A dose-response meta-analysis to evaluate the relationship between high-density lipoprotein cholesterol and all-cause and cardiovascular disease mortality

PURPOSE

Previous studies have not fully described the relationship between high-density lipoprotein cholesterol (HDL-C) and death risks from all cause and cardiovascular disease (CVD). This study quantitatively evaluates HDL-C-mortality associations.

METHODS

Embase and PubMed databases were searched for relevant articles published up to 1 June 2019. Random-effects models were used to pool relative risks (RRs) and 95% confidence intervals (CIs). We used restricted cubic splines to model the dose-response association.

RESULTS

We identified 32 prospective cohort studies including 369,904 participants and 33,473 total deaths (9426 CVD deaths). Compared to the lowest HDL-C levels, all cause and CVD mortality risks were reduced by 18% (RR 0.82; 95% CI, 0.73-0.93) and 36% (0.64, 0.46-0.89), respectively, for the highest HDL-C levels. All cause and CVD mortality risks were reduced by 15% (0.85, 0.79-0.92) and 23% (0.77, 0.69-0.87), respectively, with each 1 mmol/L increment of HDL-C. We found evidence of nonlinear and negative dose-response associations of HDL-C with all cause and CVD mortality (P_nonlinearity < 0.001), and the lowest death risks from all cause and CVD were observed at approximately 1.34 and 1.55 mmol/L, respectively.

CONCLUSION

HDL-C is inversely associated with all cause and CVD mortality risks under approximately 2.05 and 2.33 mmol/L, respectively. Optimal doses require investigation via clinical practice or high-quality research.

[Efficacy of intravenous thrombolysis for acute severe cerebral infarction and risk factors of poor prognosis: a randomized controlled trial in 152 cases]

OBJECTIVE

To investigate the clinical efficacy and safety of intravenous thrombolysis in patients with acute severe cerebral infarction and analyze the risk factors of poor prognosis after thrombolysis.

METHODS

This randomized controlled trial was conducted among 152 patients with acute severe cerebral infarction, with the onset time all within 4.5 h. The patients were randomized into control group (76 cases) and observation group (76 cases) and received treatment with routine therapy (antiplatelet aggregation, statins, neuroprotection and drugs that stimulate blood flow) and intravenous thrombolytic therapy with alteplase in addition to the routine therapy, respectively. The NIHSS scores were recorded at 24 h, 1 week and 1 month after the treatment. The mRS scores at 3 months and the incidence of symptomatic intracranial hemorrhage at one week after the treatment were compared between the two groups. According to mRS scores at 3 months, the patients in the observation group were divided into good prognosis group (30 patients) and poor prognosis group (46 patients), and the risk factors for poor prognosis were analyzed using univariate and multivariate Logistic regression analysis.

RESULTS

At 24 h, 1 week and 1 month after the treatment, the reduction of NIHSS scores was more significant in the observation group than in the control group (F=24.684, P < 0.001). At 3 months after the treatment, the mRS scores were significantly lower (t=4.396, P < 0.001) and the good prognosis rate was significantly higher (χ²=13.636, P < 0.001) in the observation group than those of the control group. Symptomatic intracranial hemorrhage occurred in 4 cases in the observation group and in 2 cases in the control group within 1 week after the treatment (χ²=0.694, P=0.405). The time from onset to thrombolysis (OR=0.173, P=0.035), prethrombolytic systolic pressure (OR=0.869, P=0.019) and baseline NIHSS score (OR=0.466, P=0.011) were identified as independent risk factors for poor prognosis after intravenous thrombolysis.

CONCLUSION

Intravenous thrombolysis is effective and safe for patients with acute severe cerebral infarction, and the time from onset to thrombolysis, prethrombolytic systolic pressure and baseline NIHSS score are independent risk factors for a poor prognosis after intravenous thrombolysis.

Accuracy of molecular diagnostic tests for drug-resistant tuberculosis detection in China: a systematic review

OBJECTIVE: To evaluate the accuracy of molecular diagnostics for the detection of drug-resistant tuberculosis (TB) in Chinese patients.METHOD: Seven databases were searched for eligible studies that evaluated the accuracy of molecular diagnostics against drug susceptibility testing (DST) for detecting drug resistance. A bivariate random-effects meta-analysis was conducted to pool sensitivity and specificity by the index test and drug resistance type.RESULTS: A total of 159 studies were included. Compared with DST (reference standard), Xpert^® could diagnose rifampicin (RMP) resistant TB accurately, with a pooled sensitivity and pooled specificity of 92% (95%CI 90-94) and 98% (95%CI 97-98), respectively. Line-probe assays (LPAs) also performed well for RMP resistance, with a pooled sensitivity of 91% (95%CI 88-93) and pooled specificity of 98% (95%CI 96-99), but not for isoniazid (INH) or second-line drugs due to lower sensitivity (<80%). The pooled sensitivity of GeneChip^® microarrays for RMP, INH and multidrug resistance was 89% (95%CI 86-91), 79% (95%CI 75-82) and 79% (95%CI 73-84), respectively, and the specificities were all >97%. Similarly, the MeltPro^® TB/STR assay had better sensitivity and specificity for first-line drugs, varying from 87% to 89% and 97% to 98%, respectively, than for second-line drugs.CONCLUSION: The Xpert assay, LPA, GeneChip assay, and MeltPro assay are credible methods with high accuracy for RMP resistance detection, but they may not be appropriate for other anti-tuberculosis drugs due to low sensitivity.

SMAD4 Y353C promotes the progression of PDAC

Background

SMAD4 is frequently inactivated and associated with a poor prognosis in pancreatic ductal adenocarcinoma (PDAC). Abnormal SMAD4 expression also plays an important role in the malignant progression of PDAC.

Methods

We investigated SMAD4 status in PDAC by immunohistochemical methods to explore the relationships between SMAD4 expression and clinicopathological features and then detected SMAD4 mutations by Sanger sequencing in 95 patients with PDAC to identify new mutation sites in PDAC. We further evaluated the effects of a missense mutation, Y353C, in the SMAD4 MH2 domain, on cell proliferation and migration in vitro.

Results

Immunohistochemistry showed that the expression of SMAD4 in PDAC carcinoma tissue was significantly lower than that in normal pancreatic tissue, and negative SMAD4 expression was closely related to tumour diameter, staging, lymph node metastasis and differentiation. Sanger sequencing analysis showed that the rate of SMAD4 mutation was 11.8% in 85 PDAC cases, and the novel SMAD4 Y353C missense mutation identified in this study promoted cell migration and invasion without affecting cell proliferation in vitro. Furthermore, SMAD4 Y353C resulted in reduced expression of E-cadherin and increased expression of Vimentin compared with wild-type SMAD4 overexpression.

