Effect of denosumab on bone mineral density and biochemical markers of bone turnover: 8-year results of a phase 2 clinical trial

In a phase 2 study, continued denosumab treatment for up to 8 years was associated with continued gains in bone mineral density and persistent reductions in bone turnover markers. Denosumab treatment was well tolerated throughout the 8-year study.

INTRODUCTION

The purpose of this study is to present the effects of 8 years of continued denosumab treatment on bone mineral density (BMD) and bone turnover markers (BTM) from a phase 2 study.

METHODS

In the 4-year parent study, postmenopausal women with low BMD were randomized to receive placebo, alendronate, or denosumab. After 2 years, subjects were reallocated to continue, discontinue, or discontinue and reinitiate denosumab; discontinue alendronate; or maintain placebo for two more years. The parent study was then extended for 4 years where all subjects received denosumab.

RESULTS

Of the 262 subjects who completed the parent study, 200 enrolled in the extension, and of these, 138 completed the extension. For the subjects who received 8 years of continued denosumab treatment, BMD at the lumbar spine (N = 88) and total hip (N = 87) increased by 16.5 and 6.8 %, respectively, compared with their parent study baseline, and by 5.7 and 1.8 %, respectively, compared with their extension study baseline. For the 12 subjects in the original placebo group, 4 years of denosumab resulted in BMD gains comparable with those observed during the 4 years of denosumab in the parent study. Reductions in BTM were sustained over the course of continued denosumab treatment. Reductions also were observed when the placebo group transitioned to denosumab. Adverse event profile was consistent with previous reports and an aging cohort.

CONCLUSION

Continued denosumab treatment for 8 years was associated with progressive gains in BMD, persistent reductions in BTM, and was well tolerated.

HLA-DPB1-COL11A2 and three additional xMHC loci are independently associated with RA in a UK cohort

The aim of this study was to investigate the complex association pattern of the extended major histocompatibility complex (xMHC) region with rheumatoid arthritis (RA) susceptibility to identify effects independent of HLA-DRB1. A total of 1804 RA cases and 1474 controls were included. High-resolution HLA-DRB1 typing was performed. Subjects were genotyped for 1546 single-nucleotide polymorphisms (SNPs) using Affymetrix GeneChip 500 K (Santa Clara, CA, USA) as part of the Wellcome Trust Case Control Consortium Study. Statistical analysis was carried out using PLINK. To avoid confounding by RA-associated HLA-DRB1 alleles, we analyzed xMHC SNPs using a data set with pairwise matching of cases and controls on DRB1 genotypes. A total of 594 case-control pairs with identical DRB1 genotypes were identified. After this adjustment, 104 SNPs remained significantly associated with RA (P<0.05), suggesting that additional RA loci independent of HLA-DRB1 can be found in the xMHC region. Of these, four loci showed the strongest associations with RA (P<0.005): ZNF391, the olfactory receptor (OR) gene cluster, C6orf26-RDBP and HLA-DPB1-COL11A2. An additional locus mapping to the BTN (butyrophilin) cluster showed independent association with RA in anti-cyclic citrullinated peptide-positive patients exclusively. We have validated the previously described independent association of the HLA-DPB1-COL11A2 locus with RA. In addition, association with three novel independent RA loci in the xMHC region (ZNF391, OR2H1 and C6orf26-RDBP) has been detected.

Rectal cancer: 3D dynamic contrast-enhanced MRI; correlation with microvascular density and clinicopathological features

PURPOSE

The primary aim of this prospective study was to evaluate the relationship between three-dimensional dynamic contrast-enhanced magnetic resonance (3D-DCE-MR) imaging parameters and clinicopathological features of rectal cancer and assess their potential as new radiological prognostic predictors.

MATERIALS AND METHODS

Three-dimensional DCE-MR was performed on 26 cases of pathologically proved rectal adenocarcinoma 1 week prior to operation. Data were analysed to calculate transfer constant (Ktrans), leakage space (Ve) and rate constant (Kep) of both tumour and normal rectal wall. Microvessel density (MVD) was evaluated by immunohistochemical staining of surgical specimens. All findings were analysed prospectively and correlated with tumour/node/metastasis (TNM) staging, Dukes staging, histological grading, presence of lymph node metastasis, serosal involvement and MVD.

RESULTS

Mean Ktrans, Ve and Kep for tumours were as follows: Ktrans 7.123±3.850/min, Ve 14.2±3.0%, Kep 49.446±20.404/min, revealing the significant difference between the tumour and normal rectal wall (p=0.001). There was a significant difference for Ktrans not only between patients with and without lymphatic involvement (p=0.000), but also among Dukes staging (p=0.04) and pTNM staging (p=0.03). Kep showed moderate correlation with TNM stages (r=0.479, p=0.02). Ve and MVD revealed no significant correlation with the clinicopathological findings described above (p>0.05).

CONCLUSION

Owing to the moderate and strong relationship between Ktrans and clinicopathological elements, Ktrans might be the prognostic indicator of rectal cancer. Threedimensional DCE high-resolution MR imaging provides a competing opportunity to assess contrast kinetics.

A study for maternal thyroid hormone deficiency during the first half of pregnancy in China

BACKGROUND

Maternal thyroid hormone deficiency is the most common disorder of thyroid function during pregnancy and can influence the outcome for mother and foetus. The purpose of this study was to investigate the prevalence of thyroid hormone deficiency during the first half of pregnancy in iodine sufficient areas of China.

MATERIALS AND METHODS

Four thousand eight hundred pregnant women from 10 hospitals during the first 20 weeks of gestation were enrolled in this study. All sera obtained from pregnant women were measured for thyrotropin, free thyroxine and thyroid peroxidase antibody. Screening for thyroid hormone deficiency was performed on pregnant women using gestational age-specific reference intervals or non-pregnant population reference intervals.

RESULTS

With gestational age-specific reference intervals as the criterion, the prevalence of subclinical hypothyroidism at 4, 8, 12,16 and 20 weeks of gestation was 4.59%, 6.15%, 4.68%, 4.53% and 5.96%, respectively, and the prevalence of hypothyroxinaemia was 3.69%, 1.11%, 2.92%, 1.29% and 2.29%, respectively. Different prevalence was obtained when non-pregnant population reference intervals was used as the criterion. If non-pregnant population reference intervals were used, the percentage of potentially misclassified cases of subclinical hypothyroidism were 0.18%, 2.85%, 4.1%, 3.24%, and 3.21%, respectively, and 3.45%, 0.66%, 2.34%, 1.29%, and 1.83%, respectively, in potentially misclassified cases of hypothyroxinaemia.

CONCLUSIONS

The percentage of potentially misclassified cases of subclinical hypothyroidism and hypothyroxinaemia in pregnant women decreased by using the gestational age-specific reference intervals as a diagnostic criteria during the first half of pregnancy.

