Antioxidant activity of gallic acid from rose flowers in senescence accelerated mice

The activities of the antioxidant enzymes catalase (CAT) and glutathione peroxidase (GPx) in the blood and liver of the aging model induced by injection of different doses of D-gal into normal mice, and in senescence accelerated mice (SAM) of different ages, were determined. The results showed that the enzyme activities in the D-gal treated mice did not alter appreciably but the enzyme activities in blood of the SAM declined significantly with the increase in age, especially in the 9-month-old SAM. When gallic acid purified from rose flowers was used to treat the 9-month-old male SAM, it not only reinstated the activities of CAT and GPx but also significantly reduced the amount of malondialdehyde (MDA) in the liver, brain and kidney. The results demonstrated that 9-month-old male SAM represent an appropriate animal model to evaluate the antioxidant activities of natural products.

Rose (Rosa rugosa)-flower extract increases the activities of antioxidant enzymes and their gene expression and reduces lipid peroxidation

The effects of rose-flower extract on antioxidant enzymes were studied. The activities of catalase (CAT) and glutathione peroxidase (GPx) in 9-month-old senescence-accelerated mice (SAM mice) were lower than those in 6-month-old SAM mice. Therefore, 9-month-old SAM mice were the most appropriate targets for treatment with the rose-flower extract. The activities of CAT and GPx in SAM mice treated with rose-flower extract showed a marked increase in whole blood and liver. At the same time, the gene-expression level of CAT and GPx was upregulated in the liver, while malondialdehyde content in liver and brain decreased. Male SAM mice were more sensitive than female SAM mice. The mean and the longest lifespan of SAM mice were longer after treatment with rose-flower extract.Key word: anti-aging, CAT, GPx, lipid peroxidation.

Clinical and electrophysiological features in Chinese patients with Kennedy’s disease

Kennedy's disease is a X-linked neuromuscular disorder caused by an expanded trinucleotide repeat in the androgen receptor gene. To ascertain the clinical diagnosis of Kennedy's disease in a Chinese population, we used a rapid, accurate PCR-based sizing method for the CAG repeat allelotype. The clinical and electrophysiological features of affected patients are described. The CAG repeats ranged from 43 to 53 and were inversely correlated with the age of onset (r = -0.63; P < 0.005).

Exposure to L-ascorbic acid or alpha-tocopherol facilitates the development of porcine denuded oocytes from metaphase I to metaphase II and prevents cumulus cells from fragmentation

It is known that alpha-tocopherol (vitamin E) and L-ascorbic acid (vitamin C) can modulate many biochemical processes intracellularly or extracellularly as antioxidants. The objective of the present study was to investigate the effects of alpha-tocopherol and L-ascorbic acid on porcine oocyte meiotic maturation, viability and the functions of cumulus cells. In two independent experiments, porcine oocytes with or free from cumulus cells were exposed to different levels of alpha-tocopherol (0, 10, 100 and 200 microM) or L-ascorbic acid (0, 50, 250 and 750 microM). Cumulus expansion, cumulus cell DNA fragmentation, meiotic maturation and degeneration of oocytes were assessed 48 h after in vitro culture. The results showed that: (1) neither alpha-tocopherol nor L-ascorbic acid influenced cumulus expansion but both prevented cumulus cell DNA fragmentation. (2) Alpha-tocopherol lowered the percentage of denuded oocytes (DOs) arrested at germinal vesicle stage (GV). Among the oocytes undergoing germinal vesicle breakdown (GVBD) proportion, fewer DOs treated by alpha-tocopherol were at metaphase I (MI) and more at metaphase II (MII). L-ascorbic acid caused lower percentage of DOs arrested at GV stage and higher percentage of DOs undergoing GVBD, especially at MII. The influences of alpha-tocopherol and L-ascorbic acid were not obvious in cumulus-enclosed oocytes (CEOs). (3) Both vitamins compromised the viability of CEOs and DOs. These results indicate that exposure to alpha-tocopherol or L-ascorbic acid promotes the development of porcine DOs from MI to MII and prevents cumulus cell DNA fragmentation at certain levels, especially 10 microM alpha-tocopherol or 250 microM L-ascorbic acid.

Embryonic development of the ganglion plexuses and the concentric layer structure of human gut: a topographical study

In this study, we performed a detailed topographical study on the development of ganglion plexuses and the smooth muscle layers of human embryonic and fetal gut. Neuron and glia differentiation was investigated with anti-PGP9.5 and anti-S100 antibodies respectively. The differentiation of smooth muscle and interstitial cells of Cajal (ICC) was studied with anti-smooth muscle alpha-actin and anti-C-Kit antibodies respectively. By week 7, rostro-caudal neural crest cell (NCC) colonization of the gut was complete, and NCCs have differentiated into neurons and glia. At the foregut, neurons and glia were aggregated into ganglion plexus in the myenteric region, and the longitudinal and circular muscle layers have started to differentiate; however, neurons and glia were not found in the submucosa. At the hindgut, neurons and glia were dispersed within the mesenchyme. Myenteric plexus, longitudinal and circular muscle layers formed along the entire gut by week 9. Scattered and individual neurons and glia, and small ganglion plexuses were detected in the foregut and midgut submucosa by week 12. Ganglion plexus was not seen in the hindgut submucosa until week 14. Muscularis mucosae was formed at the foregut and midgut by week 12 but was only discernible at the hindgut 2 weeks later. As the gut wall developed, ganglion plexus increased in size with more neurons and glia, and the formation of intra-plexus nerve fascicle. ICCs were localized in the ganglion plexus as early as week 7. ICCs were initially dispersed in the plexus and were preferentially localized at the periphery of the plexus by week 20. The specification of the annular layers of human embryonic and fetal gut follows a strict spatio-temporal pattern in a rostro-caudal and centripetal manner suggesting that interaction between (1) homotypic and/or heterotypic cells; and (2) cells and the extracellular matrix is critical for the embryonic development of the gut mesenchyme and the enteric nervous system.

Thiazolidinediones, a class of anti-diabetic drugs, inhibit Id2 expression through a PPARgamma-independent pathway in human aortic smooth muscle cells

Inhibitor of DNA binding (Id2) is a member of the helix-loop-helix family of transcription regulators that is known to play important roles in the proliferation and differentiation of many cell types. Overexpression of Id2 has been reported to result in significant enhancement of vascular smooth muscle cell growth via increased S phase entry. We hypothesized that downregulation of Id2 gene expression by thiazolidinediones (TZDs), a class of anti-diabetic drugs and peroxisome proliferator-activated receptor gamma (PPARgamma) activators, might contribute to the anti-atherosclerotic and anti-hypertensive effects of the PPARgamma. Here we document that TZDs, including troglitazone and ciglitazone, repress Id2 gene expression in a doses- and time-dependent manner. However, GW7845, a high-affinity and non-TZD PPARgamma activator, had no inhibitory effect on Id2 gene expression. In addition, PPARgamma antagonist GW9662 did not rescue TZD-induced Id2 repression. Taken together, our data suggest that TZDs repress Id2 expression through a PPARgamma-independent pathway.

The frequency of occurrence of autoantibodies against beta1-adrenoceptors and its clinical relevance in patients with hepatitis virus myocarditis

The aim of this study was to examine the frequency of occurrence of autoantibodies against beta1-adrenoceptors in patients with hepatitis virus myocarditis (HVM) and its possible correlation with clinical characteristics. A total of 103 patients with viral myocarditis were divided into a positive group (HVM group, n=29) and a negative group (Non-HVM group, n=74) according to the laboratory findings regarding their type of hepatitis virus. The study parameters included UCG, ECG, biochemical findings and screening of autoantibodies against beta1-adrenoceptor. It was shown that the positive rate of the hepatitis virus was 28.16% (29/103) in patients with viral myocarditis. The severity of myocardial or liver injuries and the frequency of occurrence of autoantibodies against beta1-adrenoceptors in patients with viral myocarditis were more pronounced, before treatment, in the HVM group than in the Non-HVM group. The positive rates of the antibodies against the hepatitis virus and the autoantibodies against beta1-adrenoceptors were highly consistent in patients with HVM (p<0.05). In conclusion, the frequency of occurrence of the autoantibodies against beta1-adrenoceptors may be one important marker of HVM and, thus, possibly involved in the pathogenesis of the HVM.

