Biomedical subjects

X M Tang

Publications and source records attributed to X M Tang.

At least 37 records · Page 2Linked to original sources

PubMed1995

Functional implication of autophagy in steroid-secreting cells of the rat.

BACKGROUND: Autophagy, while frequently observed in embryonic cells undergoing differentiation and in pathologically altered cells, appears to occur less commonly in normal, fully differentiated cells. Our previous work revealed that the frequency of autophagic activity was rather high in the Leydig cells of rat testes, but the functional significance of autophagy in Leydig cells remains obscure. The purpose of the present study is to investigate the possible role of autophagy in steroid-secreting cells. METHODS: The autophagic activity was investigated in two steroid-secreting cells, e.g., Leydig cells and adrenocortical fasciculata cells of rats. Cytidine monophosphatase (CMPase) cytochemistry was utilized to show the activity of lysosomal enzymes in autophagosomes. Electron microscopic morphometry was employed to analyze the frequencies of autophagy in the cells of the rats intact or treated with related hormones resulting in a hyper- or hypo-secretion of testosterone and corticosterone. RESULTS: Autophagy took place in normal steroid-secreting cells with higher frequencies than in many other cells including the tubular cells of kidney and hepatocytes. The large number of autophagosomes or autophagic vacuoles allowed to outline the autophagic process in these cells. The C-shaped double-membrane profiles tending to demarcate a portion of cytoplasm were referred to as pre-autophagosomes. So-called early autophagosomes were the vacuoles enclosed completely by double delimiting membranes, containing normal-looking cellular components. The majority of sequestered organelles appeared to be mitochondria and smooth endoplasmic reticulum. The autophagosomes starting digestion were considered as late autophagosomes or autophagic vacuoles, the indications of which were the destruction of their contents or the presence of lysosomal enzymes demonstrated by a positive CMPase reaction. Residual bodies were frequently observed to be exocytosed. The quantitative assay revealed an alteration of autophagic activity in close relation with steroid-secreting states. The number of autophagosomes was one-fold higher in hyposecreting Leydig cells after 2 days testosterone administration, and three-fold higher in hyposecreting adrenocortical fasciculata cells after one dosage of dexamethasone administration. In addition, the autophagosomes showed a four-fold decrease in hypersecreting Leydig cells stimulated by LRH for 2 days. CONCLUSIONS: Considering that most of the autophagocytosed organelles were steroid-producing apparatus, we may conclude that, by removing part of steroid-producing organelles, autophagy might play a role in adapting to or even regulating the secretory activity. This hypothesis was strongly supported by the fact that the intensity of autophagy varied in company with the fluctuation of steroid secretion.

Animals↗

PubMed1995

Human fallopian tube as an extraovarian source of relaxin: messenger ribonucleic acid expression and cellular localization of immunoreactive protein and 125I-relaxin binding sites.

By means of specific human relaxin primers that originated from relaxin A and B chains, a monoclonal antibody, and 125I-relaxin, the expression of mRNA and immunoreactive protein and the presence of binding sites for relaxin were investigated in human fallopian tubes. Reverse transcription polymerase chain reaction (RT-PCR) analysis of total RNA isolated from tubal tissues revealed the predicted 434-bp fragments originating from both the H1 and H2 relaxin genes. Restriction enzyme digestion of the RT-PCR products with Msp I (Hpa II), present only in the relaxin H1 sequence, resulted in the anticipated 175- and 259-bp fragments, whereas digestion with Hpa I, which is present in the relaxin H2 sequence and should have resulted in 188- and 246-bp fragments, induced a limited and partial digestion of the product. Codigestion of the RT-PCR product with Msp I+Hpa I also resulted in 175- and 259-bp fragments. The immunoreactive relaxin protein was present primarily in the tubal epithelial cells of the ampullary and isthmus regions, and with weaker intensity in tubal smooth muscle cells. Immunoreactive relaxin either was barely present or was absent in other tubal cell types. The intensity of immunostaining for relaxin in the epithelial cells appeared not to be cycle-dependent; however, these cells showed a lower immunostaining at the late secretory phase of the menstrual cycle than at other reproductive stages and an absence of immunostaining during the postmenopausal period.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoradiography↗

PubMed1994

The effect of surgical glove powder on proliferation of human skin fibroblast and monocyte/macrophage.

