pressure and reduce the risk of cardiovascular diseases. In connection with the possible subclinical magnesium deficiency, an important factor in informing about the possible morbidity of hypertension is information on the magnesium content in environmental objects.

The Exchange of Labelled Sodium in the Larva of Aedes Aegypti L

1954 ◽  
Vol 31 (3) ◽  
pp. 386-401 ◽  
Author(s):  
JOHN E. TREHERNE
Keyword(s):  
Aedes Aegypti ◽  
Body Surface ◽  
External Medium ◽  
Whole Body ◽  
Effect Of Temperature ◽  
Potassium Ions ◽  
Distilled Water ◽  
General Body ◽  
Anal Papillae

1. The exchange of labelled sodium between the external medium and the haemolymph and whole body has been investigated in the larva of Aedes aegypti. The time for half exchange was of the order of 62 hr. 2. It was found that most of the exchange of labelled sodium occurred through the anal papillae, although smaller amounts enter the haemolymph through the gut and general body surface. Transfer constants have been used to describe the resultant turnover of labelled sodium in the whole system. 3. The rate of uptake of sodium was independent of the external concentrations used in these experiments. 4. Potassium ions do not compete with sodium for uptake, which suggests that separate mechanisms are responsible for the accumulation of these two ions. 5. Larvae were able to retain the sodium in the haemolymph, with relatively little loss, in glass-distilled water. 6. The effect of temperature on the rate of uptake of labelled sodium has been investigated.

New formula for predicting standard liver and spleen volumes in Chinese adults

2019 ◽  
Author(s):  
Longbao Yang ◽  
Gang Zhao ◽  
Xinxing Tantai ◽  
Cailan Xiao ◽  
Caifeng Yang ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Body Weight ◽  
Surface Area ◽  
Body Surface Area ◽  
Body Surface ◽  
Liver Volume ◽  
Body Height ◽  
Spleen Volume ◽  
Chinese Adults ◽  
Volume Formula

Abstract BACKGROUNDThe liver volume and spleen volum are useful index for cirrhosis patients with esphageal varices. But the calculation of the volume is time-consuming and boring. To solve the problem, we successfully established the liver and spleen volume formula using the body surface area. We compared the liver volume formula with other four formulas, which be proved with highest accuracy and lowest error. Until now, except for the new spleen volume formula in the research, there are few reports about it.AIMTo obtain a reference range of morphological indices, and to establish a formula to accurately predict the standard liver and spleen volumes in Chinese adults.METHODSComputed tomography was used to calculate the estimated total liver volume and spleen volume of 305 Chinese adults without any diseases which could influence the volumes of these two organs. Gender, age, body height, body weight, body surface area and body mass index were determined. Correlation analysis and step-wise multiple linear regression analysis were performed to evaluate the impact of each parameter on the liver and spleen volumes, and then a formula to predict the liver and spleen volumes was established. Finally, the results obtained with the new liver volume formula with existing formulas in a validation group were compared.RESULTSThe average liver and spleen volume values were 1043.18 ± 244.60 cm3 and 175.07 ± 88.15 cm3, respectively. Age, body height, body weight, body surface area and body mass index were significantly correlated with liver and spleen volume. Body surface area showed the strongest correlation with liver volume and spleen volume( p<0.005 and p<0.001). Based on these results, new formulas to calculate the standard liver volume and standard spleen volume were established.CONCLUSIONSCompared the new liver volume formula with the existing formula, it is found that the new liver volume is more accurate. And the accuracy of the spleen volume formula is acceptable. Core tip: To solve the problem of time-consuming and boring in calculating the liver and spleen volume, we successfully established the liver and spleen volume formula can be used in Chinese adult. Though there are some reports about the liver volume, but it is different in spleen volume. The liver volume and spleen volume radio is an useful index to predict the esophageal varices and bleeding risk for cirrhosis patients. Only liver volume formula is not enough, the finding of the spleen volume is very meaningful.

Efficacy of body weight vs body surface area-based prednisolone regimen in nephrotic syndrome

2020 ◽  
Vol 24 (7) ◽  
pp. 622-629 ◽  
Author(s):  
Biswanath Basu ◽  
Suman Bhattacharyya ◽  
Shilpita Barua ◽  
Abhisek Naskar ◽  
Birendranath Roy
Keyword(s):  
Body Weight ◽  
Nephrotic Syndrome ◽  
Surface Area ◽  
Body Surface Area ◽  
Body Surface

Carbohydrate Metabolism of Hypophysectomized Dogs as Studied With Radioactive Glucose

1956 ◽  
Vol 187 (1) ◽  
pp. 25-31 ◽  
Author(s):  
R. Steele ◽  
J. S. Wall ◽  
R. C. de Bodo ◽  
N. Altszuler
Keyword(s):  
Body Weight ◽  
Carbohydrate Metabolism ◽  
Surface Area ◽  
Body Surface Area ◽  
Body Surface ◽  
Specific Activity ◽  
Constant Infusion ◽  
Minute Period ◽  
Endogenous Glucose ◽  
Low Rate

Minute amounts of uniformly labeled C14 glucose were administered intravenously to unanesthetized normal and hypophysectomized dogs, in the postabsorptive state, as an initial priming injection, followed by a constant infusion. From the observed specific activity of the plasma glucose during the 60–180-minute period of the constant infusion, the following parameters of carbohydrate metabolism were determined: a) the size of the glucose pool, b) the glucose space and c) the rate of turnover of the glucose pool. The rate of total CO2 production was also determined. The rate of total CO2 production, per square meter of body surface area, was found to be less in the hypophysectomized dog than in the normal one. The glucose pool, per kilogram body weight, was found to be smaller in the hypophysectomized dog than in the normal one. The glucose space, expressed as percentage of body weight, was found to be similar in the two types of animals. The rate of turnover of the glucose pool in the hypophysectomized dog, presented as grams glucose per square meter of body surface area per hour, was found to be less in the hypophysectomized dog than in the normal one. The low rate of glucose uptake by the tissues which was observed to prevail in the hypophysectomized dog is believed to reflect an adjustment in the secretion of insulin to conform to the limited availability of endogenous glucose which results from the removal of the pituitary gland.

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