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1.
1. The blood cholesterol of rabbits on a normal diet without added cholesterol is increased only slightly (19 per cent) by thyroidectomy. 2. In rabbits with a hypercholesterolemia due to long continued cholesterol feeding, thyroidectomy causes a marked rise (137 per cent) in the blood cholesterol. This rise is usually maintained. 3. When long continued cholesterol feeding has failed to cause a rise in the blood cholesterol of rabbits, thyroidectomy abolishes this resistance and a hypercholesterolemia is promptly produced. 4. A single injection of thyroxin causes a significant drop in the blood cholesterol of rabbits with hypercholesterolemia. This reaction is not influenced by thyroidectomy. 5. Potassium iodide causes an increase in the blood cholesterol of rabbits with hypercholesterolemia. This reaction is not influenced by thyroidectomy in contrast to the effect of KI in preventing a rise in blood cholesterol when given concurrently from the beginning of cholesterol feeding, an effect which is abolished by thyroidectomy. It is suggested that two different mechanisms are involved. 6. A single injection of insulin produces a fall in the blood cholesterol of rabbits with hypercholesterolemia. If anything, thyroidectomy increases the magnitude of this effect.  相似文献   

2.
In summary, evidence has been presented to show a direct connection other than through the capillaries between the coronary arteries and the chambers of the heart. This connection was shown by perfusion, injections and serial sections to be through the Thebesian veins. Communications between the larger coronary veins and the Thebesian veins were also demonstrated by the same methods. Serial sections through Thebesian veins have shown capillaries draining directly into them. Under certain conditions it has been shown that as much as 90 per cent of the arterial flow may escape via the Thebesian vessels. Lastly, in the event of gradual closure of the orifices of the coronary arteries, the Thebesian vessels can supply the heart muscle with sufficient blood to enable it to maintain an efficient circulation.  相似文献   

3.
A sample of 209 volunteer Kuwaiti undergraduates responded to an Arabic version of the Revised Collett–Lester Fear of Death Scale with 4 subscales: Death of Self, Dying of Self, Death of Others, and Dying of Others. Reliabilities of the 4 subscales and of the grand total score ranged from 0.75 to 0.92, which is considered adequate. A 4-factor solution was congruent with the allocation of items to 2 subscales (i.e. Dying of Self and Death of Others), whereas the theorized factor structure of the other 2 subscales were only partially supported by empirical analyses. The intercorrelations between the 4 total subscale scores yielded a general factor of death and dying, denoting good factorial validity of the scale.  相似文献   

4.
5.
It is the opinion of Bull, that the streptococci recovered from poliomyelitic tissues, while having no etiological or pathological relationship to the virus of poliomyelitis, occur as secondary invaders in the disease. Smillie and Amoss indicated that the bacteria may be agonal invaders. The results of the experiments reported in this paper point to another source of the streptococci. They occur as contaminants which are introduced into the cultures during the process of grinding tissues. The source of the streptococcus may therefore be the air of the place in which the cultures are made. We have come to this conclusion because first, the tissues of which cultures yielded streptococci were derived from a number of monkeys with experimental poliomyelitis still in a vigorous state. Secondly, when the tissues were ground bacteria were noted much more frequently in their cultures than in those in which fragments of the same brains were used. Thirdly, microorganisms occurred more often in cultures made in the routine laboratory than in a special room where asepsis was carried to the extreme of a major surgical operation on man. Fourthly, streptococci were obtained from the air of the places where cultures were made. Finally, there is no correlation between the cultures of two portions of the same brain. The streptococci occurred in some cultures in pure growth and in others admixed with other ordinary species of bacteria. The latter were often found, in turn, in pure culture and what applies to streptococci, as mentioned in the preceding paragraph, applies equally to the staphylococci, diphtheroids, spore-bearing rods, and other miscellaneous, familiar microorganisms. We could not determine that there exists any etiological relation of the streptococci to poliomyelitis. The fermentation reactions of the microorganisms obtained from the air, from non-poliomyelitic and poliomyelitic monkey brains indicate that bacteria from any of these sources are markedly different. So also with the serological reactions of agglutination and precipitation. Furthermore no agglutination was observed when the serum of monkeys convalescent from experimental poliomyelitis was mixed with any of the streptococci recovered or those received directly or indirectly from Rosenow. Moreover, the intracerebral injection with cultures, irrespective of their source, induced in rabbits a purulent type of meningoencephalitis, often associated with streptococcic septicemia. This result is at marked variance with any known effects of the true filtrable virus of poliomyelitis in man and in the monkey.  相似文献   