The effect of surgical glove powders (Biosorb, Keoflo, and CaCO3) and Hydrocote (powder-free lubricating agent, Biogel) was examined on human skin fibroblasts and monocyte/macrophage cell lines (U937 and HL-60). Glove powders (0.1-100 micrograms/ml) in the presence of 10% fetal bovine serum (FBS) had no significant effect on the rate of 3H-thymidine uptake and proliferation of these cells after 48 h and 7 days of exposure, respectively. However, they inhibited HL-60 growth after 10 days, and Biosorb and CaCO3 inhibited U937 after 10-21 days of exposure compared with control. In the presence of low serum (0.5%), Biosorb, but not Keoflo, CaCO3, and Hydrocote, inhibited HL-60 cells after the third day of exposure (p < 0.05), whereas they were without any effect on U937 cells. Further incubation resulted in a significant decrease in cell density in all treatments, as well as controls, because of cell death. In the presence of 2% serum, glove powder-treated HL-60 significantly increased in cell numbers during the first 3 days, and the cells became stationary thereafter, whereas Keoflo and CaCO3-stimulated U937 reached a maximal by 9 days of treatment. Coculturing of fibroblasts directly with macrophages (0.4-5 x 10(5) cells per dish) or incubation with macrophage culture-conditioned media (CCM) stimulated quiescent fibroblast growth equal to that induced by 10% and 0.5% serum, respectively (p < 0.05). However, incubation of fibroblasts with glove powder-treated HL-60 CCM (except CaCO3) inhibited (p < 0.05) and CCM from Biosorb-treated U937 stimulated (p < 0.05) fibroblast proliferation. The CCM from glove powder-treated HL-60 and U937 did not have any significant effect on the rate of 3H-thymidine incorporation into fibroblasts compared with controls. The present observations suggest that glove powder action on fibroblast and macrophage growth in vitro depends on both the serum concentration of the culture medium and the length of exposure. The results imply that glove powders may have an adverse effect in vivo by directly influencing the biologic activity of macrophages, as well as other cell types, leading to alterations in the early phases of wound healing.

Calcium Carbonate↗

PubMed1994

Insulin-like growth factor I (IGF-I), IGF-I receptors, and IGF binding proteins 1-4 in human uterine tissue: tissue localization and IGF-I action in endometrial stromal and myometrial smooth muscle cells in vitro.

The objective of the present study was to elucidate the presence and cellular distribution of insulin-like growth factor I (IGF-I), IGF-I receptor (IGF-IR), and IGF binding proteins (IGFBPs) in human uterine tissue at various reproductive stages, and to determine the effect of IGF-I and its interaction with epidermal growth factor (EGF) and platelet-derived growth factor (PDGF) in endometrial stromal and myometrial smooth muscle cells in primary culture. Using specific antibodies, immunohistochemical observations indicated that luminal and glandular epithelial cells were the major sites of immunoreactive IGF-I, IGF-IR, and IGFBPs 1-4, followed by myometrial smooth muscle and endometrial stromal cells. The immunostaining intensity of IGF-I, IGF-IR, and IGFBPs in endometrial but not myometrial tissue was cycle-dependent and higher in the late proliferative and early/mid-secretory periods than in the late secretory and postmenopausal periods, with little immunostaining at the early proliferative phase of the menstrual cycle. Stromal and smooth cells in primary cell culture also contained immunoreactive IGF-I, IGF-IR, and IGFBPs. IGF-I at 10-100 ng/ml stimulated 3H-thymidine incorporation in quiescent stromal and smooth muscle cells with maximal effect at 100 ng/ml (p < 0.05). However, in the presence of 2% serum, which induces half-maximal stimulation, IGF-I (100 ng/ml) further increased the rate of 3H-thymidine incorporation in stromal but not smooth muscle cells (p < 0.05). The effect of IGF-I was significantly lower than that induced by EGF (10 ng/ml), PDGF-BB (10 ng/ml) and their combination (p < 0.005), and higher in stromal cells from proliferative, than secretory phase of the cycle in the presence of 2% fetal bovine serum, but not serum-free condition (p < 0.005). The effect of IGF-I on myometrial smooth muscle cells was significantly higher than that induced by EGF, but lower than that induced by PDGF-BB or by EGF+PDGF-BB, without the cycle specificity seen with stromal cells. EGF, PDGF-BB, and their combination with IGF-I, but not IGF-I alone, stimulated stromal and smooth muscle cell growth as determined by a cell proliferation assay. The results indicate that human uterine tissue at various reproductive stages contains immunoreactive IGF-I, IGF-IR, and IGFBPs 1-4. Although IGF-I alone was found to be a weak mitogenic factor for stromal and smooth muscle cells, by interacting with EGF and PDGF-BB in a cycle-dependent manner it may regulate the growth and differentiation of these and other uterine cell types.

