The ossification centers in the lower end of tibiotarsus in domestic fowl.

The morphogenesis of lower end of tibia in chick is studied commonly but the process of ossification of the same has received very little attention so far. The present study is directed to throw some light on the appearance of ossification centers in the lower end of tibiotarsus of chick. The histology of lower end of tibiotarsus was studied by procuring developing tibiotarsi from chick embryos (20) of 6th day incubation till hatching and 3 post hatched chicks. The transparancies of chick embryos at different incubation periods and post hatched chicks were prepared by Dawson's Alizarin staining method. Three cartilage center (tibial, fibulare and intermedium) appeared in 6...9 days of incubation period in the tarsal region. These gradually fused with the lower end of tibia. Three ossification centres developed in the lower end of tibiotarsus. One for intermedium appeared on 16th day and two fotibial and fibulare on 20th day. All these three centres could be located in the transparancies of the chick embryos in tarsal region. The present study proves that the three cartilages centres maintain their individuality during the ossification process even though those fuse completely with the lower end of tibia in chick. The centers for tibial and fibulare are similar to epiphyseal centres of mammals in histological details.     

The formation of heart-proportion in fetal ontogenesis.

In the paper, the formation of basic heart proportions in the period from the 19th to 43rd week of intrauterine development was investigated. The material consisted of 1505 fetuses (930 male and 575 female). Length, width and thickness of the heart were measured to 0.1 mm on unpreserved fetus material within 24 hours after stillbirth or death, in the natural position of the organ. The material was divided into groups representing seven developmental periods, from the 5th to the 10th lunar month. Individuals from the 41st-43rd week were recognized as carried beyond term and included in the age category above the 10th month (< 10). Formation of heart proportions was investigated on the basis of a statistical analysis of the results, with both sexes considered separately. Evaluation of the research results confirmed previous results indicating a slightly different shape of the heart in the fetal period. In addition, the results show the changes that occur in heart proportions during the period of intrauterine development. A comparison of these proportions with analogous indices in adult individuals makes it possible to predict further developmental changes in the postnatal period. In comparison to the conical heart found in a grown-up individual, the fetal heart is more spherical. At the beginning of the fetal period, the length dimension of the heart is greater than its width. Beginning with the 9th month of development, a relatively slower elongation of the heart occurs in favour of a more rapid increase in its width dimension.(ABSTRACT TRUNCATED AT 250 WORDS)     

Morphofunctional features of the development of the thyroid gland of Dicrostonyx torquatus during the drop in population stage

By means of the histostereometrical method, peculiarities of the thyroid gland formation have been studied in the lemming (Dicrostonyx torquatus) fetuses and newborns at the stage of the population quantity drop, as well specificity of the organ's morphofunctional state during the postnatal period. On the 14th prenatal day the thyroid gland already has the follicular structure. Up to the 19th day progressive follicular growth, accumulation of colloid and increase of its density occur. On the 19th-20th days, as well as in newborn animals, there are certain signs, demonstrating as essential activation of the thyroid gland function. In the newborn animals cavities of the completely formed follicles are devastated. During the postnatal period again growth of follicles, accumulation of colloid are observed, signs of hypersecretion of the hypophysis appear.     

Haptoglobin study of sheep during the development process]

The development of haptoglobin blood system was studied in the sheeps during intrauterine development and early postnatal period. The haptoglobin content was shown to decrease with the foetus age, two peaks of its reliable increase having been, however, noted -- on the 55th and 105th days of development. After the birth the haptoglobin concentration in blood is relatively low, increases gradually and attains by the 8th month of life that in adult animals. In the blood serum of 45--120 days old foetuses two phenotypes of fetal haptoglobin were found; the adult haptoglobin is present only beginning from the 1st month of life.     

Stereological analysis of alpha and beta zones of syncytiotrophoblast in human term placenta.

The investigations were carried out to attempt to define and analyze various quantitative structural parameters of syncytiotrophoblast in human term placenta, especially of its functionally active parts, that is alpha and beta zones. The results demonstrated the following: The arrangement of alpha and beta zones in the placenta as a whole is even and regionally independent. Beta zones prevail quantitatively. Alpha zones make up only 8% of the total volume, 18% of the total surface and 39% of the thickness of beta zones. Sexual dimorphism is shown by a significantly higher volume density (VVa)(P less than 0.002), total volume (Va)(P less than 0.05) and surface density (SVa) (P less than 0.025) of alpha zones in placentas of female newborns. The fetoplacental index is higher in male newborns. During the tenth lunar month the structure of syncytiotrophoblast is changed. Between the 38th and 39th week the volume and surface densities of alpha zones are significantly higher (P less than 0.01), and in the 40th week the volume density and total volume of beta zones prevail significantly (P less than 0.01).     

