bluuebunny/crossref_metadata_2025_split huggingface dataset:
SEX DIFFERENCES IN LENGTH OF GESTATION IN MAMMALS
Authors: McKEOWN THOMAS , MacMAHON BRIAN 
Published: December 2008

Observations on length of gestation of males and females are presented for man, the guinea-pig, sheep, pig and rabbit; from the literature, data are also available for the cow, horse, camel and goat. Pregnancy is longer for males than for females in the cow, horse and possibly the sheep and camel; it is longer for females than for males in man and possibly the guinea-pig. No definite conclusion is reached about the pig and rabbit, in which litter-size is normally large, or about the goat, in which the number of observations on record is small. The sex differences in length of gestation are reflected in the sex ratios of offspring born after different periods of gestation, and in the percentage distribution of the sexes by duration of gestation.
The difference in length of gestation can be attributed to a sex difference in foetal weight in man, but not in the guinea-pig or in species such as the cow, in which gestation is longer for males than for females. It is suggested that in the cow the longer male gestation may be due to the fact that the proportion of males conceived is higher if mating takes place early, rather than late, in heat. (The only alternative explanation is a sex difference, attributable to something other than weight of foetus, in the period between fertilization and birth.) In man the earlier birth of males is apparently due to their greater weight, attributable wholly or in part to a sex difference in rate of prenatal growth. This observation does not exclude the possibility that in man, as in the cow, the proportion of males conceived is higher if mating occurs early in the cycle, since the method of recording length of gestation (from onset of menstruation) gives no information about time of mating.
CHANGES IN THE BASOPHIL CELLS OF THE RAT PITUITARY AFTER THYROIDECTOMY
Authors: PURVES H. D. , GRIESBACH W. E. 
Published: December 2008

SUMMARY
The basophil cells of the rat pituitary may be differentiated into three specific types—thyrotrophs, FSH gonadotrophs, and LH gonadotrophs. These types are considered to secrete the thyrotrophic, follicle-stimulating and luteinizing hormones, respectively. The glycoprotein granules of the thyrotrophs differ from those of the other types in being strongly stained by aldehyde-fuchsin.
After thyroidectomy the thyrotrophs are almost completely degranulated within 2 days. The degranulated cells thereafter enlarge and can be recognized as early thyroidectomy cells by the 6th day.
After thyroxine deficiency, lasting 2 weeks or longer, the thyroidectomy cells contain coarse dense granules ('T' granules) which give an intense reaction with the periodic acid-Schiff reagent for carbohydrate. These 'T' granules are different from the 'normal' granules and are apparently not related to the thyrotrophic hormone. In mild thyroxine deficiency produced by iodothiouracil administration, thyrotrophs are observed with 'normal' granules and also 'T' granules of the kind seen in thyroidectomy cells. This observation provides additional evidence that thyroidectomy cells are modified thyrotrophs.
THE LEVEL OF ADRENOCORTICOTROPHIN IN THE PLASMA OF NORMAL AND ADRENALECTOMIZED RATS
Authors: BARRETT A. M. , HODGES J. R. 
Published: December 2008

SUMMARY
The concentration of ACTH in the plasma of both normal and adrenalectomized rats appears to be less than 5 milliunits/100 ml.
The results suggest, but do not prove, that the levels of adrenocorticotrophin were identical in the two groups of animals.
CHANGES IN THE EXCRETION PATTERN OF NEUTRAL 17-KETOSTEROIDS DURING OESTROGEN ADMINISTRATION TO MALE SUBJECTS
Authors: HALKERSTON I. D. K. , HILLMAN JANET , PALMER D. , RUNDLE A. 
Published: December 2008