Definition of arthritis candidate risk genes by combining rat linkage-mapping results with human case-control association data

OBJECTIVE

To define genomic regions that link to rat arthritis and to determine the potential association with rheumatoid arthritis (RA) of the corresponding human genomic regions.

METHODS

Advanced intercross lines (AIL) between arthritis susceptible DA rats and arthritis resistant PVG.1AV1 rats were injected with differently arthritogenic oils to achieve an experimental situation with substantial phenotypic variation in the rat study population. Genotyping of microsatellite markers was performed over genomic regions with documented impact on arthritis, located on rat chromosomes 4, 10 and 12. Linkage between genotypes and phenotypes were determined by R/quantitative trait loci (QTL). Potential association with RA of single nucleotide polymorphisms (SNPs) in homologous human chromosome regions was evaluated from public Wellcome Trust Case Control Consortium (WTCCC) data derived from 2000 cases and 3000 controls.

RESULTS

A high frequency of arthritis (57%) was recorded in 422 rats injected with pristane. Maximum linkage to pristane-induced arthritis occurred less than 130 kb from the known genetic arthritis determinants Ncf1 and APLEC, demonstrating remarkable mapping precision. Five novel quantitative trait loci were mapped on rat chromosomes 4 and 10, with narrow confidence intervals. Some exerted sex-biased effects and some were linked to chronic arthritis. Human homologous genomic regions contain loci where multiple nearby SNPs associate nominally with RA (eg, at the genes encoding protein kinase Calpha and interleukin 17 receptor alpha).

CONCLUSIONS

High-resolution mapping in AIL populations defines limited sets of candidate risk genes, some of which appear also to associate with RA and thus may give clues to evolutionarily conserved pathways that lead to arthritis.

Use of colony stimulating factors (CSF) for primary prophylaxis of chemotherapy-induced neutropenia in community oncology practices to reduce risk of febrile neutropenia (FN)

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Background: In addition to proof of efficacy from randomized controlled trials (RCTs), health care decision makers need data on therapy effectiveness, specifically how well an intervention performs in routine practice. While the efficacy of filgrastim and pegfilgrastim in preventing FN has been established in RCTs, their effectiveness in community practice has not been studied. Methods: Data were obtained from medical records of patients treated with chemotherapy for a variety of malignancies in a random sample of 99 US community oncology practices in 2001 and 2003 (before and after FDA approval of pegfilgrastim in 2002). Patients receiving filgrastim or pegfilgrastim and, in 2003, every third patient not treated with a CSF, were consecutively sampled(n=6148). Only those receiving chemotherapy on 3–4 wk cycles were included in this analysis (n=3,744). Primary prophylaxis was defined as receipt of CSF within 3 days of the 1st cycle of chemotherapy. Multivariable logistic regression, adjusted for patient and treatment characteristics and weighted for patient sampling was used to estimate the odds of FN in patients who received primary prophylaxis versus those who were managed expectantly, i.e. patients who received CSF later during chemotherapy or not at all. Results: Of 3744 patients in the study population, 2966 (79%) received a CSF some time during their chemotherapy treatment. In 2003, approximately 18% of patients received CSF primary prophylaxis. Among patients who did not receive primary prophylaxis but received a CSF later during the treatment, 38% initiated CSF in the 1st cycle after day 3. In a multivariate model, increased risk of FN was associated with receiving myelosuppressive chemotherapy (OR 2.19; 95% CI 1.05–4.56) and having 3 or more drugs (vs. 1) in the regimen (OR 2.13; 95% CI 1.09–4.17). Adjusting for patient and treatment characteristics, the relative odds of FN in patients who received CSF primary prophylaxis was 0.70 (95% CI 0.50–0.98) compared with patients who either received CSF later or not at all. Conclusions: In this community practice setting, patients who received CSF primary prophylaxis had significantly lower odds of developing FN than patients managed expectantly.

No significant financial relationships to disclose.

Final results of a large, community-based, prospective study evaluating the impact of first and subsequent cycle pegfilgrastim on neutropenic events in patients receiving myelosuppressive chemotherapy

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Background: Neutropenia is the major dose-limiting complication of myelosuppressive chemotherapy (CT). The Awareness of Neutropenia in CT (ANC) Study Group has prospectively documented cycle 1 febrile neutropenia (FN) in 8% of patients (pts) receiving CT with or without growth factor support in community practice. Our study was conducted to assess the impact of first and subsequent cycle pegfilgrastim use on neutropenic events in pts receiving CT in community practice. Interim data were previously reported (Ozer ASCO 2005). Methods: Pts ≥18 years with cancers other than leukemia or MDS were eligible, including pts with major comorbidities. Key exclusion criteria of this open-label study were weekly CT or concurrent radiotherapy (RT). Pts were to receive pegfilgrastim 6 mg ∼24 hours after CT (min 4 cycles planned). Primary endpoints were neutropenic hospitalization and CT dose delays and reductions; additionally, FN (absolute neutrophil count <1×109/L with temperature ≥38.2oC) was measured. Results: 319 centers enrolled 2,249 pts (2,500 planned); 2,112 patients who received CT and pegfilgrastim after proper consent were included in final analyses. Most pts were women (75%). Major tumor types included: breast (46%), lung (16%), and ovarian (8%) cancers, and lymphoma (18%). 36% of pts were ≥65 years (mean age [SD]: 59 [12.8]), 55% had stage 3/4 or extensive disease, 23% received prior CT, 17% received prior RT, and 27% had a significant comorbidity. Neutropenic complications occurred infrequently (table). FN was experienced by 3.6% (95% CL: 2.8, 4.5) of pts in cycle 1 and in 6.3% (5.3, 7.5) in all cycles. Serious adverse events were consistent with toxicities observed in pts receiving CT. Conclusions: Pts treated in community practice receiving pegfilgrastim in every cycle of myelosuppressive CT experienced a low incidence of neutropenic complications and alterations in CT dose and schedule due to neutropenia.