Adult↗

PubMed1994

Expression of transforming growth factor-beta (TGF beta) isoforms and TGF beta type II receptor messenger ribonucleic acid and protein, and the effect of TGF beta s on endometrial stromal cell growth and protein degradation in vitro.

Reverse transcription-polymerase chain reaction analysis of total RNA and immunocytochemical observations revealed that human endometrial glandular epithelial and stromal cells in primary culture express messenger RNAs and proteins for transforming growth factor-beta 1 (TGF beta 1), TGF beta 2, and TGF beta 3 as well as TGF beta type II receptor. The epithelial and stromal cells synthesize and secrete into their culture-conditioned medium 2.6 +/- 0.3 and 1.4 +/- 0.2 ng TGF beta 1/10(6) cells, respectively; after transient acidification of the medium, the TGF beta 1 levels were 18.1 +/- 0.4 and 7.8 +/- 0.7 ng/10(6) cells. These cells also contain specific binding sites for [125I]TGF beta 1, indicated by light microscope autoradiography. TGF beta s at 0.01-10 ng/ml neither stimulated or inhibited subconfluent quiescent stromal cells under serum-free condition nor altered the mitogenic action of 10% fetal bovine serum. However, in the presence of 2% fetal bovine serum, which induced half-maximal stimulation of [3H]thymidine incorporation, TGF beta 1 and TGF beta 2 at 0.1-0.5 ng/ml and TGF beta 3 at 0.1-2.5 ng/ml significantly stimulated the rate of [3H]thymidine incorporation into quiescent stromal cells (P < 0.005); they were ineffective at higher concentrations. TGF beta s did not have any effect on cell proliferation, as determined by cell counting; however, at 0.1 ng/ml and higher concentrations, TGF beta s significantly reduced the metabolic activity of stromal cells, as determined by colorimetric 3-(4,5-dimethylthiazol-2-yl)2, 5-diphenyltetrazolium bromide assay (P < 0.05). The stimulatory and inhibitory actions of TGF beta s in both assays were reversible using 5-10 micrograms/ml TGF beta 1- and TGF beta 2- and 3-6 micrograms/ml TGF beta 3-specific neutralizing antibodies. TGF beta 1 at 1 ng/ml had no significant effect on long-lived protein degradation, assayed by incorporation of [14C]valine into newly synthesized protein by stromal cells, and was similar to the effect of epidermal growth factor or platelet-derived growth factor-BB (10 ng/ml). The data suggest that the TGF beta expression by various endometrial cell types in an autocrine/paracrine manner acts as a negative regulator essential for restraining endometrial growth and transition from proliferation to differentiation stages during the secretory phase after mitogenic stimulation during the proliferative phase of the menstrual cycle.

Adult↗

PubMed1994

[Osteoclastic resorption of trabeculae in osteoporotic femoral head: a scanning electron microscopic study].

