Effects of high dietary lead on the metabolism of intravenously dosed selenium-75 in dairy calves.

The metabolism of intravenously dosed 75Se was studied in 10 Holstein bull calves fed for ad libitum access a control diet containing no added Pb or a control diet supplemented with 1000 ppm Pb as PbSO4 for 4 wk. The Pb-supplemented calves exhibited no clinical signs often ascribed to lead toxicity. Likewise, feed intake and body weight gains were not affected adversely. The lead content of rib, kidney, liver, and brain was increased. Serum glutamic oxaloacetate transaminase activity increased in the calves fed Pb during the last 2 wk of the experiment. The kidneys of the calves supplemented with lead were 34% larger than those of controls. The total endogenous 75Se in the feces over the 4-d collection period was not different between treatments (4.14% of dose versus 3.31% of dose). Likewise, urinary 75Se excretion values were similar. About 97% of the 75Se dose disappeared from the blood within 6 h after dosing four calves on both treatments. Tissue concentrations of 75Se were reduced in kidney, spleen, pancreas, brain, and spinal cord. In summary, ingested Pb had very little effect on the endogenous excretion of 75Se in urine and feces; therefore, the data are consistent with earlier research in which the main effect of Pb on Se occurs at the absorption site.

Observations on pigment granules in the bones of silky fowls.

The distribution of melanin pigment-containing cells in the bones of both young and adult silky fowls was observed. Melanin pigment was detected not only in melanocytes which were mainly distributed in the periosteum, but also in all the other types of cells in the periosteum and bone. The continuity of the number of pigment granules in melanocytes and that in the other pigment-containing cells could not be recognized because the granules in the latter cells were much fewer than those in the former. In young fowls, the pigment-containing cells were distributed in all layers of the periosteum and bone, but their number was low. On the other hand, in aged fowls, most of the cells in the periosteum had pigment granules. In the bone, however, pigment granules were observed only in osteocyte situated near the surface. These findings suggest that the pigment granules which are observed in osteocytes have been transferred from melanocytes to osteogenic cells or osteoblasts before they differentiate to osteocytes, where they are presumed to be digested.

[Structural characteristics of collagens from the skin and rib cartilage of patients with Ehlers-Danlos syndrome type II]. / Strukturnye kharakteristiki kollagenov kozhi i rebernogo khriashcha bol'nykh s sindromom Elersa-Danlo II tipa]

Collagens were analyzed in skin and rib cartilage of 9 patients with Ehlers-Danlos syndrome of the II type. Electrophoresis and CNBr-peptide mapping showed that extended inserts and deletions as well as rough impairments of post-translation processing were not detected in collagens of the I, II and III types from these patients. In the patients with Ehlers-Danlos syndrome of the II type distinct increase was observed both in the total ratio of collagens III/I (P = 0.95) and in the ratio of intact collagens III/I free of cross-links. A decrease in content of dimers beta 11 and beta 12 was found in two patients. The data obtained suggest that the Ehlers-Danlos syndrome of the II type involved deteriorations in the structure of collagens I responsible for decrease in stability and sometimes for impairments in cross-link formation. Increase in content of collagen II fraction, predisposed to proteolytic hydrolysis of terminal sites, as well as elevated sensitivity of collagen II to pepsin hydrolysis were found in collagens of rib cartilage from patients with the syndrome and with funnel chest deformation. This suggests the lowered stability of collagen II from rib cartilage in funnel chest deformation.

Variation of trace metals in ancient and contemporary Japanese bones.

Excavated and contemporary bones (rib cortexes) of a mature age (40-60 yr) were analyzed by atomic absorption spectrometry for the concentration of seven elements, including Ca, Cd, Cu, Fe, Mn, Ni, and Pb, with a view to historically evaluating the chemical composition of the bones. Fifty-two well-preserved specimens, obtained from western Japan, were classified into six groups according to Japanese prehistoric and historic eras (Jomon, Yayoi, Kofun, Muromachi, Edo, and Contemporary). Average concentrations of Ca were 0.20-0.33 g/g in the excavated bones and 0.17 g/g in the contemporary bones. Among the trace metals, such as Cu, Fe, Mn, and Pb, which showed remarkably elevated concentrations in the Edo era bones, Cu, Fe, and Mn were found to be strongly associated with soil contamination. Lead levels only slightly increased between the Jomon and Kofun eras, but became abruptly elevated following the Edo era. In contrast, the concentrations of Cd increased abruptly in the Yayoi era to a level with an order of magnitude higher than the Edo era, and they have recently decreased to rather low contemporary levels. This tendency becomes clearer when comparing the molar ratio of trace metals to Ca. The cause of elevated Cd concentrations in early excavated bones is discussed in relation to the mineralization of bones and the surrounding environment.

