Electron microscopic observations of apoptotic cells in various etiologies of human cardiovascular diseases

OBJECTIVE

To observe apoptotic process in various cardiovascular disorders with a particular attention to the ultrastructural morphology of apoptosis in cardiomyocytes, fibroblasts, vascular endothelial cells and smooth muscle cells.

METHODS

Transmission electron microscopic observations of the tissue specimens obtained from endomyocardial biopsies or surgical excisions of left ventricular myocardium or calcified aortic valves were carried out in 50 patients with various cardiovascular diseases.

RESULTS

The ultrastructural features of apoptosis was consistently observed in cardiomyocytes, fibroblasts, vascular endothelial cells and smooth muscle cells in all diseased tissues. In cardiomyopathies and rheumatic heart diseases apoptosis was commonly observed in the cardiomyocytes. It was often found that fibroblasts underwent apoptosis in calcific aortic valve tissues. Apoptosis of arterial smooth muscle cells was a frequent finding in renal arterial stenosis due to Takayasu's arteritis and fibromuscular dysplasia. Regardless of the cell types, the nuclear hallmarks of apoptosis were identical with minor modifications of the fragmentation of the condensed cells into apoptotic bodies.

CONCLUSIONS

Based on electron microscopic findings, it is suggested that the underlying disease processes determine which type of cells predominantly undergoes apoptotic changes in various cardiovascular disorders. In addition, different cells with similar structural morphology may have common ultrastructural features of apoptosis.

Genetic heterogeneity for familial hypertrophic cardiomyopathy in Chinese: analysis of six Chinese kindreds

OBJECTIVE

Familial hypertrophic cardiomyopathy (FHCM) is a primary myocardial disease characterized by unexplained ventricular hypertrophy. The application of the techniques of reverse genetics has identified at least five chromosomal loci as the major causes for FHCM in diverse ethnic populations, suggesting substantial genetic heterogeneity for FHCM. Recently, the defective gene loci of two Chinese families with FHCM have been mapped to chromosome 11 and 14q1, respectively. For further understanding of the molecular basis of FHCM in Chinese, we analyzed the linkage between four other Chinese kindreds and DNA markers from chromosome 14q1.

METHODS

Six unrelated Chinese families with FHCM, including two previously reported, were studied. Totally 90 family members were included for analysis. DNA from 80 individuals was extracted and polymerase chain reactions were performed using the primers designed according to the sequences derived from the alpha and beta myosin heavy chain gene. Totally four polymorphisms were studied, including three polymorphic microsatellite sequences and one single strand conformation polymorphism. Genetic linkage analysis were performed using the Linkage program.

RESULTS

In the six studied families, 39 of the 90 family members were found to be affected diagnosed either by echocardiography or by clinical evaluation. The pattern of inheritance in all six studied families was most consistent with an autosomal dominant trait with a high degree of penetrance. Genetic linkage analysis using polymorphisms on the alpha and beta MHC genes showed a combined maximal lod score of 6.2 for trinucleotide repeat polymorphism AMHC-I 15 at theta = 0.00 for three studied families without recombination. Exclusion of linkage to the chromosome 14q1 location was noted in two of three other families with the maximal lod score of -2 or less.

CONCLUSIONS

These results provide further evidence that FHCM in Chinese is genetically heterogeneous. Chromosome 14q1 locus, probably the beta myosin heavy chain gene, is important as the molecular basis for FHCM in Chinese.

Mechanism of regulation of 8-hydroxyguanine endonuclease by oxidative stress: roles of FNR, ArcA, and Fur