Peroxisome proliferator-activated receptor gamma inhibits transforming growth factor beta-induced connective tissue growth factor expression in human aortic smooth muscle cells by interfering with Smad3

Activation of peroxisome proliferator-activated receptor gamma (PPAR gamma) after balloon injury significantly inhibits VSMC proliferation and neointima formation. However, the precise mechanisms of this inhibition have not been determined. We hypothesized that activation of PPAR gamma in vascular injury could attenuate VSMC growth and matrix production during vascular lesion formation. Since connective tissue growth factor (CTGF) is a key factor regulating extracellular matrix production, abrogation of transforming growth factor beta (TGF-beta)-induced CTGF production by PPAR gamma activation may be one of the mechanisms through which PPAR gamma agonists inhibit neointima formation after vascular injury. In this study, we demonstrate that the PPAR gamma natural ligand (15-deoxyprostaglandin J(2)) and a synthetic ligand (GW7845) significantly inhibit TGF-beta-induced CTGF production in a dose-dependent manner in HASMCs. In addition, suppression of CTGF mRNA expression is relieved by pretreatment with an antagonist of PPAR gamma (GW9662), suggesting that the inhibition of CTGF expression is mediated by PPAR gamma. To elucidate further the molecular mechanism by which PPAR gamma inhibits CTGF expression, an approximately 2-kilobase pair CTGF promoter was cloned. We found that PPAR gamma activation inhibits TGF-beta-induced CTGF promoter activity in a dose-dependent manner, and suppression of CTGF promoter activity by PPAR gamma activation is completely rescued by overexpression of Smad3, but not by Smad4. Furthermore, PPAR gamma physically interacts with Smad3 but not Smad4 in vitro in glutathione S-transferase pull-down experiments. Taken together, the data suggest that PPAR gamma inhibits TGF-beta-induced CTGF expression in HASMCs by directly interfering with the Smad3 signaling pathway.

[Study on the content of serum HDL subclasses in obese subjects]

OBJECTIVE

To investigate the change of the contents of serum HDL subclasses in obese subjects.

METHODS

Contents of serum HDL subclasses in healthy controls(n = 64) and obese subjects(n = 58) were determined by two-dimensional gel electrophoresis associated with immunodetection method.

RESULTS

The pre-beta 1 HDL, HDL3c and HDL3b contents increased significantly (P < 0.001) and the HDL2b content decreased significantly (P < 0.001) in obese subjects as compared with those in healthy controls. In male obese subjects, the pre-beta 1 HDL and HDL3c levels were significantly higher(P < 0.01 and P < 0.05, respectively) and HDL2b level was significantly lower(P < 0.05), compared with those in female obese subjects. In male control subjects, the level of pre-beta 1 HDL was significantly higher than that in female subjects. In obese subjects, the concentrations of BMI and serum TG had positive correlation with those of pre-beta 1 HDL(r = 0.382, P < 0.001), HDL3c(r = 0.232, P < 0.05) and HDL3b(r = 0.294, P < 0.01) and negative correlation with that of HDL2b(r = -0.304, P < 0.01).

CONCLUSION

The particle size of HDL in obese subjects showed a general shift toward smaller size, which indicated that the maturation of HDL could be abnormal in obese subjects. The particle size of HDL was found to be smaller in both obese and control male subjects than in female subjects, suggesting that sex seems to be related to the contents of serum HDL subclasses.

Platelet-derived growth factor promotes the expression of peroxisome proliferator-activated receptor gamma in vascular smooth muscle cells by a phosphatidylinositol 3-kinase/Akt signaling pathway

Vascular diseases such as atherosclerosis are characterized by abnormal accumulation of vascular smooth muscle cells (VSMCs) within the intimal lining. The intimal VSMCs exhibit an increased expression of peroxisome proliferator-activated receptor gamma (PPARgamma), and the administration of pharmacological PPARgamma agonists attenuates vascular lesion formation. The factors that regulate PPARgamma expression in the vasculature are poorly defined. Here we report that platelet-derived growth factor (PDGF) upregulates PPARgamma by the phosphatidylinositol 3-kinase (PI3-kinase)/Akt signaling pathway. Using Northern-blotting and Western-blotting analyses, we observed that the levels of PPARgamma mRNA and protein were increased by 2- to 3.5-fold in human aortic smooth muscle cells (HASMCs) treated with PDGF (20 ng/mL). This was abolished by preincubation of HASMCs with a PI3-kinase inhibitor (LY294002, 50 micromol/L), and partially inhibited by a MEK1 inhibitor (U0126, 10 micromol/L), but not affected by a p38 kinase inhibitor (SB202190, 10 micromol/L). In addition, overexpression of the dominant-negative p85 subunit of PI3-kinase or Akt proteins blocked the PDGF-induced PPARgamma expression. Taken together, our results suggest that PDGF induces PPARgamma expression in VSMCs by a PI3-kinase/Akt signaling pathway. The characterization of factors and signaling pathways that modulate PPARgamma expression in VSMCs may have important implications for understanding the pathogenesis of vascular diseases.

Zhang's ring-clamp modification of Duhamel's procedure: 30 years experience

To evaluate the efficacy of the ring-clamp procedure (RCP) in the treatment of Hirschsprung's disease (HD) 435 RCPs were compared to 54 Kocher procedures performed between 1960 and 1990. The data were analyzed by chi-square test. The RCP resulted in much less blind-pouch syndrome (7%) compared to the Kocher's procedure (40%), and represents a valid alternative in the treatment of HD in children.

Effect of primary angioplasty on total or subtotal left main occlusion: analysis of incidence, clinical features, outcomes, and prognostic determinants

BACKGROUND

Although acute left main coronary artery (LMCA) occlusion is a rare clinical entity, it carries a very high mortality rate. The purposes of this study were to evaluate the effect of primary angioplasty for a severely obstructed or totally occluded LMCA, and to determine the incidence, clinical features, outcome, and prognostic determinants in this clinical setting.

MATERIALS AND METHODS

Between May 1993 and July 2000, a total of 740 patients with acute myocardial infarction underwent primary angioplasty in our hospital. Eighteen of 740 patients (2.4%) with a severely obstructed or totally occluded LMCA constituted the population of this study.

RESULTS

Seventeen of 18 patients (94.4%) experienced pulmonary edema (including 14 patients in cardiogenic shock). Six patients (33.3%) sustained sudden death due to malignant ventricular tachyarrhythmias. Coronary angiography showed that there were variable grade flow of intercoronary collaterals in 12 patients (66.7%), a totally occluded LMCA in 8 patients (44.4%), an incompletely occluded LMCA in 10 patients (55.6%), and a dominant right coronary artery (RCA) in 16 patients (88.9%). Primary angioplasty of the LMCA was performed with a 72.2% procedural success rate. Four patients (22.2%) received coronary artery bypass surgery after angioplasty. Six patients (33.3%) died in the hospital. Two patients died after discharge. Ten of 18 patients (55.6%) survived in long-term follow-up (mean +/- SD, 44 +/- 14 months). Those patients who survived to be discharged had significantly higher combined coexisting incidence of intercoronary collaterals, dominant RCA, and incompletely occluded LMCA (100% vs 0.0%, p = 0.0006) than those patients who died in the hospital.

CONCLUSIONS

Acute obstructive LMCA disease generally presented as pulmonary edema, cardiogenic shock, or sudden death. Only those who had combined coexistence of intercoronary collaterals, a dominant RCA, and an incompletely occluded LMCA could survive to be discharged. Our experience suggests that primary LMCA angioplasty is a feasible and effective procedure, and it may save lives in this clinical setting.