Sex- and age-related variation in elemental concentrations of contemporary Japanese ribs.

Twenty elements (Al, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Sr, Ti, V, Zn, C and N) in 42 Japanese ribs (forensic medical autopsy cases) were determined using inductively coupled plasma atomic emission spectrometry (ICP-AES), atomic absorption spectrometry (AAS) and carbon and nitrogen analysis to examine sex- and age-related variation in the concentrations of these elements. Bone Fe and Pb concentrations were significantly higher, while P concentrations were lower in males. Elements which showed age-related variation were Ca, P, Al, Fe, Mg, Na, Pb and Zn. Of these, Al, Fe, Pb and Zn linearly accumulate in bone with advancing age. The elements Na and Mg showed the lowest and highest concentrations in the youngest age group (0-19 years), respectively, and reached plateau levels in older age groups. The Ca and P concentrations were highest in the 20-39-year age group, gradually decreasing throughout older age groups, indicating that osteoporotic bone loss occurs in the older subjects. In addition, the results of correlation analysis indicated that the organic matter content of the bone, represented by C or N concentration, was a factor which contributed to the elemental variation of the bone.

Utilization of femoral head for estimating the skeletal burden of U and Pu in humans.

Uranium and Pu were determined in vertebrae, ribs and femoral head samples obtained from the same population. Vertebrae and rib samples were obtained at autopsy and femoral head samples were obtained from persons undergoing hip surgery. The results indicate that there was no statistically (p less than or equal to 0.05) significant difference between the mean concentration of 239,240Pu in vertebrae and ribs. Also, there was no significant difference between the mean concentration of 239,240 Pu in ribs and femoral head. Also, statistical tests were performed to see whether the mean concentrations of 238U and 234U in three different bones differ from each other. The results suggest that there was no statistically significant difference between vertebrae and ribs, vertebrae and head of the femur nor between ribs and femoral head. These results indicate that femoral head may be an appropriate substitute for vertebrae or ribs, the most commonly used bone for inferring the skeletal burden of U and Pu in human. Femoral head samples can be obtained from living persons undergoing hip surgery, while vertebrae and ribs are obtained only at autopsy.

Presence of osteonectin/SPARC in mandibular condylar cartilage of the rat.

Osteonectin/SPARC was most abundantly present in adherent osseous tissue of the cartilage explants. In cartilage explants with ossification fronts, it appears to be present in hypertrophic chondroblasts and in the mineralised extracellular cartilage matrix. In a number of cartilage explants it could be demonstrated in the fibroblastic cells of the perichondrium and, intra- and extracellularly, in cartilage located adjacent to the perichondrium. In young mandibular condylar cartilage (20 days post-conception up to 7 days of age) osteonectin/SPARC was characteristically present in the transitional zone, a small area of differentiating skeletoblasts. In cartilage, osteonectin/SPARC might play a role in the process of mineralisation and subsequent replacement by bone. It seems to be an important marker of skeletal differentiation processes.

Immunohistochemical localization of type II collagen in cartilage-forming tumors.

The presence and distribution of type II collagen was studied in 36 cartilage and cartilage-related tumors, including five osteosarcomas and one chordoma. A monoclonal antibody prepared from chicken type II collagen was used with paraffin sections, employing the ABC (avidin biotinylated horseradish peroxidase complex) peroxidase technique. Fetal cartilage and fracture callus were used as control materials. Type II collagen was present in the matrix of all the cartilage tumors. The reaction was strongest in areas of well-differentiated cartilage and weakest in the poorly differentiated tissue of high-grade chondrosarcomas. Areas of mineralization or ossification, and areas of eosinophilic, fibrous, or degenerated cartilage gave a negative reaction.

Elevated lead concentrations in Japanese ribs of the Edo era (300-120 BP).

Nineteen elements (Al, B, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Sr, Ti, V and Zn) were analyzed in excavated bone (rib) of the Edo era (a Japanese historical era, 300-120 BP (before present] from different burial conditions in Tokyo, and in contemporary Japanese bone (rib) obtained from autopsy cases. The elemental composition of the excavated bones varied according to their burial conditions. The concentration of soil-related elements such as Fe, Mn, Co and Ti in the bone was lowest in the samples in the "wooden coffin in a stone room", next lowest in the "funeral urn with mud", and highest in the "wooden coffin full of mud". The Pb concentration was higher in excavated bones than in contemporary bones and much higher, by as much as several tens micrograms/g, in the bones in the "wooden coffin in a stone room" and in the "funeral urn with mud". These results strongly support the notion that Japanese in the city of Edo were highly polluted by environmental lead.