Osteoclastic resorption was studied by scanning electron microscopy on the trabeculae of femoral heads collected from 7 cases of aged women at an average age of 72.4 years, who underwent endoprosthetic replacement for intracapsular fracture of femoral neck. Femoral head trabeculae from 3 young adults killed in traffic accident served as control. The trabeculae of the femoral head formed round or roundish arch structure. The columnar trabeculae of the femoral head in the aged women showed overt osteoclastic resorption, manifesting thinning, tapering and perforation. The icicle-like trabeculae then became rounded, lost height and eventually turned into a small tubercle. As a result, the inter-trabecular space enlarged markedly. Under high magnification, on the trabeculae could be discerned oval, narrow oval or spindle-shaped Howship lacunae, which were various in size, depth and content, but all revealed punch-out edge. Around the lacunae the collagen fibril lamella normally covering the quiscient bone surface became resorbed sooner or later. During bone resorption, the inorganic component of the bone matrix were first dissolved and resorbed leaving behind rough and irregular collagen fibrils; nevertheless, the collagen might be degraded and resorbed first with residual inorganic crystals and irregular bone nodules. Then emerged in the Howship lacunae and surrounding area newly formed collagen fibrils and bone tissue, signifying reversal and new bone formation phases following the the bone resorption phase. In the aged women, however, this phenomenon was rather infrequently encountered, thereby leaving the bone turnover always in a negative balance state.

Aged↗

PubMed1994

[Osteogenic potential of rabbit dermal fibroblasts cultured in vitro: a histochemical and scanning electron microscopic study].

Split-thickness rabbit skin was processed into small chips that were cultured in vitro and subjected to inverted phase contrast microscopic and scanning electron microscopic observation. The fibroblasts swam out of the skin chips and they increased in number rapidly and became confluenced. The cells exhibited squamous configuration, possessing arboreal bifurcations and forming multi-layer structure. The fibroblasts then excreted numerous minute granules, heaping up on and around the cells. Henceforth emerged on the cell surface fine needle-like crystals, that agglomerated with the granules to form nodules. The fibroblasts orientated themselves in a radiating pattern around the large nodules. Neighbouring nodules could be linked up into trabecular structure. Histochemical study of both the nodules and the trabecular structure with specific new bone labeller (Tetracycline and Alizarin red S) revealed positive reaction, denoting that the nodules and the trabecular structure produced by the fibroblasts were bone tissues. These results pointed out clearly to the osteogenic potential of the dermal fibroblasts.

Animals↗

PubMed1994

Arch structure of trabeculae of the upper femoral end and its biomechanical significance in hip fractures.

We studied ultrastructurally the cancellous bone tissues of the upper femoral ends, collected from 12 patients undergoing endoprosthesis replacement for fractures of the femoral neck and from 7 fresh cadavers. The bone tissues were composed of meshwork of trabeculae, that constituted tier upon tier of anisotropic arch structures of different diameters and sizes. The arch structures of the cancellous bone tissues in the femoral heads assumed round or roundish configurations, whereas those of the femoral head-neck junctions revealed oval outlines and those of the femoral necks showed narrow oval profiles. The fine structures of the trabeculae in the femoral head could be divided into superficial zone, central zone, and transitional zone. Under weight-bearing, the central zone suited to sustain the load, while the superficial zone could produce elastic deformation lest fracture of the trabecaulae should ensue. The long axes of the oval arch structures of the femoral head-neck junction and the narrow oval arch structures of the femoral neck coincided with those of the femoral neck, thereby facilitating weight-bearing under physiological conditions. However, external violence in the form of either adduction or abduction force would act in a horizontal direction on the long axes of the oval and narrow oval arches so as to produce subcapital or transverse fracture of the femur in the aged.

Adult↗

PubMed1994

The effect of Isoptin SR on blood pressure, heart function and hypertrophy of left ventricle of hypertensive patients.

