Effects of physical training on the recovery of the autonomic nervous activity during exercise after coronary artery bypass grafting: effects of physical training after CABG

Analysis of heart rate variability (HRV) can identify patients at risk of sudden cardiac death after myocardial infarction. The present study examined the effect of 2 weeks of supervised aerobic exercise training on the recovery of the autonomic nervous activity, exercise capacity, and cardiac output (CO) after coronary artery bypass grafting (CABG). Twenty-eight patients were randomly divided into the training group or the control group and performed exercise tests at 1 week, 3 weeks, 3 months, 6 months and 1 year after CABG. The HRV was measured, and the high-frequency component of HRV was used as an index of parasympathetic nerve activity (PNA); the plasma norepinephrine concentration (NE) was used as an index of sympathetic nervous activity. Cardiac output was also measured. In the training group, peak VO2, peak CO and PNA during exercise had improved at 3 weeks, but there was no improvement in these indices in the control group. NE decreased 1 week after CABG in both groups. These results indicate that physical training soon after CABG improves not only the exercise capacity, but also PNA.

Identification of viral induced genes in Ig+ leucocytes of Japanese flounder Paralichthys olivaceus, by differential hybridisation with subtracted and un-subtracted cDNA probes

Up-regulated genes of leucocytes expressing immunoglobulin (Ig+ leucocytes) of hirame rhabdovirus (HRV)-infected Japanese flounder were identified by differential hybridisation, using subtracted and un-subtracted cDNA probes. Ig+ leucocytes were separated from apparently healthy and HRV-infected Japanese flounder by the magnetic beads antibody method using mouse anti-Japanese flounder Ig monoclonal antibody (mab). A cDNA library was constructed from HRV-infected Japanese flounder leucocytes, and was screened with subtracted cDNA probes enriched in genes up-regulated by HRV infection. Fifty cDNAs were isolated for further analysis. These included cDNAs coding for homologues of interferon-inducible 56K protein (IFI56), Stat3, CEF-10, RGS5, inducible poly(A) binding protein, prolylcarboxylpeptidase, basigin III (Ig superfamily), MUC-18 (Ig superfamily), proteasome-nexin 1 (SERPIN), herpes virus entry mediator (TNFR family), collagenase III, gelatinase-b, megakaryocyte stimulating factor, Rab8-interacting protein, IgM, IgD and 20 unknown cDNA clones. The majority of these identified genes are reported for the first time in fish. From leucocytes mRNA for homologues of IFI56, CEF-10, Stat3, SERPIN and inducible poly (A) binding protein expression was shown to increase following HRV infection.

Combination of granulocyte colony-stimulating factor and low-dose cytosine arabinoside further enhances myeloid differentiation in leukemia cells in vitro

We examined the differentiation-inducing effect on freshly isolated myeloid leukemia cells in liquid suspension culture by combined treatment with granulocyte colony-stimulating factor (G-CSF) plus low-dose cytosine arabinoside (Ara-C; 5-10 ng/ml) in 25 patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) in leukemic transformation. Culture with G-CSF alone showed leukemic cell growth stimulation in 15 out of the 25 cases (60%) and induction of cell differentiation in 19 out of the 25 cases (76%), respectively. In 23 cases (92%), either growth stimulation and/or differentiation induction of leukemia cells was observed in response to G-CSF. This suggests that most myeloid leukemia cells are able to respond to G-CSF stimulation. In addition, treatment of cells with low-dose Ara-C alone resulted in the enhancement of myeloid specific antigens expression in 16 cases (64%). Treatment of leukemia cells with higher concentrations of Ara-C (over 50 ng/ml) alone resulted in cytocidal effects but not in the induction of differentiation. Furthermore, 15 cases (60%) showed pronounced myeloid differentiation of leukemia cells after combined exposure to G-CSF plus low-dose Ara-C as compared with cells treated with either G-CSF or Ara-C alone. The enhanced effect of differentiation induction by combining G-CSF plus low-dose Ara-C was also observed in a murine myeloid leukemia cell line WEHI-3B in vitro. These data suggest that treatment with G-CSF plus low-dose Ara-C is capable of inducing differentiation of leukemic cells in vitro, and also appears to be useful for the differentiation-based therapy of patients with AML and MDS.