Mineral content of rib bone in infant deaths.

The mineral content of rib bone in infants who died unexpectedly was similar to that among those who died after acute illnesses, and it was significantly associated with both crown to heel length and age. In those dying from chronic illnesses it was lower than in the other two groups.

The autodegradation of deoxyribonucleic acid (DNA) in human rib bone and its relationship to the time interval since death.

This research explored the feasibility of using the degradation rate of deoxyribonucleic acid (DNA) in human rib bone to determine the time interval since death. Postmortem human rib samples were surface sterilized and incubated under sterile conditions in either high or low humidity conditions at room temperature for a period of weeks. At selected times, portions of the bone were cut away, and the DNA from these samples was extracted and subjected to strand separating gel electrophoresis. The DNAs in the gels were transferred to a nylon membrane, preserving their relative positions as in the gel, and probed with radioactive total genomic human DNA. Autoradiograms produced were scanned and digitized. When the samples were incubated under identical conditions, the degradation rate of DNA in samples from different individuals appeared very similar. The DNA degradation rate may vary with temperature and humidity more than it varies between individuals.

[Extractability of collagen from the rib cartilage and skin in funnel chest in children]. / Ekstragiruemost' kollagena rebernogo khriashcha i kozhi pri voronkoobraznoi deformatsii grudnoi kletki u detei.

Content of collagen and relative content of unextractable collagen were increased by 35% and 50%, respectively, while the content of immobilized water was decreased in costal cartilage of children with the isolated form of funnel chest or with the deformation accompanied by Ehlers-Danlos syndrome. These anomalies may be considered as indicators of the cartilage premature ageing. In skin of the children with isolated form of funnel chest the ratio of collagen extracted with acetic acid was increased 2-fold.

The chondrogenesis of rib perichondrial grafts for repair of full thickness articular cartilage defects in a rabbit model: a one year postoperative assessment.

The purpose of this study was to investigate the results or rib perichondrial grafting after the creation of a full thickness articular cartilage defect. In a rabbit model, rib perichondrium was used to repair defects created in the femoral condyle. The formation of repair tissue (neocartilage) and its chondrogenesis into a tissue resembling articular cartilage was found over time. The gross, histological and biochemical characteristics of the neocartilage were evaluated at intervals of 6, 12, 18, 26 and 52 weeks post transplant, and compared to normal articular cartilage. The neocartilage was characterized by the early formation of relatively large amounts of glycosaminoglycans. A steady increase in the proportion of type II collagen over the time periods was also observed. Improved attachment of the neocartilage to host tissues was seen over the period of 6 to 52 weeks. Successful grafts were seen to proliferate to fill the articular defect and to undergo a chondrogenesis over a post transplant time period of one year.

Measurements of mineralization process in the femur growth plate and rib cartilage of the mouse using pixe in combination with a proton microprobe.

The femoral bone from the 18-day pregnancy embryo and an rib cartilage of mature mice have been investigated using PIXE (proton induced X-ray emission) in combination with a proton microprobe on snap frozen cryosectioned material. The localization and the results of quantitative measurement of P, S, Cl, K, Ca, Fe and Zn have been correlated with the histochemical localization of inorganic deposits. It has been found that in calcifying and degenerating cartilage of the growth plate there is substantial loss of S; this element being indicative for sulphate groups of glycosaminoglycans. This change seems to be an important factor conditioning the process of mineralization. Zn is found in higher concentration in mineralized tissues, both in embryonal and mature cartilage as well as in the bone, and this suggests that Zn is also involved in the mineralization process. The mineralization of rib cartilage exceeds that of embryonal bone, and the Ca/P ratio is higher in the former than in the hydroxyapatite of the latter. The method described is a useful analytical tool especially for such types of studies in which elements are not easily redistributed by freezing, cutting and drying; e.g. in investigations of mineral deposits.

Mineral content of bone: measurement by energy subtraction digital chest radiography.

Several methods are presently available for measuring the mineral content of bone. Those in widespread use include dual-photon absorptiometry and quantitative CT. The feasibility of using dual-energy digital chest radiography for determination of the mineral content of posterior ribs on digital chest images was studied by using a prototype unit. The results showed a significant difference in the mineral density of the posterior ribs of control subjects and those of patients who had osteoporosis (251.1 +/- 36 mg Ca2+/cm2 of rib vs 158.8 +/- 48 mg Ca2+/cm2, p less than or equal to .01) and a close correlation with values obtained by dual-photon absorptiometry of the lumbar spine (r = .77). The results suggest that this technique can provide an accurate assessment of the presence or absence of osteoporosis.