SUMMARY
Changes are described in the excretion pattern of some neutral 17-ketosteroid substances during the administration of oestrogen to male subjects.
The total output of 17-ketosteroids was always reduced, and the quantitative interrelationships between the individual fractions altered.
The rate of excretion of androsterone was considerably reduced in all cases, and to a greater extent than that of the other fractions. The changes in etiocholanolone excretion followed the same direction but were more variable.
The percentage participation of dehydroepiandrosterone was always increased, its total rate of excretion being only slightly decreased or even increased; the latter change taking place during more intensive treatment with oestrogen.
The possible mechanisms involved in this response to oestrogen are discussed.
LONG-TERM IODINE DEFICIENCY IN THE RAT
Authors: TAYLOR SELWYN , POULSON EVELYN 
Published: December 2008

SUMMARY
Rats maintained on a low-iodine diet for 2 years grew fairly normally, but showed thyroid hyperplasia and colloid depletion.
Radio-iodine was taken up rapidly to a high level and equally rapidly discharged.
There was wide variation in the size of the thyroids, but great uniformity in the histological pattern and manner of utilizing radio-iodine.
Nodules appeared in the thyroid from the 5th month in increasing numbers. They were of a trabecular type, and autoradiographically their iodine uptake was, as a rule, similar to that of the rest of the gland.
THE EFFECT OF THE DURATION OF PROGESTERONE PRETREATMENT ON THE RESPONSE OF THE SPAYED EWE TO OESTROGEN
Authors: ROBINSON T. J. , MOORE N. W. , BINET F. E. 
Published: December 2008

SUMMARY
Four trials were conducted each with seventy-two ovariectomized Suffolk crossbred ewes, to determine the requirements of oestradiol benzoate (ODB) for behavioural and vaginal oestrus when, preceded by progesterone injections for periods of 3, 6 and 12 days. Effective daily requirements of progesterone were also determined.
There was no interaction between the daily dose-level or duration of stimulation by progesterone and the vaginal response to ODB. The respective values of ED50 and ED90 of ODB (in μg) for vaginal smears, with their associated 95% fiducial limits, were 8·4-10·7-12·1 and 16·8-18·6-21·9.
There was a progressive increase in sensitivity to ODB, as measured by oestrous behaviour, with increasing duration of progesterone pretreatment at daily dose-levels between 3 and 24 mg. The respective values of ED50 of ODB (in μg) injected following 3, 6 and 12 days' effective pretreatment, with their associated 95% fiducial limits, were 17·0-18·7-20·5, 14·8-15·7-16·6 and 11·9-13·1-14·5. The respective values of ED90 were 24·5-27·0-30·7, 20·9-22·6-25·3 and 17·0-18·9-22·0.
The requirement of ODB to induce behavioural oestrus in 90% of ewes, after pretreatment with progesterone for 12 days, was indistinguishable from that needed for characteristic vaginal changes. This clearly suggests a close approximation to physiological time-dose relationships.
The effective daily dose of progesterone, for maximum oestrous response, lay between the limits of 3 and 12 mg administered as a divided dose. A daily dose of 24 mg appeared slightly less effective, while 1·5 mg/day was much less effective.
THE EFFECTS OF HYPOPHYSECTOMY ON THE IN VITRO METABOLISM OF MAMMARY GLAND SLICES FROM LACTATING RATS
Authors: BRADLEY T. R. , COWIE A. T. 
Published: December 2008

SUMMARY
Mammary gland slices (incubated in vitro) from hypophysectomized rats used less glucose and produced more lactic acid than similar slices from normal animals. The accumulation of lactic acid was observed in the presence of glucose or glucose plus acetate as added substrates, but not in acetate alone or in the absence of added substrates. Hypophysectomy led to a substantial decrease in the respiratory quotient of the mammary gland slices. Neither ovariectomy, adrenalectomy, thyroidectomy, parathyroidectomy nor sham hypophysectomy caused the appearance of the above metabolic changes in mammary gland slices.
THE RESPONSE OF RABBIT MAMMARY GLANDS TO LOCALLY ADMINISTERED PROLACTIN
Authors: BRADLEY T. R. , CLARKE PAMELA M. 
Published: December 2008

