摘要:

AbstractThe nerve supply of the ankle joint and of the joints of the foot was studied in dissections of fetal and adult feet and in serial sections of fetal feet stained with silver.The ankle joint was supplied by the tibial, sural, deep peroneal, and saphenous nerves, and by the accessory deep peroneal nerve when present.The tarsal joints were supplied on their plantar aspects by the medial or lateral plantar nerves, and on their dorsal aspects chiefly by the deep peroneal nerve. The joint between the lateral and intermediate cuneiform received branches from the intermediate dorsal cutaneous nerve also. The lateral dorsal cutaneous nerve and the accessory deep peroneal nerve when present provided additional branches to the subtalar and calcaneocuboid joints.The tarsometatarsal joints were supplied on their plantar aspects by the medial or lateral plantar nerves. Most of them were supplied on their dorsal aspects by the deep peroneal nerve, but the cuboid‐metatarsal joints received their supply from the intermediate dorsal cutaneous nerve. The intermetatarsal joints had a similar but sparser supply. The joint between the fourth and fifth metatarsal received branches from the intermediate dorsal cutaneous nerve.The plantar digital nerves provided the main supply to the metatarsophalangeal joints. The dorsal aspect of the first metatarsophalangeal joint was supplied by the deep peroneal and the medial dorsal cutaneous nerves, of the second metatarsophalangeal joint by the deep peroneal nerve, and of the fourth and fifth metatarsophalangeal joints by the lateral dorsal cutaneous nerve. The interphalangeal joints did not receive articular branches from the dorsal digital nerves, except in the case of the interphalangeal joint of the big toe, which was supplied by the deep peroneal and the medial dorsal cutaneous nerve

ISSN:0003-276X    

DOI:10.1002/ar.1091610201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractDevelopment of redundant nuclear envelope was observed inErythrocebus patasandMacaca mulattaspermatids.As the acrosome forms around the anterior part of the nucleus, the underlying nuclear envelope becomes more dense in appearance. Changes which lead ultimately to formation of the redundant nuclear envelope of mature spermatozoa involve only the posterior region of the envelope which does not lie beneath the acrosome.The first recognized change is separation of the nuclear envelope from underlying chromatin by an intervening band of lightly stained nuclear material, around the posterior quarter of the nucleus. The separation increases and the bulged region of the nuclear envelope is drawn caudally as nuclear condensation progresses. The caudally extended region of the nucleus is comprised of nuclear material of low electron density and pores are present in the envelope of the extended areas.The chromatin aggregates in late spermatids becomes homogeneous in appearance when the nucleus flattens into a paddle shape. Nuclear protrusions are present at both posterior corners of the flattened nucleus at this stage of spermiogenesis but only one protrusion is well developed. Membrane remnants of the extended nuclear envelope remain in mature spermatozoa as the redundant nuclear envelope.

ISSN:0003-276X    

DOI:10.1002/ar.1091610202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractThe reciprocal relation between the pituitary and the gonads in perinatal rats was studied by gravimetric or volumetric measurements of gonads and by estimations of the collective volume of Leydig cells by the method of Chalkley ('43).Hypophysectomy of a 20‐day‐old male fetus by decapitation caused two days later a retardation of the testicular growth and a fall of the collective volume of Leydig cells, these effects being prevented by injected GTH. Testosterone prevented somewhat the retardation but did not prevent the change in Leydig cells. The collective volume of Leydig cells fell sharply just after birth and this fall was overcome with injected GTH. In fetuses unilateral castration caused some enlargement of the remaining testis, but in newborn rats such change did not occur. These observations suggest that the pituitary governs largely the Leydig cells before birth and reduces its LH activity after birth.The fetal ovaries were not affected by decapitation or decapitation and GTH injection and the newborn ovaries were not modified by injected GTH. In an extra uterine parabiosis of a decapitated male and an intact female fetus, the testes failed to gain weight, although the adrenals grew normally. These observations suggest that the female pituitary during late fetal and early postnatal days has no gonad‐stimulating act