Cloning of TCFL5 encoding a novel human basic helix-loop-helix motif protein that is specifically expressed in primary spermatocytes at the pachytene stage

We have isolated a novel human gene that is expressed specifically in primary spermatocytes in the testis. The cDNA contains an open reading frame of 1356 bp, encoding a 452-amino-acid protein that includes a basic Helix-Loop-Helix (bHLH) motif. The gene, which was mapped to chromosome region 20q13.3-->qter by fluorescence in situ hybridization, consists of six exons and spans approximately 24 kb of genomic DNA. Immunohistochemical staining located the gene product exclusively in cell nuclei of primary spermatocytes at the pachytene stage, but not in those at the leptonema stage. We named this gene TCFL5 (transcription factor-like 5, basic helix-loop-helix). The cell-type and stage-specific expression of TCFL5 indicates that this protein may function in a crucial role in spermatogenesis as a transcription factor by regulating cell proliferation or differentiation of cells through binding to a specific DNA sequence like other bHLH molecules.

Syntheses of optically active trifluoronorcoronamic acids

Syntheses of optically active trifluoronorcoronamic acid 6 and its diastereomer 9 are described. Highly stereospecific and diastereoselective S(N)2 cyclization of gamma-cyanohydrins 3a and 3b gave cyclopropyl nitriles 4a and 4b. Hydrolysis of the cyano group and deprotection of the amino group of 4a provide trifluoronorcoronamic acid 6. Hofmann rearrangement of the amide which was generated by hydrolysis of the cyano group and oxidative cleavage of the aryl ring of 4b to provide trifluoro-allo-norcoronamic acid 9.

Aberrant luteinizing hormone-releasing hormone-stimulated adrenocorticotropic hormone secretion in a patient with pituitary hyperplasia due to primary hypothyroidism

We report a patient with primary hypothyroidism associated with an aberrant ACTH response to the LH-RH test. A 40-year-old woman was admitted to our hospital displaying headache, nausea, and numbness on the left side of her face, upper limbs, and tips of her toes. Computed tomography and magnetic resonance imaging revealed a mass-like lesion in the pituitary. A high serum TSH concentration with concomitant low thyroid hormone concentrations resulted in a diagnosis of primary hypothyroidism. To exclude the possibility of a coexisting pituitary tumor including a TSH-secreting tumor, we performed dynamic TSH secretion tests. TRH testing showed an excessive, delayed TSH response, typical of primary hypothyroidism. Serum TSH decreased not only after administration of CRH, octreotide, or L-DOPA, but also after administration of LH-RH. In this case, LH-RH testing induced ACTH secretion. To determine if aberrant ACTH secretion in response to LH-RH loading is a common phenomenon in severe primary hypothyroidism, we performed the LH-RH test on 4 additional patients with pituitary enlargement due to primary hypothyroidism. Two patients demonstrated aberrant ACTH secretion in response to LH-RH loading, but the others did not. To our knowledge, this is the first report of aberrant LH-RH-stimulated ACTH secretion in primary hypothyroidism.

Src homology region 2 (SH2) domain-containing phosphatase-1 dephosphorylates B cell linker protein/SH2 domain leukocyte protein of 65 kDa and selectively regulates c-Jun NH2-terminal kinase activation in B cells

Src homology region 2 (SH2) domain-containing phosphatase-1 (SHP-1) is a cytosolic protein tyrosine phosphatase containing two SH2 domains in its NH2 terminus. That immunological abnormalities of the motheaten and viable motheaten mice are caused by mutations in the gene encoding SHP-1 indicates that SHP-1 plays important roles in lymphocyte differentiation, proliferation, and activation. To elucidate molecular mechanisms by which SHP-1 regulates BCR-mediated signal transduction, we determined SHP-1 substrates in B cells using the substrate-trapping approach. When the phosphatase activity-deficient form of SHP-1, in which the catalytic center cysteine (C453) was replaced with serine (SHP-1-C/S), was introduced in WEHI-231 cells, tyrosine phosphorylation of a protein of about 70 kDa was strongly enhanced. Immunoprecipitation and Western blot analyses revealed that this protein is the B cell linker protein (BLNK), also named SH2 domain leukocyte protein of 65 kDa, and that upon tyrosine phosphorylation BLNK binds to SHP-1-C/S in vitro. In vitro kinase assays demonstrated that hyperphosphorylation of BLNK in SHP-1-C/S-expressing cells was not due to enhanced activity of Lyn or Syk. Furthermore, BCR-induced activation of c-Jun NH2-terminal kinase was shown to be significantly enhanced in SHP-1-C/S transfectants. Taken collectively, our results suggest that BLNK is a physiological substrate of SHP-1 in B cells and that SHP-1 selectively regulates c-Jun NH2-terminal kinase activation.