Conclusion

This study supports the key role of SMAD4 as a tumour suppressor gene in PDAC and shows that SMAD4 Y353C is associated with poor progression of PDAC.

P6290Enhanced IL-6/pSTAT3/fibroblast signaling pathway contributes to spontaneous postoperative atrial fibrillation in a novel simulated cardiac surgery mouse model

Background

Cumulative evidences have shown that IL-6 in atrium might play an important role in the pathogenesis of postoperative AF (POAF) via activation of atrial fibrosis in patients undergoing CABG. However, whether atria produces IL-6 after the stimulation of CABG and its causal relationship with spontaneous POAF (sPOAF) and its specific pathways is still unclear.

Purpose

To test the hypothesis that atrium will produce IL-6 after CABG and causes sustained sPOAF (ssPOAF) through activating pSTAT3-mediated fibroblast proliferation.

Methods

To determine the causal relationship between IL-6 and sPOAF, IL-6−/− and wild type (WT) mice were both divided into three groups (10 mice/group): CABG group (NAI, mimic CABG), anti-inflammatory group (AI, mimic CABG with pericardial administration of methylprednisolone for 3 days via chest tube), and control group (anesthesia only). Mice were monitored for ssPOAF for 7 days using implanted telemetry device. Another two sets of mice, using the same models mentioned above, were euthanatized at 48th hours postoperatively. The atria of one set animals were excised and separated into pericardium (PC), pulmonary vein (PV), left atrium (LA), and right atrium (RA) and cultured for 4 hours. IL-6 levels in the supernatant were measured at 10 min and 4 hours of culture using ELISA test. The region producing the largest amount of IL-6 in the other set of animals was harvested for analyzing expressions of IL-6, pSTAT3/STAT3, connexin 43 and 40, fibroblast deposition, and collagen I and III. Path analysis was performed to determine the causal relationship of CABG induced IL-6 release, pSTAT3/fibroblast signaling, and the onset of ssPOAF.

Results

40% NAI-WT mice developed ssPOAF (Figure 1A) which was completely protected in IL-6−/− and AI groups. IL-6 was produced by all 4 atrial regions at 4hrs after CABG stimulation with the LA producing the highest amount. Western blotting (Figure 1B), RT-CPR, Masson staining, and immunofluorescence all showed a significantly upregulation of IL-6, pSTAT3/STAT3, fibroblasts, collagen I and III, and downregulation of Cx40 an 43 in NAI-WT mice, but not in IL-6−/− and AI mice. IL-6 was colocalized with vimentin to a large extent in cytoplasm (Figure 1C). IL-6 had strong positive correlation with pSTAT3/STAT3, collagen I and III (all r>0.700, P<0.001), moderate and weak negative correlation with Cx40 and 43 (r=−0.505, P<0.001; r=−0.307, P=0.048, respectively). Path analysis (Figure 1D) revealed that every 1 unit increase in IL-6 upregulated a 0.589 unit increase in ssPOAF, which was mediated by pSTAT3/collagen indirectly and collagen I/ collagen III directly.

Conclusion

Our study, for the first time, to the best of our knowledge, established a novel pathophysiological role of IL-6/pSTAT3/fibroblast signaling in the pathogenesis of ssPOAF and demonstrated that inhibition of atrial IL-6 might be a potential novel sPOAF prevention strategy.

Acknowledgement/Funding

The National Natural Science Foundation (No.81170170)

Litopenaeus vannamei attenuates white spot syndrome virus replication by specific antiviral peptides generated from hemocyanin

Recent studies have shown that hemocyanin plays immune-related functions apart from its canonical respiratory function. While shrimp hemocyanin is found to generate antimicrobial peptides, antiviral related peptides have not been reported. In the present study, the serum of white spot syndrome virus (WSSV) infected Litopenaeus vannamei analyzed by two-dimensional gel electrophoresis, revealed 45 consistently down-regulated protein spots and 10 up-regulated protein spots. Five of the significantly up-regulated spots were identified as hemocyanin derived peptides. One of the five peptides, designated LvHcL48, was further characterized by analyzing its primary sequence via Edman N-terminal sequencing, C-terminal sequencing and amino acid sequence alignment. LvHcL48 was found to be a 79 amino acid fragment (aa584-662) from the C-terminal domain of L. vannamei hemocyanin protein (ADZ15149). Both in vivo and in vitro functional studies revealed that LvHcL48 has immunological activities, as recombinant LvHcL48 protein (rLvHcL48) significantly inhibited the transcription of the WSSV genes wsv069 and wsv421 coupled with a significant reduction in WSSV copy numbers. Further analysis showed that LvHcL48 could interact with the WSSV envelope protein 28 (VP28). Our present data therefore reveals the generation of an antiviral hemocyanin derived peptide LvHcL48 from WSSV infected shrimp, which binds to the envelope protein VP28 of WSSV.

Higher plane of nutrition pre-weaning enhances Holstein calf mammary gland development through alterations in the parenchyma and fat pad transcriptome

Background

To reduce costs of rearing replacement heifers, researchers have focused on decreasing age at breeding and first calving. To increase returns upon initiation of lactation the focus has been on increasing mammary development prior to onset of first lactation. Enhanced plane of nutrition pre-weaning may benefit the entire replacement heifer operation by promoting mammary gland development and greater future production.

Methods

Twelve Holstein heifer calves (< 1 week old) were reared on 1 of 2 dietary treatments (n = 6/group) for 8 weeks: a control group fed a restricted milk replacer at 0.45 kg/d (R, 20% crude protein, 20% fat), or an accelerated group fed an enhanced milk replacer at 1.13 kg/d (EH, 28% crude protein, 25% fat). At weaning (8 weeks), calves were euthanized and sub-samples of mammary parenchyma (PAR) and mammary fat pad (MFP) were harvested upon removal from the body. Total RNA from both tissues was extracted and sequenced using the Illumina HiSeq2500 platform. The Dynamic Impact Approach (DIA) and Ingenuity Pathway Analysis (IPA) were used for pathway analysis and functions, gene networks, and cross-talk analyses of the two tissues.