We found previously that 8-hydroxyguanine (oh8Gua) endonuclease in E. coli is induced in response to oxidative stress in a fashion similar to the oxidative response of the Mn-superoxide dismutase (MnSOD). In this study, attempts were made to identify the genes involved in the co-regulation of E. coli endonuclease and MnSOD (sodA). oh8Gua nuclease is induced by molecular oxygen and a superoxide radical generator (paraquat) but not by H2O2, suggesting that the regulation of this endonuclease is dependent on SoxRS but independent of OxyR. This enzyme was induced by paraquat in all of the soxRS mutant strains used (soxR-, soxS- and soxRc), whereas glucose-6-phosphate dehydrogenase (a member of the soxRS regulon) showed the expected responses; therefore, this possibility was excluded. The presence of metal chelators in the growth medium caused the induction of this enzyme, and this induction was suppressed by the addition of Fe++. Consistent with this finding, this enzyme was expressed under anaerobiosis in all of the mutant strains of fnr in particular, as well as fur, arcA, and combinations thereof. These findings suggest that the oxidative regulation of oh8Gua endonuclease is under control of fnr, fur, and arcA, where fnr plays a predominant role. The multiple involvement of regulatory genes as well as co-regulation with antioxidant enzyme will enhance the efficiency of cellular growth and survival in the aerobic environment.

Differential expression of protein kinase C isoforms in diethylnitrosamine-initiated rat liver

Although protein kinase C (PKC), a family of 12 related isoforms, plays an important role in carcinogenesis, little is known about the specific role of each isoform in the initiation stage of hepatocarcinogenesis. The subcellular distribution of PKC isoforms in the early stages of diethylnitrosamine (DEN)-initiated hepatocarcinogenesis was therefore examined. Three-week-old female Sprague-Dawley rats were intraperitoneally injected twice in 1 week with DEN; all animals were sacrificed at 1, 2 and 24 h and 3 and 7 days after the second injection. PKCalpha and -beta expression in both cytosolic and particulate fractions decreased as a result of 1 h of DEN treatment and this effect lasted for 7 days. In both fractions, PKCepsilon expression showed a marked increase by DEN treatment, while the expression of PKCdelta and -zeta was almost unchanged. These results suggest that differential expression of PKC isoforms may play an important role in the early stage of DEN-initiated hepatocarcinogenesis in rats.

Retroviral gene transfer in chondrogenic limb bud micromass cultures

We report development of a model of retroviral gene transduction in high-density limb bud cell micromass culture. The replication competent avian retrovirus RCAS BP (A) carrying the human placental alkaline phosphatase gene (RCAS AP) was used as a marker for retroviral infection and spread. The final protocol balances the need to allow time for retroviral integration and gene transduction against loss of chondrogenic potential when limb bud cells are plated at low density. It includes: (i) incubation of the dissociated limb bud cells with RCAS virus for 2 h followed by low-density culture for 48 h to allow retroviral gene expression; and (ii) secondary replating as high-density micromass culture to initiate chondrogenesis. The pattern and level of chondrogenesis in the retrovirus-transduced micromass cultures is similar to regular micromass cultures. At least 40%-50% of cells express the retroviral-transduced genes 24 h after high-density plating. This new approach facilitates ectopic gene expression in micromass culture, enabling molecular dissection of chondrogenesis and serves as a model for gene transduction in other organotypic cultures.

Molecular level investigation of exocytosis in cultured human pheochromocytoma cells: insights from high resolution scanning electron microscopy combined with autoradiogram and cytochemistry

OBJECTIVE

To investigate molecular events of exocytosis in cultured human pheochromocytoma cells with stimulation.

METHODS

The cultured pheochromocytoma cells prepared from human adrenal pheochromocytoma tumor were stimulated for the release of catecholamines by depolarization with the administration of 50 mmol/L KCl. Transmission electron microscopy (TEM) and high resolution scanning electron microscopy (HR-SEM) combined with autoradiography and cytochemistry were used to observe molecular mechanisms of exocytotic release of catecholamines from the stimulated cells labelled with 3H-noradrenaline and the filipin-treated cells.

RESULTS

TEM and HR-SEM observations of the stimulated cells labelled with 3H-noradrenaline revealed that the initial exocytotic fusion pores even less than 10 nm in diameter in human pheochromocytoma cells can be clearly observed in a single lipid bilayer. Furthermore, HR-SEM examinations of the filipin-treated cells showed that the derangement of the particles of the filipin-sterol complexes (FSCs) in the fused membranes of granule and plasma membranes occurred as the exocytotic fusion pores opened. In addition, the aggreates of the FSCs particles were consistently demonstrated around the openings of the differently sized closing exocytotic pores.