Identification of Rad51 alteration in patients with bilateral breast cancer

The human Rad51 gene, HsRAD51, is a homolog of RecA of Escherichia coli and functions in recombination and DNA repair. BRCA1 and BRCA2 proteins form a complex with Rad51, and these genes are thought to participate in a common DNA damage response pathway associated with the activation of homologous recombination and double-strand break repair. Additionally, we have shown that the pattern of northern blot analysis of the RadS gene is closely similar to those of the BRCA1 and BRCA2 genes. It is therefore possible that alterations of the Rad51 gene may be involved in the development of hereditary breast cancer. To investigate this possibility, we screened Japanese patients with hereditary breast cancer for Rad51 mutations and found a single alteration in exon 6. This was determined to be present in the germline in two patients with bilateral breast cancer, one with synchronous bilateral breast cancer and the other with synchronous bilateral multiple breast cancer. In both patients, blood DNAs showed a G-to-A transition in the second nucleotide of codon 150, which results in the substitution of glutamine for arginine. As this alteration was not present in any patients with breast or colon cancer examined, we assume that this missense alteration is likely to be a disease-causing mutation.

An Arabidopsis gene encoding a Ca2+-binding protein is induced by abscisic acid during dehydration

An Arabidopsis thaliana RD20 cDNA, which was isolated as one of drought-inducible genes, encodes a putative protein with a conserved EF-hand Ca2+-binding domain. The recombinant RD20 protein was shown to bind Ca2+. The transcription of RD20 gene was induced not only by drought but also by ABA and high salinity.

Chronic inhalation toxicity and carcinogenicity studies of 3-chloro-2-methylpropene in BDF1 mice

Chronic toxicity and carcinogenicity studies of 3-chloro-2-methylpropene (CMP), which has been widely used as an insecticide and chemical intermediate, were carried out in BDF1 mice. CMP was administered to mice in groups of 50 male and 50 female mice by the inhalation route 5 days per week for 104 weeks at doses of 0, 50, 100 or 200 ppm. Male and female mice in the CMP-exposed groups had decreased body weight but no noticeable clinical signs when compared with the control group. Dose-related increases in the incidences of gastric mucosal hyperplasia and squamous cell papilloma were observed in both sexes, and squamous cell carcinoma was observed in only one male mouse in the 100 ppm group. An increased incidence of Harderian gland adenoma in female mice was also recognized. In the nasal cavity, eosinophilic exudate associated with atrophy of olfactory epithelia, respiratory metaplasia of olfactory epithelia and olfactory gland, and eosinophilic changes in respiratory and olfactory epithelia were increased in both sexes.

Bradykinin B(2) receptor gene polymorphism is associated with angiotensin-converting enzyme inhibitor-related cough