Isoptin SR was used in 65 essential hypertensive patients. 240mg Isoptin SR (German Knoll Pharmaceutical company) per day was used in group A (35 cases) for 6 weeks, and in group B (30 cases) for 24 weeks, BP in group A and B decreased obviously in the first and second week after treatment. Marked effective rate and total effective rate were 65.7% and 74.3% respectively in group A, and 70.0% and 83.3% in group B. There were no significant changes of HR in group A before and after treatment while there was a decrease of HR in group B (P < 0.001). Left atrium (LA) decreased after 6 weeks in group A with an obvious increase of E/A ratio. There was significant decrease in LA, increase in E/A ratio, regression of IVS, LVPW and LVMI, but no changes in SV, CO, LVEF after 24 weeks of treatment of Isoptin SR in group B. E/A ratio was very sensitive and occurred earliest both in group A and group B. Side effects such as headache, dizziness, constipation, insomnia, peripheral oedema, sinus bradycardia occurred mainly in the first week of treatment. These symptoms disappeared gradually in the course of continued administration of Isoptin SR.

Adult↗

PubMed1993

Origin of bone hyperplasia in osteoarthritic femoral head. Tetracycline labelling and scanning electron microscopic study.

Total hip replacement was carried out in 7 patients with advanced osteoarthritis of the hip joint. The patients were given tetracycline orally before operation to label the newly formed bone tissues. The excised femoral heads were processed into undecalcified sections, which were subjected to both fluorescence microscopic and scanning electron microscopic (SEM) observation. Band-shaped golden fluorescence was detected along the trabeculae, reflecting newly formed bone tissues by the cambium layer of the periosteum. In the intertrabecular space, reticular and spherical golden fluorescence was detected, implying newly formed bone tissues by the marrow stromal cells. Under SEM, both reticular and spherical new bone tissues were discovered in the inter-trabecular space as mentioned above. There were two forms of reticular new bone tissues, a diffuse form and a tape-shaped new bone tissues. The diffuse bone tissues grew and expanded and eventually studded the inter-trabecular space. The tape shaped tissues, which were first deposited on the trabecular arch surface, increased in amount and then woven into thin and dense tapes of the reticulum. These tapes contacted in an end-to-end fashion, and appeared to shuttle back and forth through the trabecular arches, forming new secondary arch structures. The spherical new bone tissues were deposited on the surface of the trabecular arch structures and gradually packed the intertrabecular space. These new bone tissues were contributed to hyperplasia in the osteoarthritic femoral head.

Femur Head↗

PubMed1993

[The biological behaviors of inoculated B16 melanoma in mice: correlation with NK activity of the host].

B16 melanoma cells with different natural killer (NK) cell activity were inoculated subcutaneously in mice. Observations were made on the relation of NK cell activity to tumor growth, infiltration and metastasis on the one hand and, the sensitivity of the tumor cells to NK cells before and after tumor implantation on the other. It was seen that NK cells could not only inhibit tumor growth, infiltration and metastasis, but also induce tumor NK-tolerance of the tumor. When the NK-tolerant tumors were resected and implanted into ordinary mice, the biological behaviors of NK-tolerant B16 tumor cells were more malignant than wild (original) B16 cells. The results of this study show that the in vivo interaction between NK cells and tumor cells can positively and negatively influence the tumor's biological behaviors.

Animals↗

PubMed1993

[Lysosomes in the regulation of hormone secretion in the pituitary-adrenal gland axis].

The morphology and morphometrics of the lysosomes and associated structures were studied in hyposecreting corticotrophs and the cells of adrenal cortex zona fasciculata of the rats. Hyposecretion of this two types of the cells in the pituitary-adrenal gland axis was induced by dexamethasone administration. The lysosomes and other hydrolydase-positive structures were identified with CMPase cytochemistry. Quantitative evaluation of the lysosomes, crinophagic and autophagic vacuoles was carried out on the micrographs with MOP-Videoplan system. The results indicated that while inhibited secretion of ACTH accompanied by the increase of the crinophagic and autophagic vacuoles in corticotrophs, inhibited secretion of corticosterone accompanied by the increase of the autophagic vacuoles containing the mitochondria, ER which were steroid-synthesizing apparatus in adrenal cortex cells. The findings in the present study suggested that lysosomal degradation mechanism play a significant role in the regulation of hormone secretion in pituitary-adrenal gland axis. In addition to affirming earlier data that lysosomes took part in the regulation of protein secretion by crinophagy, the main conclusion derived from the present study was that lysosomes also functioned in the regulation of steroid secretion. By the way of autophagy i.e. sequesting and degrading a part of the steroid-synthesizing apparatus, the lysosomes rendered a mechanism in steroid-secreting cells to involve to the regulation process of hormone secretion. This might be an important and general rule as the crinophagy be to the protein-secreting cells.