CONCLUSIONS

Based on our results, it is suggested that the rearrangement of the sterol molecules in the fused membranes of granule and plasma membranes plays an important role in the opening and closing mechanisms of exocytotic fusion pores. We hope that morphological data obtained in this study can provide some new insights into the understanding of molecular mechanisms of exocytosis, particularly the opening and closing of exocytotic fusion pores in relation to the distribution of the membrane sterols.

Nucleotides in the panhandle structure of the influenza B virus virion RNA are involved in the specificity between influenza A and B viruses

Influenza A and B viruses share common sequences and potentially similar panhandle structures in the terminal noncoding regions of virion RNA (vRNA). Interesting differences exist, however, in the number of conserved nucleotides at the 5' and 3' ends of the vRNAs, in base pairs constituting the panhandle duplex, and the length of uridine stretch (U stretch) juxtaposed to the RNA duplex. To analyse the contribution of these signals to the specificity between the two viruses, a transient ribonucleoprotein transfection method was used for the expression of the chloramphenicol acetyltransferase (CAT) reporter gene flanked by the noncoding nucleotides derived from influenza B vRNA. While the base pairing in the RNA duplex was primarily important for template activity, mismatch mutations G11 x G12' and C12 x A13' in the terminal RNA duplex region were utilized by influenza B virus, whereas these mutations were detrimental for influenza A virus. Different activity profiles were observed in the length preference of the RNA duplexes: maximum template activity was observed with 11 base pairs for influenza B virus, and 8 base pairs for influenza A virus. When the mutants with various lengths of U stretch were tested, highest CAT activities were observed with 5 to 7 uridine residues in influenza A virus, whereas in influenza B virus the activity was drastically decreased with 7 uridine residues. We suggest that the specific interaction of influenza virus RNA polymerase with these noncoding cis-acting signals in transcription of the RNA genome, along with unique coding strategies adopted by influenza B virus, has contributed to the divergence of these two closely related viruses.

A distinct region of chromosome 19p13.3 associated with the sporadic form of adenoma malignum of the uterine cervix

Adenoma malignum (AM) is known to be one of the malignant tumors that is commonly associated with Peutz-Jeghers syndrome. Recently, the genetic locus of Peutz-Jeghers syndrome was mapped to the telomeric region of chromosome 19p. We analyzed nine sporadic cases of AM with high-density loss of heterozygosity to study the region of chromosome 19p13.2-13.3 using eight microsatellite markers. Our deletion mapping data revealed a distinct region with 100% loss of heterozygosity frequency at marker D19S216. This result indicates that a putative tumor suppressor gene for AM is located at D19S216 on chromosomal band 19p13.3 and plays an important role in AM tumorigenesis.

Catalytic mechanism of aldose reductase studied by the combined potentials of quantum mechanics and molecular mechanics

The catalytic reduction of D-glyceraldehyde to glycerol by aldose reductase has been investigated with the combined potentials of quantum mechanics (QM) and molecular mechanics (MM) to resolve the question of whether Tyr48 or His110 serves as the proton donor during catalysis. Site directed mutagenesis studies favor Tyr48 as the proton donor while the presence of a water channel linking the N delta 1 of His110 to the bulk solvent suggests that His110 is the proton donor. Utilizing the combined potentials of QM and MM, the binding mode of substrate D-glyceraldehyde was investigated by optimizing the local geometry of Asp43, Lys77, Tyr48, His110 and NADPH at the active site of aldose reductase. Reaction pathways for the reduction of D-glyceraldehyde to glycerol were then constructed by treating both Tyr48 and His110 as proton donors. Comparison of energetics obtained from the reaction pathways suggests His110 to be the proton donor. Based on these findings, a reduction mechanism of D-glyceraldehyde to glycerol is described.