Distribution of uranium in human bones.

Uranium and calcium contents in human bones (skull, rib and femur) were determined by the fission track method and the inductively coupled plasma-atomic emission spectroscopic method (ICP-AES), respectively. The U/Ca concentration ratio in the bones was found to decrease in the order of rib greater than femur greater than skull, which is in accordance with the decreasing order of the mean annual replacement percentage of bone components. Several femur bones were cut into several longitudinal segments, and uranium and calcium contents in each segment were determined. Among these, the U/Ca ratio in the epiphysis was higher than those in the diaphysis.

Elemental changes associated with chondrocyte differentiation in rat rib growth plate.

Quantitative X-ray microanalysis was under-taken to follow the elemental changes that occur in the process of chondrocyte differentiation. For analysis at the cellular level, semi-thick freeze-dried cryosections of rat rib growth plate cartilage were used. For evaluation of the elemental concentrations at the subcellular level, thin sections of freeze-dried and low temperature vacuum embedded cartilage were analyzed. Levels of Na, P, S, Cl, K, and Ca were determined in the cells and extracellular matrix in different zones of the cartilage--resting, proliferative, and hypertrophic. Proliferative cells had a sodium concentration that was twice that of resting cells, suggesting that Na may play an important role in the regulation of DNA- and protein-synthesis in chondrocytes, A concomitant rise in Na and S concentration occurred between resting zone and proliferative zone cartilage matrix. The high concentrations of Na and K in the matrix are probably due to the high amount of sulfate in proteoglycans which may bind these cations.

[Heavy metal deposits in pathologically modified hard tissues. Clinical and experimental studies]. / Schwermetallablagerungen in pathologisch veränderten Hartgeweben. Klinische und experimentelle Untersuchungen.

Various studies have shown a relationship to exist between toxic heavy metal accumulation and pathologic processes in various tissues. In the present study pathologic processes were found to be associated with an increase in the concentrations of various elements including Hg, Cd, Pb, Zn, Cu and Mn. Our results suggest the accumulation of toxic heavy metals and the increase in the Zn concentration to be a secondary phenomenon. If the tissue damage becomes irreversible, the zinc concentration drops, while toxic heavy metals continue to accumulate. consequently, zinc could be an indicator of the biological reactivity of tissues.

[Concentration of stable zinc in human bones. Determination by x-ray fluorescence spectrography]. / Concentration de zinc stable dans les os humains. Dosage par spectrographie de fluorescence X.

Zinc has been analysed in bone samples taken from ribs and from vertebrae collected in the Paris region. X-ray fluorescence, with a detection limit of 30 ppm, has been applied to the bone ash. In the ash, the individual average concentration is 234 +/- 125 micrograms g-1 and is quite independent of age (p = 0.95 for one analysis). The vertebrae contain 14% more zinc than the ribs; the difference is significant at the 0.01 level. No difference between the sexes has been observed. An adult ingests on the average 20 mg Zn daily with his food intake. The inhaled amount is much less, approximately 9 micrograms. A skeleton contains on the average 520 mg Zn.

Tissue mineral levels in victims of sudden infant death syndrome I. Toxic metals--lead and cadmium.

Lung, liver, kidney, and rib specimens were obtained at autopsy from 66 sudden infant death syndrome (SIDS) infants and 23 infants who died suddenly from other causes between the ages of 4-26 wk. Tissue levels of lead and cadmium were measured by atomic absorption spectroscopy and are expressed as microgram/g dry weight. Because these metals are cumulative with age in storage tissues, the levels were corrected for age (adjusted to age 13 wk). The SIDS liver and rib specimens contained significantly more lead than non-SIDS tissues (liver, 1.095 microgram/g versus 0.761 microgram/g, P less than 0.05; rib, 1.754 microgram/g versus 1.041 microgram/g, P less than 0.01, respectively). There were no significant differences in cadmium concentration between the SIDS and non-SIDS tissues. All four tissues showed significant increases with age in both lead and cadmium concentrations in SIDS. The increase in lung lead concentration with age was significantly greater in SIDS than in non-SIDS cases, P less than 0.05. In non-SIDS only kidney cadmium showed an increase with age (P less than 0.0001). These data collectively suggest an increased exposure of the SIDS infant to lead either prenatally and/or postnatally. Any physiologic effects of the increased tissue lead levels are unknown. They may be only a marker of the known epidemiology of SIDS.