THE EFFECT OF PREVIOUS EXPOSURE TO COLD ON SHOCK SECONDARY TO LIMB ISCHAEMIA

1959 ◽  
Vol 37 (1) ◽  
pp. 211-223
Author(s):  
H. Schachter ◽  
S. Sidlofsky ◽  
D. G. Baker ◽  
J. R. Hamilton ◽  
R. E. Haist
Keyword(s):  
Oxygen Consumption ◽  
Survival Time ◽  
The Body ◽  
Limb Ischaemia ◽  
Cold Environment ◽  
Previous Exposure ◽  
Survival Times ◽  
Exposure To Cold ◽  
Colonic Temperature ◽  
And Control

Previous exposure to a cold environment for a period of 12 weeks increased the incidence of survival and prolonged the survival time of heavy rats shocked by a clamping technique. The oxygen consumption at 27 °C in rats previously exposed to cold for 12 weeks was elevated. During the clamping period the oxygen consumption became more nearly the same in the cold-acclimatized and control rats. After release of the clamps there was a slower fall in oxygen consumption in the previously cold-acclimatized rats than in the control animals. The body temperature, measured in the colon, fell more slowly in the previously cold-exposed rats than in the control rats. This slower fall in colonic temperature was found also in rats previously exposed to cold for shorter periods and was not necessarily associated with changes in survival time. Rats exposed to cold for 6 weeks were "acclimatized" in the sense that they withstood exposure to cold after removal of their fur, but they failed to show significantly lengthened survival times when shocked by this clamping procedure. The administration of thyroxine shortened survival times in the shocked rats but reduced the rate of fall of colonic temperature. The administration of cortisone, thyroxine, and cortisone plus thyroxine shortened survival times in the shocked rats.

THE EFFECT OF PREVIOUS EXPOSURE TO COLD ON SHOCK SECONDARY TO LIMB ISCHAEMIA

1959 ◽  
Vol 37 (2) ◽  
pp. 211-223 ◽  
Author(s):  
H. Schachter ◽  
S. Sidlofsky ◽  
D. G. Baker ◽  
J. R. Hamilton ◽  
R. E. Haist
Keyword(s):  
Oxygen Consumption ◽  
Survival Time ◽  
The Body ◽  
Limb Ischaemia ◽  
Cold Environment ◽  
Previous Exposure ◽  
Survival Times ◽  
Exposure To Cold ◽  
Colonic Temperature ◽  
And Control

Previous exposure to a cold environment for a period of 12 weeks increased the incidence of survival and prolonged the survival time of heavy rats shocked by a clamping technique. The oxygen consumption at 27 °C in rats previously exposed to cold for 12 weeks was elevated. During the clamping period the oxygen consumption became more nearly the same in the cold-acclimatized and control rats. After release of the clamps there was a slower fall in oxygen consumption in the previously cold-acclimatized rats than in the control animals. The body temperature, measured in the colon, fell more slowly in the previously cold-exposed rats than in the control rats. This slower fall in colonic temperature was found also in rats previously exposed to cold for shorter periods and was not necessarily associated with changes in survival time. Rats exposed to cold for 6 weeks were "acclimatized" in the sense that they withstood exposure to cold after removal of their fur, but they failed to show significantly lengthened survival times when shocked by this clamping procedure. The administration of thyroxine shortened survival times in the shocked rats but reduced the rate of fall of colonic temperature. The administration of cortisone, thyroxine, and cortisone plus thyroxine shortened survival times in the shocked rats.

Effects of pentobarbital on temperature and heart rate of rats subjected to cold

1962 ◽  
Vol 203 (4) ◽  
pp. 758-761 ◽  
Author(s):  
C. L. Gemmill ◽  
K. M. Browning
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Standard Dose ◽  
The Body ◽  
Sodium Pentobarbital ◽  
Previous Exposure ◽  
Exposure To Cold ◽  
Before And After

A study at 5 C was made of body temperature and heart rate after a standard dose of sodium pentobarbital in normal, thyroidectomized, and hypermetabolic rats before and after subjection to 5 C for 46 hr. It was found that after subjection to cold in the normal rats, the body temperature and heart rate in some animals had more ability to recover after the barbiturate than in rats without previous exposure to cold. There was no ability to recover in the thyroidectomized animals either before or after subjection to cold. Most of the normal and thyroidectomized rats either with or without previous exposure to cold given sodium 3,3',5-l-triiodothyronine (T-3) had recoveries after the barbiturate. Some rats given T-3 and subjected to cold had a primary fall in temperature and heart rate that was followed by recovery and then a secondary fall.