Results

When comparing EH vs R 1561 genes (895 upregulated, 666 downregulated) and 970 genes (506 upregulated, 464 downregulated) were differentially expressed in PAR and MFP, respectively. DIA and IPA results highlight a greater proliferation and differentiation activity in both PAR and MFP, supported by an increased metabolic activity. When calves were fed EH, the PAR displayed transcriptional signs of greater overall organ development, with higher ductal growth and branching, together with a supportive blood vessel and nerve network. These activities were mediated by intracellular cascades, such as AKT, SHH, MAPK, and Wnt, probably activated by hormones, growth factors, and endogenous molecules. The analysis also revealed strong communication between MFP and PAR.

Conclusion

The transcriptomics and bioinformatics approach highlighted key mechanisms that mediate the mammary gland response to a higher plane of nutrition in the pre-weaning period.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5303-8) contains supplementary material, which is available to authorized users.

Concurrent use of capecitabine with radiation therapy and survival in breast cancer (BC) after neoadjuvant chemotherapy

PURPOSE

Capecitabine has been studied as a radiosensitizer, and our study seeks to examine the association of concurrent capecitabine/radiation therapy (RT) on event-free- (EFS) and overall survival (OS) in women with breast cancer (BC) with residual disease after neoadjuvant chemotherapy (NAC).

METHODS/PATIENTS

In a retrospective study of women with BC who received adriamycin/taxane-based NAC from 2004-2016, we identified 21 women administered concurrent capecitabine/RT. To assess differences in survival, we selected a clinical control cohort (n = 57) based on criteria used to select patients for capecitabine/RT. We also created a matched cohort (2:1), matching on tumor subtype, pathological stage and age (< 50 or 50+ years). Differences in EFS, using STEEP criteria, and OS, using all-cause mortality, between those who received capecitabine/RT and controls were assessed.

RESULTS

Of the 21 women who received capecitabine/RT, median age was 52 years. The majority were pathologic stage III (n = 15) and hormone receptor-positive/HER2-negative BC (n = 20). In those receiving capecitabine/RT, there were 9 events, compared with 14 events in clinical and 10 events in matched controls. Capecitabine/RT was associated with worse OS in clinical (HR 3.83 95% CI 1.12-13.11, p = 0.03) and matched controls (HR 3.71 95% CI 1.04-13.18, p = 0.04), after adjusting for clinical size, pathological stage and lymphovascular invasion. Capecitabine/RT was also associated with a trend towards worse EFS in clinical (HR 2.41 95% CI 0.86-6.74, p = 0.09) and matched controls (HR 2.68 95% CI 0.91-7.90, p = 0.07) after adjustment.

CONCLUSION

Concurrent capecitabine/RT after NAC is associated with worse survival and should be carefully considered in BC.

Canceling the Gravity Gradient Phase Shift in Atom Interferometry

Gravity gradients represent a major obstacle in high-precision measurements by atom interferometry. Controlling their effects to the required stability and accuracy imposes very stringent requirements on the relative positioning of freely falling atomic clouds, as in the case of precise tests of Einstein's equivalence principle. We demonstrate a new method to exactly compensate the effects introduced by gravity gradients in a Raman-pulse atom interferometer. By shifting the frequency of the Raman lasers during the central π pulse, it is possible to cancel the initial position- and velocity-dependent phase shift produced by gravity gradients. We apply this technique to simultaneous interferometers positioned along the vertical direction and demonstrate a new method for measuring local gravity gradients that does not require precise knowledge of the relative position between the atomic clouds. Based on this method, we also propose an improved scheme to determine the Newtonian gravitational constant G towards the 10 ppm relative uncertainty.

RNA interference unveils the importance of Pseudotrichonympha grassii cellobiohydrolase, a protozoan exoglucanase, in termite cellulose degradation

Based on prior work, a cellulase from glycosyl hydrolase family 7 (GHF7) was identified and found to be expressed at a high level in Coptotermes formosanus. To determine the function of GHF7 family members in vivo, we used RNA interference (RNAi) to functionally analyse the exoglucanase gene Pseudotrichonympha grassii cellobiohydrolase gene (PgCBH), which was highly expressed in Pseudotrichonympha grassii, a flagellate found in the hindgut of C. formosanus. In this study, the expression level of PgCBH was down-regulated by RNAi, causing the death of P. grassii, but no effect was observed for other flagellates found in C. formosanus. RNAi also resulted in significantly reduced exoglucanase activity, and no effect was observed for endoglucanase and β-glucosidase activities. This result demonstrated that the PgCBH gene plays a role in the protist lignocellulolytic process and is also important for host survival. PgCBH can be used as a target gene and has potential as a bioinsecticide for use against termites.

Identification and characterization of an 18.4kDa antimicrobial truncation from shrimp Litopenaeus vannamei hemocyanin upon Vibrio parahaemolyticus infection

Hemocyanin (HMC) is a multifunctional protein which plays many essential roles in invertebrate organism. Recently more and more immune-related functions have been discovered on this protein. Here the shrimp was infected with Vibrio parahaemolyticus and the shrimp sera were analyzed by two-dimensional gel electrophoresis. Totally 15 spots were identified as significantly up-regulated spots and further analyzed by MALDI-TOF/TOF mass spectrometry (MS). Four of them were identified as HMC derived truncations (HMCS1, HMCS3, HMCS4 and HMCS5). The HMCS4 primary sequence was further determined via Edman N terminal sequencing, MALDI-TOF MS and amino acid sequence alignment. The result indicated that the HMCS4 was a 165aa fragment from shrimp HMC small subunit C-terminal. The HMCS4 immunological activities were further analyzed by agglutination experiment and antibacterial assay in vitro. The results showed that the recombinant HMCS4 (rHMCS4) had strong agglutination and antibacterial activities against pathogenic bacteria at the optimum bacteriostasis concentration. In addition, the HMCS4 immunological activities were explored via mortality assay in vivo. The shrimp was challenged with V. parahaemolyticus and rHMCS4 V. parahaemolyticus mixture separately. The shrimp mortality rate was significantly decreased at 96 h post-infection with rHMCS4 injection. Our data showed that shrimp HMC truncation generation upon infection was an effective immune response against invaded pathogens. Moreover, these findings may have some potential applications in shrimp industry.

The cardiovascular effects of glucagon-like peptide-1 receptor agonists: a trial sequential analysis of randomized controlled trials

WHAT IS KNOWN AND OBJECTIVE

Glucagon-like peptide-1 (GLP-1) receptor agonists are a new class of antidiabetic drugs. Their wider use for the treatment of patients with type 2 diabetes mellitus has led to concerns about its cardiovascular effects. However, the robustness of data leading to those concerns is unclear. The purpose of this study is to systematically assess the robustness of the available evidence on the adverse cardiovascular effects of GLP-1 receptor agonists in patients with type 2 diabetes.