[Table: see text]

[Table: see text]

Leu7Pro polymorphism in the neuropeptide Y (NPY) gene is associated with impaired glucose tolerance and type 2 diabetes in Swedish men

The neuropeptide Y (NPY) is a neuropeptide with a role in the regulation of satiety and energy balance of body weight, insulin release, cardiovascular and central endocrine systems. In order to evaluate whether the NPY gene variations contribute to development of type 2 diabetes (T2DM), we have performed a genetic association study for Leu7Pro (T1128 C) polymorphism of the NPY gene in impaired glucose tolerance (IGT) and T2DM. Genotyping experiments for this non-synonymous single nucleotide polymorphism (SNP) in 263 patients with T2DM, 309 subjects with IGT and 469 non-diabetic healthy individuals in Swedish Caucasians were performed by using Dynamic Allele Specific Hybridisation (DASH). We found that the frequencies of the "risk" allele C in the subjects with IGT and the patients with T2DM in Swedish men were 13 % (p = 0.002, OR = 3.70, 1.65 - 8.29 95 % CI) and 10 % (p = 0.007, OR = 4.80, 1.47 - 11.33 95 % CI) respectively, which were significantly higher than the C allele frequency in non-diabetic controls (6 %). Furthermore, we found that the carriers with TC and CC genotypes in the subjects with IGT in Swedish men had significantly higher fasting plasma glucose in comparison with the TT carriers (5.6 +/- 0.7 mmol/l vs. 5.2 +/- 0.7 mmol/l, p = 0.021). The present study thus provides the evidence that Leu7Pro polymorphism in the NPY gene is associated with IGT and T2DM in Swedish men, and indicates that the NPY gene variations contribute to development of T2DM. Questions of gender specificity may be explained by genetic backgrounds, sense of coherence for stress and other factors in environment.

VEGF165 and angiopoietin-1 decreased myocardium infarct size through phosphatidylinositol-3 kinase and Bcl-2 pathways

Angiogenic growth factors, vascular endothelial growth factor (VEGF) and angiopoietin-1 (Ang1) could decrease myocardial infarct size, which was assumed to be related with newly formed capillaries. We doubted that these capillaries could do this solely and the potential protective mechanisms of VEGF and Ang1 on myocardium need to be evaluated. Three types of adenoviruses encoding human VEGF(165) (Ad-VEGF(165)), human angiopoietin-1 (Ad-Ang1) and green fluorescent protein (Ad-GFP, as a parallel control) were constructed. Experiments were taken both in vitro and in vivo. As in vitro, the antiapoptosis effect of VEGF(165), Ang1 and VEGF(165)+Ang1 on cardiac myoblasts was observed, which seemed to be related with the activation of phosphatidylinositol-3 kinase and Bcl-2 pathways. As in vivo, adenoviruses were intramyocardially injected immediately after the ligation of the left anterior descending coronay arteries in rats. The results showed positive effect of VEGF(165), Ang1 and VEGF(165)+Ang1 on decreasing the myocardial infarct size at the 7th day. Myocardial PI-3K activity and Bcl-2 expression were elevated relatively at the 3rd day. The protective effect of VEGF(165) and Ang1 on the myocardium may broaden their functional research and contribute to their clinical use in the future.

Mutations in SCN9A, encoding a sodium channel alpha subunit, in patients with primary erythermalgia

Primary erythermalgia is a rare autosomal dominant disease characterised by intermittent burning pain with redness and heat in the extremities. A previous study established the linkage of primary erythermalgia to a 7.94 cM interval on chromosome 2q, but the causative gene was not identified. We performed linkage analysis in a Chinese family with primary erythermalgia, and screened the mutations in the two candidate genes, SCN9A and GCA, in the family and a sporadic patient. Linkage analysis yielded a maximum lod score of 2.11 for both markers D2S2370 and D2S2330. Based on critical recombination events in two patients in the family, we further limited the genetic region to 5.98 cM between D2S2370 and D2S2345. We then identified two missense mutations in SCN9A in the family (T2573A) and the sporadic patient (T2543C). Our data suggest that mutations in SCN9A cause primary erythermalgia. SCN9A, encoding a voltage-gated sodium channel alpha subunit predominantly expressed in sensory and sympathetic neurones, may play an important role in nociception and vasomotor regulation.

DNA-based prenatal diagnosis in a Chinese family with xeroderma pigmentosum group A

BACKGROUND

Xeroderma pigmentosum (XP) is a group of autosomal recessive diseases characterized by hypersensitivity to ultraviolet rays. Among its eight complementation groups, XP group A (XPA) is the most severe type. The XPAC gene has been identified as the defective gene in XPA patients.

OBJECTIVES

To examine genomic DNA from a Chinese family with XPA, to determine the XPAC mutation and, after genetic counselling, to undertake DNA-based prenatal diagnosis in a subsequent pregnancy.

METHODS

Fetal DNA was extracted from amniotic fluid and used to amplify exon 5 of XPAC containing the potential mutation. Direct sequencing and restriction endonuclease digestion were used for prenatal diagnosis.

RESULTS

We identified a homozygous nonsense XPAC mutation of 631C-->T, which results in an R211X mutation in XPA protein, in the proband. Both her parents are heterozygous. Prenatal diagnosis demonstrated a heterozygous sequence predicting an unaffected child, and a healthy girl was born.

CONCLUSIONS

These data provide the first example of a DNA-based prenatal test for genodermatosis in China.

Distribution of the NPY 1128C allele frequency in different populations

Neuropeptide Y (NPY) is a member of the pancreatic polypeptide family. It plays a critical role in the regulation of satiety, reproduction, the central endocrine and cardiovascular systems. The T1128C polymorphism of human NPY gene has been shown to be associated with many cardiovascular diseases. The allele frequency of the 1128C was investigated in 6626 subjects from Europe, North-America, South-America, Asia and the Middle-East. The 1128C allele was observed in all populations of European descent and the Israeli population, with a mean frequency of about 4%. The allele frequency showed a geographical north to south gradient of decreasing frequency. The highest allele frequencies were found in Nordic countries. The NPY 1128C allele might originate in the north of Europe, and then spread to neighboring regions.

The single nucleotide polymorphism T1128C in the signal peptide of neuropeptide Y (NPY) was not identified in a Korean population

OBJECTIVE

A single nucleotide polymorphism (SNP) T1128C, which causes an amino acid change from leucine(7) to proline(7) in the signal peptide of neuropeptide Y (NPY), has been found to be associated with multiple clinical parameters or disease. However, this SNP was not identified in the Japanese population. We asked if this is also true in the Korean population.

METHODS

Genotyping was conducted by pyrosequencing, a newly developed real-time high-throughput SNP scoring technique.

RESULTS

All 242 Korean subjects showed T1128/T1128 genotype.

CONCLUSIONS

The T1128C SNP does not appear to exist in this Korean population.