[Analysis of mandibular position of patients with angles Class I and Class II, division 1 malocclusion]

OBJECTIVE

To study changes of condyle position and occlusion between centric jaw relation and maximum intercuspation positions.

METHODS

The power centric registration advocated by Roth was used to take centric relation bite registration for 50 patients (25 Class I and 25 Class II, Division 1) and diagnostic models were mounted and analysed with Panadent articulator and condyle position indicator.

RESULTS

Nearly all patients had CR-MI differences in all three planes of space. 70% of the sagittal displacement was within 2.0 mm and 87% of the transverse displacement was within 1.0 mm. Most of the condyles moved posteriorly and inferiorly. 65% of the initial contacts in CR occured on the most posterior molar on single side. Correlation was found between some variables of condylar displacement and occlusion changes. No significant difference was observed in condylar position and occlusion changes between Class I and Class II, Dvision 1 patients.

CONCLUSIONS

The occlusion in centric jaw relation should be analysed before treatment to reveal the disharmony between occlusion and jaw position.

SOX10 is abnormally expressed in aganglionic bowel of Hirschsprung's disease infants

BACKGROUND

The primary pathology of Hirschsprung's disease (HD) is a congenital absence of ganglion cells in the caudal most gut. The spastic aganglionic bowel is often innervated by a network of hypertrophied nerve fibres. Recently, mutations of SOX10 have been identified in patients with HD but only in those with Waardenburg-Shah syndrome.

AIMS

To understand the molecular basis for the pathogenesis of HD we intended to determine the specific cell lineages in the enteric nervous system which normally express SOX10 but are affected in disease conditions.

METHODS

We studied colon biopsies from 10 non-syndromic HD patients, aged three months to four years, and 10 age matched patients without HD as normal controls. The absence of mutation in the SOX10 gene of HD patients was confirmed by DNA sequencing. Expression and cellular distribution of SOX10 in bowel segments of normal and HD infants were examined by reverse transcription-polymerase chain reaction and in situ hybridisation.

RESULTS

We found that in normal infants and normoganglionic bowel segments of HD patients, SOX10 was expressed in both neurones and glia of the enteric plexuses and in the nerves among the musculature in normal colon. In the aganglionic bowel segments of patients, SOX10 expression was consistently lower and was found to be associated with the hypertrophic nerve trunks in the muscle and extrinsic nerves in the serosa.

CONCLUSION

We conclude that SOX10 is normally required postnatally in the functional maintenance of the entire enteric nervous system, including neurones and glia. In non-syndromic HD patients who do not have the SOX10 mutation, the SOX10 gene expressed in the sacral region may be involved in the pathogenesis of the abnormal nerve trunks through interaction with other factors.

Inhibition of egg hatching success and larvae survival of the scallop, Chlamys farreri, associated with exposure to cells and cell fragments of the dinoflagellate Alexandrium tamarense

We report an apparently novel toxic effect of the dinoflagellate Alexandrium tamarense, manifested by inhibition of the egg hatching success of the scallop, Chlamys farreri. The hatching rate of C. farreri approached only 30% of controls when its fertilised eggs were exposed for 36h to A. tamarense cells or cellular fragments at a concentration of 100 cells/ml, and the hatching rate was just 5% after exposure to A. tamarense of 500 cells/ml. Similar exposures of the fertilised scallop eggs to two other algal species, the diatom Phaeodactylum tricornutum and the raphidophyte Heterosigma carterae, resulted in no such toxicity or inhibitory effects. Likewise, exposure of eggs to standard STX toxin, as well as to A. tamarense cell contents (supernant of re-suspended algal cells following ultrasonication and centrifugation), did not elicit this inhibitory response. However, exposure of the scallop eggs to cell cultures, intact algal cells, or cell fragments of A. tamarense produced marked toxicity. The alga also influenced larvae at early D-shape stage of scallop. The survival rates began to decrease significantly after exposed for 6 days at concentration of 3000 cells/ml and above; no larvae could survive after 14-day exposure to A. tamarense at 10,000 cells/ml or 20-day at 5000 cells/ml. The results indicated the production of novel substances from A. tamarense which can cause adverse effects on egg hatching and survival of the scallop larvae. The experiment also found that the developmental stages before blastula was the developmental period most sensitive to the A. tamarense toxin(s) and the alga at early exponential stage had the strongest effect on egg hatching comparing with other growth phases. The adverse effect of A. tamarense on early development of scallops may cause decline of shellfish population and may have further impact on marine ecosystem.

beta(1)-Adrenoceptor antibodies induce positive inotropic response in isolated cardiomyocytes

beta(1)-Adrenoceptor autoantibodies are present in approximately 30% of patients suffering from dilated cardiomyopathy. The inotropic effects mediated by these antibodies remain to be studied. Monoclonal antibodies were raised against a peptide corresponding to the second extracellular loop of the human beta(1)-adrenoceptor in balb/C mouse (n=6), and were characterized by enzyme immunoassay after purification by protein A. Purified immunoglobulin G from non-immunized animals (controls) did not influence Ca(2+) transient and cell shortening of rat cardiomyocytes measured by confocal-laser-scanning-microscopy. beta(1)-adrenoceptor antibodies caused a dose-related increase in Ca(2+) transient (dilution 1:2: +35.3+/-5.1%), and in cell shortening (dilution 1:2: +40.5+/-6.3%) (P<0.01 vs. controls). The effect of the beta(1)-adrenoceptor antibodies was blocked by the antigenic peptide and by the antagonist metoprolol. In addition, beta(1)-adrenoceptor antibodies induced a dose-dependent increase of the cyclic adenosine monophosphate. The inotropic response induced by isoproterenol was attenuated by the beta(1)-adrenoceptor antibody. beta(1)-adrenoceptor antibodies as partial agonists induce a specific positive inotropic effect via the protein-kinase-A-cascade.

Efficacy of nonprescription doses of ibuprofen for treating migraine headache. a randomized controlled trial

OBJECTIVE

To evaluate the efficacy and safety of ibuprofen, 200 mg and 400 mg, compared with placebo and each other for the treatment of pain of migraine headache.

BACKGROUND

Migraine headache is a common illness with significant social and economic impact.

DESIGN

Randomized, placebo-controlled, double-blind trial of 6 hours' treatment duration.

METHODS

Fifteen investigators at 17 private practice and referral centers in the United States participated in this study of 660 outpatient adults aged 18 to 84 years with migraine headache of moderate to severe intensity. Each patient was randomly assigned to a single dose of study medication: ibuprofen 200 mg (n = 216) or 400 mg (n = 223), or placebo (n = 221). The percentage of patients with a reduction in baseline headache intensity from severe or moderate to mild or none 2 hours after treatment and the headache pain intensity difference from baseline at 2 hours were the primary efficacy measures. Secondary outcomes included other measures of pain relief, severity differences from baseline for migraine-associated symptoms of nausea, photophobia, phonophobia, and functional disability, and percentage of patients with migraine-associated symptoms reduced to none.

RESULTS

Significantly (P < or = .006) more patients treated with ibuprofen, 200 mg or 400 mg, reported mild to no pain after 2 hours (41.7% and 40.8%, respectively), compared with those treated with placebo (28.1%). The mean pain intensity difference from baseline measured at 2 hours was significantly (P < or = .001) greater for patients treated with ibuprofen 200 mg or 400 mg (0.68 and 0.65, respectively), compared with those treated with placebo (0.39). Statistically significant differences in favor of both doses of ibuprofen over placebo were observed for mean pain intensity difference at 1 hour after treatment. In patients with severe baseline pain intensity, ibuprofen, 400 mg, was significantly (P < or = .048) superior to placebo for the primary efficacy end points, while ibuprofen, 200 mg, was not. Ibuprofen, 200 mg and 400 mg, were statistically significantly more effective than placebo for all clinically important secondary pain relief outcomes. Mean severity changes of migraine-associated symptoms of nausea, photophobia, phonophobia, and functional disability at 2 and 6 hours were significantly (P < or = .03) in favor of both doses of ibuprofen over placebo, and results for the percentage of patients with symptoms reduced to none consistently, although less often statistically significant, favored ibuprofen. No statistically significant differences in adverse events were found among treatment groups.