METHODS

The Cochrane library, MEDLINE, EMBASE and www.clinicaltrials.gov were searched from inception through to 25 January 2013. Randomized controlled trials (RCTs) were selected if they compared GLP-1 receptor agonists with placebo or other drugs with a duration ≥12 weeks. Mantel-Haenszel odds ratio (MH-OR) of cardiovascular events with 95% confidence interval (CI) was estimated using a random effects model. Trial sequential analysis based on required information size with an assumption of plausible reductions in relative risk in the low-bias trials, 5% risk of a type I error and 20% risk of a type II error was used to explore the robustness of available evidence.

RESULTS

Fifty-eight trials were included in the analysis (10 466 patients receiving GLP-1 receptor agonists and 7138 patients receiving comparators, respectively). Overall, the OR for cardiovascular events with GLP-1 receptor agonists was 0·52 (95% CI: 0·27-0·99) compared with placebo and 0·84 (95% CI: 0·52-1·36) with active controls. Trial sequential analyses showed that the actual accumulated sample size was only 11% (7445 of 65 212) and 13% (10 157 of 79 198) of the required information size for placebo-controlled trials and active-controlled trials, respectively. These results indicate that there is still insufficient evidence on cardiovascular events.

WHAT IS NEW AND CONCLUSION

GLP-1 receptor agonists do not seem to show any increased risk of cardiovascular events However, the available data from RCTs remain insufficient to confirm an absence of detrimental effect. More long-term trials and population-based studies are required to provide the necessary reassurance on the cardiovascular safety of GLP-1 receptor agonists.

Progressive elevation of ap-1 activity during preneoplastic-to-neoplastic progression as modeled in mouse jb6 cell variants

The JB6 mouse epidermal cell system has been used extensively as an in vitro model for the study of tumor promotion and progression. The present study was directed to assessing the role of basal AP-1 activity in JB6 variants which represent preneoplastic to neoplastic progression and to addressing whether AP-1 activity is required for maintenance of the tumor phenotype. Constitutively higher AP-1 activity was found in tumorigenic JB6 RT101 cells than in later or earlier preneoplastic P+ or P- cells. Levels of c-jun mRNA and protein correlated with progression stage. Enhancement of AP-1 activity by TPA increased the formation of anchorage independent colonies by tumorigenic RT101 cells. Inhibition of AP-1 activity by retinoic acid or fluocinolone acetonide inhibited expression of tumor phenotype as measured by AI growth. These data together with our previous results suggest that in the JB6 model (i) basal levels of Jun and AP-1 appear to be important for preneoplastic-to-neoplastic progression; (ii) induced AP-1 appears to be required for further progression by tumor cells; (iii) constitutively elevated AP-I activity may be important for the expression of transformed phenotype; (iv) inhibition of AP-1 activity by RA or FA is not a general suppression of transcription but is gene-specific; and (v) even though both inhibition of AP-1 activity and activation of RARE-dependent or GRE-dependent gene transcription correlate with inhibition of AI growth in RT101 cells by RA or FA, transactivation of RARE or GRE might better correlate with the inhibition of AI growth than the inhibition of AP-1 activity in RT101 cells.

Frequency of glycated hemoglobin monitoring was inversely associated with glycemic control of patients with Type 2 diabetes mellitus

BACKGROUND

The frequency of monitoring glycated hemoglobin (HbA(1c)) and its impact on glycemic control of Chinese Type 2 diabetes mellitus (T2DM) patients have not been well understood.

AIM

To explore the current status of the glycemic control, the frequency of HbA(1c) monitoring, and their relationship in T2DM outpatients in urban China.

SUBJECTS AND METHODS

A cross-sectional study was carried out in 15 hospitals purposely sampled from 4 cities of China. T2DM outpatients were consecutively recruited, and underwent a face-to-face interview in outpatient consulting rooms using a self-developed structured questionnaire to collect information. All consented patients were invited to have a free HbA(1c) test.

RESULTS

Among 1511 subjects, the average level of HbA(1c) was 8.1±1.6% with the ideal percents of 13.6% and 24.8% (HbA(1c)<6.5% and <7.0%, respectively). Less than 1/3 (339/1157) had received 2 or more HbA(1c) tests per yr, and they had a significantly lower average of HbA(1c) than those having only 1 or no test per yr (F=5.012, p=0.007). After adjustment for possible confounders including age, gender, and city, there was a significantly inverse association with adjusted odds ratios of 2.56 [95% confidence interval (CI): 1.71, 3.86] and 1.67 (95% CI: 1.11, 2.50), respectively, between the frequency of monitoring HbA(1c) (null, once vs ≥2 times per yr) and worse glycemic control (HbA(1c)≥7.0%).

CONCLUSIONS

Glycemic control of T2DM outpatients was poor in urban China. Frequency of HbA(1c) monitoring is seriously insufficient in majority of patients. Lower frequency of HbA(1c) monitoring is significantly associated with poor glycemic control.

Application of an ELISA-elution assay to dissociate digoxin-antibody complexes in immunoaffinity chromatography

In this study, we used a modified enzyme-linked immunosorbent assay (ELISA)-elution technique as a screening tool to select specific elution conditions. We examined 12 different elution conditions for the removal of antibodies from a complex on an ELISA plate; 0.2 mol/l glycine-HCl (pH 2.5), 1.0 mol/l acetic acid (pH 2.5), 25% methanol (pH 2.5) and 3 mol/l NaSCN showed a higher elution efficiency. We conducted affinity chromatography with these four conditions for the purification of anti-digoxin antibodies from hyperimmune sera with a digoxin-specific column using omega-aminoalkyl derivatives of Sepharose 4B, whose elution efficiency was similar to that of ELISA. We also monitored the relative specific activities during elution from the digoxin-specific column. The optimum, general-purpose dissociation reagent for this immunoaffinity system was identified as 25% methanol (pH 2.5) with an elution efficiency and relative specific activity of 88.40% and 62.25%, respectively. The high purity of the purified antibodies was demonstrated with sodium dodecyl sulphate-polyacrylamide gel electrophoresis.

Drug-metabolising enzyme polymorphisms and predisposition to anti-tuberculosis drug-induced liver injury: a meta-analysis

BACKGROUND

Although some case-control studies have investigated the association between drug-metabolising enzyme (DME) gene polymorphisms and susceptibility to anti-tuberculosis drug-induced liver injury (ATLI), their results are conflicting, mainly due to limited power.