Adrenocorticotropic Hormone↗

PubMed1992

[Leydig cells--a normal cell model of cellular autophagy].

In the present study, we tried to estimate, in a semiquantitative way, the relative frequency of the autophagic activity in various cell types under physiological condition. The results indicated that the highest activity appeared to be in the Leydig cells of rat testes. Autophagosomes were frequently observed in electron microscope photographs of Leydig cells, which provide a good model to study the autophagocytosis in normal cells. The autophagic process in Leydig cells was observed with the electron microscope in preparations treated to show CMPase activity. The mode of formation of autophagosomes in Leydig cells can be divided into three steps. Step 1, flattened membranous elements expand to enclose a small cytoplasmic territory to form pre-autophagosome. Step 2, The double membrane profile of the pre-autophagosome then completely encloses the cytoplasmic territory to form early autophagosome in which structurally normal organelles are contained. Step 3, the transformation of an early autophagosome into a late one is accompanied by the loss of one of the two delimiting membranes, the partial disintegration of the enclosed content and simultaneous acquisition of acid phosphatase activity. The enzymatic reactivity is acquired following a close association with the lysosomes. The late autophagosome then reaches the cell surface and appear to exocytose their residual content.

Animals↗

PubMed1991

Glucose-6-phosphatase activity of endoplasmic reticulum and Golgi apparatus in spermatocytes and spermatids of the rat: an electron microscopic cytochemical study.

The glucose-6-phosphatase (G6Pase) activity of cytoplasmic components of spermatocytes and spermatids of the rat was examined by electron microscope cytochemistry using cerium chloride as a capture agent. G6Pase activity, a recognized ER-resident enzyme, was present in all ER cisternae of spermatocytes. In spermatids, while some ER cisternae were G6Pase-reactive, others were negative or only slightly reactive, indicating an unequal distribution of the enzymatic activity throughout the network of ER cisternae in these cells. In spermatocytes, the cis- and trans-elements of the stacks of Golgi saccules were slightly but significantly reactive for G6Pase. In the Golgi apparatus of spermatids, the cis-element, 4 or 5 underlying saccules, as well as one or two thick trans Golgi elements were G6Pase reactive. The G6Pase activity of the various Golgi elements, like that of the ER cisternae was not affected by the pH of the medium and was completely inhibited by Na-vanadate, a known G6Pase inhibitor. Sertoli and Leydig cells, submitted to the same cytochemical conditions, showed complete G6Pase reactivity of their ER; however in Sertoli cells, all Golgi components were consistently negative while in Leydig cells the cis- and trans-elements of the Golgi stacks were slightly reactive, as in spermatocytes. Thus, the G6Pase reactivity of Golgi elements, appeared variable from one cell type to another. The compact juxtanuclear Golgi apparatuses of spermatocytes and spermatids were both associated with numerous G6Pase reactive ER cisternae; some were present at their surface, others crossed their cortices between Golgi stacks and formed elaborate networks in their cores.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

[Lysosomes in the regulation of hormone secretion in endocrine cells].