SUMMARY
The response of rabbit mammary glands to intraductally-injected prolactin preparations has been investigated with a view to developing an assay procedure for prolactin, based on milk formation in mammals. Milk was clearly detectable in the glands by the 3rd day after injection of prolactin, and there was evidence of an increase in response with increased dose, but the variability so far encountered has been high. Intraductal injection of pituitary extracts rich in activities other than that of prolactin did not lead to milk formation.
THE EFFECT OF META-XYLOHYDROQUINONE ON MICE AND RATS
Authors: BATRA B. KUMARI , HAKIM SAFIA 
Published: December 2008

SUMMARY
Meta-xylohydroquinone (M-X) in various doses was fed to male and female rats and mice in order to observe its effect on their reproductive physiology.
The administration of 1 mg M-X to breeding mice in a single dose resulted in resorption, abortion or still-birth. Toxic effects were not seen with any other dose.
It is suggested that the substance may have some effect on the oestrous cycle, causing irregularities.
The evidence available from the experiments carried out does not support the view that M-X prevents nidation.
THE EFFECT OF ERGOTAMINE AND DIHYDROERGOTAMINE ON LACTATION IN THE RAT
Authors: TINDAL J. S. 
Published: December 2008

SUMMARY
The daily administration of ergotamine (0·2 mg) or dihydroergotamine (0·2 mg) to rats from the 12th to 21st day of pregnancy caused considerable pup mortality. This appeared to be due to a toxic effect in utero rather than an inhibition of lactation.
The daily administration of ergotamine (0·2 mg) to rats from 2nd to 13th day of lactation caused a significant reduction in growth-rate of the pups. There was also a significant reduction in food intake by the lactating rats. Daily administration of dihydroergotamine (0·2 mg) to rats over the same period had no effect on lactational performance.
When studied by the paired-feeding technique, daily administration of ergotamine (0·4 mg) had no effect on lactational performance in the rat.
These findings appear to contradict previous reports, and have been discussed in relation to them.
THE EFFECT OF STRESS ON THE LEVEL OF ADRENOCORTICOTROPHIN IN THE PLASMA OF NORMAL AND ADRENALECTOMIZED RATS
Authors: BARRETT A. M. , HODGES J. R. 
Published: December 2008

SUMMARY
Changes in the concentration of ACTH in the plasma of normal and adrenalectomized rats subjected to mock adrenalectomy were studied at various time intervals after the operations. The time relationships of the changes in ACTH concentration in the plasma of both groups of animals were similar. The possible significance of the findings is discussed.
SOME OBSERVATIONS ON THE HISTOLOGY AND HISTOCHEMISTRY OF THE SEMINAL VESICLES OF THE BULL
Authors: CONS D. N. 
Published: December 2008

SUMMARY
1. The account of the cells of the seminal vesicles of the mature bull given by Mann et al. [1949] has been confirmed.
2. Evidence is presented that cells of the inner layer of the alveolus undergo cyclic changes. These cells, at one stage of the cycle, contain much glycogen and are probably responsible for the secretion of fructose.
3. Fat, in large part phospholipid, is mainly confined to the cells of the outer layer of the alveolus.
4. Comparable cells in the calf and bullock contain no glycogen and virtually no fat, confirming that the secretion of these substances is dependent upon the presence of androgenic hormone.
LOCAL ANTAGONISM OF THE EFFECTS OF STEROID HORMONES BY METHYL CHOLANTHRENE
Authors: JACKSON D. , ROBSON J. M. 
Published: December 2008