6.
7.
1. The serum of rabbits treated intravenously with neosalvarsan, and of syphilitic patients treated intravenously with salvarsan or neosalvarsan, has a definite spirochæticidal action upon Spirochœta duttoni. 2. Although this spirochæticidal action is exerted in vitro, it can be demonstrated only after the treated spirochætæ are injected into susceptible animals. 3. A curative action of the serum of neosalvarsan-treated rabbits is exercised on mice infected with Spirochœta duttoni. 4. The spirochæticidal action of the serum of salvarsan-treated rabbits and patients is markedly increased by heating at 56° C. for thirty minutes. 5. The increased spirochæticidal action produced by heating is due in part to the destruction of some inhibitory substance contained in normal serum and in part to a direct effect of the heat upon the serum and salvarsan mixture. 6. Cerebrospinal fluid does not contain the inhibitory substance present in normal unheated serum.  相似文献   

8.

Background and Purpose:

The potential adverse effects of static stretching on athletic performance are well documented, but still appears to be controversial, especially as they relates to sprinting. The prevalence of this practice is demonstrated by the number of competitive and recreational athletes who regularly engage in stretching immediately prior to sprinting with the mindset of optimizing their performance. The purpose of this study was to examine the effects of acute static, dynamic, and ballistic stretching, and no stretching of the iliopsoas muscle on 40‐yard sprint times in 18‐37 year‐old non‐competitive, recreational runners.

Methods:

Twenty‐five healthy recreational runners (16 male and 9 female) between the ages of 24 and 35 (Mean = 26.76 yrs., SD = 2.42 yrs.) completed this study. A repeated measures design was used, which consisted of running a 40‐yard sprint trial immediately following each of 4 different stretching conditions aimed at the iliopsoas muscle and lasting 1 minute each. The 4 conditions were completed in a randomized order within a 2‐week time period, allowing 48‐72 hours between each condition. Prior to each 40‐yard sprint trial, a 5‐minute walking warm‐up was performed at 3.5 mph on a treadmill. The subject then ran a baseline 40‐yard sprint. After a 10‐minute self‐paced walk, each subject performed one of the 4 stretching conditions (ballistic, dynamic, static, and no stretch) and then immediately ran a timed 40‐yard sprint.

Results:

There was a significant interaction between stretching conditions and their effects on sprint times, F(3,72) = 9.422, p<.0005. To break down this interaction, simple main effects were performed with 2 repeated measures ANOVAs and 4 paired t‐tests using a Bonferroni corrected alpha (α = .0083). There were no significant differences between the 4 pre‐condition times, p = 0.103 (Greenhouse‐Geisser) or the post‐condition times, p = 0.029. In the no stretch condition, subjects improved significantly from pre‐ to post‐ sprint times (p<0.0005). There were no statistically significant differences in pre‐ and post‐stretch condition sprint times among the static (p = 0.804), ballistic (p = 0.217), and dynamic (p = 0.022) stretching conditions.

Conclusions:

Sprint performance may show greatest improvement without stretching and through the use of a walking generalized warmup on a treadmill. These findings have clinically meaningful implications for runners who include iliopsoas muscle stretching as a component of the warm‐up.