The effects of acids on a soil nematode

Parasitology ◽  
1945 ◽  
Vol 36 (3-4) ◽  
pp. 158-164 ◽  
Author(s):  
William Stephenson
Keyword(s):  
Organic Acids ◽  
Survival Time ◽  
Molecular Size ◽  
Great Variability ◽  
The Body ◽  
Anterior Region ◽  
Soil Nematode ◽  
Survival Times ◽  
Acid Media ◽  
Mineral Acids

1. The effects of the following acids were studied: hydrochloric, nitric, sulphuric, formic, acetic, propionic, butyric, isovaleric, glycollic, lactic, oxalic, malonic, succinic, malic, tartaric, and citric.2. The general effects of immersion in acid media include an increased stickiness of the cuticle in certain solutions, and the development of lateral bulges in the cuticle at the anterior region of the body, not necessarily in the same solutions. Movement gradually decreases, and death eventually occurs, often followed by swelling.3. The survival times in various solutions were noted. Preliminary experiments showed that the logarithm of the survival time was approximately proportional to the logarithm of the normality of the acid. Later results showed great variability, and it was necessary to restrict the work to a single normality of each acid.4. The toxicities of 0·206 N solutions of the sixteen acids were measured. These results showed that the mineral acids had markedly greater effects than the organic acids, and the importance of the former was further illustrated by using mixtures of HCl containing varying amounts of organic acids. The differences between the mineral acids may be explained by the lyotropic effects of the anions.5. Equal normalities of organic acids were made up in a solution of HCl sufficiently strong to render the organic acids almost entirely undissociated. The relative toxicities of the mixtures were essentially the same as those of the dissociated acids.6. The differences between the acids are thus partly due to the pH differences, and partly due to the dissimilar effects of the undissociated acids. The latter are believed to be due to a variety of causes, including molecular size, polarity of the molecule, and other factors as yet undecided.

The Haemostatic Mechanism and Menstruation: The Role of Intra-Uterine Contraceptive Devices

1979 ◽  
Vol 42 (05) ◽  
pp. 1548-1556 ◽  
Author(s):  
S M Rajah ◽  
M E Foley ◽  
J K Clayton ◽  
S R Aparicio ◽  
C C Bird ◽  
...  
Keyword(s):  
Survival Time ◽  
Survival Times ◽  
Platelet Function Tests ◽  
Control Groups ◽  
Contraceptive Devices ◽  
Platelet Survival ◽  
Before And After ◽  
And Control ◽  
Platelet Functions

SummaryThe haemostatic mechanism of 40 female patients undergoing menstruation, 20 with intra-uterine devices (IUCD) and 20 without (Control), were studied. The patients’ coagulation profiles, fibrinolytic system and platelet functions were studied before and after hysterectomy. Platelet survival times and platelet consumption was determined using 51Cr. labelled autologous platelets. Patients who menstruated during the study had their pads collected and radioactivity measured. Histology, autoradiography and scintillation counting was performed on uteri obtained from a hysterectomy performed towards the end of the platelet survival study period. There were no significant differences in the coagulation, fibrinolytic and platelet function tests in these 2 groups, though in each group there were the expected changes after operation.Platelet survival time, consumption and radioactivity in the tampons showed no significant differences between the IUCD and control groups, although there were 6 patients with low platelet survival times in the IUCD group. Resected uteri showed surprising lack of concentration of platelets which may have been due in part to loss of blood at operation and handling of the uterus. Surprisingly, in the control patients, platelet survival time in response to the severe haemosatic challenge of menstruation were normal. However in the IUCD group, 6 patients showed shortening of platelet survival. Also surprisingly and equally in both control and IUCD groups, was the small amount of platelet related radioactivity in the menstruating fluid.

EFFECT OF COLD ON RATS CHRONICALLY EXPOSED TO MALATHION

1962 ◽  
Vol 40 (1) ◽  
pp. 1671-1676 ◽  
Author(s):  
A. V. Marton ◽  
E. A. Sellers ◽  
W. Kalow
Keyword(s):  
Oxygen Consumption ◽  
Wistar Rats ◽  
Initial Period ◽  
High Rate ◽  
Cold Environment ◽  
Body Temperatures ◽  
Control Groups ◽  
Normal Appearance ◽  
Daily Diet ◽  
And Control

Wistar rats received 4000 p.p.m. of malathion in their daily diet without showing evidence of intoxication (normal appearance, growth, food intake). When the animals were clipped and exposed to an ambient temperature of 1.5 °C they survived for a much shorter period in the cold environment than did control animals not receiving malathion. In both experimental and control groups, deaths occurred when body temperatures had dropped to about 18 °C. During the initial period in the cold environment, animals of both groups were able to increase their oxygen consumption to the same extent. There was no indication of an increased heat loss by the malathion-treated rats. It thus appeared likely that the insecticide decreased the ability of rats to produce heat continuously over a prolonged period at a high rate. The activities of cholinesterase in plasma were reduced in the malathion-treated rats but were not affected by the cold stress.