Species, strain and sex differences in susceptibility to gamma radiation combined with diethylnitrosamine

Our previous data suggested that in Sprague-Dawley (SD) rats, a short-term in vivo radiation carcinogenesis model can be established using glutathione S-transferase placental form (GST-P) positive hepatic foci induced by diethylnitrosamine (DEN) after gamma radiation. In the present study, differences between species, strain and sexes in susceptibility to radiation or radiation combined with DEN were examined. Newborn Fischer 344 (F344) and SD rats, and N:GP(S) mice were irradiated with whole body single 3Gy of gamma rays with or without intraperitoneally-injected DEN (15 mg/kg body weight) within 1 h of irradiation. Three weeks later, 0.05% phenobarbital was given in drinking water as a promoter, and at week 21 after birth, all animals were sacrificed. In both the radiation alone and radiation combined with DEN groups, F344 rats were more susceptible than SD rats to the induction of GST-P+ foci. In F344 rats, no significant difference in foci induction was seen between the sexes in both radiation alone and radiation combined with DEN groups, but in SD rats, female rats were more susceptible than males. In the case of mice, lung tumor incidence was examined, and in the radiation alone group, no differences between the sexes were seen; in the radiation combined with DEN group, however, females were more susceptible than males. These results suggested that susceptibility to radiation carcinogenesis could be potentiated by chemical carcinogens and showed wide variation between species, strains and sexes, of experimental animals.

Involvement of liver-associated immunity in hepatic metastasis formation

AIMS

Hepatic metastasis formation and prevention were studied from the viewpoint of liver-associated immunity.

METHODS

RCN-9, a colonic cancer cell line derived from Fischer rats, and its subclone RCN-H4, in which the cancer is highly metastatic to the liver, were used. Fischer rats that were inoculated with parent RCN-9 colonic cancer cells (5 x 10(6)) via the portal vein showed liver metastasis in less than 60% of the animals. In contrast, all rats (100%) that received RCN-H4 produced multiple liver metastases. To investigate the difference of hepatic metastasis formation, we assessed the susceptibility of both cell lines against hepatic sinusoidal lymphocytes (HSL) by 51Cr-release assay, and the expression of MHC class I and class II of both cell lines by flow cytometry. In addition, we examined whether activation of HSL by interleukin-12 (IL-12) can prevent liver metastasis of highly metastatic clone RCN-H4.

RESULTS

The RCN-H4 clone showed decreased susceptibility to lysis by natural cytotoxic cells in HSL. This decrease in cell susceptibility was attributable to an increase in cell surface expression of MHC class I antigen. Administration of IL-12, a potent NK/CTL stimulatory cytokine, augmented the cytotoxic activity against the RCN-H4 clone and prevented liver metastasis of RCN-H4 inoculated into the portal vein.

CONCLUSIONS

Liver metastasis formation is positively correlated with the strength of the hepatic immune system which mainly consists of ontogenetically primitive T cells. As these effectors exert their cytotoxicity in a MHC-nonrestricted fashion, tumor cells that highly express MHC class I antigen can readily avoid hepatic surveillance and apt to cause liver metastasis. Augmentation of the hepatic immune system, for instance, with IL-12 administration, can prevent liver metastasis even in tumor cells with a high potential for liver metastasis.

Acidic polysaccharide from Panax ginseng, ginsan, induces Th1 cell and macrophage cytokines and generates LAK cells in synergy with rIL-2

We previously reported that an acidic polysaccharide from Panax ginseng named ginsan inhibits the incidence of benzo[a]pyrene-induced autochthonous lung tumors in mice. To elucidate the mechanism of antineoplastic activity, ginsan was tested for its ability to generate LAK cells and to produce cytokines. Spleen cells became cytotoxic to a wide range of tumor cells after 5 days of culture with ginsan in a non-major histocompatibility restricted manner and the activity of ginsan was 12 times higher than that of lentinan. The generation of killer cells by rIL-2 was neutralized only in the presence of anti-IL-2, whereas by ginsan it was neutralized in the presence of anti-IL-2 as well as anti-IFN gamma, or anti-IL-1 alpha. It was confirmed that ginsan induces the expression of mRNA for IL-2, IFN gamma, IL-1 alpha, and GM-CSF. Depletion of AsGM1+ cells from spleen cells reduced the generation of LAK by rIL-2. In contrast, depletion of AsGM1+ as well as Thy1+ cells, CD4+ cells, or DC8+ cells reduced the generation of LAK cells by ginsan. The serologic phenotype of rIL-2 induced LAK cells was CD8- cells, whereas the ginsan induced LAK cells, were CD8+ cells. Ginsan synergized with rIL-2 to generate LAK cells (2.0-15 fold) and the most dramatic synergy was seen at rIL-2 concentrations below 3 U/ml. Ginsan alone inhibited pulmonary metastasis of B16-F10 melanoma cells and enhanced the inhibition of lung colonies by rIL-2. These findings demonstrate that ginsan generates LAK cells from both NK and T cells through endogeneously produced multiple cytokines. This property may contribute to its effectiveness in the immunoprevention and immunotherapy of cancer.