ISSN:0003-276X    

DOI:10.1002/ar.1091610203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractThe cycle of the seminiferous epithelium of the boar was divided into eight stages which are described. The relative frequencies of the stages were determined for ten Yorkshire and ten Lacombe boars approximately 11 months of age. The mean relative frequencies for stages 1 through 8 were 10.8, 14.4, 3.5, 11.6, 8.9, 20.3, 18.5 and 12.0%, respectively. Generally, there was a constancy of the relative frequencies of the stages between breeds, among boars within breeds and between testes within boars.The absolute duration of the cycle of the seminiferous epithelium and the duration of spermatozoan transit through the epididymis were determined by injecting a single dose of 19 mCi of thymidine‐methyl‐H3into the marginal ear vein of each of four Yorkshire (15.2 months old) and four Lacombe boars (14.9 months old). Unilateral castrations were performed at 0.2, 11.5, 20.0, 24.0 and 25.0 days after the isotope injection. Two intact and two unilaterally castrated animals were ejaculated for eight and seven weeks, respectively, to determine the interval between the thymidine‐H3injection and the appearance of the isotope in the ejaculated semen. Autoradiographs were prepared from the testis tissues and the semen smears. The most mature germ cells that incorporated the thymidine‐H3were the late preleptotene primary spermatocytes. Twenty‐five days after injection the label had progressed from late preleptotene primary spermatocytes to spermatozoa leaving the testes. Epididymal transit times for four boars (ejaculated daily) were 9, 10, 10 and 12 days. The duration of one cycle of the seminiferous epithelium based on 12 estimates was 8.6 ± 0.1 days. The durations of stages 1 through 8 were 0.9, 1.2, 0.3, 1.0, 0.8, 1.7, 1.6 and 1.0 days, respectively. The life span of primary spermatocytes was 12.3 days, of secondary spermatocytes 0.4 days, of spermatids with round nuclei 6.3 days, of spermatids with elongated nuclei 1.5 days, and of spermatozo

ISSN:0003-276X    

DOI:10.1002/ar.1091610204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractThe effect of some steroids on the lymphoid differentiation of embryonic mouse thymus glands was studied. Most of the adrenal cortex hormones tested could inhibit lymphoid differentiation when applied in low concentrations to prelymphoid 13‐day glands. The most effective was corticosterone. Careful washing of the affected glands allowed them to develop normally into lymphoid organs. The application of a high dose of corticosterone produced an effect not reversed by thorough washing. Such permanently affected glands were restituted to lymphoid organs by fusion with 13 or 15‐day embryonic mouse liver or with 15‐day spleen. Lymphoid glands were much less sensitive to low concentrations of corticosterone than the prelymphoid glands. The same concentration of corticosterone was more toxic to more advanced fetal glands. The sex hormones tested were practically ineffective at comparatively high doses; very high concentrations were toxic however.Basophilic cells normally found in 12 and 13‐day embryonic thymus glands disappeared after corticosterone treatment even in glands which were still potentially capable of lymphoid differentiation suggesting that these cells are not ste

ISSN:0003-276X    

DOI:10.1002/ar.1091610205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractOrgan and tissue phagocytosis of intravenously injected cobaltic oxide was studied quantitatively over a wide range of dose levels by means of radioassay of Co260O3in rats.There is a single linear relationship between the amount of particulate administered and the amount recovered from liver, spleen, and lung combined. The same is true for the uptake by the liver alone. However, the spleen and lung each has two linear relationships. For the spleen the two different linear trends are related to the dose administered, while for the lung the determining parameter is the weight and (or) age of the animal. Notwithstanding these different linear trends, the uptake by spleen and lung is interdependent.Although the liver is the main phagocytic organ, per unit weight the phagocytic uptake of the spleen exceeds that of the liver at amounts of cobaltic oxide larger than 40 mg. The reverse is true for amounts less than or equal to 40 mg. The phagocytic uptake by other components of the RES was not sufficient for reliable quantitative estimation.