The increase in levels of interferon-inducible proteins p202a and p202b and RNA-dependent protein kinase (PKR) during myoblast differentiation is due to transactivation by MyoD: their tissue distribution in uninfected mice does not depend on interferons

The murine 200 family proteins p202a, p202b, and p204, and also RNA-dependent protein kinase (PKR) are inducible by interferons (IFNs). p202a, p202b, and p204 modulate the activity of a large variety of transcription factors and also are involved in muscle differentiation. PKR is a multifunctional serine/threonine kinase, which is involved in antiviral defense and cell growth control and in the response to various stress signals. We reported earlier that the level of p204 increases during cultured C2C12 myoblast differentiation to myotubes in consequence of transactivation by the skeletal muscle-specific MyoD protein. The levels of p202a, p202b, and PKR also increase during the differentiation. We report here that these increased protein levels also are due to the transactivation of their genes by MyoD. This is made possible by the occurrence in each of these genes of at least six E boxes, which are recognition sites for MyoD. We also show that the distribution of the p204, p202a, p202b, and PKR proteins in five tissues of adult C129 mice is the same in wild-type mice and mice lacking the IFN-alpha, IFN-beta, and IFN-gamma receptors. This indicates that the synthesis and distribution of these proteins in uninfected adult mice are not affected by endogenous IFNs.

Potato spindle tuber viroid as inducer of RNA silencing in infected tomato

Potato spindle tuber viroid (PSTVd), an RNA plant pathogen encoding no known proteins, induces systemic symptoms on tomato plants. We report detection of small RNAs of approximately 25 nucleotides with sequence specificity to PSTVd in infected plants: an indication of the presence of RNA silencing. RNA silencing, however, did not appear to be responsible for the differing symptoms induced by a mild and a severe strain of PSTVd. The unique structural and biological features of viroids make them attractive experimental tools to investigate mechanisms of RNA silencing and pathogen counterdefense.

Identification of Sarcocystis hominis-like (Protozoa: Sarcocystidae) cyst in water buffalo (Bubalus bubalis) based on 18S rRNA gene sequences

DNA templates were extracted from isolates of Sarcocystis hominis-like cysts collected from cattle and water buffalo, as well as from Sarcocystis fusiformis cysts and Sarcocystis suihominis cysts. The 18S rRNA genes were amplified using DNA from a single cyst as the templates. Approximately 1,367-1,440 bp sequences were obtained. The sequence difference in isolates of Sarcocystis hominis-like cysts from water buffaloes, and isolates of S. hominis cysts from cattle were very low, only about 0.1%, much lower than the lowest value (1.7%) among different species. Combined with their morphological structure, these sequence data indicate that the 4 isolates from cattle and water buffalo might be the same species, i.e., S. hominis, suggesting that both cattle and water buffalo may serve as the intermediate hosts for this parasite. Apparently, this is the first report using a single cyst to do such work and is a useful way to distinguish the Sarcocystis cyst in an intermediate host that may be simultaneously infected by several different Sarcocystis species.

Possible involvement of the phloem lectin in long-distance viroid movement

Incubation with cucumber phloem exudate in vitro results in a dramatic decrease in the electrophoretic mobility of Hop stunt viroid. UV cross-linking and a combination of size exclusion and ion exchange chromatography indicate that this phenomenon reflects a previously unsuspected ability of phloem protein 2, a dimeric lectin and the most abundant component of phloem exudate, to interact with RNA. In light of its demonstrated ability to move from cell to cell via plasmodesmata as well as long distances in the phloem, our results suggest that phloem protein 2 may facilitate the systemic movement of viroids and, possibly, other RNAs in vivo.

Metoprolol attenuates postischemic depressed myocardial function in papillary muscles isolated from normal and postinfarction rat hearts

The present study was designed to test the hypothesis that metoprolol treatment may enhance tolerance to ischemia in normal and postinfarction rat myocardium. Myocardial infarction was induced by permanent ligation of the left coronary artery in adult rats. Animals were divided into sham-operated and infarction groups with or without metoprolol treatment. Metoprolol treatment (60 mg/kg/day via gastric gavage) was started on the second day after surgery and continued until sacrifice at 6 weeks after myocardial infarction. Isometric force and intracellular Ca(2+) ([Ca(2+)](i)) transients were simultaneously recorded in isolated left ventricular papillary muscles. Ischemia was simulated by immersing the muscles into fluorocarbon with hypoxia. Metoprolol treatment induced a significant improvement of isometric force and ameliorated diastolic [Ca(2+)](i) overload in postinfarction rat myocardium at baseline. Metoprolol treatment also reduced diastolic [Ca(2+)](i), ameliorated the depression of developed tension during ischemia, and enhanced recovery of postischemic depressed myocardial function in sham-operated and postinfarction rat papillary muscles. Protein levels of the sarcoplasmic reticulum Ca(2+) ATPase of left ventricles and postischemic papillary muscles from metoprolol-treated rats were higher than those in placebo-treated animals. We concluded, therefore, that metoprolol treatment produced appreciable improvement of intracellular Ca(2+) handling during ischemia-reoxygenation cycles, and enhanced recovery of postischemic depressed myocardial function in both normal and postinfarction rat myocardium.

Cardiac-specific overexpression of cyclin-dependent kinase 2 increases smaller mononuclear cardiomyocytes

Cyclin-dependent kinase 2 (cdk2) plays a critical role in the G1- to S-phase checkpoint of the cell cycle. Adult cardiomyocytes are believed to withdraw from the cell cycle. To determine whether forced overexpression of cdk2 results in altered cell-cycle regulation in the adult heart, we generated transgenic mice specifically overexpressing cdk2 in hearts. Transgenic hearts expressed high levels of both cdk2 mRNA and catalytically active cdk2 proteins. Cdk2 overexpression significantly increased the levels of cdk4 and cyclins A, D3, and E. There was an increase in both DNA synthesis and proliferating cell nuclear antigen levels in the adult transgenic hearts. The ratio of heart weight to body weight in cdk2 transgenic mice was significantly increased in neonatal day 2 but not in adults compared with that of wild-type mice. Analysis of dispersed individual adult cardiomyocytes showed a 5.6-fold increase in the proportion of smaller mononuclear cardiomyocytes in the transgenic mice. Echocardiography revealed that transgenic heart was functionally normal. However, adult transgenic ventricles expressed beta-myosin heavy chain and atrial natriuretic factor. Surgically induced pressure overload caused an exaggerated maladaptive hypertrophic response in transgenic mice but did not change the proportion of mononuclear cardiomyocytes. The data suggest that overexpression of cdk2 promotes smaller, less-differentiated mononuclear cardiomyocytes in adult hearts that respond in an exaggerated manner to pressure overload.

Cellular basis of potato spindle tuber viroid systemic movement

Viroids are small, nontranslatable pathogenic RNAs that replicate autonomously and traffic systemically in their host plants. We have used in situ hybridization to analyze the trafficking pattern of Potato spindle tuber viroid (PSTVd) in tomato and Nicotiana benthamiana. When PSTVd was inoculated onto the stem of a plant, it replicated and trafficked to sink, but not source, leaves. PSTVd was absent from shoot apical meristems. In the flowers of infected plants, PSTVd was present in the sepals, but was absent in the petals, stamens, and ovary. The replicative form of PSTVd was detected in the phloem. Our data demonstrate that (i) PSTVd traffics long distance in the phloem and this trafficking is likely sustained by replication of the viroid in the phloem, and (ii) PSTVd trafficking is governed by plant developmental and cellular factors. The dependency of PSTVd and other viroids on cellular mechanisms for RNA trafficking makes them excellent tools to study such mechanisms.