On-line multiplane transesophageal echocardiography for balloon mitral commissurotomy

This study describes in detail the technique and results of on-line multiplane transesophageal echocardiographic guidance of balloon mitral commissurotomy in 150 consecutive patients with symptomatic mitral stenosis. The mitral valve area improved significantly and there were no in-hospital deaths, strokes, or emergency valve operations.

Production of inducible nitric oxide is required for monocytic differentiation of U937 cells induced by vitamin E-succinate

Many putative differentiating agents arrest cell growth prior to progression of the cell through differentiation. Vitamin E-succinate is known to be a potent modulator of haematopoietic differentiation as well as an inhibitor of cell growth in vitro and in vivo. In this study, we examined whether vitamin E-succinate could modulate the monocytic differentiation of U937 human monoblasts. Treatment with vitamin E-succinate for 1–4 days inhibited the proliferation of U937 cells. Vitamin E-succinate also induced monocytic differentiation as indicated by the increase in nitro blue tetrazolium reduction activity, and the expression of monocyte specific cell surface antigen, CD11c, and integrins alpha5 and beta1. The monocytic differentiation of U937 cells was also induced when the cells were cultured in fibronectin-coated wells. Monocytic differentiation was enhanced when the cells were treated with both vitamin E-succinate and fibronectin, suggesting that vitamin E-succinate and fibronectin synergistically act on monocytic differentiation of U937 cells. During monocytic differentiation of U937 cells induced by vitamin E-succinate and/or fibronectin, nitric oxide was detected in supernatants. The production of nitric oxide was not detected when monocytic differentiation of U937 cells was induced by phorbol-12 myristate 13-acetate, a well known inducer of macrophage-like cell differentiation. Vitamin E-succinate and/or fibronectin induced monocytic differentiation was blocked by the treatment of nitric oxide synthase inhibitor, N-G-monomethyl-L-arginine. In contrast, treatment of cells with sodium nitroprusside, a chemical nitric oxide donor, stimulated monocytic differentiation of U937 cells at an early time point. Taken together, these results suggest that nitric oxide is an important intermediator at an early stage of vitamin E-succinate- and/or fibronectin-induced monocytic differentiation of U937 cells.

mdm2 and bax, downstream mediators of the p53 response, are degraded by the ubiquitin-proteasome pathway

Upon activation in response to cellular stress or DNA damage, the p53 tumor suppressor induces the expression of gene products involved in cell cycle arrest and apoptosis. Using the proteasome-specific inhibitors, MG132 (N-acetyl-L-leucinyl-L-leucinal-L-leucinal) and lactacystin, here we show that the p53-response proteins, bax and mdm2 as well as p21, are degraded by the ubiquitin-proteasome pathway in HeLa cells. MG132 also increased expression of the three proteins in cells that lack p53, showing that stabilization of the p53 response proteins is not due to increased levels of p53 itself. Increases in mdm2 protein levels by MG132 was accompanied by increases in polyubiquitinated forms of the proteins. Our results indicate that ubiquitin-dependent protein degradation influences the turnover of downstream targets of p53, therefore suggesting that the proteasome plays a role in regulating apoptosis and cell cycle arrest in response to p53.