Quantitative studies of the ABO blood group system. Quantitative changes in agglutinability of antigens A, B and H with regard to the patient's age]

The results of a comparative quantitative investigation about the agglutinability of erythrocyte antigens A, B, and H to be found in fetus (fifth to ninth lunar month), newborns, adults, and old age people are represented. In investigating with anti-H sera it could be found that A-antigens in fetus undergo the same development to be observed in newborns; it amounts to 75% of the agglutinability present in adults. After delivery the agglubinability will essentially increase up to the fifth month; it will only reach the average values of adults, however, after the seventh year of age and will remain unchanged then until the end of life. The agglutinability of B-erythrocytes with anti-B will also change in the same way. In fetus and newborns the agglutinability of A1 erythrocytes with anti-A1 sera is markedly weaker than that determined by anti-A sera. After delivery it will rapidly increase, will be stronger afterwards than the agglutinability with anti-A sera and will have the values to be found in adults after the third year of age. After the 85 year of age, however, there is a tendency of weakening the agglutinability with anti-A1 serum. With growing age the agglutinability of O-erythrocytes with anti-H serum is changed in the same way. Furthermore, it could be detected that the interaction between genes A1 and B to be found in adults will find its expression in a weakening of the agglutinability of A1B-erythrocytes with anti-A1 and anti-B sera, the agglutinability with anti-A serum remaining constant. This behaviour is valid for the whole life of man. In all stages of life an interaction between weak and strong genes can be observed in A2B-erythrocytes.     

Development of the ductule system of the epididymis in the prenatal period of human ontogeny

In 285 human embryos, prefetuses, fetuses and newborns by means of a complex of morphological methods, development of the epididymal canalicular system has been studied. The anlage of the epididymal canalicular system is stated to appear in embryos 13.0-17.0 mm long (the 6th week of development) and is presented as an accumulation of epithelial cells and primary germ cells between reducing glomeruli and mesonephric canaliculi. The canalization process of the cellular accumulations and their transformation into real canaliculi takes place during the first half of the prefetal period (the 8th week of development). Further growth and development of the epididymal canaliculi takes place in the craniocaudal direction and by the end of the prefetal period (the 12th week) the canaliculi of the head are already formed, they have a twisted course; within the limits of the body and tail they are yet poorly differentiated and their course is nearly straight. During the fetal period of ontogenesis, further differentiation of the epididymal parts occurs and structure of their canaliculi becomes more complex. They acquire a twisted course in all the parts of the organ; by the end of the fetal period the form and structure of the epididymal canaliculi resemble those of the definitive organ.     

Effect of triiodothyronine (T3) thyroparathyroidectomy and mercaptoimidazole treatment on enchondral bone growth. II. Growth dynamics in the proximal growth organ of the tibia in young rats.

The 24 hour growth rate of the tibial proximal growth organ was investigated in triiodothyronine or mercaptoimidazole-treated, and in thyroidectomized male rats. Longitudinal growth of the tibia of the same period was also studied. After one week treatment, the 24 hour rate of growth in the triiodothyronine-treated rats was retarded as compared with the controls, whereas at the end of the 3rd and 5th weeks the growth rate of the treated animals exceeded that of the controls. The tibia was somewhat longer in the treated rats than in the untreated controls, though the difference was not significant. The growth rate in the growth organ of mercaptoimidazole-treated and thyroidectomized animals was generally higher than that measured in the controls. The length of the tibia was less than in the controls, but the difference was not significant. The phenomenon is attributed to the altered hormonal conditions.     

Age-related changes in the rates of polypeptide chain elongation

The time of an average polypeptide chain synthesis, ts, in the liver and brain cortex of rats of various age--from the 17th day of prenatal life up to the 24th month of the postnatal period--was estimated. At the end of the prenatal period the value of t is much higher than in postnatal life. In newborns, the t value is minimal, showing a gradual increase during the postnatal development. Determination of an average molecular mass of newly synthesized polypeptides demonstrated that the increase of t in postnatal life is due to the decrease of the rate of polypeptide chain elongation.     