OBJECTIVE

To review the literature systematically, by means of a meta-analytical review, to evaluate the putative association and provide a quantitative summary estimate on the association with ATLI.

DESIGN

We searched the databases of MEDLINE, PubMed, EMBASE and CBMdisc from 1966 to May 2007 using 'DME', 'hepatotoxicity', 'genetic polymorphism', 'genetic susceptibility' in combination with 'antitubercular agents', performed a manual search of citations from relevant original studies and review articles, and corresponded with authors.

RESULTS

Nine eligible articles were included in this meta-analysis, including five on N-acetyltransferase 2 (NAT2), four on cytochrome P450 2E1 (CYP2E1) and two on glutathione S-transferase (GST) studies, separately. The overall ORs of ATLI risk associated with NAT2 homozygous variant genotype (mt/mt), CYP2E1 homozygous wild genotype (*1A/*1A), GSTM1 homozygous null genotype (null/null) and GSTT1 homozygous null genotype (null/null) were respectively 1.93 (95%CI 0.81-4.62), 2.22 (95%CI 1.06-4.66), 2.62 (95%CI 1.45-4.75) and 1.18 (95%CI 0.61-2.29). In addition, the OR for Asian ATLI associated with the NAT2 homozygous variant (mt/mt) and the combined genotype (w/w + w/mt) was 2.52 (95%CI 1.49-4.26).

CONCLUSIONS

NAT2 mt/mt, CYP2E1*1A/*1A and GSTM1 null/null were observed to increase the risk of ATLI in tuberculosis patients. Our results support the hypothesis that NAT2 mt, CYP2E1*1A and GSTM1 null have a modest effect on genetic susceptibility to ATLI, but no significant evidence for GSTT1 null/null.

Fine mapping of E(kp)-1, a locus associated with silkworm (Bombyx mori) proleg development

The silkworm homeotic mutant E(kp) has a pair of rudimentary abdominal legs, called prolegs, in its A2 segment. This phenotype is caused by a single dominant mutation at the E(kp)-1 locus, which was previously mapped to chromosome 6. To explore the possible association of Hox genes with proleg development in the silkworm, a map-based cloning strategy was used to isolate the E(kp)-1 locus. Five E(kp)-1-linked simple sequence repeat markers on chromosome 6 were used to generate a low-resolution map with a total genetic distance of 39.5 cM. Four additional cleaved amplified polymorphic sequence markers were developed based on the initial map. The closest marker to E(kp)-1 was at a genetic distance of 2.7 cM. A high-resolution genetic map was constructed using nine BC1 segregating populations consisting of 2396 individuals. Recombination suppression was observed in the vicinity of E(kp)-1. Four molecular markers were tightly linked to E(kp)-1, and three were clustered with it. These markers were used to screen a BAC library. A single bacterial artificial chromosome (BAC) clone spanning the E(kp)-1 locus was identified, and E(kp)-1 was delimited to a region less than 220 kb long that included the Hox gene abdominal-A and a non-coding locus, iab-4. These results provide essential information for the isolation of this locus, which may shed light on the mechanism of proleg development in the silkworm and possibly in Lepidoptera.

Subthalamic nucleus stimulation for primary dystonia and tardive dystonia

With the renaissance of stereotactic pallidotomy for Parkinson's disease in 1990s, pallidotomy has become increasingly used as an effective treatment for various manifestations of medically refractory dystonia. More recently, deep brain stimulation of globus pallidus internus (GPi) has been replacing pallidotomy. Although GPi DBS has great promise for treating dystonia, there are some disadvantages. We introduce our experiences in subthalamic nucleus (STN) DBS for primary dystonia and tardive dystonia in this chapter. We propose that STN DBS has the following advantages over GPi DBS: (1) symptomatic improvement is seen immediately after stimulation, allowing us to quickly select the most suitable stimulation parameters; (2) the stimulation parameters for the STN are lower than those used for the GPi, resulting in longer battery life; and (3) STN DBS results in better symptomatic control than GPi DBS in dystonia patients when our STN data is compared to that obtained by others with using the GPi as the target. We suggest that STN DBS may be the most appropriate surgical technique for dystonia.

Decrease in density of INa is in the common final pathway to heart block in murine hearts overexpressing calcineurin

Overexpression of calcineurin in transgenic mouse heart results in massive cardiac hypertrophy followed by sudden death. Sudden deaths are caused by abrupt transitions from sinus rhythm to heart block (asystole) in calcineurin-overexpressing (CN) mice. Preliminary studies showed decreased maximum change in potential over time (d V/d tmax) of phase 0 of the action potential. Accordingly, the hypothesis was tested that decreased activity of the sodium channel contributes to heart block. Profound decreases in activity of sodium currents ( INa) paralleled the changes in action potential characteristics. Progressive age-dependent decreases were observed such that at 42–50 days of life little sodium channel function existed. However, this was not paralleled by decreased protein expression as assessed by immunocytochemistry or by Western blot. Since calcineurin can interact with the ryanodine receptor, we assessed whether chronic in vitro treatment with BAPTA-AM, thapsigargin, and ryanodine could rescue the decrease of INa. All of these treatments rescued INa to levels indistinguishable from wild type. The nonspecific PKC inhibitor bisindolylmaleimide I also rescued the decrease of INa. To assess whether decreased sodium channel activity contributes to sudden death in vivo, the response to encainide (20 mg/kg) was assessed: 6 of 10 young CN mice died because of asystole, whereas 0 of 10 wild-type mice died ( P < 0.01). Moreover, encainide produced exaggerated prolongation of the QRS width in sinus beats before the heart block. Catecholamine tone appears necessary to support life in older CN mice because propranolol (1 mg/kg) triggered asystolic death in five of six CN mice. We conclude that decrease in sodium channel activity is in the common final pathway to asystole in CN mice.

[Adverse drug reaction and rational use of levofloxacin: a prospective study]

OBJECTIVE

To study the rate of adverse drug reaction(ADR) and the rational use of levofloxacin among in-patients.

METHOD

All in-patients treated with levofloxacin were prospectively observed in 7 hospitals of Beijing.

RESULTS

One hundred and five ADR cases were found in 2,661 patients injected with levofloxacin. The ADR rate was 3.9% while 4.8% of them were classified as severe cases. All severe ADR cases had a nature of double infections. The ADR occurrence was related to older age, irrational drug use, combined medicine and allergic history. The rate of levofloxacin irrational use was 19.9%, especially in the elderly population, due to too long or too short course of treatments.