SUMMARY
Methyl cholanthrene applied locally to the vagina of ovariectomized mice antagonizes the vaginal cornification produced by 0·2μg oestradiol. Much larger doses of oestradiol abolish this effect. Previous exposure to the carcinogen does not produce this antagonism. The carcinogen prevents the production of vaginal mucification in pregnant mice and also in mice treated with 750 μg progesterone and 0·05 μg oestradiol. Again, previous exposure to the carcinogen does not produce this antagonism.
The effects of testosterone on the seminal vesicle in the rat and of deoxycorticosterone on the endometrium of the rabbit are antagonized by the local implantation of methyl cholanthrene.
These results suggest that there is competitive antagonism between methyl cholanthrene and the steroid hormones investigated. The possible significance of these findings is discussed.
THYROIDECTOMY AND ITS EFFECT UPON OXYGEN CONSUMPTION OF A TELEOST FISH, PSEUDOSCARUS GUACAMAIA
Authors: MATTY A. J. 
Published: December 2008

SUMMARY
1. Thyroidectomy of the teleost parrot fish, Pseudoscarus guacamaia, is described.
2. Pseudoscarus is able to survive for at least 3 months in the absence of the thyroid gland. It is concluded, therefore, that the gland is not essential for the maintenance of life in this species.
3. Thyroidectomy does not result in any change in the oxygen consumption of parrot fish. Likewise, injection of l-thyroxine or an extract of parrot fish thyroid into intact parrot fish does not affect the rate of oxygen uptake.
EFFECT OF DESTRUCTION OF THYROID TISSUE BY RADIOACTIVE IODINE ON REPRODUCTION IN MICE
Authors: BRUCE HILDA M. , SLOVITER H. A. 
Published: December 2008

SUMMARY
The effect of complete destruction of the thyroid gland by radioactive iodine on reproduction in the female mouse has been examined in detail. Possible direct effects of radiation on reproduction were differentiated from those due to thyroid destruction.
Destruction of the thyroid tissue in the male mouse had no effect on fertility.
In the thyroid-deficient female both fertility and litter frequency were unaffected, but the oestrous cycle was prolonged and the duration of 46% of gestations was longer than normal.
There was a general shift in the distribution of litter size towards small litters in the thyroid-deficient group which reduced the average number of young per litter.
Lactation, as judged by the weight of the offspring at weaning, was not affected by complete absence of the maternal thyroid gland.
After weaning the growth rate of offspring of either sex from both thyroid-deficient and normal mothers was the same.
Although the pituitary glands were enlarged in all the thyroid-deficient animals examined, tumours were not observed.
GROWTH IN THE CELL POPULATIONS OF THE THYROID GLAND OF RATS TREATED WITH THIOURACIL
Authors: SANTLER JOYCE E. 
Published: December 2008

SUMMARY
The effect of thiouracil administration on the numbers of the follicular and stromal cells in the thyroid gland of the male albino rat was investigated. Both were found to increase in number, but a relatively greater increase occurred in the stromal cell population than in that of the follicular cells.
The mitotic rates for both types of cell were estimated. The maximum mitotic rates were seen in the group that had received 6 day's thiouracil treatment, after which there was a decline.
A difference between the effect of the fixatives, Carnoy and Zenker-acetic, on treated and nontreated thyroid glands was noted, more shrinkage occurring when treated glands were fixed in Zenker-acetic.
Tissue-culture experiments showed an increase in the numbers of both epithelial cells and fibroblasts migrated outwards from explants from stimulated glands.
THE EXCRETION OF PREGNANEDIOL AND ADRENOCORTICAL ACTIVITY
Authors: KLOPPER A. , STRONG J. A. , COOK LINDA R. 
Published: December 2008

SUMMARY
A new method of assay was applied to the determination of pregnanediol in urines from patients in whom the presence of a placenta or a corpus luteum could be excluded. The normal variation of pregnanediol content in such urines was examined. It was shown that operative stress or the intravenous administration of corticotrophin caused an increased output of pregnanediol. Quantitatively significant amounts of urinary pregnanediol could not be detected after adrenalectomy nor did adrenalectomized patients respond to corticotrophin by an increased pregnanediol output. It is considered that the adrenal contributes to the pregnanediol found in urine and that the determination of urinary pregnanediol may be of value in the study of adrenal function.
BODY WEIGHT CHANGES IN THE MOUSE DURING THE OESTROUS CYCLE AND PSEUDOPREGNANCY
Authors: DEWAR A. D. 
Published: December 2008