[A cross-sectional study on the effects of microcystin in drinking water to the health of human beings]

OBJECTIVE

To understand the effects of microcystin (MC) in drinking water on health of human beings.

METHODS

In Taixing, a cross-sectional study was conducted in two middle schools with different types of drinking water, from which 111 and 92 students were randomly selected and investigated. Blood samples from all individuals were collected and tested for serum HBsAg, HBeAg, anti-HBe, anti-HBs, anti-HBc with enzyme linked immunoabsorbent assay and for serum alanine aminotransferase (ALT), gamma-glutamyltransferase (gamma-GT) and alkaline phosphatase (ALP) contents by colorimetry. These levels of enzymes in sera were compared after the students were stratified according to the status of HBV infection.

RESULT

With the exclusion of the effect of HBV infection, three enzymes levels in sera between two groups of students showed significant differences (P < 0.01), much higher in exposure group than those in control group.

CONCLUSION

MC was possibly harmful to human beings in drinking water and induced the contents of some enzymes from the liver of human beings to increase in sera.

[The relationship among human, gorilla, chimpanzee and orangutan]

The phylogeny of hominoid is still an open question. The contrary point is which relationship is more closed related between human and gorilla and human and chimpanzee. Tyrosinase is the essential enzyme in melanogenesis. The mutation of tyrosinase gene causes albinism. The five exons of tyrosinase gene were sequenced for gorilla, chimpanzee, orangutan and gibbon in hominoid. Combined with the human tyrosinase gene sequence, the gene tree was constructed using parsimony method. The results show that the relationship between human and gorilla is more closed related than between human and chimpanzee.

[Comparison of susceptibility testing results of M. tuberculosis by different methods]

OBJECTIVE

To compare the susceptibility testing results of M. tuberculosis detected with different standards and methods.

METHOD

158 strains of M. tuberculosis isolated from clinical patients were detected for the drug sensitivity by Chinese standard and method (absolute concentration method), 1% resistance ratio and absolute concentration method of WHO/IUATLD standard.

RESULTS

The drug-resistant rate detected by the standard of WHO/IUATLD was 53.8%(85/158), while by the Chinese standard 50.0%(79/158). The drug-resistant rates to INH, SM, EMB and RFP by WHO/IUATLD standard were 41.8%(66/158), 34.2%(54/158), 22.1%(35/158) and 27.8%(44/158) respectively, whereas by the Chinese standard 34.2%(54/158), 30.4% (48/158), 18.4%(29/158) and 27.2%(43/158) respectively. There was no significant difference between the results detected with WHO/IUATLD and Chinese standard, except for the results of INH. There was no significant difference between the results detected with WHO/IUATLD standard by 1% resistant ratio and absolute concentration methods.

CONCLUSION

The results of drug-sensitivity were interfered by the detected standards but not by the tested methods.

Left ventricular hypertrophy in ascending aortic stenosis mice: anoikis and the progression to early failure

BACKGROUND

To determine potential mechanisms of the transition from hypertrophy to very early failure, we examined apoptosis in a model of ascending aortic stenosis (AS) in male FVB/n mice.

METHODS AND RESULTS

Compared with age-matched controls, 4-week and 7-week AS animals (n=12 to 16 per group) had increased ratios of left ventricular weight to body weight (4.7+/-0.7 versus 3.1+/-0.2 and 5. 7+/-0.4 versus 2.7+/-0.1 mg/g, respectively, P<0.05) with similar body weights. Myocyte width was also increased in 4-week and 7-week AS mice compared with controls (19.0+/-0.8 and 25.2+/-1.8 versus 14. 1+/-0.5 microm, respectively, P<0.01). By 7 weeks, AS myocytes displayed branching with distinct differences in intercalated disk size and staining for beta(1)-integrin on both cell surface and adjacent extracellular matrix. In vivo left ventricular systolic developed pressure per gram as well as endocardial fractional shortening were similar in 4-week AS and controls but depressed in 7-week AS mice. Myocyte apoptosis estimated by in situ nick end-labeling (TUNEL) was extremely rare in 4-week AS and control mice; however, a low prevalence of TUNEL-positive myocytes and DNA laddering were detected in 7-week AS mice. The specificity of TUNEL labeling was confirmed by in situ ligation of hairpin oligonucleotides.

CONCLUSIONS

Our findings indicate that myocyte apoptosis develops during the transition from hypertrophy to early failure in mice with chronic biomechanical stress and support the hypothesis that the disruption of normal myocyte anchorage to adjacent extracellular matrix and cells, a process called anoikis, may signal apoptosis.

Cell-to-cell movement of the 25K protein of potato virus X is regulated by three other viral proteins

The 25K, 12K, and 8K proteins and coat protein (CP) of Potato virus X (PVX) are required for virus cell-to-cell movement. In this study, experiments were conducted to determine whether the PVX 25K protein moves cell to cell and to explore potential interactions between the PVX 25K, 12K, and 8K proteins and CP. The PVX 25K gene was fused to the green fluorescent protein (GFP) gene and inserted into plasmids adjacent to the cauliflower mosaic virus 35S promoter. These plasmids were introduced by biolistic bombardment to transgenic tobacco expressing the PVX 12K, 8K, and CP genes. The GFP:25K fused proteins moved cell to cell on nontransgenic tobacco and tobacco expressing either the 12K or 8K proteins. However, the GFP:25K proteins did not move on transgenic tobacco expressing the combined 12K/8K genes or the CP gene. Thus, movement of the PVX 25K protein through plasmodesmata may be regulated by interactions with other PVX proteins.

Molecular basis of albinism in the rhesus monkey

Sequence analysis of the tyrosinase (TYR) coding region from one albino rhesus monkey (Macaca mulatta) family revealed that the two monkeys with phenotype similar to human TYR-negative oculocutaneous albinism (OCA) were homozygous for a missense mutation (S184TER) in exon 1 at codon 184. The offspring of one of the albino monkey ("Kangkang") are all heterozygous for the S184TER mutation, but the S184TER mutation was not observed in 93 control individuals. We conclude that the point mutation is responsible and sufficient to generate the albino rhesus monkey phenotype. The rough age of the S184TER nonsense mutation may be about 0.8 million years using a rate of 0.16% per million years.