CONCLUSION

Levofloxacin is viewed as a safe injection in clinical practice, however, combined medicine and elderly patients should be paid more attention when on administration of this medication. The irrational use of levofloxacin was recognized as one of the main reasons causing the increase of ADR.

Bid is cleaved by calpain to an active fragment in vitro and during myocardial ischemia/reperfusion

Reperfusion after myocardial ischemia is associated with a rapid influx of calcium, leading to activation of various enzymes including calpain. Isolated perfused adult rabbit hearts subjected to global ischemia and reperfusion were studied. Calpain or a calpain-like activity was activated within 15 min after reperfusion, and preconditioning suppressed calpain activation. In contrast, caspase activation was not detected although cytochrome c was released after ischemia and reperfusion. The pro-apoptotic BH3-only Bcl-2 family member, Bid, was cleaved during ischemia/reperfusion in the adult rabbit heart. Recombinant Bid was cleaved by calpain to a fragment that was able to mediate cytochrome c release. The calpain cleavage site was mapped to a region within Bid that is extremely susceptible to proteolysis. These findings suggest that there is cross-talk between apoptotic and necrotic pathways in myocardial ischemia/reperfusion injury.

Ultrasound detection of blunt splenic injury

The purpose of this study was to determine the sensitivity of emergency ultrasound (US) for the detection of blunt splenic injury (BSI), and to describe sonographic parenchymal patterns. Over 3 years, 2138 emergency US were performed, and 162 patients had BSI. CT was performed for 76 patients, and there were 86 laparotomies. Seventy patients (43%) had concomitant intraabdominal injuries. Ultrasound detected free fluid in 109 patients (67%), and parenchymal injury in 31 patients (19%). There were 48 false negative US (30%). Sonographic patterns included a diffuse heterogeneous appearance, hyperechoic and hypoechoic perisplenic crescents, and discrete hypoechoic or hyperechoic areas within the spleen. Overall sensitivity of US for detection of BSI was 69%, but was 86% for grade III or higher injuries. Ultrasound is most sensitive for the detection of grade III or higher BSI based on the presence of haemoperitoneum. Ultrasound may also identify BSI on the basis of parenchymal abnormality, with a diffuse heterogeneous pattern most commonly encountered. Sonographic evaluation for both free fluid and parenchymal injury improves sensitivity of US.

[The relationship of low density lipoprotein receptor gene polymorphism and hyperlipidemia]

OBJECTIVE

To study the relationship of low density lipoprotein receptor gene polymorphism and hyperlipidemia in the population with essential hypertension.

METHODS

People with different lipid levels including 107 hyperlipidemia, 104 at margin level and 108 normal were recruited in the study. Their polymorphisms of LDL-R gene were analyzed using PCR-RFLP.

RESULTS

There were three kinds of genotype: (+/+), (+/-), (-/-). In male, the frequencies of the (+/-) in three study groups were shown as follows: 41.18% in hyperlipidemia, 46.15% in margin level, 19.05% in normal lipid. The frequency of (+) allele was significantly higher in hyperlipidemia than that in normal lipid (24.51%, 25.00% and 11.11%, respectively). In women, the differences were not statistically significant. The nonconditional univariate and multivariate logistic regression analysis demonstrated that (+) allele of Ava II polymorphism of LDL-R was a genetic marker of male's hypercholesterolemia.

CONCLUSIONS

The frequency of (+/-) hyperlipidemia in males was higher than that in normal lipid group and the (+) allele in male hyperlipidemia was significantly more frequent seen than that in normal lipid group. These results suggested that polymorphisms of LDL-Rgene might play an independent role of risk factor for hyperlipidemia.

Single subject research designs for disability research

PURPOSE

The objective of this article is to offer an overview of single subject designs and provide clinicians with information regarding the components of single subject designs and how they can be used in clinical and other rehabilitation environments.

METHOD/RESULT

Three basic designs in single subject research are presented, with corresponding examples illustrating each design. A review of visual and statistical analysis techniques commonly used in single subject designs is provided, and the advantages and limitations of each are noted.

CONCLUSION

Single subject designs are ideally suited for research in the rehabilitation practice environment. If properly applied, these designs can help establish the efficacy of rehabilitation practice and contribute to rehabilitation science.

Radio-frequency electrocautery ablation of mammary tissue in swine

PURPOSE

To establish the size, configuration, and histopathologic features of acute, subacute, and chronic radio-frequency (RF) electrocautery of mammary tissue in swine.

MATERIALS AND METHODS

Eighteen RF treatments were performed in the mammary tissue of three domestic swine under ultrasonographic (US) guidance. Histopathologic examination was performed immediately after (acute animal); 2 weeks after (subacute animal); and 4 weeks after (chronic animal) treatment.

RESULTS

In the acute animal, lesions were firm nodules on palpation and had a distinct line of demarcation between necrotic and viable mammary tissue (mean lesion volume, 14.24 cm(3); largest volume, 29.06 cm(3)). In the subacute animal, there was diffuse coagulation necrosis with neutrophilic infiltrates at the periphery (mean lesion volume, 6.46 cm(3); largest volume, 9.47 cm(3)), and two treatment areas had a secondary bacterial infection. In the chronic animal, lesions were still palpable and firm (mean lesion volume, 11.67 cm(3); largest volume, 25.5 cm(3)), and five of six treatment sites had an area of gray to white fibrotic tissue that blended with the surrounding tissue. However, one site had a pale yellow area of central necrosis surrounded by a fibrotic area. In both the subacute and chronic animals, two and one treatment site, respectively, had minimal areas of skin necrosis.

CONCLUSION

RF ablation of breast tissue is feasible in this animal model. Problems included minimal skin erythema, residual firm treatment regions at 4 weeks, slightly variable margins of coagulation necrosis, and occasional bacterial infection.

[Community -based comprehensive prevention and control of hypertension in China (CCPACH Study)-prevalence and epidemiological characteristics in urban and rural area]

OBJECTIVE

To understand the epidemiological features and prevalence of essential hypertension in the rural communities.

METHODS

A community-based survey on essential hypertension was carried out in urban and rural areas involving 280,000 population.

