Dynamic age-related changes in the human physique at stages in postnatal development

In 926 children (7 age groups) combined group differences of the signs have been studied by means of a unified standardized method, using the hand length as a linear measure; the conformity index to definitive size has been applied. For newborns proportional discrepancy to the definitive sizes is specific. They have a relatively long, thick and round body, short extremities, large dimensions of the head and abundant adipose subcutaneous deposits. According to the constitutional peculiarities the newborns resemble the children of the digestive type in mature persons--pycnotic or endomorphic. Beginning from birth, including children of early and first childhood (4-7 years of age), age changes of complexion go in two directions: a) dolichomorphy of complexion is realized; for it decreasing diameters of the chest and dimensions of the neck, chest, abdomen, pelvis (in boys), shoulder, arm, hand, foot and decrease in the subcutaneous adipose tissue are specific; b) longitudinal proportions of body and extremity segments change under influence of biomechanical adaptations to physical loads in connection with adaptation to the vertical position.     

Introduction of the human recombinant angiogenin at the early stages of postnatal development inhibits the growth of mice

We studied the influence of recombinant DNA containing the cloned angiogenin gene, plasmid DNA without angiogenin gene, and purified recombinant angiogenin injected to Tg8 mice at the age of two days on the body mass of 28- and 40-day old mice. The body mass of mice that were injected with the cloned angiogenin gene or purified angiogenin was less than in the control mice. The body mice of Tg8 mice injected with recombinant DNA containing the cloned angiogenin gene did not increase from day 2 to day 40, while in the mice with purified recombinant angiogenin and control mice it increased by 24 and 57%, respectively. These data suggest that the elevated level of angiogenin at the early developmental stages inhibits the increase of body mass. The effect we described as related, in al likelihood, to the known inhibitory effect of angiogenin on protein synthesis.     

Variability in the myeloarchitectonics of the nerves of the thyroid arteries during postnatal human development

Serial transversal sections on the nerve-vascular complexes of four thyroid arteries in newborns, in persons of the 1st and 2d periods of mature age, in elderly and old persons (40 complexes in each age group) are stained after Weigert--Pahl. Amount of myelin fibers (MF) of three dimensional classes are defined micromorphometrically. Total amount of the MF in the nerves of all thyroid plexuses is the greatest in the persons belonging to the second mature period of age: it is 2.7 times as great as in the newborns. In the elderly persons it is 1.5 times, and in the old persons--1.8 times as little as in the persons of the second period of maturity. Thin MF make the absolute majority. The amount of the MF with middle caliber in the thyroid nerves of the mature persons is 6.6 times as great as in the newborns. Their amount in the old persons is 1.7 times as little as in the mature persons. Thick MF are absent in the newborns; in the mature and elderly persons they are observed now and then. The thick MF are characterized by a high variation coefficient (up to 84%). According to the criteria of absolute and relative contents of both total and group composition of the MF in postnatal period, three stages in development of the thyroid innervational connections performed by the MF are revealed: productive, stabilization and involution. The correlative analysis reveales a direct dependence in the system diameter of each thyroid artery--number of the MF in nerves of its plexus in the newborns and mature persons. This dependence becoms negative in the elderly and old persons.(ABSTRACT TRUNCATED AT 250 WORDS)     

Natriuretic peptide system gene expression in human coronary arteries.