Prevention of intima hyperplasia by mitogen-activated protein kinase antisense oligodeoxynucleotide

AIM

To investigate the preventive effect of Ca(2+)-calmodulin dependent kinase (CCDPK) (formerly: mitogen-activated protein kinase or MAPK) antisense phosphorothioate oligodeoxynucleotide (ODN) on vascular smooth muscle cell (VSMC) proliferation in vitro and on intima hyperplasia after injury in vivo.

METHODS

Liposomal transfection was used to introduce phosphorothioate-protected 17-mer antisense CCDPK ODN directed against the initiation of translation sites of the p42 and p44 CCDPK isoforms into cultured rat VSMC to deplete CCDPK and DNA synthesis induced by endothelin-1 (ET) or platelet derived growth factor (PDGF). A 17-mer sense and a random sequence CCDPK ODN were used as controls. CCDPK protein p44 and p42 levels were measured by Western blot. DNA synthesis was measured by [3H]thymidine incorporation. In in vivo study, rat balloon angioplasty was performed by a 2F Fogarty catheter. The antisense CCDPK ODN 200 micrograms was administered to the adventitial surface of the injured carotid artery by pluronic gel 30% (w/v) solution. Two weeks after vascular injury, carotid arteries were removed and cross sections were made and stained with hematoxylin/eosin for patho-histological examination. Fluorecein isothiocynate (FITC)-labeled and phosphorothioate-protected ODN was used to detect the uptake of ODN in vitro and in vivo.

RESULTS

CCDPK antisense ODN (0.4 mumol.L-1) reduced p42/p44 protein expression and inhibited VSMC [3H]thymidine incorporation stimulated by ET and PDGF. Antisense CCDPK ODN treatment at 2 wk after injury resulted in a significant inhibition of intima hyperplasia, compared with untreated vessels.

CONCLUSION

The p42/p44-CCDPK antisense ODN inhibits in vitro stimulated rat VSMC proliferation and in vivo injured arterial intima hyperplasia.

Antisense Ca(2+)-calmodulin dependent protein kinase oligonucleotide inhibits bFGF-induced proliferation of rat vascular smooth muscle cells

AIM

To investigate the role of Ca(2+)-calmodulin dependent protein kinase (CCDPK) on basic fibroblast growth factor (bFGF)-induced vascular smooth muscle cell (VSMC) proliferation and the inhibitory effect of antisense CCDPK oligonucleotides (ODN).

METHODS

Before being exposed to bFGF, cultured rat VSMC CCDPK activity was inhibited by pretreatment with either a phosphorothioate-protected 17-mer antisense CCDPK ODN-directed against the initiation of translation sites of the p42 and p44 CCDPK isoform or with CCDPK kinase inhibitor PD98059. All ODN were introduced into cells by liposomal transfection. DNA synthesis was measured by [3H]thymidine incorporation. P44- and p42-CCDPK protein expression and phosphorylation were measured by Western blot.

RESULTS

PD98059 inhibited bFGF-induced phosphorylation of CCDPK and DNA synthesis. Antisense CCDPK ODN 0.2-0.8 mumol.L-1 reduced both p44- and p42-CCDPK expression and phosphorylation of CCDPK in a concentration-dependent manner and DNA synthesis induced by bFGF. Lipofectin alone or sense and random CCDPK ODN did not affect p44- and p42-CCDPK protein expression or bFGF-induced phosphorylation of CCDPK or DNA synthesis.

CONCLUSION

bFGF-stimulated rat VSMC proliferation is mediated by CCDPK. The antisense CCDPK ODN can inhibit bFGF-induced VSMC proliferation through down-regulating p44- and p42-CCDPK level.

Effect of PKC-zeta mediating Ang II-stimulated activation of CCDPK on rat cardiac fibroblast proliferation

AIM

To investigate whether the effect of angiotensin (Ang) II or epidermal growth factor (EGF) on cardiac fibroblast proliferation involved in activation of extracellular signal-regulated kinase (ERK) 1/2 or Ca(2+)-calmodulin dependent protein kinase(CCDPK) mediated by protein kinase C (PKC)-zeta.

METHODS

Relative activity of CCDPK was measured by Western blotting. DNA synthesis was assayed by [3H]thymidine incorporation.

RESULTS

PDBU caused no decrease in Ang II- and 10% FCS-stimulated CCDPK activity and DNA synthesis. In contrary, 65% or 75% EGF- or tetradecanoylphorbol acetate (TDPA, formally called PMA)--stimulated CCDPK activity and 38% or 42% [3H]thymidine incorporation treated by PDBU were inhibited, respectively. Meanwhile 70% and 72% CCDPK activities induced by Ang II and EGF were inhibited by PD 98059, respectively.

CONCLUSION

PKC-zeta mediated Ang II-induced activation of CCDPK and cardiac fibroblast proliferation.

Inhibitory effect of MAP kinase antisense oligonucleotide on angiotensin II-induced c-myc gene expression and proliferation of rat cardiac fibroblast

AIM

To investigate the inhibitory effect of down-regulating mitogen activated protein kinase (MAPK) on c-myc gene expression and further on cardiac fibroblast proliferation.

METHODS

Cultured neonatal rat cardiac fibroblasts was pretreated with a phosphorothioate-protected 17-mer antisense MAPK oligodeoxynucleotide (ODN) directed against the initiation of translation sites of the p42 and p44 MAPK isoforms by liposomal transfection. A 17-mer sense and mismatch sequence MAPK ODN were used as controls. After liposomal transfecting, cells were exposed to angiotensin II (Ang II) 10 nmol.L-1 for 5 min and then harvested in lysis buffer. MAPK activity was measured by Western blot and P-81 phosphocellulose filter paper method by using [gamma-32P]ATP and myelin basic protein as substrates. c-myc mRNA expression stimulated by Ang II for 30 min was measured by Northern blot. DNA synthesis and collagen protein synthesis induced by Ang II for 24 h were measured by [3H]thymidine incorporation and [3H]Proline incorporation, respectively.

RESULTS

Antisense ODN 0.2 mumol.L-1 reduced Ang II-induced MAPK activities by 72%, MAPK protein expression by 80%, and suppressed c-myc mRNA expression by 97%, respectively. [3H]thymidine incorporation and [3H]proline incorporation in Ang II-induced cardiac fibroblast were inhibited by 59% and 58%, respectively.

CONCLUSION

A 17-mer MAPK antisense oligonucleotide directed againsts the initiation of translation sites of MAPK could specifically inhibit Ang II-stimulated cultured neonatal rat cardiac fibroblast proliferation through down-regulating MAPK activity and further depleting c-myc mRNA expression.