The appearance of cough in association with angiotensin-converting enzyme (ACE) inhibitors is thought to be related to bradykinin, and it has been speculated that the elicitation of adverse effects is genetically predetermined. Several polymorphisms of the human bradykinin B(2) receptor gene may be involved in ACE inhibitor-related cough. To investigate this possibility, we identified the -58 thymine (T)/cytosine (C) polymorphism in subjects with ACE inhibitor-related cough. We classified the study population into 4 groups: subjects with and without cough that were treated with ACE inhibitors (n=30/30), nontreated essential hypertensive subjects (n=100), and normotensive subjects (n=100). The -58T/C was genotyped by the polymerase chain reaction single-strand conformation polymorphism method. The frequencies of the CC genotype and C allele of -58T/C were significantly higher in the nontreated hypertensive subjects than in the normotensive subjects. Conversely, the frequencies of the TT genotype and T allele were significantly higher in the subjects with cough than in the subjects without cough. These tendencies were more pronounced in females. Among the promoter assays of the human bradykinin B(2) receptor, -58T was found to have a higher transcription rate than that of -58C. This finding seems to suggest that the transcriptional activity of promoter might be involved in the appearance of ACE inhibitor-related cough. A genetic variant of the bradykinin receptor is involved in the elicitation of ACE inhibitor-related cough. It may be possible to predict the side effects of ACE inhibitors in advance.

Protein-tyrosine kinase Pyk2 is involved in interleukin-2 production by Jurkat T cells via its tyrosine 402

We established Jurkat transfectants that overexpress Pyk2 or its mutants, K457A (lysine 457 was mutated to alanine), Pyk2-Y402F (tyrosine 402 to phenylalanine), and Pyk2-Y881F to investigate the role of Pyk2 in T cell activation. Pyk2 as well as kinase-inactive Pyk2-K457A, was phosphorylated at tyrosine residues 402, 580, and 881 upon T cell antigen receptor cross-linking, indicating that these residues are phosphorylated by other tyrosine kinase(s). However, no tyrosine phosphorylation of Pyk2-Y402F was detected while more than 60% of the tyrosine phosphorylation was observed in Pyk2-Y881F. Pyk2-Y402F inhibited the activation of endogenous Pyk2. The degree of activation of both c-Jun NH(2)-terminal kinase and p38 mitogen-activated protein kinase but not extracellular signal-regulated protein kinase after concurrent ligation of T cell antigen receptor and CD28 was reduced by more than 50% in the clones expressing Pyk2-Y402F. Consistent with this inhibition, IL-2 production was significantly diminished in the Pyk2-Y402F-expressing clones. Furthermore, we found that Pyk2, when overexpressed, associates with Zap70 and Vav. Taken together, these findings suggest that Pyk2 is involved in the activation of T cells through its tyrosine 402.

Skeletal abnormalities in doubly heterozygous Bmp4 and Bmp7 mice

Analysis of the skeletal phenotypes caused by the genetic inactivation of individual Bmps, along with the study of their expression patterns, suggest possible functional redundancy of these molecules. To investigate the effect on skeleton development of the combined absence of some Bmp genes expressed in the same areas, we have intercrossed heterozygous Bmp7 mice with Bmp2 +/-, Bmp4 +/-, or Bmp5 +/- animals. Bmp2/7 and Bmp5/7 double heterozygous animals do not present with any abnormalities. In contrast, Bmp4/7 double heterozygotes develop minor defects in two restricted areas of the skeleton, the rib cage, and the distal part of the limbs. In the ribs, Bmp4 and Bmp7 seem to act in the same pathway to assure proper guidance of mesenchymal condensations of the ribs extending toward the sternum. In the limbs, these molecules appear to play a similar role in controlling digit number, possibly through induction of apoptosis in the interdigital and anterior mesenchyme.

Plasma endothelin-1 and thrombomodulin levels in coronary sinus during right atrial pacing and percutaneous transluminal coronary angioplasty

Increases in the levels of plasma endothelins (ETs) have been reported after percutaneous transluminal coronary angioplasty (PTCA). To examine the mechanism of this increase, we measured plasma endothelin-1 (ET-1) and thrombomodulin (TM) levels in both the Valsalva sinus (VAL) and the great cardiac vein (GCV) together with oxygen saturation of the GCV (Sat.GCVO2) during right atrial pacing and PTCA. Thirty patients with stenoses in the left anterior descending coronary arteries were enrolled. A fiberoptic pulmonary artery catheter was placed in GCV for monitoring Sat.GCVO2, and blood sampling was repeated before and after each procedure. ET-1 did not increase during pacing, but after PTCA it significantly increased from basal levels to 24.4+/- 8.3 pg/ml in GCV (P<0.01) and 19.3 +/-7.4 in VAL (P<0.05). Basal TM levels in GCV and VAL were significantly higher in diabetic than in non-diabetic patients, but TM did not change during pacing and PTCA. Sat.GCVO2 significantly decreased from the basal level during pacing and PTCA. We speculate that direct endothelial cell damage is more responsible for the increase of ET-1 during PTCA than myocardial ischemia. Our data indicate that ET-1 may be a useful marker for acute endothelial damage, while TM reflects only chronic and general damage of endothelial cells.