Level of Evidence:

Level 2  相似文献   

9.
Aëdes aegypti have been shown to be capable of multiplying the Asibi strain of yellow fever virus in their bodies. Following the ingestion of infected blood, the content of virus falls for several days, reaching a minimum during the 1st week. It then increases rapidly until quantities of virus greater than those previously encountered can be demonstrated. The actual final amount of virus demonstrable, however, is subject to variations of which we know little.  相似文献   

10.
1. Following massive doses of India ink injected intravenously into guinea pigs before a subcutaneous injection of diphtheria toxin-antitoxin mixture, no antitoxin was found in the blood serum for 3 weeks, as indicated by intracutaneous tests, whereas an appreciable amount could be detected in non-blocked, immunized control animals. 2. During the 4th week following immunization, the titer of the serum of blocked animals equaled that of non-blocked controls within the limits of the intracutaneous test dose. 3. The smaller doses of India ink used in these experiments, given before immunization, had no stimulating effect on the production of diphtheria antitoxin but, on the contrary, also inhibited the appearance of this antibody, although to a less extent.  相似文献   

11.
1. Blockade of the reticulo-endothelial system by means of a single injection of India ink caused a marked retention of neoarsphenamine in the blood of guinea pigs during the first twenty minutes of observation after intravenous injection, as contrasted with the rapid disappearance of the drug from the blood of normal controls. 2. Rabbits blocked by a single dose of India ink showed a slower elimination of the drug from the circulation following the first few hours after intravenous injection than corresponding controls. 3. The arsenic content of the liver of mice, which received neoarsphenamine intravenously after a preceding blocking injection with India ink, was appreciably lower than the arsenic content of the normal organ under similar experimental conditions.  相似文献   

12.
The effect of alcohol ingestion upon the development of naturally occurring and stilbestrol-induced arteriosclerosis was studied in the domestic fowl. In two experiments, a 15 per cent ethyl alcohol solution was used for drinking purposes, and in a third experiment wine containing 12 per cent of it was administered. The caloric intake of both food and alcohol was carefully controlled by pair-feeding, a glucose solution being used for drinking purposes to equalize the caloric intakes of the control birds with those of the alcohol-treated birds. A total of 224 cockrels was studied, and the period of observation for each experiment lasted 12 months. The degree of arteriosclerosis in the thoracic and abdominal aortas was determined in the gross and microscopically, and the degree of lipide infiltration was determined microscopically. The gross grading of arteriosclerotic lesions agreed closely with the microscopic analysis of intimal thickening and lipide infiltration of the arterial wall. The gross gradings were subjected to a critical statistical analysis which allowed precise statements to be made on the probability that a real effect would be overlooked. This analysis yielded no evidence that alcohol or the wine used had affected the degree of gross arteriosclerosis or lipide infiltration.  相似文献   

13.
DAVID LESTER 《Death Studies》2013,37(8):795-798
In a study of 144 college students, the factorial structure of the Collett–Lester Fear of Death Scale matched the face content of the subscales quite closely, ameliorating the criticism of the scale by R. A. Neimeyer et al. (2003) Neimeyer, R. A., Moser, R. P. and Wittkowski, J. 2003. Assessing attitudes toward dying and death. Omega, 47: 4576. [Web of Science ®] [Google Scholar].  相似文献   

14.
By a study of the enzymes contained in fibrinous exudates produced by injection of a sterile inflammatory irritant (turpentine) conditions have been found in which each of two enzymes occurs alone. The one, leucoprotease, digests in the presence of alkali; the other, resembling lymphoprotease, digests in the presence of acid, yet both exhibit almost maximum activity in an approximately neutral medium. It is probable that both enzymes, in the body, exert their greatest activity in an approximately neutral medium, slight changes in reaction increasing digestion by the one, and suspending digestion by the other. The enzyme digesting in acid, present in the fibrinous exudate obtained after a single injection of turpentine, disappears when repeated injection of the same irritant transforms the sero-fibrinous into a purulent exudate, and causes accumulation of leucoprotease in great quantity.  相似文献   