[Inhibitory effects of antisense oligonucleotides targeting mitogen-activated protein kinase (MAPK) mRNA on neonatal rat cardiac fibroblast proliferation induced by Ang II and EGF]

In the present study, the antisense oligodeoxynucleotide (ODN) approach was used to investigate whether mitogen-activated protein kinase (MAPK) is necessary for the proliferation response in neonatal rat cardiac fibroblast (FB) induced by angiotensin II (AngII) or epidermal growth factor (EGF), the proximal cytosolic signal transduction pathways which are quite different processes. A phosphorothioate-protected 17-mer directed against the initiation of translation sites P42 MAPK mRNA was introduced into FB by liposomal transfection. The results showed that (1) after a 24 h treatment with AngII or EGF (all 10(-8) mol/L), the FB numbers were increased by 39% and 68%, while the rate of DNA synthesis increased by 60% and 102%, respectively. (2) Following 5 min or 10 min stimulation with AngII or EGF, MAPK activity ([gamma-32P] ATP incorporation) increased by 202% and 305%, and phospho-MAPK protein content increased by 545% and 646% correspondingly. (3) As compared with lipofectin + AngII/EGF control, after pretreatment with MAPK antisense ODN, the MAPK protein expression was inhibited significantly; the rate of DNA synthesis of FB induced by AngII or EGF was reduced by 53% and 46%, cell numbers by 38% and 44%, respectively. Meanwhile, MAPK activity was decreased by 74.2% and 65.9%, phospho-MAPK protein content by 85% and 90%. The sense or random ODN has not much effect on them. Consequently, it can be concluded that (1) MAPK activity is essential in the event of involving FB proliferation response reduced by AngII and EGF, and (2) FB proliferation response could be inhibited by the MAPK antisense ODN through depletion of MAPK.

Target selectivity of MAPK phosphorothioate antisense ODN on p42/p44, p38 MAPK, and JNK protein expression and its inhibitory effect on VSMC DNA synthesis

AIM

To analyze the target selective and sequence-specific inhibitory effect of mitogen-activated protein kinase (MAPK) phosphorothioate antisense oligodeoxynucleotides (ODN) on p42/p44, p38 MAPK, c-jun NH2-terminal protein kinases (JNK) protein expression, and DNA synthesis in vascular smooth muscle cell (VSMC).

METHODS

Using a phosphorothioate-protected 17-mer antisense MAPK ODN directed against the initiation of translation sites of the p42/p44 MAPK isoforms by liposomal transfection to deplete cultured rat, rabbit, and fetal calf VSMC MAP kinases. The 17-mer sense and random sequence MAPK ODN were used as controls. After liposomal transfection, cells were exposed to 20% serum for 24 h, and then harvested in lysis buffer. P42/p44, p38 MAPK, and p46/p58 JNK protein expression were measured by Western blot. DNA synthesis was measured by [3H]thymidine incorporation.

RESULTS

Treatment with MAPK antisense ODN (0.1-0.8 mumol.L-1) for 48 h reduced phosphored p42/p44 MAPK protein expression but without effect on p38 MAPK and JNK expression, and inhibited cultured rat, rabbit, and fetal calf VSMC [3H]thymidine incorporation stimulated by 20% serum in a concentration-dependent manner.

CONCLUSION

The MAPK antisense ODN target-selectively and sequence-specifically reduces the p42/p44 MAPK protein expression and concentration-dependently inhibits proliferation of rat, rabbit and fetal calf VSMC.

Genetic diversity of Chinese native pigs inferred from protein electrophoresis

We examined protein polymorphism of 20 native pig breeds in China and 3 introduced pig breeds. Thirty loci have been investigated, among which six loci were found to be polymorphic. Especially, the polymorphism of malate dehydrogenase (MDH), adenylate kinase (AK), and two new alleles of adenosine deaminase (ADA) had not been reported in domestic pigs and wild pigs. The percentage of polymorphic loci (P), the mean heterozygosity (H), and the mean number of alleles (A) are 0.200, 0.065, and 1.300, respectively. The degree of genetic variability of Chinese pigs as a whole was higher than that of goats, lower than that of cattle and horses, and similar to that of sheep. Using the gene frequencies of the 30 loci, Nei's genetic distance among the 20 native breeds in China and 3 introduced pig breeds was calculated by the formula of Nei. The program NEIGHBOR in PHYLIP 3.5c was chosen to construct an UPGMA tree and a NJ tree. Our results show that, of the total genetic variation found in the native pig breeds in China, 31% (0.31) is ascribable to genetic differences among breeds. About 69% of the total genetic variation is found within breeds. Most breeds are in linkage disequilibrium. The patterns of genetic similarities between the Chinese native pig breeds were not in agreement with the proposed pig type classification.

Role of endothelial nitric oxide synthase in endothelial cell migration

Endothelium-derived nitric oxide (NO) and its precursor L-arginine have been implied to promote angiogenesis, but little is known about the precise mechanism. The inhibition of endogenous NO formation by Nomega-nitro-L-arginine methyl ester (L-NAME) (1 mmol/L) but not its inactive enantiomer D-NAME (1 mmol/L) inhibited endothelial cell sprouting from the scratched edge of the cultured bovine aortic endothelial cell monolayer. Inhibition of endogenous NO release by L-NAME was confirmed by amperometric measurement using an NO-specific electrode. In the modified Boyden chamber, L-NAME (1 mmol/L) significantly inhibited endothelial cell migration, whereas L-NAME did not affect endothelial DNA synthesis as assessed by analysis of [3H]thymidine incorporation. We then examined alteration of endothelial cell adhesion molecule expression after the inhibition of NO by L-NAME in cultured human umbilical vein endothelial cells. In both normoxic and hypoxic conditions, L-NAME (1 mmol/L) inhibited surface expression of integrin alphavbeta3, which is an important integrin facilitating endothelial cell survival and angiogenesis. However, L-NAME did not affect the expression of platelet endothelial cell adhesion molecule-1, intercellular adhesion molecule-1, vascular endothelial adhesion molecule-1, gap junction protein connexin 43, and VE-cadherin, which have been reported to potentially affect angiogenesis. In summary, inhibition of endothelial NO synthase by L-NAME attenuated endothelial cell migration but not proliferation in vitro. Furthermore, endogenous endothelium-derived NO maintains the functional expression of integrin alphavbeta3, a mediator for endothelial migration, survival, and angiogenesis. Endothelium-derived NO, thus, may play an important role in mediating angiogenesis by supporting endothelial cell migration, at least partly, via an integrin-dependent mechanism.

