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Biomedical subjects

R Yagil

Publications and source records attributed to R Yagil.

At least 37 records · Page 2Linked to original sources
PubMed1982

Renal involvement following near-drowning in the sea.

1. The metabolic changes in rats following introduction of sea water directly into the stomach were studied. The results were compared with those of a human case report of acute renal failure following swallowing of sea water. 2. In both rats and man, acute renal failure appeared within the first 24 hr. A slight improvement was found five days later. 3. There was an acute hypocalcemia. This was supposedly due to the large magnesium content of the sea water. 4. It is probable that water entering the alimentary canal, dry drowning, affects the kidneys by the initial flow of water to the intestines. This results in hemo-concentration and reduced kidney function. The abnormality is a transient one and could be due to a partial anoxia due to shrinking of the erythrocytes. 5. It is concluded that an apparently uneventful swallowing of sea water can turn into secondary drowning with transient acute renal failure.

Animals↗
PubMed1982

Cooking-smoke as a factor affecting thyroid metabolism and oxygen transport capability.

1. Young Bedouin women found to be prone to illnesses of the thyroid gland and lungs. It was surmised that the cause of both complaints had the same origin: the smoke from cooking over a fire. 2. Laboratory rats were placed in the cooking space in a Bedouin encampment for 2 months. These rats (termed "smoke" animals) were smaller and less active than normal siblings. 3. The smoke animals had increased secretion of thyroid hormones and TSH and the thyroid glands were enlarged, when compared to body weight. 4. Histology of the thyroid showed areas of atrophy, areas of hypertrophy and cysts. There was increased erythropoiesis, allowing for enhanced oxygen transport capability. 5. It is concluded that the smoke, directly, or indirectly by hampering normal lung function, caused a reaction in the thyroid gland, which in turn led to increased production of hemoglobin, probably to guarantee sufficient oxygen for basic cell metabolism.

Animals↗
PubMed1980

Hormonal and behavioural patterns in the male camel (Camelus dromedarius).

Androgen levels in blood and the behaviour of male camels were determined during 1 year. In the months January to April large amounts of androgens were found in blood serum (approximately 30 ng/ml compared with approximately 2 ng/ml throughout the remaining months) as well as in a secretion from glands on the back of the neck (36 ng/ml). During this period when hormone levels were high the behaviour of the camels changed: they became unmanageable, blew-out a palatal flap from the mouth, vocalized, and spread urine over their backs with the aid of their tails. The changes in the sexual cycle of the male camels corresponded with the oestrous period in female camels.

Androgens↗
PubMed1978

25-Hydroxycholecalciferol levels in camel, sheep and goat.

1. The plasma levels of 25-hydroxycholecalciferol were measured in female dromedary camels, female sheep and Sinai desert goats. 2. The camels had levels of 443 +/- 96 ng/ml in summer, and 267 +/- 113 ng/ml in winter. 3. The sheep had levels of 40.7 +/- 9.09 ng/ml in summer and 37.1 +/- 8.82 ng/ml in winter, i.e. roughly the same as man in that region. 4. The goats had lower levels: 23.9 +/- 5.67 ng/ml in summer.

Animals↗
PubMed1978

Response of the renin-aldosterone system in the camel to acute dehydration.

Plasma renin activity (PRA), renin substrate concentration (PRS), aldosterone concentration (PA), and cortisol levels were determined in five camels during dehydration (8-10 days complete denial of water) and at timed intervals after rapid rehydration in cool spring and hot summer weather. Plasma sodium concentration increased from 138 +/- 3.7 to 147 +/- 2.5 (mean +/- SE) meq/l during spring dehydration, and from 146 +/- 1.3 to 157 +/- 1.14 meq/l during dehydration in the summer. Plasma sodium concentration returned to control levels over the course of several hours following rapid rehydration. Only minor changes in plasma potassium concentration occurred. The hormonal changes were accentuated in the summer dehydration. PRA increased slightly on dehydration, and returned to control levels over the course of several hours following rehydration. PA increased slightly on dehydration but was markedly elevated 24 h after rehydration. PRS showed a slight increase following rehydration in the spring experiment, but no significant change in the summer experiment. Changes in cortisol were insignificant. The results are consistent with a role for angiotensin and aldosterone in enhancing sodium and water reabsorption from kidney and large intestine on dehydration in this species.

Aldosterone↗
PubMed1978

Camel thyroid metabolism: effect of season and dehydration.

The thyroid function of normally hydrated and dehydrated camels was examined in winter, spring, and summer. The thyroid was stimulated in summer when water was available, but was inhibited following dehydration. It is concluded that the decline of thyroid function, as gauged by hormone secretion during dehydration in the summer, aids in preservation of body water by decreasing pulmonary water loss and dropping basic metabolism.

Animals↗
PubMed1977

Glucose loading and dehydration in the camel.