[Unification of Oriental and Western medicine with study on Oriental and Western medicine]

In Korea the system of medical management has been bifurcated into two parts since the restoration of nation from Japanese after World War II. One is 'Western Medicine' and the other is 'Oriental Medicine' like Chinese but not like Japanese. The authors attempted to study on the unification of both medicines to prevent the confusion of medicare for people. The major part of medical care is accomplished by Western medicine among people in Korea and China. However, Oriental medicine is still present as well as college of Oriental medicine in small number. There have been long struggles between two parts of medicine because of each assertions for the theories. The ancient medicine has been likely to have its characteristics either in Western or Oriental medicine although in many countries were succeeded by Western medicine except a few Asian countries such as Korea and China. In Japan since the license of Oriental(herb) medicine was ceased about one hundred years ago, the Western medicine has been authorized by law until today and the herb is the secondary medicine as a kind of folk treatment as well as continuous and enormous study for scientification. In only China and Korea this herb medicine has been kept to use as a part of medicine by law though China has developed combined medicine to use both Western and Oriental medicine by one physician since previous prime minister Chou En-Lai around the year 1950 who made a recommendation to the two medical societies, Western and Oriental. This fact has a big sense to establish the unification of two medicines in near future in Korea as well as China. For this accomplishment of medical unification both parts of medicine require sincere and enormous efforts to study the theory and practice of herb medicine even from now on. This unification of two medicines will provide the best medicare in most convenient way to the people in the world creating new world medicine like the third medicine including alternative medicine. The acupuncture is changing to a new method in Western medicine especially applying into anesthesia and pain clinic in even USA and Western countries at this time. In conclusion the unification of the Western and Oriental medicine will provide the most reasonable and practical medicare including alternative medicine to people in the world. Because the Oriental medicine will be used at least separately to supplement the Western medicine by one physician.

Intracellular Ca2+ release mediates ursolic acid-induced apoptosis in human leukemic HL-60 cells

The effect of ursolic acid (UA) on tumor cell apoptosis was investigated using HL-60 human promyelocytic leukemia cells as a model cellular system. Treatment with UA resulted in a concentration-dependent decreased cell viability assessed by MTT assay. UA also induced genomic DNA fragmentation, a hallmark of apoptosis, indicating that the mechanism by which UA induced cell death was through apoptosis. The intracellular Ca2+ level was increased by treatment with UA. Intracellular Ca2+ inhibitors, such as intracellular Ca2+-release blockers (dantrolene, TMB-8 and ruthenium red) and an intracellular Ca2+ chelator (BAPTA/AM), significantly blocked the UA-induced increased intracellular Ca+ concentration. These inhibitors also blocked the effects of UA on cell viability and apoptosis. These results suggest that enhanced intracellular Ca2+ signals may be involved in UA-induced apoptosis in HL-60 cells.

Bronchiolitis obliterans organizing pneumonia as an initial manifestation in patients with systemic lupus erythematosus

Diverse pleuropulmonary manifestations including diaphragmatic dysfunction, pleural effusion, acute lupus pneumonitis, pulmonary hemorrhage, pulmonary hypertension, and diffuse interstitial lung disease have been described in patients with systemic lupus erythematosus (SLE). Bronchiolitis obliterans organizing pneumonia (BOOP) as an initial manifestation of SLE is rarely reported. We describe 2 patients who had SLE concurrent with the onset of BOOP. Their respiratory symptoms, followup pulmonary function tests, and radiologic findings showed much improvement after steroid therapy.

Integrin-mediated activation of mitogen-activated protein kinase is independent of the activation of protein kinase C epsilon during the spreading of HeLa cells on a gelatin substratum

Spreading of HeLa cells on a gelatin substratum is initiated by the activation of protein kinase C epsilon (PKC epsilon) upon contact of the cells with the matrix. In this study, we examined the functional role of PKC epsilon in the activation of mitogen-activated protein kinase (MAP kinase) and its relationship to cell spreading. MAP kinase isoforms, Erk-1 and -2, are activated upon attachment of HeLa cells to gelatin. Inhibition of PKC with calphostin C blocked cell spreading without any effect on MAP kinase activation. In contrast, inhibition of MAP kinase kinase blocked adhesion-induced MAP kinase activation, but showed no effect on either translocation of PKC epsilon or cell spreading. Thus, activation of PKC epsilon that occurs upon HeLa cell attachment to gelatin is related to cell spreading but not to the activation of MAP kinase, and MAP kinase is activated upon HeLa cell attachment in the absence of cell spreading.