Enzyme cytochemistry and immunocytochemistry were utilized to study the morphological alterations of the lysosomes and associated crinophagic and autophagic structures in the hypo-secreting pituitary gonadotrophin and Leydig cells induced by exogenous androgen. The lysosomes and autophagic vacuoles in the electron micrographs were quantitatively analysed. The morphological and quantitative data led to the following conclusions: 1) The hypo-secreting gonadotrophin showed an increase in the number of lysosomes and an enhancement of crinophagy. It demonstrated once again that the lysosomes in the protein and polypeptide hormone secreting cells play a role in the regulation of secretion process by means of the crinophagy. 2) The hypo-secreting Leydig cells showed an increase in the number of lysosomes and an enhancement of autophagic activity. This indicated that the lysosomes in the steroid hormone secreting cells also function in the regulation of hormone secretion but by means of autophagy which scavenge a part of steroid-producing apparatus and hormone. The autophagy might have similar effect in regulation of steroid secretion to the crinophagy in regulation of protein secretion.

Animals↗

PubMed1991

[Analysis of sister-chromatid exchange rate from peripheral lymphocyte of people exposed to environmental cadmium].

Sister-chromatid exchanges (SCEs) were analyzed using peripheral lymphocyte from 38 persons (20 men and 18 women) who had been exposed to environmental cadmium (Cd), and 9 controls (7 men and 2 women). Correlations between SCE rates and urinary Cd-concentrations were done. There were no significant differences in SCE rates between the Cd-polluted and nonpolluted groups. There were no significant correlations between SCE rates and urinary Cd concentrations.

Adolescent↗

PubMed1991

Scanning electron microscopic study of subchondral bone tissues in osteoarthritic femoral head.

During total hip replacement for 12 cases of advanced osteoarthritis of the hip joint in aged women, three types of diseased or abnormal articular cartilage with different degrees of severity (white articular cartilage, white and hyperplastic articular cartilage, and yellowish articular cartilage) and ivory bone were obtained together with their subchondral bone tissues. These specimens were processed and studied under scanning electron microscope and were compared with sex- and age-matched non-osteoarthritic femoral head articular cartilage specimens. The following findings were observed: 1. In non-osteoarthritic femoral head, the subchondral bone plate was quite thin. The bone plate connected on its deep surface with the lattice-work of trabeculae of the epiphyseal region. The trabeculae were fine and smooth and some revealed round or spindle-shaped callus resulted from microfracture. 2. In osteoarthritic femoral heads, with increased the severity of the articular lesion, the articular cartilage gradually became thinned out and eventually lost. The subchondral bone plate was markedly thickened. The epiphyseal trabeculae were also thickened and turned rough so that the lattice-work pattern gradually disappeared. The thickened trabeculae finally fused into a large piece of dense bone tissue. No microfracture was detected. These changes were attributable to the increased stress imposed on the subchondral bone tissues as a result of defective articular cartilage. Consequently, the changes on the part of the subchondral bone tissues of the osteoarthritic femoral heads were the sequent, rather than the cause, of the articular lesions.

Cartilage, Articular↗

PubMed1990

Cytogenetic investigation in lymphocytes of people living in cadmium-polluted areas.

Chromosome aberrations were analyzed from peripheral lymphocyte cultures of 21 men and 19 women who had been exposed to environmental cadmium, and 11 controls (9 men and 2 women). The average cadmium level in the urine of the Cd-polluted group was 3.32 micrograms/l for men and 3.83 micrograms/l for women. There were significant differences in chromosome aberration frequencies between the Cd-polluted and non-polluted groups. The number of individuals with relatively high aberration frequencies (greater than or equal to 5%) in the Cd-polluted group was greater than in the controls. Individuals with a high cadmium content in urine (greater than or equal to 3 micrograms/l) had higher aberration frequencies and more severe aberration types in comparison with the low-cadmium group (less than 3 micrograms/l). There were significant correlations between chromosome aberration frequencies and urinary cadmium content (r = 0.463). The linear regression equation was determined. Considering the conflicting results in other published reports, it is hard to say that the conclusion that cadmium only acts synergistically to enhance the mutagenicity of other compounds present in the environment is correct. According to our study, environmental cadmium cannot only induce chromosome aberrations but also increases the chromosomal aberration frequencies and the frequency of severe aberration types.

Adult↗