Five female bedouin camels were subjected to large infusions of glucose, both when water was readily available and following 10 days of water deprivation. When the camels were hydrated the extra glucose was readily given off in the urine with only a slight increase in blood levels. Following dehydration, the blood glucose levels increased greatly while the urinary excretion was limited. Dehydration led to decreased blood insulin levels, while glucose infusion led to increased levels. The data show that the acclimatization of the camel to dehydration is not only a question of long-term adaption to desert conditions but that even following acute nonphysiological stress, i.e., glucosuria, excess loss of body water was prevented.

Adaptation, Physiological↗
PubMed1976

Uptake of aluminium ion by the liver.

The specific uptake by the rat liver of 28Al was shown. There was specific uptake of 28Al by liver cell nuclei and DNA. This uptake was blocked by prior treatment with stable aluminium. It is concluded that aluminium enters the liver cell by some specific mechanism and that the reaction of aluminium with DNA inside the hepatocyte nucleus could be a mechanism responsible for the development of aluminium-induced experimental porphyria in the rat.

Aluminum↗
PubMed1976

Acid-base changes in milk and blood of rats in acidosis and alkalosis.

Lactating white rats (Rattus norvegicus) were subjected to metabolic and respiratory acidosis and metabolic alkalosis. Before and during the various treatments, the acid-base status of heart blood and milk was determined. Acute metabolic acidosis lowered the pH of plasma and milk; Pco(2) and bicarbonate concentrations in plasma were lowered, and in milk Pco(2) was raised and the bicarbonate concentration remained unchanged. Respiratory acidosis and acetazolamide caused a drop in blood pH and in blood and milk bicarbonate concentrations; milk pH remained unchanged, but Pco(2) was raised in both plasma and milk. Acute metabolic alkalosis raised the blood pH and milk Pco(2); plasma Pco(2) and bicarbonate concentrations in blood and milk remained unchanged. The data show that greater changes occur in acid-base parameters of blood than milk when animals are exposed to acidifying and alkalinizing stimuli.

Acid-Base Equilibrium↗
PubMed1976

Sodium and potassium metabolism in the dehydrated and rehydrated Bedouin camel.

The effects of 10 days dehydration and rapid rehydration on the sodium and potassium metabolism in the one-humped camel were examined. The research was carried out during two periods in the summer, a cool and a hot period. In the hot period the effects of dehydration were found to be more severe. The potassium metabolism was more affected than that of the sodium. The concentrations of potassium in the urine declined while those of sodium increased. There were also marked changes in the filtered loads, excreted loads, and reabsorption of the two cations. Following rehydration significant changes in the cation metabolism were recorded within 15-45 min. It is suggested that antidiuretic hormone and not aldosterone caused the changes in the two-cation metabolism.

Animals↗
PubMed1976

Hemoconcentration and erythrocyte fragility in chickens exposed to heat and dehydration.

Chickens were exposed to heat and dehydration, and the effects on their erythrocytes were examined. As chicken and camel (Camelus dromedarius) erythrocytes are of similar shape, the erythrocytes of the exposed chickens were compared with those of the camel. The salient findings were that chickens kept at 35 C without drinking water remained visibly unaffected. Their blood, however, showed hemoconcentration and increased erythrocyte osmotic fragility. Hemoconcentration could lead to an increase in body temperature of chickens in increased environmental temperatures.

Animals↗
PubMed1976

Changes in rat milk quantity and quality due to variations in litter size and high ambient temperature.

The effects of variations in suckling stimulus (changes in letter size) and exposure to high ambient temperatures on the quality and quantity of rat's milk and mammary tissue structure were determined. By increasing the number of suckling pups per dam, it was found that the amount of milk produced by the animals was proportionally increased, as each pup was able to drink the same amount of milk per day. With more than 6 pups per litter, the quality of the milk was not significanly changed. Smaller letters led to changes in the amount of milk suckled per milking and to considerable changes in the content of the milk. Exposure to high ambient temperatures, although for only 8 hr per day, drastically affected the amount of milk produced by the lactating rat as well as the quality of the milk produced. Microscopic examination of mammary tissue revealed changes in the alveolar area and height of the alveolar cells as the suckling stimulus varied. After heat exposure the gland changed to one of diminished synthesizing capability. It was concluded that 10-pup litters are the optimal litter size for research concerning rat milk, and the exposure to high ambient temperatures affects the milk yield by directly affecting the alveolae.

Animals↗
PubMed1975

Acid-base parameters in the dehydrated camel.

The effect of prolonged (10 days) dehydration on acid-base parameters of camel blood was examined. The pH and PCO2 levels rose significantly in the course of dehydration. This state was comparable with compensated non-respiratory alkalosis found in other animals. The plasma sodium, and magnesium levels rose significantly also. The plasma oxygen and calcium levels declined significantly. There were no significant changes in potassium and phosphate levels. It is concluded that the changes found in acid-base status following dehydration are further evidence of water preservation mechanisms in the dehydrated camel.

Acid-Base Equilibrium↗