Pressure overload induces severe hypertrophy in mice treated with cyclosporine, an inhibitor of calcineurin

Cardiac hypertrophy is the fundamental adaptation of the adult heart to mechanical load. Recent work has shown that inhibition of calcineurin activity with cyclosporine suppresses the development of hypertrophy in calcineurin transgenic mice and in in vitro systems of neonatal rat cardiocytes stimulated with peptide growth factors. To test the hypothesis that the calcineurin signaling pathway is critical for load-induced hypertrophy in vivo, we examined the effects of cyclosporine treatment on left ventricular hypertrophy induced by experimental ascending aortic stenosis for 4 weeks in mice. Left ventricular systolic pressure was elevated to a similar level in aortic stenosis mice that were treated with cyclosporine versus no drug. Left ventricular mass and myocyte size were similar in treated and untreated aortic stenosis animals and significantly greater than control animals, showing that cyclosporine treatment does not suppress hypertrophic growth. Both treated and untreated animals showed increased left ventricular expression of the load-sensitive gene atrial natriuretic factor. Calcineurin activity was measured in the left ventricle and the spleen from control mice and aortic stenosis mice treated with cyclosporine versus no drug. Levels of calcineurin activity were similar in the spleens of control and untreated aortic stenosis mice. However, calcineurin activity was severely depressed in left ventricular tissue of untreated aortic stenosis mice compared with control mice and was further reduced by cyclosporine treatment. Thus, pathological hypertrophy and cardiac-restricted gene expression induced by pressure overload in vivo are not suppressed by treatment with cyclosporine and do not appear to depend on the elevation of left ventricular calcineurin activity.

[Library search of UV spectra of organic environmental pollutants by artificial neural network]

In this paper, the artificial neural network (ANN) was applied to the library search of UV spectra of organic environmental pollutants. The optimization of network parameters was discussed and the effects of noise and impurity were investigated in detail. The use of derivative spectra for ANN library search was proposed to enhance the resolution of the UV spectra. This method could speed up the convergence of the network and could enhance the tolerance of impurity level, but was subject to noise comparing with the ANN using conventional UV spectra. Results show that the ANN is superior to the correlation coefficient method in resistance to noise and impurity.

Stapled anastomosis in esophageal resections with Chinese staplers: a retrospective study of 1965 consecutive cases

OBJECTIVES

To investigate the safety and efficacy of mechanical anastomosis with Chinese staplers in the surgical treatment of esophageal carcinoma and carcinoma of gastric cardia in order to find out an alternative effective anastomotic technique to hand-sewn method.

METHODS

From August 1980 to April 1996, there were totally 1264 cases of esophageal carcinoma and 701 cases of carcinoma of gastric cardia receiving esophagogastric anastomosis with Chinese staplers combined with telescope suturing of seromuscular layers after resection of tumors, with age ranging from 28 years to 81 years and a man to woman ratio of 4:1 (1572/393). The anastomosis was performed at the cervical region in 44 patients, and intrathoracically in 1921. Our technical essential points also included fixation of the gastric substitute to the thoracic apex or mediastinum with 3-4 stitches to relieve the anastomotic tension.

RESULTS

Compared with the reported postoperative leakage rate from 2%-4% in China and 4.2%-12.3% abroad, our techniques reduced the total leakage rate to 0.8%, that is, cervical leakage rate was 11.4% (5/44), and intrathoracic leakage rate 0.57% (11/1921). The intrathoracic leakage rate was 0.99% (8/808) for the first 8 years, and 0.27% for the following 8 years. There was no leakage (0/350) in the last 3 years. There anastomotic stricture occurred in 98 patients (4.99%) which could be relieved by Bougie or balloon dilatation. The total operative mortality was reduced to 0.76%.

CONCLUSIONS

Mechanical anastomosis with Chinese staplers combined with telescope suturing should be an effective method to prevent the occurrence of anastomotic leakage after esophageal resections.

Effects of simulated weightlessness and gamma-irradiation on myocardial cells and osteoblasts

The effects of simulated weightlessness and gamma-irradiation on the structure and function of the myocardial cells and osteoblasts were investigated with a rotating clinostat and 2 Gy 60Co gamma-irradiation. The results showed: (1) Under the simulated weightlessness (SWL), the diameter of the myocardial cells decreased 40%. And the long-short diameter proportion decreased 70%, (P < 0.01); SWL affected the cell skeleton and the distribution of microfilament became ununiform, the orientation was unclear; SWL had significant effects on osteoblast disintegration and proliferation. The disintegration function decreased and the proliferation process was inhibited; (2) 2 Gy 60Co gamma-ray irradiation had significant effects on Lactate Dehydrogenase (LDH) activity and Superoxide Dismutase (SOD), Malonaldehyde (MDA) content in the myocardial cells, (P < 0.05) (5) A synergistic effect was observed between irradiation and SWL.

Intercellular protein trafficking through plasmodesmata

During plant morphogenesis, groups of cells differentiate to form specialized tissues possessing distinct structures and functions. Cell specialization is a result of specific gene expression at the individual cell level. Coordination of differential gene expression among cells requires that cells communicate with one another. Plasmodesmata provide a cytoplasmic pathway for direct intercellular communication. Recent discoveries that macromolecules such as transcription factors, viral proteins, and plant defense-related proteins can traffic through plasmodesmata suggest that intercellular protein trafficking is potentially an important means to regulate plant developmental processes, physiological functions, plant-pathogen interactions, and plant defense reactions. Thus, elucidating the specific functions and mechanisms of intercellular protein trafficking has broad implications in understanding how a plant develops and functions at the molecular level. This review is to provide an update on this rapidly developing area of plant biology, with emphasis on the discussion of possible mechanisms underlying intercellular protein trafficking.

Effect of antisense mitogen-activated protein kinase oligonucleotides on rat vascular smooth muscle cell proliferation induced by EGF in vitro

AIM

To study the preventive effect of down-regulating mitogen-activated protein kinase (MAPK) on vascular smooth muscle cell (VSMC) proliferation.

METHODS

Cultured rat VSMC was pretreated with a phosphorothioate-protected 17-mer antisense MAPK oligodeoxynucleotides (ODN) directed against the initiation of translation sites of the p42- and p44-MAPK isoforms by liposomal transfection. A 17-mer sense and a random sequence MAPK ODN were used as control. After liposomal transfection, cells were exposed to epidermal growth factor (EGF) 1 nmol.L-1 for 10 min and then harvested in lysis buffer. MAPK activity was measured by Western blot and P-81 phosphocellulose filter papers method by using [gamma-32P] ATP and myelin basic protein as substrate. DNA synthesis was measured by [3H]thymidine incorporation.

RESULTS

Antisense ODN 0.2 mumol.L-1 reduced EGF-induced MAPK activities by 84%, and inhibited VSMC [3H]thymidine incorporation stimulated by EGF.

CONCLUSION

A 17-mer MAPK antisense oligonucleotide directed against the initiation of translation sites of the p44- and p42-MAPK inhibited EGF-stimulated rat VSMC proliferation.