The natriuretic peptides (NPs) ANF, BNP, and CNP have potent anti-proliferative and anti-migratory effects on vascular smooth muscle cells (SMCs). These properties make NPs relevant to the study of human coronary atherosclerosis because vascular cell proliferation and migration are central to the pathophysiology of atherosclerosis. However, the existence and cytological distribution of NPs and their receptors in human coronary arteries remain undetermined. This has hampered the development of hypotheses regarding the possible role of NPs in human coronary disease. We determined the pattern of expression of NPs and their receptors (NPRs) in human coronary arteries with atherosclerotic lesions classified by standard histopathological criteria as fatty streak/early atherosclerotic lesions, intermediate plaques, or advanced lesions. The investigation was carried out using a combination of immunocytochemistry (ICC), in situ hybridization (ISH), and semi-quantitative polymerase chain reaction (PCR). Both by ICC and ISH, ANF was found in the intimal and medial layers of all lesions. BNP was highly expressed in advanced lesions where it was particularly evident by a strong ISH signal but weak ICC staining. CNP was demonstrable in all types of lesions, giving a strong signal by ISH and ICC. This peptide was particularly demonstrable in the endothelium, as well as in the SMCs of the intima, media, and vasa vasorum of the adventitia and in macrophages. By ISH, NPR-A was not detectable in any of the lesions but both NPR-B and NPR-C were found in the intimal and the inner medial layers. By RT-PCR, mRNA levels of all NPs tended to be increased in macroscopically diseased arteries, but only the values for BNP were significantly so. No significant changes in NPR mRNA levels were detected by PCR. In general, the signal intensity given by the NPs and their receptors by ICC or ISH appeared dependent on the type of lesion, being strongest in intermediate plaques and decreasing with increasing severity of the lesion. This study constitutes the first demonstration of NPs and NPR mRNAs in human coronary arteries and supports the existence of an autocrine/paracrine NP system that is actively modulated during the progression of atherosclerotic coronary disease. This suggests that the coronary NP system is involved in the pathobiology of intimal plaque formation in humans and may be involved in vascular remodeling.     

Specific features of satellite cells and myoblasts at different stages of rat postnatal development

A cell culture consisting mainly of satellite cells and mononuclear myoblasts was derived from femoral muscles of infant (aged 3–7 days) and adult rats. Satellite cells identified by expression of the specific marker Pax7 accounted for approximately 80% of the isolated cell fraction. Mononuclear myoblasts represented by proliferating and postmitotic cell pools were identified immunocytochemically by the expression of markers Ki67 and desmin. Differentiation of satellite cells and myoblasts in the culture depended on the concentration of Ca²⁺ in the culture medium (F12 with different Ca²⁺ concentrations or DMEM). Differentiation of myogenic cells manifested in myoblasts fusion, formation of myotubes, and expression of myosin in myofibrils was observed only in the medium with a high Ca²⁺ concentration (2mM). Satellite cells and myoblasts from the muscles of newborn and adult rats did not differ noticeably in their capacity for differentiation.     

Quantitative criteria for assessing the stages in the postnatal period of mammalian development

Methods of mathematical statistics have been used to develop a quantitative method for periodization of the systems of mammalian organism in the postnatal development period. The method has been evaluated as to 32 histomorphological indices of blood system, thyroid gland and adrenal glands. The distinguished dependences are shown to fit adequately the qualitative changes noted in the published works of other authors.     

Branching characteristics of human coronary arteries

Branching angles and branch diameters were measured in a total of 850 arterial junctions in the coronary networks of two human hearts. Comparison is made with similar data obtained previously from the coronary networks of rats, and with what is considered to be optimum on theoretical grounds. It is concluded that the branching characteristics of the human coronary arteries are closer to the theoretical optimum than those of the coronary networks of rats. While the human data exhibit some departure from optimality and a good amount of scatter, these are well within levels observed elsewhere in the cardiovascular systems of man and animals, and considerably better than those found in the coronary networks of rats. The departure from optimality, in terms of physiological cost to the system, is within 5% for most data points.     

Therapeutic treatments of mtDNA diseases at the earliest stages of human development

More than 150 pathogenic mitochondrial DNA (mtDNA) mutations associated with a range of illnesses have been described in humans. These mutations are carried by one in 400 people and their inheritance is exclusively maternal. Currently there is no method to prevent mtDNA diseases, which highlights the need for strategies to predict their transmission. Here we outline the scientific background and unique difficulties in understanding the transmission of mtDNA diseases, explaining why their management has lagged so far behind the genetics revolution. Moreover, both current and future management options, including cytoplasmic and nuclear transfer, are also discussed.     