ISSN:0003-276X    

DOI:10.1002/ar.1091610206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractThe fine structure of the ameloblasts which secrete the inner enamel matrix in rat incisors was described using light and electron microscopy. The tissue was fixed by perfusion with 2.5% glutaraldehyde and gently decalcified in isotonic EDTA.The ameloblasts are tall cells forming a simple columnar epithelium. The base is adjacent to the stratum intermedium and the apex (Tomes' process) extends into newly‐formed enamel. The infranuclear zone is divided by the basal cell web into a small basal bulge adjacent to the stratum intermedium, and a larger compartment containing most of the cell's mitochondria. The supranuclear zone contains the rough endoplasmic reticulum and the Golgi apparatus. The rough endoplasmic reticulum predominates in the proximal and distal regions of this zone where it occupies most of the cell width. In the intermediate region, the rough endoplasmic reticulum surrounds a central tubule‐shaped Golgi apparatus, the tubule wall being made up of flattened saccules. The Golgi region of ameloblasts is associated with coated vesicles, two types of granules (light and dark) which may be lysosomes, and a characteristic dense content granule shown to be the enamel precursor (0.16 μ diameter).The supranuclear zone is separated from Tomes' process by the apical cell web. Tomes' process is devoid of endoplasmic reticulum and Golgi material, but contains numerous dense content granules as well as microtubules and coated vesicles. The amorphous dense content granules are the precursors of the highly orientated fibrous enamel matrix. The proximity of the process to the fibrous enamel suggests that it is involved in orientation of these fibrils. Since bundles of fibrils constitute rods, the process would seem also to be involved in enamel rod orienta

ISSN:0003-276X    

DOI:10.1002/ar.1091610207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractThe telencephalic vesicles of the human brain appear during the fifth week of embryonic life. These vesicles are closed containers filled with ventricular fluid until the fifteenth week when it escapes through the newly‐formed foramen of Magendie.The light and electron microscopic studies reported here support the notion that the germinal layer of the telencephalon has an absorptive role between the eighth and fifteenth weeks of fetal life. This assumption is based on the structure and the arrangement of the cells of the germinal layer, which resemble and are arranged in a manner similar to that of other absorptive units such as the renal proximal tubules, the gallbladder and the intestine. The absorbed material is presumably contained in the ventricular flui

ISSN:0003-276X    

DOI:10.1002/ar.1091610208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractMicrocurie amounts of p32, Na22, Fe59, and Cl36in normally occurring compounds were injected directly into the vitelline vessels of developing chick embryos at stage 24 (Hamburger and Hamilton, '51). The surviving embryos were sacrificed at stage 41. Hearts were removed and examined intact or sectioned for later examination. Coronary vessels were identified, classified according to size (large, diameter =>80 μ; medium, diameter = 40–80 μ; small, diameter<40 μ) and counted. There was a significant increase in the numbers of small and medium vessels which had developed in the presence of gamma radiation emitted by Na22‐ and Fe59‐compounds. The p32‐ and Cl36‐containing compounds did not affect the numbers of vessels of any size. The resulting increased vascularity is shown to be a matter of a distinct increase in numbers of blood vessels as opposed to a simple alteration of the normally occur

ISSN:0003-276X    

DOI:10.1002/ar.1091610209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractThe possibility that the incidence of polyovular follicles and multinucleate ova may depend upon hormonal balance, in the hamster, has been investigated with respect to circulating estrogens. Samples were drawn at weekly intervals from the third through the seventh week of age. An inverse correlation was found to exist. Total blood estrogen decreased from day 21 to day 35, then increased through day 49. Polyovular follicles are most numerous at day 35 while multinucleate ova are most numerous on day 42. Non‐polar estrogen decreased from day 21, achieving a low 28 day level which was maintained throughout the study period. More polar estrogens dropped to the thirty‐fifth day and rose by the forty‐ninth day. The limiting factor in the decrease of more active polar estrogens may be lack of conversion of non‐polar to polar estrogens or a tendency toward rapid degradation and loss of polar estrogens. The role of the fluctuating estrogen titres in the development of ovarian abnormalities is di

ISSN:0003-276X    

DOI:10.1002/ar.1091610210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY