Cartilage canals in the human spheno-occipital synchondrosis during fetal life.

Spheno-occipital synchondroses were studied histologically in eight human fetuses ranging from 100 mm CRL to term. Cartilage canals were present in all seven specimens over 110 mm CRL. With age the canals grew longer and wider and the larger ones developed some branching. The histologic structure, external morphology and spatial arrangement of these cartilage canals were described. Some attributes of cartilage canals were reviewed from available data in the literature and their significance for the present findings discussed. It was suggested that the canals, containing blood vessels and connective tissue elements, actively invade the cartilage of the synchondrosis. It was suggested further that they probably serve as a source of nutrition or as an extension of the perichondrium (and a source of prospective chondroblasts) or both.     

Cartilage channels of the human patella up to birth

In the human patella from the 4th month up to the birth were examined contents and surrounding structures of vascular channels. Except the articular area the cartilage of the patella is covered by the perichondrium. From here mesenchym and blood vessels enter, and penetrate into the cartilage by forming channels. Dependent on the stages of development the construction of cartilage around the channels is different in comparison with other territories. The findings will be compared with the results from the channels in the cartilaginous anlage of different bones.     

Elastogenesis in the wall of the human thoracic aorta

The results of this study dealing with the human thoracic foetal aorta testify that even in the middle of the fifth month of development the internal elastic membrane is not yet completely continuous. Furthermore they show that elastogenesis in the tunica media of the human thoracic aorta does not begin directly below the internal elastic membrane, as it does in the foetal aorta of the laboratory rat, but, as it can be seen in our material, somewhat deeper in the developing tunica media. A thin layer of less differentiated tunica media cells persists for a long time in the vicinity of the internal elastic membrane. In the middle of the fifth month, the fusing elastic membrane segments in the tunica media still consist of very immature elastic tissue with a large proportion of the microfibrillar component. The collagen fibrils in the intercellular spaces in the whole depth of the wall of the developing aorta do not become a part of the elastic membranes. Their bundles merely accompany all the elastic membranes in the wall of the thoracic aorta, including the internal elastic membrane.     

Proteolipid and human aorta calcification, in vitro

The objective of this study was to determine whether in vitro calcification of human aorta is proteolipid dependent. Homogenates were prepared from tissue with no gross pathologic manifestations. Samples were examined for calcifiability in a metastable calcium phosphate solution before and after lipid extraction. Fractions of the extracted lipid were similarly examined. The tissue calcified before but not after lipid extraction. Calcifiability was restricted to the proteolipid portion of the lipid extract. Under the conditions employed, therefore, proteolipid is required for calcification of human aorta, in vitro.     

Anatomo-functional features of the blood supply to the thoracic part of the canine spinal column

In an acute experiment, performed in 10 dogs with application of radiological methods, zones of the vertebral part of the intercostal arteries reservoirs and extent of their anastomization with each other both in transversal and longitudinal directions have been stated. The vertebral part of the reservoir of each intercostal artery supplies with blood that half of the corresponding segment of the spinal column, which has the same name, and tissues around, and spreads to the adjoining caudal segment.     

Cartilage polysaccharide induces apoptosis in human leukemia K562 cells

In this study, we extracted a polysaccharide (short-chain polysaccharide [PS]) from porcine cartilage and examined its function in chronic myeloid leukaemia by using human K562 cells and mouse L1210 cells. Results of cell proliferation assay indicated that PS inhibited cancer cell growth at different concentrations, while it had little effect on normal cells. The presence of morphological aspects of apoptosis, such as nuclear shrinkage, was shown in H&E stained sections. The occurrence of PS-induced apoptosis was confirmed by TUNEL assay and cell cycle analysis. The results of immunofluorescent staining indicated the molecular mechanism underlying. Through interfering with the cell cycle of tumor cells, PS may induce apoptosis by downregulating the expression level of cyclin D1 and upregulating the level of p21 protein. Correlation analysis of apoptosis and MAPK suggested that inactivation of ERK was crucial for PS induced apoptosis, while JNK phosphorylation had a small effect and p38 was not involved. In vivo assay showed that PS inhibited L1210 cell growth in vivo and prolonged the life span of L1210-bearing mice. We conclude that PS is a polysaccharide with anticancer effects and induced apoptosis in human K562 cells.     

Elastostatic analysis of the human thoracic skeleton

An elastostatic, finite element model (designated THORAX I) of the human thoracic skeleton has been developed. The model includes the primary load-carrying members of the thorax; namely, the sternum, costal cartilage, ribs, and vertebral column. The soft tissue has been neglected.

Using gross geometric data measured from a skeleton with an apparent ‘small’ frame and approximate cross-sectional properties, the THORAX I model has been subjected to three loading distribution applied to the anterior chest wall in the anterior-posterior direction. Calculations were carried out on the IBM 7094 computer, and primary attention was focused upon the displacement fields of the sternum, costal cartilage and ribs and stresses in costal cartilage and ribs. The sternum and rib nodal point displacement fields are reported in detail, and a simple 2-degree-of-freedom model for the sternum, which correlates well with the analytic results, is also presented. Maximum normal stresses in the cartilage and bony regions of the individual ribs for one loading condition are also given.     

Optical measurement of age-related calcification in human blood vessels

Vascular calcification is commonly associated with aging. Quantification of calcium accumulation in vessel walls is important in understanding the mechanisms of vascular calcification. To elucidate age-related change of calcification, site dependence of calcification, and the effect of hemodynamic stress on calcification, we measured calcium contents in various blood vessels with atomic emission spectrometry and simulated blood flow in the vessels by computational fluid dynamics. The content of calcium in the arteries increased progressively with aging while there is no change in the veins. The higher accumulation of calcium occurred in the arteries of the lower limb in comparison to the arteries of the upper limb. In the arterial bifurcation, there was the correlation at hemodynamic stress distribution and calcium content. The results of this study quantitatively support clinical findings of nonuniform calcification, and suggest that hemodynamic stress affects vascular calcification.     

Moment-rotation responses of the human lumbosacral spinal column

The objective of this study was to test the hypothesis that the human lumbosacral joint behaves differently from L1-L5 joints and provides primary moment-rotation responses under pure moment flexion and extension and left and right lateral bending on a level-by-level basis. In addition, range of motion (ROM) and stiffness data were extracted from the moment-rotation responses. Ten T12-S1 column specimens with ages ranging from 27 to 68 years (mean: 50.6+/-13.2) were tested at a load level of 4.0 N m. Nonlinear flexion and extension and left and right lateral bending moment-rotation responses at each spinal level are reported in the form of a logarithmic function. The mean ROM was the greatest at the L5-S1 level under flexion (7.37+/-3.69 degrees) and extension (4.62+/-2.56 degrees) and at the L3-L4 level under lateral bending (4.04+/-1.11 degrees). The mean ROM was the least at the L1-L2 level under flexion (2.42+/-0.90 degrees), L2-L3 level under extension (1.58+/-0.63 degrees), and L1-L2 level under lateral bending (2.50+/-0.75 degrees). The present study proved the hypothesis that L5-S1 motions are significantly greater than L1-L5 motions under flexion and extension loadings, but the hypothesis was found to be untrue under the lateral bending mode. These experimental data are useful in the improved validation of FE models, which will increase the confidence of stress analysis and other modeling applications.     

The elongation of the human cervical vertebral column

Cervical vertebral elongation has been studied using serial cephalometric radiographs of 32 children examined regularly from 0.25 to 17 years. Mean vertebral body heights increased rapidly to about 2.5 years and then decelerated except for a spurt at about the age of peak height velocity. There were only small sex differences in vertebral body elongation to 12 years. From then to 15 years, the vertebral body heights in the girls exceeded those in the boys; later this sex difference was reversed. There was no pubertal spurt in disc elongation. The correlation coefficients were negative between vertebral body heights and the heights of adjoining intervertebral discs, e.g., body C3 and disc C3–4, but those between body heights or between disc heights were positive. The heights of adjacent cervical vertebral bodies were correlated more highly than the heights of non-adjacent bodies. There was a similar pattern of differences between correlation coefficients for the heights of adjacent and non-adjacent intervertebral discs.     

Staining of the calcification front in human bone using contrasting fluorochromes in vitro

Histological studies on bone from the human iliac crest have suggested that if the customary techniques of labeling in vivo with certain fluorochromes such as tetracycline are replaced or augmented by simple whole tissue staining in vitro using the same reagents, differences in the pattern of extracellular fluorescence between normal and pathological states are retained. In particular, the association of the fluorescence with the calcification front in stained examples is closely comparable to similar examples that have been labeled (r = 0.988, p less than 0.001) and to other tinctorial methods (r = 0.891, p less than 0.001). While the stain alone lacks the time lapse of multiple labels, when administered some days after a single label at the time of biopsy, it provides an effective second marker and a measure of mineralization rate that does not differ significantly from that using double labels. Moreover, since the problems of toxicity are avoided by staining, a range of contrasting fluorochromes previously restricted to animal studies may now be used in man. In particular, the enhanced color differentiation brought about by the combination of tetracycline label followed by xylenol orange stain improves image resolution and greatly aids interpretation.     

Adrenoceptors of the human internal thoracic artery.

Adrenoceptor function in the human internal thoracic artery (ITA) was characterized in vitro using segments of the artery obtained during coronary bypass operations. Specimens were prepared as isolated arterial rings mounted in a tissue bath, and mechanical activity (isometric tension) was measured in response to drugs. The ITA responded to phenylephrine (PE), epinephrine, and norepinephrine with concentration-dependent contractions. The PE-induced contractions were antagonized by phenoxybenzamine, prazosin, and high concentrations of yohimbine. The ITA was not effectively contracted by clonidine in the concentration range normally associated with alpha 2-adrenoceptor stimulation. The beta-adrenoceptor agonist, isoproterenol, had a weak and variable effect on the ITA; samples from 9 out of 12 subjects did not respond to isoproterenol, whereas samples from 3 subjects responded with relaxations of between 33 and 42%. These in vitro studies indicate that the most important adrenoceptors of the human ITA are alpha-adrenoceptors; this may be relevant for the pharmacologic management of patients undergoing coronary bypass surgery using the ITA.     

Age-related change of mineral content in the human thoracic aorta and in the human cerebral artery

The relative contents (RCs) of mineral elements in aortae and cerebral arteries from 23 subjects, with ages ranging between 45 and 99 yr, were analyzed by inductively coupled plasma atomic emission spectrometry. The RCs of calcium, phosphorus, and magnesium in the aortae increased markedly after the age of 70. While the RC of sulfur in aortae decreased gradually after that age. It was found that accumulation of calcium and phosphorus occurred primarily in the tunica media of aorta, and secondarily in the tunica intima. Furthermore, the RCs of calcium, phosphorus, and magnesium in cerebral arteries increased markedly after the age of 70, whereas the RC of sulfur in cerebral arteries decreased after age 70. It was found that accumulation of calcium and phosphorus in the cerebral arteries were 30 and 60%, respectively, lower than those in the aortae with ages ranging between 45 and 99 yr.     

Silicon compatible with the height of human vertebral column

In the study on human vertebral composites, silicon was found to be related to the height of the vertebral column. The element ratio of silicon to calcium in the lumbar vertebra was twice that of the lowest one in the cervical vertebra. The element ratio gradually increased from approx 0.5 at the cervical vertebra to approx 1.0 at the lumbar one. Silicon is preserved catastropically much more in the lower height of the backbone in contrast with the calcium amount, and the ratio to sulfur appears to be unchanged. This suggests that silicon is compatible with the biokinetics of the vertebral bone structure of calcium.     

Nerves and nerve plexuses of the human vertebral column

The origin, distribution, and termination pattern of nerves supplying the vertebral column and its associated structures have been studied in the human fetus by means of an acetylcholinesterase whole-mount method. The vertebral column is surrounded by ventral and dorsal nerve plexuses which are interconnected. The ventral nerve plexus consists of the nerve plexus associated with the anterior longitudinal ligament. This longitudinally oriented nerve plexus has a bilateral supply from many small branches of the sympathetic trunk, rami communicantes, and perivascular nerve plexuses of segmental arteries. In the thoracic region, the ventral nerve plexus also is connected to the nerve plexuses of costovertebral joints. The dorsal nerve plexus is made up of the nerve plexus associated with the posterior longitudinal ligament. This nerve plexus is more irregular and receives contributions only from the sinu-vertebral nerves. The sinu-vertebral nerves originate from the rami communicantes and, in the cervical region, also from the nerve plexus of the vertebral artery. Thick and thin sinu-vertebral nerves are found. Most frequently three types of thick sinu-vertebral nerves are observed, i.e., ascending, descending, or dichotomizing ones. Finally, the distribution of the branches of the ventral and dorsal nerve plexuses and of the sinu-vertebral nerves is described.     

Elements of calcified sites in human thoracic aorta

To elucidate the manner of element accumulation in the arteries with aging, the authors investigated the element contents in the calcified and surrounding sites of the thoracic aortas by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of three men and five women, ranging in age from 45 to 99 yr. The calcified, calcification-surrounding, and control (which appeared normal) sites were removed from the thoracic aortas and the element contents were determined. It was found that the contents of calcium, phosphorus, magnesium, zinc, and aluminum were higher in the calcified site than in the control site, whereas the contents of sulfur, iron, and lead were lower in the calcified site than in the control site. The contents of the elements in the surrounding site were intermediate between those of the calcified and control sites, except for the magnesium and lead contents, which were the lowest. The mass ratios of magnesium to calcium and phosphorus were lower in the calcified site compared with the surrounding and control sites, and as calcium and phosphorus increased in the aorta, the mass ratios lowered gradually in the aorta.