SUMMARY
Apart from a tendency to a slight increase in weight at oestrus, no marked cyclic alterations in body weight are evident in the mouse during the oestrous cycle. In pseudopregnancy, however, a definite weight increase (on average 7%) occurs; this weight gain is rapidly lost after removal of the ovaries, but may be maintained after spaying by the administration of progesterone, thus indicating a close similarity to the weight change of pregnancy.
THE PREVENTIVE EFFECT OF GLUCAGON (HGF) AGAINST THE DIABETOGENIC ACTION OF ALLOXAN AND ITS ANTAGONISM BY INSULIN
Authors: ARTETA J. L. , CARBALLIDO A. 
Published: December 2008

SUMMARY
The intravenous injection of glucagon (0·4 mg/kg) 12–30 min before the administration of a diabetogenic dose of alloxan (60 mg/kg) prevents the development of alloxan diabetes in dogs.
The protection obtained with glucagon is abolished by a subcutaneous injection of insulin (2 i.u./kg) administered 2 hr previously.
The possible mechanism of this protection and of its antagonism by insulin is discussed.
MODIFICATION OF RESPONSE TO ADRENOCORTICO-TROPHIC HORMONE BY THE SIMULTANEOUS ADMINISTRATION OF GONADOTROPHIC HORMONES OR OESTROGEN
Authors: CLAYTON BARBARA E. , HAMMANT JOYCE E. 
Published: December 2008

SUMMARY
1. The urinary excretion of 17-ketosteroids (KS) and 17-ketogenic steroids (KG) has been used as a measure of response to administered adrenocorticotrophic hormone (ACTH).
2. In intact female guinea-pigs the excretion of KG was less when pregnant mares' serum gonadotrophin (PMS) and chorionic gonadotrophin (CG) were administered simultaneously with ACTH, as compared with ACTH alone. The ovaries were essential for this effect. The KS response was not affected by gonadotrophin administration. These observations were reproduced in intact female and ovariectomized guinea-pigs by the administration of oestradiol, but not of progesterone, with ACTH.
It is suggested that there is probably a direct inhibition of adrenocortical hormone production by the adrenal glands as a result of treatment with oestrogen, or secretion of oestrogen by ovaries stimulated by administered gonadotrophins.
3. No modification of response to ACTH was obtained by the simultaneous administration of PMS + CG or oestradiol to male guinea-pigs.
THE ACTION OF TESTOSTERONE ON THE SEBACEOUS GLANDS AND EPIDERMIS IN CASTRATED AND HYPOPHYSECTOMIZED MALE RATS
Authors: EBLING F. J. 
Published: December 2008

SUMMARY
1. Castration of male albino rats, aged 30 weeks at death, caused reduction in volume of the sebaceous glands by diminishing the size of the cells and their rate of proliferation. Cell life or 'turnover time' appeared to be increased.
2. Implantation of testosterone in castrated rats increased the volume of the glands by increasing the size of the cells and their rate of proliferation; at the same time cell life was reduced.
3. Testosterone had no effect on the size of the sebaceous glands in hypophysectomized castrated rats.
4. Nevertheless, in hypophysectomized castrated animals treated with testosterone there appeared to be larger sebaceous cells than in similar untreated animals, and a higher rate of cell proliferation in the sebaceous glands than in untreated castrated rats. The explanation of this anomaly may be that in all hypophysectomized castrated animals, and particularly in those treated with testosterone, cell life was very short. These results suggest that the pituitary does not exert a clear-cut, 'all or none' effect but rather facilitates the full action of testosterone on the sebaceous gland.
5. Testosterone increased the rate of cell proliferation in the epidermis of castrated rats, but this did not affect the thickness of the Malpighian layer.
6. Hypophysectomy of castrated rats significantly increased the thickness of the Malpighian layer, and this appeared to be due to an increased rate of cell proliferation over that of castrated rats rather than to an increase in the length of cell life. Testosterone did not reduce epidermal thickness in these animals.
THE EFFECT OF LONG PERIODS OF CONTINUOUS HYDRATION ON THE NEUROSECRETORY MATERIAL IN THE HYPOTHALMUS OF THE DOG
Authors: ANDERSSON B. , JEWELL P. A. 
Published: December 2008