CONCLUSIONS

Ibuprofen at doses of 200 mg and 400 mg is an efficacious, cost-effective, well-tolerated, single-ingredient nonprescription treatment for pain of migraine headache. In addition, while not always statistically significant, ibuprofen provided a beneficial effect on associated symptoms of migraine including nausea, photophobia, phonophobia, and functional disability.

[Fluorescence quenching method for the determination of p-hydroxyphenylpyruvic acid]

A fluorescence quenching method for the determination of p-hydroxyphenylpyruvic acid with trytophan in the medium pH 11.01 NH3-NH4Cl is studied. The calibration curve is linear for p-hydroxyphenylpyruvic acid from 0 to 15 micrograms.mL-1 with lambda ex/lambda em = 285/356 nm. The detection limit is 0.37 microgram.mL-1. Twenty replicate determinations of solutions containing 10 micrograms.mL-1 p-hydroxyphenylpyruvic acid show a relative standard deviation of 1.2%. This method can be applied to the determination of p-hydroxyphenylpyruvic acid in serum with satisfactory results.

Direct acetylation of the estrogen receptor alpha hinge region by p300 regulates transactivation and hormone sensitivity

Regulation of nuclear receptor gene expression involves dynamic and coordinated interactions with histone acetyl transferase (HAT) and deacetylase complexes. The estrogen receptor (ERalpha) contains two transactivation domains regulating ligand-independent and -dependent gene transcription (AF-1 and AF-2 (activation functions 1 and 2)). ERalpha-regulated gene expression involves interactions with cointegrators (e.g. p300/CBP, P/CAF) that have the capacity to modify core histone acetyl groups. Here we show that the ERalpha is acetylated in vivo. p300, but not P/CAF, selectively and directly acetylated the ERalpha at lysine residues within the ERalpha hinge/ligand binding domain. Substitution of these residues with charged or polar residues dramatically enhanced ERalpha hormone sensitivity without affecting induction by MAPK signaling, suggesting that direct ERalpha acetylation normally suppresses ligand sensitivity. These ERalpha lysine residues also regulated transcriptional activation by histone deacetylase inhibitors and p300. The conservation of the ERalpha acetylation motif in a phylogenetic subset of nuclear receptors suggests that direct acetylation of nuclear receptors may contribute to additional signaling pathways involved in metabolism and development.

Inhibition of cellular proliferation through IkappaB kinase-independent and peroxisome proliferator-activated receptor gamma-dependent repression of cyclin D1

The nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma) is a ligand-regulated nuclear receptor superfamily member. Liganded PPARgamma exerts diverse biological effects, promoting adipocyte differentiation, inhibiting tumor cellular proliferation, and regulating monocyte/macrophage and anti-inflammatory activities in vitro. In vivo studies with PPARgamma ligands showed enhancement of tumor growth, raising the possibility that reduced immune function and tumor surveillance may outweigh the direct inhibitory effects of PPARgamma ligands on cellular proliferation. Recent findings that PPARgamma ligands convey PPARgamma-independent activities through IkappaB kinase (IKK) raises important questions about the specific mechanisms through which PPARgamma ligands inhibit cellular proliferation. We investigated the mechanisms regulating the antiproliferative effect of PPARgamma. Herein PPARgamma, liganded by either natural (15d-PGJ(2) and PGD(2)) or synthetic ligands (BRL49653 and troglitazone), selectively inhibited expression of the cyclin D1 gene. The inhibition of S-phase entry and activity of the cyclin D1-dependent serine-threonine kinase (Cdk) by 15d-PGJ(2) was not observed in PPARgamma-deficient cells. Cyclin D1 overexpression reversed the S-phase inhibition by 15d-PGJ(2). Cyclin D1 repression was independent of IKK, as prostaglandins (PGs) which bound PPARgamma but lacked the IKK interactive cyclopentone ring carbonyl group repressed cyclin D1. Cyclin D1 repression by PPARgamma involved competition for limiting abundance of p300, directed through a c-Fos binding site of the cyclin D1 promoter. 15d-PGJ(2) enhanced recruitment of p300 to PPARgamma but reduced binding to c-Fos. The identification of distinct pathways through which eicosanoids regulate anti-inflammatory and antiproliferative effects may improve the utility of COX2 inhibitors.

Cyclin D1 binds the androgen receptor and regulates hormone-dependent signaling in a p300/CBP-associated factor (P/CAF)-dependent manner

The androgen receptor (AR) is a ligand-regulated member of the nuclear receptor superfamily. The cyclin D1 gene product, which encodes the regulatory subunit of holoenzymes that phosphorylate the retinoblastoma protein (pRB), promotes cellular proliferation and inhibits cellular differentiation in several different cell types. Herein the cyclin D1 gene product inhibited ligand-induced AR- enhancer function through a pRB-independent mechanism requiring the cyclin D1 carboxyl terminus. The histone acetyltransferase activity of P/CAF (p300/CBP associated factor) rescued cyclin D1-mediated AR trans-repression. Cyclin D1 and the AR both bound to similar domains of P/CAF, and cyclin D1 displaced binding of the AR to P/CAF in vitro. These studies suggest cyclin D1 binding to the AR may repress ligand-dependent AR activity by directly competing for P/CAF binding.

Primary angioplasty in acute inferior myocardial infarction with anomalous-origin right coronary arteries as infarct-related arteries: focus on anatomic and clinical features, outcomes, selection of guiding catheters and management

BACKGROUND

Inferior wall myocardial infarction caused by obstruction of an anomalous-origin right coronary artery (RCA) is a rare angiographic finding; primary angioplasty to an anomalous-origin RCA has never been reported.

METHODS

In 185 patients with acute inferior wall myocardial infarction resulting from RCA occlusion who underwent primary angioplasty, eight patients (4.3%) had anomalous-origin RCAs.

RESULTS

Coronary angiography showed that all 8 patients had a dominant RCA. Six patients (75%) had an anomalous-origin RCA arising from the anterior aspect of the ascending aorta above the sinotubular line and the other 2 patients (25%) had an anomalous-origin RCA arising from the left sinus of Valsalva with a separate ostium from the left main coronary artery. The standard Judkins right guiding catheter did not offer adequate support in these patients. In the group of 6 patients, an Amplatz guiding catheter offered good support, while a standard Judkins left guiding catheter was adequate in the other 2 patients. Obstruction of the proximal RCA occurred in 6 patients (75%). Successful reperfusion was achieved in 6 patients (75%), resulting in an uneventful clinical course and long-term survival (mean follow-up, 24.9 +/- 16.5 months). Two patients (25%) had unsuccessful reperfusion and died from cardiogenic shock.

CONCLUSIONS

In this small series, anomalous-origin RCAs were the dominant artery and predisposed to atherosclerosis at the proximal portions. We suggest that appropriate guide catheter selection and careful manipulation are essential for the success of revascularization. Complete reperfusion results in an excellent clinical and long-term outcome in patients with anomalous-origin RCAs.