Irreversible morphological changes in leg bone following chronic gravitational unloading of growing rats

Effects of gravitational unloading or loading on the growth and development of hindlimb bones were studied in rats. Male Wistar rats were hindlimb-unloaded or loaded at 2-G from the postnatal day 4 to month 3. The morphology and mineral content of tibia and fibula, as well as the mobility of ankle joints, were measured at the end of 3-month suspension or loading, and 1, 2, and 3 months after ambulation recovery. Growth-related increases of bone weight and mineral density were inhibited by unloading. But they were gradually recovered toward the control levels, even though they were still less than those in the age-matched controls after 3 months. None of the parameters were influenced by 2-G loading. However, here we report that chronic unloading causes abnormal morphological development in hindlimb bone of growing rats. Irreversible external bend of the shaft and rotation of the distal end of tibia, which limit the dorsiflexion of ankle joints, were induced following chronic gravitational unloading during developing period. It is also suggested that such phenomena are caused by the abnormal mechanical forces imposed by muscle utilization with altered patterns. The activity of ankle dorsiflexor was increased and that of plantarflexor was inhibited during unloading.     

Anthropological measurements of the skeleton and parathyroid glands growth during fetal development

The article presents the investigation of histomorphological differentiation and growth of parathyroid glands in human fetus from the second to the ninth lunar month. The longer and the shorter diameter of these glands were measured. The obtained values are compared with the development and the growth intensity of the skeleton (biparietal head diameter and femoral length of a fetus from lunar months 3 to 9) and with the role of the placenta in the mentioned processes. The results of our investigation show the concordance of the skeletal growth with the development and histomorphological differentiation of these glands. The factors involved in these processes point out the complex relationship between the mother and fetus during osteogenesis, expressed on the hormonal level, in mineral metabolism and placental activity.     

Correlations in the development of the spinal cord, dura mater and spinal canal in humans

The spinal cord axial structures (AS) (its dura mater and vertebral canal) demonstrate the greatest growth rate during the intrauterine period and on the 18th month. After birth for the dura mater this age is 3 years, and for the spinal cord and the vertebral canal--7 years of age. The pubertal jump in growth of these formations is noted during the adolescent age (17-21 years). During the first two decades AS demonstrate asymptotic type of growth. In AS development the following periods in common have been revealed: a) intensive growth in children up to 7 years of age; b) growth stabilization (from 8 up to 16 years of age); c) period of a relative morphological stability (22-35 years); d) period of unstable compensatory-adaptive rearrangements (36-60 years); e) period of involutive changes (61-90 years).     

Developmental relations between the weight of internal organs and somatic features of fetuses and newborns

The paper contains results of investigations on statistical developmental interrelations between the weight of brain, heart, lungs, liver, spleen, kidneys, adrenal glands and thymus, and the total length, the crown-rump length and the body weight, and the circumference of head, shoulders, chest and abdomen of fetuses and newborns in the age from 17 to 43 weeks of life. The character and the force of the relations between the degree of the development of the weight of organs and the body dimensions was investigated by statistical methods on three levels. On the basis of the value of linear correlation coefficients, statistical relations were determined between the weight of the particular organs and the particular sometic features. The dependence between the particular organs and the complex of somatic features was determined on the basis on the multiple regression analysis. On the other hand the relation between two complexes of features, i.e. all organs and all somatic features was investigated with the help of canonical correlation coefficients. The analysis of results indicated that between the weight of internal organs and the somatic features in the fetal period there exists a statistical developmental relation. The developmental relations are most strongly marked between the 6th and the 10th months of intrauterine life, while in the 5th month of life and in postmature fetuses and newborns they are weaker.     

The ultrastructure of the developing neural lobe

Summary The ultrastructure of the developing neural lobe of rats was studied. The results revealed three periods in its development. The first period lasts till the 17th day of fetal life. At its beginning the anlage of the neural lobe is formed as a mass of cells very similar in appearance and in connection with the subependymal cells of the future median eminence. During the first period the cells of the anlage differentiate into pituicytes, and the penetration of the first nerve fibres and blood vessels among them is seen. The second period is from the 18th day of fetal life till one month after birth. At its beginning the first signs of neurosecretory activity were detected. During the period increasing numbers of neurosecretory fibres penetrate into the neural lobe, and the pituicytes show morphological signs characteristic of active cells. An increase in the functional activity of the neural lobe is also detected. The third period is from the end of the 1st till the end of the third month. During this period the development of the neural lobe proceeds and at the end it has the appearance of the adult gland. During this period the pituicytes gradually lose the signs of activity and at the end of the period they look like those observed in adult animals. Considering the results from the study, together with some data from previous investigations it is suggested that the pituicytes exert some stimulating and regulative influences on the process of neurosecretion in the neural lobe.Research fellow of the Alexander von Humboldt Foundation.     