SUMMARY
Dogs were kept in a state of excessive hydration by the oral administration of water, or its infusion into the stomach, for periods varying from 3 hr to 10 days. The effect of this procedure on the stainable neurosecretory material (NSM) in the hypothalamus was determined by histological examination.
At the end of the longer periods of hydration there was seen an accumulation of NSM in the descending tracts from the paraventricular and supraoptic nuclei. In the 10-day hydrated animal a high proportion of the cell-bodies in these nuclei were depleted of NSM. The staining properties of the pars nervosa did not differ from normal.
The hydrated animals exhibited large numbers of vesiculated neurones in the hypothalamic neurohypophysial nuclei.
THE ACTION OF FURAZOLIDONE ON PREGNANCY
Authors: JACKSON D. , ROBSON J. M. 
Published: December 2008

SUMMARY
1. Furazolidone (0·75 g/kg) will interrupt pregnancy in mice.
2. Foetal tissue is particularly sensitive to the drug at the time of or before implantation of the ovum.
3. Intra-amniotic injection of furazolidone in rabbits causes foetal death and resorption.
4. Furazolidone applied locally does not antagonize the proliferative effect of progesterone on rabbit endometrium.
5. The mode of action of furazolidone on pregnancy is discussed. It is suggested that it acts directly on the foetus.
THE SUPPRESSION OF ADRENOCORTICAL SECRETION WITH 17α-ETHYL-19-NORTESTOSTERONE
Authors: BROOKS R. V. , PRUNTY F. T. G. 
Published: December 2008

SUMMARY
Administration of 17α-ethyl-19-nortestosterone (50–100 mg/day) to four men with peptic ulcers caused a reduction in the excretion of 17-ketosteroids and 17-ketogenic steroids. All the major urinary 17-ketosteroids were decreased by this treatment, but 11β-hydroxyandrosterone appeared to be least affected.
Single injections of androst-4-ene-3:17-dione were given to one patient both before and during the period of ethyl-nortestosterone treatment. Recovery of the metabolites of androstenedione in the 48 hr following injection was virtually the same in the pretreatment and treatment periods. This was interpreted to mean that alteration of the metabolism of this adrenal steroid was not the basis of the suppression of ketosteroid excretion.
It is therefore concluded that 17α-ethyl-19-nortestosterone can cause suppression of adreno-cortical secretion.
AN EVALUATION OF A CHEMICAL METHOD FOR THE ESTIMATION OF OESTRIOL, OESTRONE AND OESTRADIOL-17β IN HUMAN URINE
Authors: BROWN J. B. , BULBROOK R. D. , GREENWOOD F. C. 
Published: December 2008

SUMMARY
The method described by Brown [1955] for the estimation of oestrone, oestradiol-17β and oestriol in urine has been critically investigated.
1. All checks on specificity so far carried out have confirmed that the method is specific for these oestrogens.
2. The method gives recoveries of 70–95%.
3. The precision of the method has been calculated for oestrogen levels between 0·0 and 40·0 μg/24 hr. From the figures obtained the fiducial ranges and percentage errors of determinations and the limits of sensitivity of the method have been calculated.
4. A number of substances which may occur in urine and which interfere in the method are listed.