15.
1. Pulmonary consolidation may be produced in normal mice by the inhalation of Friedländer''s bacillus or Streptococcus hæmolylicus. 2. The initial lesion is in both instances interstitial in character and the spread is by way of the interstitial tissue, though the ultimate consolidation may come to resemble in the gross a lobar pneumonia. 3. The lesions grossly and microscopically may be distinguished from the lobar consolidation associated with pneumococcus infection of the lung. 4. Friedländer''s bacillus and Streptococcus hæmolyticus give rise to pneumonia in mice previously normal, whereas the pneumococcus produces pulmonary lesions only under special circumstances, as when the animals are alcoholized after partial immunization.  相似文献   

16.
We conclude therefore that this series of eleven lactose-negative organisms of the Friedländer type, grouped together by Perkins on the basis of fermentation reactions represents a single biological group. It can be distinguished from Bacillus aerogenes and other similar bacilli by cultural, fermentative, and serological reactions. There appears to be a close analogy between this group and Pneumococcus mucosus in the possession of a fixed cultural type, and the behavior toward immune serum. Both represent apparently a single biological group. Unfortunately no immune sera have been developed against the two strains that grew in moist and dry phases; it is possible that with immune sera for these light could be thrown on the relation suggested by Fitzgerald that the capsulated bacilli represent a parasitic development of the Bacillus coli group.  相似文献   

17.
By the suppression, through anaerobiosis, of the exotoxin-producing activity of Bacillus dysenteriæ Shiga a pure endotoxin is produced directly from the culture. The duality of the poison of Shiga bacillus is further substantiated by studies on the diffusion of exotoxin, or neurotoxin, and endotoxin, or enterotoxin, by means of collodion sacs, implanted intraabdominally in rabbits or placed in vitro.  相似文献   

18.
The leucocytes of the blood of normal individuals and of patients showing a marked polymorphonuclear leucocytosis contain enzymes capable of digesting coagulated blood serum in neutral, alkaline or acid solutions. The cells in pus that is composed principally of polymorphonuclear leucocytes and the leucocytes of the circulating blood in myelogeneous leukæmia contain similar proteolytic enzymes, which act best when the reaction is alkaline. The leucocytes of the circulating blood and of the enlarged lymph nodes from a case of large cell, acute, lymphatic leukæmia contain proteolytic enzymes that act qualitatively in much the same way as the leucocytes of pus and as the white corpuscles of the blood in myelogenous leukæmia. These large lymphocytes in acute lymphatic leukæmia can be differentiated biologically from the small lymphocytes in chronic lymphatic leukæmia which possess no proteolytic enzymes, and from the large endothelioid cells of the hyperplastic lymph glands which are proteolytic only in the presence of acid. These results seem to show that the large cells of the so-called acute lymphatic leukæmia are not true lymphocytes, but are nearly related to the granular myelocytes and should probably be considered as the forerunners to these cells.  相似文献   

19.
The development or ripening of the oocyst of the coccidium of the rabbit is prevented by acridine hydrochloride provided that the cysts are exposed to the action of the chemical before development has started. After sporoblasts are formed acridine does not prevent further development. Many other substances, some of them known to be active against certain protozoan parasites, have no influence on the ripening of the oocysts of the coccidium.  相似文献   

20.
1. The importance of the leucocyte in the resistance of animals to experimental pneumonia is emphasized by the fact that animals treated with benzol, a leucotoxic substance, rapidly succumb to the disease, while animals treated in like manner with toluol, a very similar chemical substance causing no leucopenia, show no decreased resistance. 2. The rôle of the leucocyte in the resistance of animals to experimental pneumonia is further emphasized by the fact that animals that respond to the pneumococcus infection with a leucocytosis, as occurs after the repeated injection of toluol, are more resistant to the pneumonia. Further, the hyperleucocytosis produced by repeated injection of nutrose before the production of pneumonia likewise seems to increase the resistance of the animals. 3. Experimental pneumonia is not necessarily fatal in rabbits. The factors determining the outcome of the disease are numerous; among these is the number of bacteria inoculated. Animals receiving small doses usually survive, while those receiving comparatively large numbers usually succumb.  相似文献   

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