The occurrence of c-myc, p53 and Bcl-2 family proteins in the early phase of development of duodenal epithelium

In last few years, numerous groups of proteins participating in the regulation of cell proliferation, differentiation and death during ontogenesis have been described. In this study we compared the occurrence of Bcl-2, p53 and myc protein families with the level of proliferative activity and apoptosis during development of duodenal epithelium. Paraffin embedded tissues of eight human embryos and foetuses aged from the 6th-18th week of IUD were used. For the detection of apoptotic cells the TUNEL method was performed, the proliferative marker PCNA and all the proteins studied were detected by means of indirect three-step immunohistochemical method. In the 6th and 8th week of intrauterine development we observed isolated TUNEL positive epithelial cells only and this was accompanied by the disperse presence of PCNA as well as by all the studied proteins: Bcl-2, Bax, Bcl-XL, c-myc, N-myc, p53, p63 and p73. In the early foetal period of duodenal development we registered changes in PCNA and TUNEL positivity in accordance with the constitution of the stem cell pool on base of villi, where more numerous Bcl-2 positive cells were also found. The separation of primitive crypts and villi was not accompanied by any differences in distribution of Bax, Bcl-XL, c-myc, N-myc, p63 and p73 proteins between those compartments: all the studied proteins showed dispersed character. P53 rapidly decreased in this period. In the 18th week of intrauterine development the balance between proliferation in crypts and apoptosis of villi epithelium was well established and no p53 positive cells were found. In the presence of Bcl-2, Bax, Bcl-XL, p63 and p73 we did not find any dramatic changes. The myc proteins were restricted within the epithelium of the Lieberkuhn crypts only.     

Proliferative activity of cells of the intermediate lobe of the rat pituitary during the postnatal period.

Cellular proliferation was studied in the intermediate lobe (IL) of the pituitary gland of developing rats by labelling cells at the S-phase of the cell cycle with bromodeoxyuridine (BrdU). The number of BrdU-labelled cells in the IL decreased from birth until the 14th postnatal day and was low from that day until the end of the first month after birth. Throughout the postnatal period a large proportion of BrdU-labelled cells was found in the marginal layer (ML) of the IL, suggesting for the ML a role as a germinative layer of the IL during postnatal growth. Double immunostaining with anti-BrdU and anti-MSH showed that MSH cells actively proliferate as from the day of birth. Cells doubly immunostained with anti-BrdU and anti-S100 protein were first seen on the 14th postnatal day. From then onwards, most proliferating cells were labelled with either anti MSH or anti S-100 protein. This, together with the high proportion of proliferating cells found in the ML marks a clear difference with the pattern of cellular proliferation previously reported during a similar period in the anterior lobe of the rat pituitary.     

The development of the activity-rest cycle in the rabbit fetus

On 25-30-day rabbit foetuses, in chronic experiments using constant synchronous recording of the motor activity and heart rate, studies have been made of temporal organization of the activity-rest cycle. Already in 25-day foetus, three functional conditions may be distinguished: active, intermediate and resting ones, the duration of the latter increasing to the end of gestation up to 8-10 min, whereas the duration of the intermediate phase decreases, reaching its minimum to the 30th day if not being completely reduced. Cyclic pattern of active and resting phases is observed in 28-day foetuses; to the 29th-30th day, these phases from a unique activity-rest cycle, its duration reaching 20-30 min to the end of intrauterine period. It is suggested that the resting phase in foetal rabbits serves as a basis for the development of polyphasic sleep in adult animals.     

Trace element content in the internal female genitalia of the fetus in the 2d half of pregnancy]

The dynamics of increasing the concentration of microelements in the ovary, uterine tubes, uterus and vagina in the second half of intrauterine life were studied. Changes in the concentration of microelements depend on increasing the weight of the organs in question beginning from the 4th up to the 10th month of the fetal period. Hence, copper, zinc, manganese, titanium, lead, molybdenum are necessary for development and formation of internal female genitalia.