RESULTS

The prevalence rate of hypertension in age 35 years and over was 31.7% and 32.9% in urban and rural respectively; the average age of the patients' in urbans was significantly higher than in rural areas. Among non-hypertensive cases, more than 50% of the population having risk factors of hypertension in both urban and rural areas. Rates of treatment and control awareness of hypertension were 56.3%, 26.8% and 4.4% respectively in urban; comparing to 40.3%, 17.5% and 2.6% respectively, in the rural areas. More than half of the diagnosed patients before survey did not take antihypertensive medicine for treatment in both areas. The proportions the classification of hypertension were similar in both areas with majority of them, mild and isolated systolic hypertension.

CONCLUSIONS

It was demonstrated that there is an urgent need to carry out comprehensive prevention and control for hypertension in urban and rural area.

[Evaluation on the effect of Benazepril for hypertension through postmarketing surveillance]

OBJECTIVE

To evaluate the efficacy and safety of Benazepril used among the essential hypertensives.

METHODS

1 831 essential hypertensive patients aged 35 to 75 were randomly selected from a community and followed for 18 months. The level of blood pressure, status of taking Benazepril and side effects were sequencially collected.

RESULTS

1/3 of the patients had taken antihypertensive drug before the study and the rate of compliance was over 96%. The effective rate of Benazepril was 73.6% at three months and increased to 84.7% at 18 months. Comparing with the baseline data, SBP and DBP declined 10.8 mmHg and 6.7 mmHg respectively. The rate of side effect was 22.7%. Cough was most commonly seen among side effects. The peak of first recording on side effect occurred at three months including 60% of them mild.

CONCLUSION

Results showed that Benazepril had good efficacy and safety for the essential hypertension patients in a long-term observation.

[Evaluation on the effects of community-based comprehensive prevention and control of hypertension in the rural areas in China]

OBJECTIVE

To explore the strategies and measures of community-based comprehensive prevention and control of hypertension in the rural areas.

METHODS

Community-based comprehensive prevention and control of hypertension was put in practice in 120,000 people in Fangshan District of Beijing during the period of "The Ninth Five-Year Plan (1996 - 2000)".

RESULTS

After intervention, blood pressure of the whole subjects were under control and kept the level of baseline data; the rate of increase of prevalence in the intervention areas was below the rate of that from 1979 to 1991 in China (the former was 14.7%, while the latter was 53.7%); the incidence rate of the subjects was 1.4%, close to the average rate of age 15 and above in China; the rates of awareness, treatment and control were above the levels of baseline data; SBP and DBP of the patients decreased by 2.9% and 5.6%, respectively; while the rate of having high risk factors reduced by 13.4% on average.

CONCLUSION

The community-based comprehensive strategies and measures played an important and effective role in prevention and control of hypertension in rural areas.

[An genetic epidemiology study of MTHFR gene and blood level (sibpair linkage analysis)]

OBJECTIVE

To explore the relationship between MTHFR gene and blood pressure.

METHODS

A total of 142 sibpairs were collected from rural communities of CCPACH. MTHFR gene genotypes were determined by an assay based on the polymerase chain reaction. Phenotype of this study was the level of blood pressure. Covariates were measured by questionnaire, physical examination and clinical indices. Sibpair linkage analysis was used to analyse data by SAGE software.

RESULTS

In this study, prevalence of TT genotype of MTHFR gene was 9.3%, while CT was 41%. There was no evidence for linkage of the MTHFR gene with either systolic or diastolic blood pressure identified.

CONCLUSION

In our study population, MTHFR gene did not seem to be not related to blood pressure.

[A case-control study on the relationship between abnormal homocysteine metabolism and essential hypertension]

OBJECTIVE

To examine the relationship between abnormal homocysteine metabolism and essential hypertension in a Chinese population, a community-based case-control study was conducted.

METHODS

127 essential hypertensive patients aged 35 to 75 were randomly selected from a community. Another 170 control subjects with blood pressure < 140/90 mmHg were selected from the same community. Serum homocysteine was determined using HPLC. Folate and vitamin B(12) were measured by radioimmunoassay. MTHFR genotypes were identified by PCR and restriction fragment length polymorphism analysis with Hinf I digestion.

RESULTS

After adjusting for age and sex, the mean homocysteine level was 10.56 micromol/L for hypertensive patients and 10.34 micromol/L for controls (F = 0.234, P = 0.63). No association between either SBP or DBP and Hcy concentration was found in subjects without anti-hypertensive medications. The prevalence of homozygousity for thermolabile MTHFR variant for this population was 13.1%, and the mutant allele frequency was 38.7%. There was no significant difference on genotype distributions and the mutant allele frequency for the two studied groups. However, the concentrations of folate and B(12) for the hypertensive subjects were generally higher than the controls.

CONCLUSIONS

The present study did not discover that the elevation of Hcy levels or MTHFR mutation were independent risk factors for essential hypertension. The higher folate and B(12) in the hypertensive subjects might contribute to a lower risk.

[The epidemiological characteristics of multiple metabolic disorders in hypertensive patients in the communities]

OBJECTIVES

To describe the epidemiological characteristics of multiple metabolic disorders on hypertensive patients living in the communities.

METHODS

The characteristics of metabolic disorders in the hypertensives from one community in Shanghai urban area were analyzed. Metabolic disorders would include dyslipidemia (high cholesterol and/or high triglycerides and/or low HDL cholesterol), diabetes and obesity.

RESULTS

59.2% of the hypertensives at least had one metabolic disorder. Proportionally, 83.9%, 15.5%, 0.6% of the patients would combine one, two, or all of the disorders. The percentages of patients combined with dyslipidemia, diabetes and obesity were 53.0%, 9.7%, 6.3%, respectively. 74.0% of patients with metabolic disorders were combined with dyslipidemia while 9.1% were combined with both dyslipidemia and diabetes. The standardized prevalence rate of male patients with metabolic disorders was 58.1%, higher than the rate of women (54.5%). The prevalence rate of postmenopausal female patients with metabolic disorders was 67.6%, significantly higher than that of the premenopausal women (44.4%) (chi(2) = 37.49, P < 0.01).

CONCLUSION

Nearly 60% of the total patients combined with metabolic disorders. Dyslipidemia occurred in more than half of the patients in total. The proportion of senile patients with metabolic disorders was higher than the younger patients. Results suggested that attempts to maintain the coronary heart disease at low levels in the population should include treatment of dyslipidemia to keep lipid and diabetes prevalence at low levels other than regular antihypertensive therapy.