Histone acetylation and the cell-cycle in cancer

A number of distinct surveillance systems are found in mammalian cells that have the capacity to interrupt normal cell-cycle progression. These are referred to as cell cycle check points. Surveillance systems activated by DNA damage act at three stages, one at the G1/S phase boundary, one that monitors progression through S phase and one at the G2/M boundary. The initiation of DNA synthesis and irrevocable progression through G1 phase represents an additional checkpoint when the cell commits to DNA synthesis. Transition through the cell cycle is regulated by a family of protein kinase holoenzymes, the cyclin-dependent kinases (Cdks), and their heterodimeric cyclin partner. Orderly progression through the cell-cycle checkpoints involves coordinated activation of the Cdks that, in the presence of an associated Cdk-activating kinase (CAK), phosphorylate target substrates including members of the "pocket protein" family. One of these, the product of the retinoblastoma susceptibility gene (the pRB protein), is phosphorylated sequentially by both cyclin D/Cdk4 complexes and cyclin E/Cdk2 kinases. Recent studies have identified important cross talk between the cell-cycle regulatory apparatus and proteins regulating histone acetylation. pRB binds both E2F proteins and histone deacetylase (HDAC) complexes. HDAC plays an important role in pRB tumor suppression function and transcriptional repression. Histones are required for accurate assembly of chromatin and the induction of histone gene expression is tightly coordinated. Recent studies have identified an important alternate substrate of cyclin E/Cdk2, NPAT (nuclear protein mapped to the ATM locus) which plays a critical role in promoting cell-cycle progression in the absence of pRB, and contributes to cell-cycle regulated histone gene expression. The acetylation of histones by a number of histone acetyl transferases (HATs) also plays an important role in coordinating gene expression and cell-cycle progression. Components of the cell-cycle regulatory apparatus are both regulated by HATs and bind directly to HATs. Finally transcription factors have been identified as substrate for HATs. Mutations of these transcription factors at their sites of acetylation has been associated with constitutive activity and enhanced cellular proliferation, suggesting an important role for acetylation in transcriptional repression as well as activation. Together these studies provide a working model in which the cell-cycle regulatory kinases phosphorylate and inactivate HDACs, coordinate histone gene expression and bind to histone acetylases themselves. The recent evidence for cross-talk between the cyclin-dependent kinases and histone gene expression on the one hand and cyclin-dependent regulation of histone acetylases on the other, suggests chemotherapeutics targeting histone acetylation may have complex and possibly complementary effects with agents targeting Cdks.

Beneficial effect of angiotensin-converting enzyme inhibitor on dilated cardiomyopathy induced by autoimmune mechanism against beta1-adrenoceptor

We have shown that a peptide corresponding to the sequence of the second extracellular loop of the human beta1-adrenoceptor (beta1-peptide) was able to induce an autoimmune cardiomyopathy in rabbits. In this study, we examined the effect of angiotensin-converting enzyme inhibitor (ACEI) on beta1-peptide-induced cardiomyopathy. Rabbits were divided into four groups: (1) control group (n= 6) receiving saline injection; (2) beta1-peptide group (n = 8) immunized with beta1-peptide; (3) ACEI group (n = 6), lisinopril (3 mg/day) given orally and receiving saline injection; and (4) ACEI + beta1-peptide group (n = 7), lisinopril (3 mg/day) given orally and immunized with beta1-peptide. Our results showed that, after 1 year, all rabbits in the beta1-peptide group had an increase in heart weight, wall thinning and dilatations of both ventricles as compared with rabbits in the ACEI + beta1-peptide group that had normal heart weight and shape. All rabbits in the beta1-peptide group exhibited multifocal degeneration and necrosis of myocardial cells with moderate infiltration of inflammatory cells. In the ACEI + beta1-peptide group, three rabbits showed focal degeneration and necrosis of myocardial cells accompanied by mononuclear cells. The lesions in this group were apparently less marked than those in the beta1-peptide group. In conclusion, ACEI protects the myocardium from injury induced by an autoimmune mechanism against beta1-adrenoceptor.

[Clinical application and evaluation of polymerase chain reaction-microwell plate hybridization assay in the detection of Mycobacterium tuberculosis]

OBJECTIVE

To evaluate the clinical application and feasibility of polymerase chain reaction-microwell plate hybridization assay in the detection of Mycobacterium tuberculosis.

METHODS

1130 specimens with strong suspicion for mycobacterium tuberculosis were collected from the hospitals and were detected by fast bacilli stain, culture, PCR-electrophoresis and PCR-microwell plate hybridization respectively. The laboratory results were analyzed in combination with the symptoms and signs of patients and the observations on treatment. Also detected were 100 samples from the clinically evidenced non-tuberculosis patients.

RESULTS

In the 100 samples collected from the patients without tuberculosis, the PCR-hybridization method and culture method did not detect Mycobacterium tuberculosis, but the fast bacilli stain method and PCR-electrophoresis method brought out one and two false-positive results respectively. The results of testing the 1030 clinical samples which probably contained Mycobacterium tuberculosis demonstrated that the PCR-hybridization method had the highest positive rate (481/1030) among the four methods, and the positive rates of the other three methods were PCR-electrophoresis (406/1030), culture (365/1030) and fast bacilli stain (256/1030) in proper order. The chi-square test showed that there were significant difference between the PCR-hybridization method and the other three methods respectively (P < 0.0083 or P < 0.0017).

CONCLUSION

PCR-Hybridization method is specific, sensitive, accurate and fast in detecting mycobacterium tuberculosis; it is worthy to be used clinically.

Role of calcineurin in angiotensin II-induced cardiac myocyte hypertrophy of rats

OBJECTIVE

The present study investigated the role of calcineurin in angiotensin II(AngII) -induced cardiac myocyte hypertrophy of rats.

METHOD

The primary cardiac myocytes were cultured under the standard conditions. The calcineurin activity in AngII-treated cardiomyocytes was tested by using PNPP; protein synethsis rate was assessed by 3H-leucine incorporation; atrial natriuretic factor(ANF) mRNA level was determined by Northern blot analysis. Cell viability was estimated by lactate dehydrogenase (LDH) levels in cultured medium and by dyed cell numbers.

RESULT

After stimulation of 10, 100 and 1 000 nmol/L of AngIi, calcineurin activities in the cardiomyocytes were increased by 13%, 57% (P < 0.05) and 228% (P < 0.01) respectively, compared with control group. Cyclosporin A(CsA), a specific inhibitor of calcineurin, markedly inhibited the calcineurin activity and decreased the 3H-leucine incorporation in AngII-treated cardiomyocytes in a dose-dependent manner. It was also found that CsA slightly reduced the mRNA level of ANF gene in AngII-stimulated cardiomyocytes.

CONCLUSION

During AngII-induced cardiac myocyte hypertrophy, calcineurin signal pathway is activated, and inhibition of the pathway can attenuate AngII-induced cardiac myocyte hypertrophy, which suggests that the calcineurin signal pathway may play an important role in AngII-induced myocardial hypertrophy of rats.

[Individual studies of parent-offspring similarity in Class II division 1 malocclusion]

OBJECTIVE

To study the parent-offspring similarity of class II division 1 malocclusion.

METHODS

On the basis of family units, the polygonic curves and superimposed graphs of parents with those of the offspring were compared.

RESULTS

(1) Craniofacial structure of most parents of the class II division 1 patients have class II convex tendency. (2) The curves of the offspring resemble one or two of the parent's in 84% of the families, and the resemblance mainly concentrates in skeleton.

CONCLUSIONS

(1) Class II division 1 malocclusion is characterized by familial aggregativity. (2) High probability of heredity exists in parent-offspring similarity, and we believe that hereditary factors dominate in skeletal area while in dental area there is a higher probability that environmental factors dominate.