Endothelial alterations and senile calcific aortic stenosis: an electron microscopic observation

Calcific degeneration of aortic valves were investigated in 10 patients with senile calcific aortic stenosis by means of high resolution scanning electron microscopy (HR-SEM) and transmission electron microscopy (TEM). All the specimens obtained during aortic valve surgery HR-SEM and TEM examinations consistently showed various degrees of pathological alterations and calcification involving surface endothelium, underlying basement membranes and deeper layers of interweaving networks of collagen fiber bundles in the pars fibrosa of the valve tissues. Calcific deposits in the valve tissues always occurred in the vicinity of the endothelial defects and in the subendothelial structures just beneath the defective endothelium. The amount of calcific deposits in the valve tissues increased in proportion to the severity of endothelial damage and gradually decreased from the defective endothelial surface to the deeper layer of collagen tissue. In addition, apoptotic cell death, particularly of the fibrocytes in the valve tissue, was closely related to the severity of endothelial injury. Cellular fragments derived from the apoptotic cells were always associated with calcium deposits. Based on the above findings, our results provide evidence that the alteration of endothelial integrity plays a contributory role in calcific degeneration in the aortic valve leading to the development of senile calcific aortic stenosis.

Interaction between obesity and genetic polymorphisms in the apolipoprotein CIII gene and lipoprotein lipase gene on the risk of hypertriglyceridemia in Chinese

To understand the effects of the interaction between genetic polymorphisms and obesity on the risk of hypertriglyceridemia (HTG), two polymorphisms, an SstI polymorphism on the apolipoprotein CIII gene and a HindIII polymorphism on the lipoprotein lipase gene, were analyzed in 339 Chinese subjects with (82 cases in the HTG group) or without HTG (257 cases in the control group). Our data revealed that the frequencies of obesity, the SstI minor allele (S2), and the HindIII major allele (H+) in the HTG group were significantly higher than in the control group. Subgroup analysis revealed that the association between these two polymorphisms and HTG occurred predominantly in nonobese subjects and in subjects with the less hypertriglyceridemic genotype of another polymorphism. Multivariate logistic regression analysis showed that all three risk factors (obesity, S2-containing chromosome, and H+ homozygosity) were associated with HTG, and an interaction was found between obesity and H+ homozygosity for the occurrence of HTG. The risk of HTG increased significantly with combinations of risk factors. Subjects can be divided into low or high risk groups for HTG using such combinations. These results provide evidence of interaction between obesity and the HindIII polymorphism of the lipoprotein lipase gene on the risk of HTG.

Skeletal status of men with early and late ankylosing spondylitis

PURPOSE

To assess the influence of extent of disease on the skeletal status of men with ankylosing spondylitis (AS).

PATIENTS AND METHODS

Fourteen men with AS were studied at entry and again after 15 months. Bone mineral density (BMD) was assessed by single photon absorptiometry (SPA), dual energy x-ray absorptiometry (DXA), and quantitative computed tomography (QCT). Calciotropic hormones and bone turnover were also assessed, and biopsies of iliac crest and skin were taken after tetracycline double-labeling from 10 subjects. Clinical evaluation and Health Assessment Questionnaires were used to assess functional status.