Vitamin D receptor initiation codon polymorphism in Japanese patients with Graves' disease

Recent studies have shown that related genetic influences on bone mineral density (BMD) and bone turnover are related to allelic variations in the vitamin D receptor (VDR) gene. Osteoporosis as a complication of hyperthyroidism is characterized by increased rates of both bone formation and bone resorption. In addition, VDR gene polymorphism influences susceptibility to some autoimmune diseases such as insulin-dependent diabetes mellitus (IDDM) and multiple sclerosis (MS). In the gene encoding the VDR, we investigated the distribution of a VDR-FokI polymorphism that changes the predicted protein sequence. The subjects were 131 female Japanese patients with Graves' disease and 150 female controls. The distribution of genotype frequencies differs between Graves' disease and controls (chi2 = 5.99, degrees of freedom = 2, p = 0.0386). We found overexpression of F allele (69% vs. 61%, p = 0.0472) and homozygote FF (48% vs. 33%, p = 0.0118) in Graves' disease patients compared with controls. We also correlated a VDR-FokI polymorphism with BMD in the distal radius and biochemical markers of bone turnover in patients with Graves' disease in remission. Although generally, no significant association was seen between age-adjusted BMD and genotype, patients in remission for fewer than 5 years showed significantly lower age-adjusted BMD in Ff heterozygotes than in ff homozygotes (z = 1.14 ff vs. z = -0.43 Ff, p < 0.05). Moreover, serum concentrations of bone alkaline phosphatase were significantly greater in Ff homozygotes than in FF homozygotes (78 +/- 12 vs. 59 +/- 10, p < 0.05). The genotypes did not differ in serum concentrations of osteocalcin, urinary hydroxyproline, or urinary deoxypyridinoline. Our results indicate, for the first time, an association between Graves' disease and a VDR polymorphism in the Japanese and suggest that a VDR-FokI polymorphism may affect bone mineral metabolism and can predict risk of osteoporosis as a complication of Graves' disease in patients in remission.

[Changes of serum hepatocyte growth factor in coronary artery disease]

Hepatocyte growth factor (HGF) is an endothelial cell specific growth factor involved in the repair of endothelial cells and collateral formation, however, the role for coronary artery disease is still unknown. We measured serum HGF level in various coronary artery diseases to examine the clinical significance. Serum HGF level was measured using the enzyme-linked immunosorbent assay method in patients with stable effort angina pectoris (n = 26), old myocardial infarction (n = 18), unstable angina pectoris (UAP; n = 10) and acute myocardial infarction (AMI; n = 21). As a control group, we selected 11 patients with neurocirculatory asthenia. Blood samples from peripheral veins were collected at cardiac catheterization before heparin administration. In the AMI group, blood samples were also collected at 48, 72 hr, 1, 2, 3 and 4 weeks from the peripheral veins and 48 and 72 hr after reperfusion from the coronary sinus. Serum HGF level was significantly higher in the UAP (0.41 +/- 0.12 ng/ml, p < 0.001) and AMI groups (0.38 +/- 0.26 ng/ml, p < 0.05) compared to the control group (0.19 +/- 0.09 ng/ml). Serum HGF level peaked 48 hr after reperfusion in both the peripheral veins (0.42 +/- 0.16 ng/ml) and coronary sinus (0.58 +/- 0.23 ng/ml) in the AMI group, with a significantly higher level in the coronary sinus than the peripheral veins (p < 0.05). No significant correlation between peak HGF level in the peripheral veins and peak creatine kinase (CK), CK-MB, ejection fraction and cardiac index was observed. Serum HGF was elevated in acute coronary syndrome, indicating advanced endothelial cell damage. HGF is produced, at least partially, in the heart in patients with AMI. Serum HGF level may be useful to detect endothelial cell damage rather than myocardial cell damage.