NF-kappaB and cell-cycle regulation: the cyclin connection

The cyclins are a family of proteins that are centrally involved in cell cycle regulation and which are structurally identified by conserved "cyclin box" regions. They are regulatory subunits of holoenzyme cyclin-dependent kinase (CDK) complexes controlling progression through cell cycle checkpoints by phosphorylating and inactivating target substrates. CDK activity is controlled by cyclin abundance and subcellular location and by the activity of two families of inhibitors, the cyclin-dependent kinase inhibitors (CKI). Many hormones and growth factors influence cell growth through signal transduction pathways that modify the activity of the cyclins. Dysregulated cyclin activity in transformed cells contributes to accelerated cell cycle progression and may arise because of dysregulated activity in pathways that control the abundance of a cyclin or because of loss-of-function mutations in inhibitory proteins.Analysis of transformed cells and cells undergoing mitogen-stimulated growth implicate proteins of the NF-kappaB family in cell cycle regulation, through actions on the CDK/CKI system. The mammalian members of this family are Rel-A (p65), NF-kappaB(1) (p50; p105), NF-kappaB(2) (p52; p100), c-Rel and Rel-B. These proteins are structurally identified by an amino-terminal region of about 300 amino acids, known as the Rel-homology domain. They exist in cytoplasmic complexes with inhibitory proteins of the IkappaB family, and translocate to the nucleus to act as transcription factors when activated. NF-kappaB pathway activation occurs during transformation induced by a number of classical oncogenes, including Bcr/Abl, Ras and Rac, and is necessary for full transforming potential. The avian viral oncogene, v-Rel is an NF-kappaB protein. The best explored link between NF-kappaB activation and cell cycle progression involves cyclin D(1), a cyclin which is expressed relatively early in the cell cycle and which is crucial to commitment to DNA synthesis. This review examines the interactions between NF-kappaB signaling and the CDK/CKI system in cell cycle progression in normal and transformed cells. The growth-promoting actions of NF-kappaB factors are accompanied, in some instances, by inhibition of cellular differentiation and by inhibition of programmed cell death, which involve related response pathways and which contribute to the overall increase in mass of undifferentiated tissue.

Endogenous indoles as novel polyamine site ligands at the N-methyl-D-aspartate receptor complex

High-throughput ligand displacement screens of a series of endogenous indoles revealed that tryptamine, serotonin and 5-methoxytryptamine readily displace [3H]spermidine and [3H]MK-801 from their respective binding sites in rat brain homogenate. These data, coupled with their potent inhibition of spermidine-potentiated [3H]MK-801 binding, suggest that certain endogenous indoles may act as ligands to one or more polyamine binding sites in the brain, including those on the N-methyl-D-aspartate receptor complex.

Cytogenetic analysis in 61 couples with spontaneous abortions

OBJECTIVE

To examine the relationship between spontaneous abortion and chromosomal abnormalities.

METHODS

Couples who had one or more consecutive spontaneous abortions and had normal genitals were enrolled for cytogenetic karyotype analysis.

RESULTS

In the 61 couples, the detected incidence was 11.5%, with five Robertsonian translocations, one reciprocal translocation, and one pericentric inversion of chromosome 7.

CONCLUSION

Chromosomal abnormalities may play an important role in fetal wastage.

Unusual complication of retrograde dissection to the coronary sinus of valsalva during percutaneous revascularization: a single-center experience and literature review

BACKGROUND

While coronary dissection, which is one of the most frequently occurring complications during interventional procedures, has various forms, extensive coronary dissection retrograde to the coronary sinus of Valsalva (CSV) is very rarely observed.

METHODS AND RESULTS

Within the last 5 years, we retrospectively reviewed our experience with 4,700 consecutive patients who underwent angioplasty procedures, 7 of whom (0.15%) developed extensive coronary dissection retrograde to the CSV. Six of the seven patients developed retrograde dissection of the right CSV during angioplasty to the right coronary artery. One of the seven patents developed retrograde dissection of the left CSV during angioplasty to the left anterior descending artery. Retrograde dissection, which extended to the ascending aorta in two patients, was observed by transthoracic echocardiography and surgical findings, respectively. Five patients were successfully treated by coronary stenting. However, this complication caused four patients to have acute myocardial infarctions, resulting in emergency surgery for one patient and in-hospital death for another.

CONCLUSIONS

Our experience increased our understanding of this very rare complication. However, this complication may be life threatening, and patients in this clinical setting may have a potential risk for acute myocardial infarction, emergency surgery, or even sudden cardiac death. Therefore, it is important to learn how to promptly diagnose and manage this complication.

Molecular therapy with recombinant antisense c-myc adenovirus for human gastric carcinoma cells in vitro and in vivo

BACKGROUND AND AIMS

This study used a recombinant antisense c-myc adenovirus (Ad-ASc-myc) to evaluate how alterations of c-myc expression in the SGC7901 human gastric carcinoma cells could influence the proliferation, apoptosis and the growth of human gastric tumors in nude mice.

METHODS

The human gastric carcinoma cell line, SGC7901, treated with Ad-ASc-myc or adenovirus recombinants carrying LacZ gene (Ad-LacZ) were analyzed by using X-gal stain, MTT, DNA ladder, TUNEL assay, flow cytometric analysis, polymerase chain reaction and western blot in vitro. The tumorigenicity and experimental therapy in nude mice models were assessed in vivo.

RESULTS

The Ad-ASc-myc could strongly inhibit cell growth and induce apoptosis in SGC7901 cells. The proliferation of the Ad-ASc-myc-infected SGC7901 cells was reduced by 44.1%. The mechanism of killing gastric carcinoma cells by Ad-ASc-myc was found to be apoptosis, which was detected by the use of a DNA ladder, TUNEL and flow cytometric analysis. Infection of Ad-ASc-myc in nude mice showed that all three mice failed to form tumors from the 7 to 30 day period, compared with injection of Ad-LacZ and parent SGC7901 cells. Experimental therapy on the nude mice bearing subcutaneous tumors of SGC7901 cells showed that intratumor instillation of Ad-ASc-myc inhibited the growth of the tumors. Recombinant antisense c-myc adenovirus-treated tumors were inhibited by 68.9%, compared with tumors injected with Ad-LacZ and control (LacZ and phosphate-buffered saline).

CONCLUSION

The expression of Ad-ASc-myc can inhibit growth and induce apoptosis of gastric cancer cells in vitro and in vivo and thus is a potential clinical utility in gene therapy for the treatment of gastric carcinoma.

[Preliminary study on orthodontic treatment before and after distraction osteogenesis]

OBJECTIVE

To get some guidelines for the orthodontic treatment before and after distraction osteogenesis (DO).

METHODS

DO was performed in 4 patients maxilla and two for mandible. The patients were aged from 19 to 25 (average 21.5). We try to sum up the procedures and clinical experiences of pre- and post-surgery orthodontics.

RESULTS

The procedures and experiences obtained are the followings: 1. Pre-surgery orthodontics for DO is simplified as alignment of dental arch in a short period. 2. Post-surgery orthodontics for DO is more complicated and peculiar. The main task is to make the opened posterior teeth occlude as soon as possible by light force vertical elastics. At the same time, some cross elastics may be needed for correction of posterior occlusal relationship. 3. Expansion of upper arch may be needed in some patients because of constricted dental arch. 4. Class II or III elastics may be used for prevention of relapse after DO.

CONCLUSIONS

DO is a new technique in orthognathic surgery. Post-surgery orthodontics is more complicated and important in the treatment course.

[The change of genioglossus muscle activity of OSAS patients with and without snoreguard]

OBJECTIVE

The effect of snoreguard on the genioglossus (GG) muscle activity of OSAS patients was investigated.

METHODS

Fifteen male patients with mild to severe OSAS were diagnosed by overnight polysomnographic and GG EMG studies, and reexamined with snoreguard. GG muscle activities of these patients with and without snoreguard were compared.

RESULTS

The results revealed that the overnight GG muscle activity decreased significantly and the fluctuating GG muscle activity was improved effectively by the treatment of snoreguard.

CONCLUSION

The treatment mechanisms of mandibular advancing appliance on OSAS are mechanical enlargement of upper airway and the passivity of GG muscle during treatment.

Efficacy and safety of acetaminophen in the treatment of migraine: results of a randomized, double-blind, placebo-controlled, population-based study

BACKGROUND

Although most persons with migraine treat their headaches with over-the-counter medication, systematic data on the safety and efficacy of widely used treatment, including acetaminophen, are sparse.