RESULTS

Of the 14 participants, 7 had sacroiliitis alone without radiologic evidence of spinal involvement (early disease) and 7 had sacroiliitis with extensive vertebral calcifications and immobilization (late disease). QCT baseline lumbar spine BMD was very low in both groups compared with normative standards (Z score = -3.08 +/- 1.83, P < 0.0001) and did not change significantly over 15 months. This low BMD was more marked in late disease than in early disease subjects (P < 0.01). DXA BMD at the lumbar spine was lower than predicted in early disease subjects (Z score = -1.08 +/- 0.67, P = 0.005) but not in the late disease group. DXA BMD was also low at the all three hip sites (Z score = -0.96 +/- 0.86, P < 0.01). Significant differences between late disease group and normative values were apparent at all hip sites. Values in early disease subjects, however, did not differ from age-predicted norms. Bone mineral status did not change significantly over the 15-month period of observation. Circulating parathyroid hormone (PTH) and vitamin D metabolites were normal in both groups as were creatinine clearance and urinary excretion of calcium and hydroxyproline. Osteocalcin levels were normal in all but the two youngest subjects in the early disease group. Histomorphometry of the iliac crest showed no consistent change in bone turnover. Bone volume and trabecular width were low in many cases. Cancellous bone volume correlated with lumbar spine BMD by QCT (r = 0.69, P = 0.026) but not with DXA. Although beneficial changes occurred in exercise tolerance and pain over time, anthropometric measurements did not improve.

CONCLUSION

BMD is low in both the axial and peripheral skeleton in men with AS and is independent of spinal immobilization. Anterioposterior lumbar spine DXA in late AS is less useful than QCT in determining the degree of osteopenia in late AS. Bone mineral deficits in AS do not reflect measurable metabolic derangement or hypogonadism. Although bone histomorphometry suggests both trabecular thinning and loss of structural elements as mechanisms involved in low bone volume, the exact cause of osteopenia in AS remains to be determined.

Fibrin(ogen)-related antigens in rabbits experimentally infected with rabbit haemorrhagic disease virus

We investigated fibrin(ogen)-related antigens in liver tissues of rabbits infected with rabbit haemorrhagic disease (RHD) virus. Fibrin(ogen)-related antigens were detected in the sinusoids of liver at six hours post infection (pi). At 18 hours pi, the antigens were clearly detected in the hepatocytes infiltrated with heterophils rather than in the sinusoid. In the rabbits that spontaneously died (30 hours pi), fibrin(ogen)-related antigens were detected in both degenerating and some intact hepatocytes. They were also expressed in the necrotic foci of hepatocytes infiltrated by heterophils. By immunoprecipitation fibrin(ogen)-related antigens were extracted from the infected liver homogenates and analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis and Western blot analysis. There was an increase in fibrinogen and A alpha polypeptide chains in the liver homogenates from rabbits sacrificed at 18 and 24 hours pi, including those that died. Disseminated intravascular coagulation developed after progress of degeneration and necrosis of hepatocytes in RHD. It is assumed that the resultant consumption of fibrinogen triggers replenishment of fibrinogen by hepatocytes.

Angiotensinogen and angiotensin-I converting enzyme gene polymorphisms and the risk of coronary artery disease in Chinese

The homozygous deletion allele (DD) of the angiotensin-I converting enzyme (ACE) gene and the T235 homozygote of the angiotensinogen (AGT) gene have been reported to be correlated with an increased prevalence of coronary artery disease (CAD) and myocardial infarction (MI). The importance of the DD genotype and T235 homozygote as genetic risk factors for CAD in Chinese remains uncertain. This study included 426 patients who underwent coronary angiography and 180 healthy subjects without clinical evidence of CAD. Coronary angiography identified 268 patients with CAD (CAD group) and 158 patients without CAD. The healthy subjects and patients without angiographic evidence of CAD constituted the control group. Three polymorphisms were studied: an insertion/deletion (I/D) polymorphism of the ACE gene and the T174 M and M235T polymorphisms of the AGT gene. No association was found between any of the three studied polymorphisms and the risk of CAD or MI in Chinese using univariate or multivariate analysis. In multivariate analysis, the relative risks were 1.20 (95% confidence interval = 0.91-1.61, P = 0.20) for the DD genotype, 1.05 (95% CI = 0.82-1.35, P = 0.69) for the T174 homozygote, and 1.19 (95% CI = 0.91-1.55, P = 0.20) for the T235 homozygote. Similarly, no significant difference was found in the frequencies of the DD genotype and the T174 and T235 homozygotes between the control group, the CAD group, the non-MI group, and the MI group when analyzed according to sex, age, or degree of risk. Our data suggest that neither the DD genotype of the ACE I/D polymorphism nor the T174 and T235 homozygotes of the AGT gene confer significant risk for CAD or MI in Chinese.