Vitamin D receptor initiation codon polymorphism in Japanese patients with Graves' disease

Recent studies have shown that related genetic influences on bone mineral density (BMD) and bone turnover are related to allelic variations in the vitamin D receptor (VDR) gene. Osteoporosis as a complication of hyperthyroidism is characterized by increased rates of both bone formation and bone resorption. In addition, VDR gene polymorphism influences susceptibility to some autoimmune diseases such as insulin-dependent diabetes mellitus (IDDM) and multiple sclerosis (MS). In the gene encoding the VDR, we investigated the distribution of a VDR-FokI polymorphism that changes the predicted protein sequence. The subjects were 131 female Japanese patients with Graves' disease and 150 female controls. The distribution of genotype frequencies differs between Graves' disease and controls (chi2 = 5.99, degrees of freedom = 2, p = 0.0386). We found overexpression of F allele (69% vs. 61%, p = 0.0472) and homozygote FF (48% vs. 33%, p = 0.0118) in Graves' disease patients compared with controls. We also correlated a VDR-FokI polymorphism with BMD in the distal radius and biochemical markers of bone turnover in patients with Graves' disease in remission. Although generally no significant association was seen between age-adjusted BMD and genotype, patients in remission for >5 years showed significantly lower age-adjusted BMD in Ff heterozygotes than in ff homozygotes (Z = 1.14 ff vs. Z = -0.43 Ff, p < 0.05). Moreover, serum concentrations of bone alkaline phosphatase were significantly greater in Ff homozygotes than in FF homozygotes (78 +/- 12 vs. 59 +/- 10, p < 0.05). The genotypes did not differ in serum concentrations of osteocalcin, urinary hydroxyproline, or urinary deoxypyridinoline. Our results indicate, for the first time, an association between Graves' disease and a VDR polymorphism in the Japanese and suggest that a VDR-FokI polymorphism may affect bone mineral metabolism and can predict risk of osteoporosis as a complication of Graves' disease in patients in remission.

[Clinicopathological study of left ventricular remodeling after first acute myocardial infarction]

The morphological characteristics of post-infarction ventricular remodeling were determined by comparison of infarct location and histological changes of noninfarcted myocardium at autopsy. A total of 94 cases of first acute myocardial infarction with clinical courses of 0 to 37 days were studied. Hearts were sliced on the short axis at the level of 1/3 of the distance from the atrioventricular ring to the apex. Wall thicknesses of the infarcted and noninfarcted areas, and the endocardial and epicardial perimeter lengths of the left ventricle were measured. Myocyte diameter and number of myocytes in the noninfarcted area were measured. Infarcts were classified into 3 groups based on infarct location (51 anterior, 22 posterior, and 21 nontransmural circumferential) and each group was further divided according to the clinical course of less than 72 hours or longer. Fifty two patients died within 72 hours. Cardiac rupture was the most common cause of death in the anterior group. Patients in the posterior group chiefly died due to cardiogenic shock and in the circumferential group chiefly died to pump failure. According to the number of stenosed coronary arteries, cardiac rupture was the most common cause of death in single-vessel disease in both anterior and posterior groups (62.1% and 55.6%, respectively). In double-vessel disease, the most common cause of death in the anterior group was still cardiac rupture (50.0%). On the other hand, 50.0% of the posterior group died of cardiogenic shock in double-vessel disease. Patients with triple-vessel disease mainly died due to heart failure in all groups. Wall thickness of the infarcted myocardium was decreased in the anterior group after 72 hours (11.8 +/- 3.5 vs 7.8 +/- 2.5 mm). Endocardial perimeter length was increased in the anterior and circumferential groups (83.6 +/- 25.6 vs 116.3 +/- 29.5 mm, 75.2 +/- 12.0 vs 117.6 +/- 3.1 mm, respectively). Endocardial/epicardial perimeter length ratio increased with longer clinical course in the anterior group. No specific change in wall thickness or perimeter length was found in the posterior group. Noninfarcted wall thickness was preserved in both the anterior and posterior groups. Myocyte diameter and number of myocytes in the noninfarcted area showed no significant difference after 72 hours. The nature of ventricular remodeling differs with infarct location. Ventricular dilation occurred during the clinical course in the anterior group. The transmural and adjacent areas are more important than the remote noninfarcted area in post-infarction remodeling within this period.