Roots and calibers of the human coronary arteries

The anatomical structure of the coronary-aortic junctions in humans is studied by using corrosion casts of the coronary network. A model is proposed for the specification of these junctions in terms of vessel diameters and branching angles, and the model is used to produce morphological data on these junctions which hitherto have not been available. This anatomical model correlates poorly with the accepted theoretical model of arterial bifurcations in the cardiovascular system. The results suggest that the structure of the coronary-aortic junctions is very different from the structure of typical arterial bifurcations and, by implication, that the flow conditions under which they function are very different. A good understanding of these junctions is important in coronary bypass surgery, where the coronary-aortic junctions are emulated by creating a new anastomosis for the graft at the base of the ascending aorta, and in coronary artery disease, where atherosclerotic lesions occur not far from the coronary-aortic junctions.     

The atrioventricular branches of the human coronary arteries

Branches of the coronary arteries of normal human hearts, supplying both atria and ventricles, were found by fine dissection and have been named rami atrioventriculares. They comprise atrial branches from ventricular arteries and ventricular branches from atrial arteries. Their incidence was 74% in the 50 adult individuals studied. The subjects had committed suicide with a poison which did not damage the coronary arteries. The atrioventricular branches constitute communications across the coronary sulcus, thus establishing a continuity between the atrial and the ventricular arterial supply. Therefore, there is not invariably a sharp demarcation of blood supply between atria and ventricles, as has been commonly taught. Neither atrial nor ventricular branches consist exclusively of ascending and descending branches of the coronary arteries, as has been assumed. Atrioventricular branches can play a role in collateral circulation and may, in individuals who are born with them, provide an explanation for some of the variability in signs and symptoms incidental to heart attacks.     

Fiber type composition of the plantarflexors of giraffes (Giraffa camelopardalis) at different postnatal stages of development

1. A sample of fibers from deep (close to the bone) and superficial (away from the bone) regions of the plantaris (PLT) and medial (MG) and lateral (LG) gastrocnemius muscles of a neonatal, a 17-day-old and an adult giraffe were typed qualitatively as dark or light based on alkaline preincubation myosin ATPase staining properties and then sized. 2. Each muscle at all ages showed a higher percentage and a larger cross-sectional area (CSA) or light ATPase fibers in the deep than the superficial region. This relationship was qualitatively, although not quantitatively, similar to that reported in hindlimb muscles of other mammals. 3. At all ages, the PLT, the deepest muscle in the synergistic group, had the highest relative total CSA of light ATPase fibers among the muscles sampled. 4. At birth, the PLT had an unusually high percentage of light ATPase fibers in comparison to that found in the same muscle of other mammals. With age, the total CSA of light ATPase fibers increased dramatically in the PLT and decreased slightly in the MG and LG. 5. These data suggest that the PLT, especially the deep portion, may functionally replace the soleus muscle which is absent in the giraffe. In addition, the fiber type results demonstrate that the changes in the fiber type composition of individual muscles observed at different postnatal ages in the giraffe are relatively similar to that reported in smaller mammals, suggesting the existence of similar regulatory mechanisms.     

Modeling the large-scale geometry of human coronary arteries

Two principles suffice to model the large-scale geometry of normal human coronary arterial networks. The first principle states that artery diameters are set to minimize the power required to distribute blood through the network. The second principle states that arterial tree geometries are set to globally minimize the lumen volume. Given only the coordinates of an arterial tree's source and "leaves", the model predicts the nature of the network connecting the source to the leaves. Measurements were made of the actual geometries of arterial trees from postmortem healthy human coronary arteriograms. The tree geometries predicted by the model look qualitatively similar to the actual tree geometries and have volumes that are within a few percent of those of the actual tree geometries. Human coronary arteries are therefore within a few percent of perfect global volume optimality. A possible mechanism for this near-perfect global volume optimality is suggested. Also, the model performs best under the assumption that the flow is not entirely steady and laminar.