EFFECT OF COLD ON RATS CHRONICALLY EXPOSED TO MALATHION

1962 ◽  
Vol 40 (12) ◽  
pp. 1671-1676 ◽  
Author(s):  
A. V. Marton ◽  
E. A. Sellers ◽  
W. Kalow
Keyword(s):  
Oxygen Consumption ◽  
Wistar Rats ◽  
Initial Period ◽  
High Rate ◽  
Cold Environment ◽  
Body Temperatures ◽  
Control Groups ◽  
Normal Appearance ◽  
Daily Diet ◽  
And Control

Wistar rats received 4000 p.p.m. of malathion in their daily diet without showing evidence of intoxication (normal appearance, growth, food intake). When the animals were clipped and exposed to an ambient temperature of 1.5 °C they survived for a much shorter period in the cold environment than did control animals not receiving malathion. In both experimental and control groups, deaths occurred when body temperatures had dropped to about 18 °C. During the initial period in the cold environment, animals of both groups were able to increase their oxygen consumption to the same extent. There was no indication of an increased heat loss by the malathion-treated rats. It thus appeared likely that the insecticide decreased the ability of rats to produce heat continuously over a prolonged period at a high rate. The activities of cholinesterase in plasma were reduced in the malathion-treated rats but were not affected by the cold stress.

Cerebral Energy Requirement of Neonatal Rats

1957 ◽  
Vol 188 (2) ◽  
pp. 277-280 ◽  
Author(s):  
Frederick E. Samson ◽  
Nancy A. Dahl
Keyword(s):  
Body Temperature ◽  
Survival Time ◽  
Energy Requirement ◽  
Iodoacetic Acid ◽  
The Body ◽  
Effect Of Temperature ◽  
Neonatal Rats ◽  
Survival Times ◽  
Respiratory Centers ◽  
Respiratory Movements

The survival times of neonatal rats in nitrogen with and without injected iodoacetic acid and at diverse ages and temperatures are presented. It is shown that the survival time in nitrogen is greatly shortened if iodoacetic acid has been injected. Also, in iodoacetic acid treated rats the survival time is decreased with the daily development of the animal; the survival time is lengthened by a decrease in body temperature; the effect of temperature decreases with the daily development of the animal; the logarithm of the survival time has a linear relationship with the body temperature. It is concluded that these survival times are a measure of the energy requirement of the respiratory centers and the influence of age and temperature upon the requirement. A calculation is made which indicates that a deficiency of one micromole of energy-rich phosphate per gram of tissue in the respiratory centers results in the cessation of respiratory movements.

THE ACTION OF THYROID HORMONES ON THE OXYGEN CONSUMPTION AND RESISTANCE TO COLD OF ADRENALECTOMIZED AND THYROIDECTOMIZED-ADRENALECTOMIZED MICE

1958 ◽  
Vol 16 (4) ◽  
pp. 396-402 ◽  
Author(s):  
S. N. GANJU ◽  
MARY F. LOCKETT
Keyword(s):  
Oxygen Consumption ◽  
Thyroid Gland ◽  
Oxygen Uptake ◽  
Thyroid Hormones ◽  
Survival Time ◽  
Survival Times ◽  
Thyroid Medication ◽  
Do So

SUMMARY The effect of thyroid medication on the oxygen uptake and resistance to cold of normal, adrenalectomized (adx) and thyroidectomized-adrenalectomized (thyx-adx) mice was studied. All adx animals were maintained on salt. 1. 3–12 mg dried thyroid gland or 2·5 μg l-thyroxine, given daily for 7 days, prolonged the survival times of adx and thyx-adx mice in cold. 24 mg, however, decreased survival time. 2. 3–6 mg dried thyroid gland given daily for 6 days raised the oxygen uptake of both normal and thyroidectomized (thyx) but not of adx mice. 3. 10 μg l-thyroxine given daily for 14 days increased the oxygen uptake of adx mice, but 40 μg failed to do so in mice which were also thyx.

scholarly journals Factors affecting time until myocardial infarction in hypertension patients using truncated Cox regression

2019 ◽  
Vol 21 (4) ◽  
pp. 169-174
Author(s):  
Abolfazl Hosseinnataj ◽  
Jamshid Yazdani-Charati ◽  
Hossein Mohsenipouya ◽  
Ali Ghaemian ◽  
Roja Nikaein ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cox Regression ◽  
The Body ◽  
Survival Times ◽  
Statistical Population ◽  
Factors Affecting ◽  
Akaike Criterion ◽  
Cox's Model ◽  
And Control ◽  
First Time

Background and aims: Hypertension is one of the most common and important risk factors of cardiovascular diseases. This phenomenon, if not cured, causes lots of problems in vital organs of the body like kidneys, brain, eyes, and heart. The aim of the current study was to identify factors which affect the time until myocardial infarction (MI) in hypertension patients using truncated Cox regression. Methods: This study was a population retrospective cohort and its statistical population included patients with hypertension symptoms, who had MI for the first time in Sari. A decision was made based on continuing the study as a nested case and control study because the number of MI incidents was low (7%) in the studied sample. In addition, the Cox’s model and truncated Cox were used for determining the factors affecting the patients’ survival. Results: The median and mean survival times in this sample were equal to 57 and 66.44 months, respectively. Considering time truncation, family history (HR=1.70) and the age at diagnosis (HR=0.99) were statistically significant in the Cox’s model (P< 0.05). Conclusion: Overall, using the Akaike criterion for comparing the survival time without the effect of truncation, the Cox’s model demonstrated better fitness by controlling the truncation effect. These results show the importance of controlling the truncation in those diseases in which it is impossible to distinguish the time of the appearance from the symptoms.

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