METHODS

This is a randomized, double-blind, placebo-controlled study comparing oral acetaminophen, 1000 mg (two 500-mg Extra Strength Tylenol tablets), with identical placebo in the treatment of a single acute migraine attack. Eligible subjects met International Headache Society diagnostic criteria for migraine with or without aura. Patients who usually required bed rest with their headaches or who vomited more than 20% of the time were excluded.

MAIN OUTCOME MEASURES

The percentage of subjects who, at 2 hours after dosing, experienced a change in baseline pain intensity from severe or moderate pain to mild or no pain (headache response); and pain intensity difference from baseline at the 2-hour postmedication assessment.

RESULTS

The headache response rate 2 hours after dosing was 57.8% in the acetaminophen group and 38.7% in the placebo group (P =.002). Pain-free rates at 2 hours were 22.4% in the acetaminophen group and 11.3% in the placebo group (P =.01). The mean pain intensity difference from baseline 2 hours after dosing was 1.08 in the acetaminophen group and 0.73 in the placebo group (P<.001). At 2 hours, other migraine headache characteristics, such as functional disability (P =.002), photophobia (P =.02), and phonophobia (P =.08), were significantly improved after treatment with acetaminophen vs placebo.

CONCLUSIONS

Acetaminophen was highly effective for treating pain, functional disability, photophobia, and phonophobia in a population-based sample of persons with migraine, excluding the most disabled persons with migraine. The drug also had an excellent safety profile and was well tolerated. Arch Intern Med. 2000;160:3486-3492.

Aminoanthraquinones as novel ligands at the polyamine binding site on the N-methyl-D-aspartate receptor complex

As part of a drug discovery program using high-throughput radioligand-binding assays, aminoanthraquinones were identified as potential modulators of N-methyl-D-aspartate (NMDA) receptor function. Aminoanthraquinones may represent a novel class of polyamine binding site ligands with a unique pharmacophore and may facilitate the rational design of novel NMDA-receptor modulators.

Dobutamine enhances both contractile function and energy reserves in hypoperfused canine right ventricle

Although the beta(1)-adrenergic agent dobutamine is used clinically to provide inotropic support to the failing myocardium, it could jeopardize the myocardium by depleting energy reserves. This investigation delineated the contractile and energetic effects of low versus high dobutamine doses in the hypoperfused right ventricular (RV) myocardium. The right coronary artery (RCA) of anesthetized dogs was cannulated for controlled perfusion with arterial blood, and regional RV contractile function was measured. RCA perfusion pressure was lowered from 100 mmHg baseline to 40 mmHg, and flow fell by 54%. At 15-min hypoperfusion, dobutamine was infused into the RCA at either 0.01 (low-dose dobutamine) or 0.06 microgram. kg(-1). min(-1) (high-dose dobutamine) for 15 min. Regional power (systolic segment shortening x isometric developed force x heart rate) stabilized at 63% of baseline during hypoperfusion. Low-dose dobutamine restored power to baseline but did not increase RV myocardial O(2) consumption (MVO(2)) and thus increased myocardial O(2) utilization efficiency (O(2)UE:power/MVO(2)). At 5 min, high-dose dobutamine enhancement of power was similar to that of low-dose dobutamine, but by 15 min, power and O(2)UE fell to untreated levels. Remarkably, low-dose dobutamine tripled cytosolic phosphorylation potential; in contrast, high-dose dobutamine lowered phosphorylation potential to 45% of the untreated value. Analyses of glucose uptake and glycolytic intermediates revealed sustained enhancement of glycolysis by low-dose dobutamine, but glycolysis became limited at glyceraldehyde 3-phosphate dehydrogenase during high-dose dobutamine treatment. In summary, low-dose dobutamine improved mechanical performance and efficiency of the hypoperfused RV myocardium while increasing myocardial energy reserves, but high-dose dobutamine failed to sustain improved function and depleted energy reserves. Dobutamine is capable of improving both contractile function and cellular energetics in the hypoperfused RV myocardium, but dosage should be carefully selected.

Growth hormone improves bioenergetics and decreases catecholamines in postinfarct rat hearts

The aims of this study were to examine, in vivo, the effects of GH treatment on myocardial energy metabolism, function, morphology, and neurohormonal status in rats during the early postinfarct remodeling phase. Myocardial infarction (MI) was induced in male Sprague Dawley rats. Three different groups were studied: MI rats treated with saline (n = 7), MI rats treated with GH (MI + GH; n = 11; 3 mg/kg x day), and sham-operated rats (sham; n = 8). All rats were investigated with 31P magnetic resonance spectroscopy and echocardiography at 3 days after MI and 3 weeks later. After 3 weeks treatment with GH, the phosphocreatine/ATP ratio increased significantly, compared with the control group (MI = 1.69 +/- 0.09 vs. MI + GH = 2.42 +/- 0.05, P < 0.001; sham = 2.34 +/- 0.08). Treatment with GH significantly attenuated an increase in left ventricular end systolic volume and end diastolic volume. A decrease in ejection fraction was prevented in GH-treated rats (P < 0.05 vs. MI). Myocardial and plasma noradrenaline levels were significantly lower in MI rats treated with GH. These effects were accompanied by normalization of plasma brain natriuretic peptide levels (sham = 124.1 +/- 8.4; MI = 203.9 +/- 34.7; MI + GH = 118.3 +/- 8.4 ng/ml; P < 0.05 vs. MI). In conclusion, GH improves myocardial energy reserve, preserves left ventricular function, and attenuates pathologic postinfarct remodeling in the absence of induction of left ventricular hypertrophy in postinfarct rats. The marked decrease in myocardial content of noradrenaline, after GH treatment, may protect myocardium from adverse effects of catecholamines during postinfarct remodeling.

Induction of cardiomyopathy in severe combined immunodeficiency mice by transfer of lymphocytes from patients with idiopathic dilated cardiomyopathy

Growing evidence suggests that autoimmune mechanisms play an important role in the pathogenesis of idiopathic dilated cardiomyopathy (DCM). The aim of the study was to evaluate the effects of transfer of lymphocytes from patients with DCM into severe combined immunodeficiency (SCID) mice on the heart structure and function. Thirty CB-17 SCID (6-8 weeks old) mice were used and divided into 3 groups (n = 10). Mice were injected intraperitoneally with up to 25 x 10(6) peripheral blood lymphocytes (PBL) from either patients with DCM which contain human autoantibodies against cardiac beta1-adrenergic receptors and M2-muscarinic receptors (DCM group) or PBL from healthy controls (control-H group). Ten mice did not receive any injections and were used as baseline controls (control-N group). Echocardiography and morphological studies were performed seventy five days after the transfer. Results showed that in DCM group, left ventricle dimensions (LVD) in diastole were increased (4.2 +/- 0.1mm) as compared to both control-H group (3.8 +/- 0.1mm) and control-N group (3.6 +/- 0.1 mm) (p < 0.01). Further, there was a trend for increased LVD in systole. Fractional shortening was not different between groups. Histological evaluation revealed accumulation of human lymphocytes in the capillaries and scarce infiltration of the lymphocytes in the hearts from DCM group. Diffuse fibrosis was significant increased in DCM mice as compared to mice receiving PBL from normal subjects (2.2 +/- 0.3% vs. 0.8 +/- 0.1%, p < 0.01). In conclusion, transfer of the PBL from the patients with DCM was able to induce early stage of heart dilatation in SCID mice. These data provide for the first time the direct evidence supporting that the autoimmune mechanism is important in the pathogenesis of human DCM.

The practice of evidence-based medicine in an acute medical ward: retrospective study

OBJECTIVE

To review the practice of evidence-based medicine with respect to drug treatment given to medical in-patients.

DESIGN

Retrospective study.

SETTING

Teaching hospital, Hong Kong.

PATIENTS

Medical records of 129 consecutive patients who were admitted to the acute adult general medical ward from 1 September 1998 to 30 September 1998 were reviewed.