Potential role of BRCA2 in a mitotic checkpoint after phosphorylation by hBUBR1

BRCA2, a gene responsible for inherited susceptibility to breast cancer in a number of families, is thought to be critical for replication and repair of DNA during S-phase. To elucidate the physiological functions of BRCA2, we used a yeast two-hybrid system to screen for proteins that could associate with BRCA2. Here we report interaction of BRCA2 with a mitotic checkpoint protein, hBUBR1, and its phosphorylation by hBUBR1 in vitro. After cotransfection of BRCA2 and hBUBR1 expression vectors into the COS7 cell line, both proteins were stained together in the nuclei of cells whose spindle fibers were disrupted, but not in undamaged cells. Treatment with vincristine, which disrupts microtubules, significantly increased expression of both hBUBR1 and BRCA2 in the MCF7 cells. The results suggest that BRCA2 protein might be involved in a mitotic checkpoint in vivo after it has been phosphorylated by hBUBR1.

Hyperlipemic-very low density lipoprotein, intermediate density lipoprotein and low density lipoprotein act synergistically with serotonin on vascular smooth muscle cell proliferation

BACKGROUND

Previous studies have shown that very low density lipoprotein (VLDL), intermediate density lipoprotein (IDL) and low density lipoprotein (LDL) from hyperlipidemic plasma are more atherogenic than those from normal plasma. Since platelet aggregation at sites of atherosclerotic injury exposes the cells to high concentrations of serotonin (5HT), a known mitogen for vascular smooth muscle cells (VSMCs), it was examined whether VLDL, IDL or LDL from plasma of 1% cholesterol-fed rabbits can potentiate the mitogenic effect of 5HT on VSMC.

METHODS

Growth arrested primary aortic VSMC in 1st or 2nd passage were incubated with different concentrations of VLDL, IDL or LDL in the presence or absence of pertusis toxin (PTX) for 24 h followed by incubation with 5HT for 24 h. The amount of [3H]thymidine incorporated into the DNA as well as the increase in cell number was measured.

RESULTS

Either VLDL, IDL or LDL at a concentration of 60 microg/ml induced proliferation of VSMC by themselves (196, 137 or 122% increase in [3H]thymidine incorporation, or 122, 119 or 122% increase in cell number, respectively when compared to the control, P<0.05). This effect on DNA synthesis was markedly potentiated by 50 microM 5HT to 465, 714 and 1369%, respectively. PTX reversed the mitogenic effect of 5HT, but not that of VLDL, IDL or LDL.

CONCLUSION

These results suggest that even low concentration of VLDL, IDL or LDL from hypercholesterolemic plasma may significantly potentiate the mitogenic effect of 5HT, that is released by aggregating platelets at sites of vascular damage.

[Evaluation of restenosis by serum levels of soluble Fas, Fas ligand and nuclear matrix protein before and after coronary intervention]

Serum levels of soluble Fas, soluble Fas ligand, and nuclear matrix protein (NMP) were measured in 38 patients with ischemic heart disease before and after coronary angiography or coronary intervention. Serum levels of soluble Fas, soluble Fas ligand and NMP were determined by enzyme-linked immunosorbent assay. Patients one week after undergoing stent implantation had much higher levels of soluble Fas ligand and significantly lower levels of soluble Fas than patients without coronary intervention. Serum levels of soluble Fas ligand and NMP in patients with coronary restenosis were significantly higher than those in patients without restenosis. Serum levels of soluble Fas and soluble Fas ligand in patients one week after undergoing stent implantation who had coronary restenosis were markedly lower and higher than in patients without restenosis, respectively. Serum levels of soluble Fas ligand were positively correlated with NMP in those patients. These results indicate that coronary restenosis might be affected by the Fas/Fas ligand system. We conclude that measurement of soluble Fas, soluble Fas ligand and NMP is useful for determination of coronary restenosis in patients with ischemic heart disease.