MAIN OUTCOME MEASURES

Primary diagnoses, drug treatments prescribed, and the level of evidence (based on a literature search of randomised controlled trials and relevant studies) that supported the treatment given.

RESULTS

For the 129 patients studied, 91 drug interventions had been prescribed on 312 occasions. Treatment that was supported by randomised controlled trials was prescribed in 162 (52.9%) cases. In 121 (38.8%) cases, patients were given standard and commonly used drugs that were not supported by evidence from clinical trials, and in 29 (9.3%) cases, the treatments given had no substantial supporting evidence. The management of some frequently encountered medical conditions was not based on trial data, because the relevant studies had not been conducted.

CONCLUSION

Basing treatment on comparative efficacy results is a worthwhile goal, but there are limitations in conducting literature searches to identify relevant trials and studies. Evidence-based medical practice is not applicable in a large number of commonly encountered conditions.

Ral GTPases contribute to regulation of cyclin D1 through activation of NF-kappaB

Ral GTPases have been implicated as mediators of Ras-induced signal transduction from observations that Ral-specific guanine nucleotide exchange factors associate with Ras and are activated by Ras. The cellular role of Ral family proteins is unclear, as is the contribution that Ral may make to Ras-dependent signaling. Here we show that expression of activated Ral in quiescent rodent fibroblasts is sufficient to induce activation of NF-kappaB-dependent gene expression and cyclin D1 transcription, two key convergence points for mitogenic and survival signaling. The regulation of cyclin D1 transcription by Ral is dependent on NF-kappaB activation and is mediated through an NF-kappaB binding site in the cyclin D1 promoter. Ral activation of these responses is likely through an as yet uncharacterized effector pathway, as we find activation of NF-kappaB and the cyclin D1 promoter by Ral is independent of association of Ral with active phospholipase D1 or Ral-binding protein 1, two proteins proposed to mediate Ral function in cells.

Three-dimensional echocardiographic image of atrial septal aneurysm: report of two cases

Atrial septal aneurysm (ASA) is a rare congenital anomaly. It may occur as an isolated pathology or in association with other cardiovascular lesions such as mitral valve disease, atrial septal defect, and others. The diagnosis of ASA became more widely recognized with the use of 2-dimensional echocardiography. Three-dimensional echocardiography is a recently developed imaging technique. It can be used as an adjunct to conventional transesophageal echocardiography. Images of different aspects of cardiac chambers and valves can be obtained with 3-dimensional echocardiography. This paper reports on 2 cases of different types of ASA imaged by 3-dimensional echocardiography. The images were obtained from the left and right atriums, respectively. The 3-dimensional image taken from the left atrium showed the ASA to be a localized concave structure, and the 3-dimensional image taken from the right atrium showed the ASA to be a localized bulging structure. Our pictures are the first reported 3-dimensional echocardiographic images of ASA. We hope this report will allow for a more comprehensive understanding of its pathology.

The integrin-linked kinase regulates the cyclin D1 gene through glycogen synthase kinase 3beta and cAMP-responsive element-binding protein-dependent pathways

The cyclin D1 gene encodes the regulatory subunit of a holoenzyme that phosphorylates and inactivates the pRB tumor suppressor protein. Cyclin D1 is overexpressed in 20-30% of human breast tumors and is induced both by oncogenes including those for Ras, Neu, and Src, and by the beta-catenin/lymphoid enhancer factor (LEF)/T cell factor (TCF) pathway. The ankyrin repeat containing serine-threonine protein kinase, integrin-linked kinase (ILK), binds to the cytoplasmic domain of beta(1) and beta(3) integrin subunits and promotes anchorage-independent growth. We show here that ILK overexpression elevates cyclin D1 protein levels and directly induces the cyclin D1 gene in mammary epithelial cells. ILK activation of the cyclin D1 promoter was abolished by point mutation of a cAMP-responsive element-binding protein (CREB)/ATF-2 binding site at nucleotide -54 in the cyclin D1 promoter, and by overexpression of either glycogen synthase kinase-3beta (GSK-3beta) or dominant negative mutants of CREB or ATF-2. Inhibition of the PI 3-kinase and AKT/protein kinase B, but not of the p38, ERK, or JNK signaling pathways, reduced ILK induction of cyclin D1 expression. ILK induced CREB transactivation and CREB binding to the cyclin D1 promoter CRE. Wnt-1 overexpression in mammary epithelial cells induced cyclin D1 mRNA and targeted overexpression of Wnt-1 in the mammary gland of transgenic mice increased both ILK activity and cyclin D1 levels. We conclude that the cyclin D1 gene is regulated by the Wnt-1 and ILK signaling pathways and that ILK induction of cyclin D1 involves the CREB signaling pathway in mammary epithelial cells.

Computer modeling of interactions of an electric motor, circulatory system, and rotary blood pump

The innovative ventricular assist systems (IVAS) is the next generation ventricular assist device for use as a permanent implantable device. Its practical application depends upon control of the electric motor and interactions of the electric motor, blood pump, and circulatory system. Computer modeling and simulation are necessary to investigate and evaluate the interactions and feasibility of sophisticated control algorithms. In this paper, a computer model of the complete system, including the cardiovascular system, blood pump, and electric motor, is proposed. The model is obtained based on an electric circuit model of the cardiovascular system, a parametric model of the blood pump, and a dynamic model of the electric motor. The cardiovascular system uses nonlinear parameters to simulate the time-varying property of the ventricles, and the cannula collapse effect caused by over-pumping. The blood pump model can be obtained either from pump design data, or test data. The motor control can be operated with closed-loop regulation, depending upon physiologic requirements. Different operation modes (current or speed) of the electric motor can be simulated. The computer model is implemented using MATLAB. Various motor operation modes are simulated and their effects are evaluated. By adjusting the motor input, the pump can achieve proper output so that normal physiology can be obtained. In addition to evaluating existing operation modes and their effect on the physiologic system, the computer simulation results show that this computer model can contribute significantly to the development of new physiologic control algorithms. It is demonstrated that, using this motor-pump-physiology interaction model, development of an innovative ventricular assist system can be greatly facilitated.

Effects of a mandibular repositioner on obstructive sleep apnea

The purpose of this study was to investigate the effects of a mandibular repositioner on airway, sleep, and respiratory variables in patients with obstructive sleep apnea. Twenty-two patients selected for this study were confirmed with a diagnosis of obstructive sleep apnea based on initial nocturnal polysomnography. The patients were fitted with a mandibular repositioner designed to hold the mandible anteroinferiorly. Six months later, an outcome polysomnographic study was undertaken for each patient with the appliance in place. Lateral cephalometric radiographs in the upright position were also obtained before and after 6 months of treatment. The respiratory disturbance index decreased in 21 of the 22 patients with the appliance in place. The mean respiratory disturbance index of the 22 patients decreased significantly from 40.3 to 11.7 events per hour (P <.01). Some 59.1% of subjects were considered a treatment success with follow-up respiratory disturbance index < 10 events per hour. The mean minimum blood oxygen saturation level during sleep also improved significantly from 73.4% to 81.3% (P <. 01). The mandibular repositioner was constructed to position the mandible at 75% of the maximal mandibular advancement and with a 7 mm opening between the upper and lower incisors, and no aberrant effect on temporomandibular joint was noted. The retropalatal airway space increased and the cross-sectional area of the soft palate and the vertical distance of the hyoid bone to the mandibular plane decreased significantly. The tongue posture became significantly flatter. A significant linear correlation was found between the reduction in apnea index and specific craniofacial skeletal structures (length of anterior cranial base, mandibular plane angle, and upper to lower facial height ratios, P <.05). Subjects with a smaller reduction in apnea index tended to have shorter anterior cranial bases, steeper mandibular planes, and smaller upper to lower facial height ratios. We conclude that a mandibular repositioner may be an effective treatment alternative for obstructive sleep apnea and that a reduction in the frequency of apneic episodes is mainly attributed to the effects of the appliance on oropharyngeal structures.