Genomic structure of the human p47-phox (NCF1) gene

The cytosolic factor p47-phox, encoded by the NCF1 gene, is an essential component of the phagocyte NADPH-oxidase system. Upon activation of this multicomponent system, p47-phox translocates to the membrane and participates in the electron transfer from NADPH to molecular oxygen. A deficiency or absence of p47-phox is the most common autosomal form of chronic granulomatous disease (CGD). We have cloned and characterized the NCF1 gene from four bacteriophage clones, a P1 clone and genomic DNA from normal individuals. The gene is 15,236 base pairs long and includes 11 exons. It is 98.6% homologous in sequence to at least one pseudogene that maps to the same region of chromosome 7q11.23. Slightly more than half (50.37%) of the wild-type NCF1 gene consists of repetitive elements. In particular, the density of Alu sequences is high (1.4 Alu/kb); there are 21 Alu repeats interspersed through 10 introns. These findings are consistent with the observation that recombination events between the wild-type gene and its highly homologous pseudogenes account for the majority of potentially lethal mutations in p47-phox-deficient chronic granulomatous disease. Analysis of 1.96 kb of sequence 5' of the start of translation revealed a high homology (99.6%) between wild-type and pseudogene clones. Characterization of NCF1 establishes a foundation for detailed molecular analysis of p47-phox-deficient CGD patients as well as for the study of the regulation of the NCF1 gene and pseudogenes, both of which are present as full-length transcripts in normal individuals.

Differentially expressed protein Pdcd4 inhibits tumor promoter-induced neoplastic transformation

An mRNA differential display comparison of mouse JB6 promotion-sensitive (P+) and -resistant (P-) cells identified a novel gene product that inhibits neoplastic transformation. The JB6 P+ and P- cells are genetic variants that differ in their transformation response to tumor promoters; P+ cells form anchorage-independent colonies that are tumorigenic, and P- cells do not. A differentially displayed fragment, A7-1, was preferentially expressed in P- cells at levels >/=10-fold those in P+ cells, making its mRNA a candidate inhibitor of neoplastic transformation. An A7-1 cDNA was isolated that was identical to murine Pdcd4 gene cDNAs, also known as MA-3 or TIS, and analogous to human H731 and 197/15a. Until now, the function of the Pdcd4 protein has been unknown. Paralleling the mRNA levels, Pdcd4 protein levels were greater in P- than in P+ cells. Pdcd4 mRNA was also expressed at greater levels in the less progressed keratinocytes of another mouse skin neoplastic progression series. To test the hypothesis that Pdcd4 inhibits tumor promoter-induced transformation, stable cell lines expressing antisense Pdcd4 were generated from parental P- cells. The reduction of Pdcd4 proteins in antisense lines was accompanied by acquisition of a transformation-sensitive (P+) phenotype. The antisense-transfected cells were reverted to their initial P- phenotype by overexpression of a Pdcd4 sense fragment. These observations demonstrate that the Pdcd4 protein inhibits neoplastic transformation.

E1A can provoke G1 exit that is refractory to p21 and independent of activating cdk2

E1A can evoke G1 exit in cardiac myocytes and other cell types by displacing E2F transcription factors from tumor suppressor "pocket" proteins and by a less well-characterized p300-dependent pathway. Bypassing pocket proteins (through overexpression of E2F-1) reproduces the effect of inactivating pocket proteins (through E1A binding); however, pocket proteins associate with a number of molecular targets apart from E2F. Hence, pocket protein binding by E1A might engage mechanisms for cell cycle reentry beyond those induced by E2F-1. To test this hypothesis, we used adenoviral gene transfer to express various E2F-1 and E1A proteins in neonatal rat cardiac myocytes that are already refractory to mitogenic serum, in the absence or presence of several complementary cell cycle inhibitors-p16, p21, or dominant-negative cyclin-dependent kinase-2 (Cdk2). Rb binding by E2F-1 was neither necessary nor sufficient for G1 exit, whereas DNA binding was required; thus, exogenous E2F-1 did not merely function by competing for the Rb "pocket." E2F-1-induced G1 exit was blocked by the "universal" Cdk inhibitor p21 but not by p16, a specific inhibitor of Cdk4/6; p21 was permissive for E2F-1 induction of cyclins E and A, but prevented their stimulation of Cdk2 kinase activity. In addition, E2F-1-induced G1 exit was blocked by dominant-negative Cdk2. Forced expression of cyclin E induced endogenous Cdk2 activity but not G1 exit. Thus, E2F-1-induced Cdk2 function was necessary, although not sufficient, to trigger DNA synthesis in cardiac muscle cells. In contrast, pocket protein-binding forms of E1A induced G1 exit that was resistant to inhibition by p21, whereas G1 exit via the E1A p300 pathway was sensitive to inhibition by p21. Both E1A pathways-via pocket proteins and via p300-upregulated cyclins E and A and Cdk2 activity, consistent with a role for Cdk2 in G1 exit induced by E1A. However, p21 blocked Cdk2 kinase activity induced by both E1A pathways equally. Thus, E1A can cause G1 exit without an increase in Cdk2 activity, if the pocket protein-binding domain is intact. E1A also overrides p21 in U2OS cells, provided the pocket protein-binding domain is intact; thus, this novel function of E1A is not exclusive to cardiac muscle cells. In summary, E1A binding to pocket proteins has effects beyond those produced by E2F-1 alone and can drive S-phase entry that is resistant to p21 and independent of an increase in Cdk2 function. This suggests the potential involvement of other endogenous Rb-binding proteins or of alternative E1A targets.

[Excimer laser photorefractive keratectomy for lower to moderate myopia: 5 year follow-up]

OBJECTIVE

To evaluate the long-term effectiveness and safety of photorefractive keratectomy (PRK) for patient with lower to moderate myopia.

METHODS

148 myopic eyes (-1.5 to -6.00 D) after PRK follow-up of more than 5 years were analyzed.

RESULTS

Uncorrected visual acuity was >or= 1.0 in 136 eyes (91.9%), >or= 0.8 in 4 eyes (2.7%) and >or= 0.6 in 8 eyes (5.4%). The mean spherical equivalent change was from (-4.43 +/- 0.97) D to (-0.12 +/- 0.22) D, and the keratometric power (K value) was reduced from (43.81 +/- 1.10) D to (41.36 +/- 1.30) D in the 5 years of follow-up (P < 0.01).

CONCLUSION

The long-term effectiveness of PRK for myopia (-1.5 to -6.00 D) is satisfactory.

Diminished G1 checkpoint after gamma-irradiation and altered cell cycle regulation by insulin-like growth factor II overexpression

High levels of insulin-like growth factor II (IGFII) mRNA expression are detected in many human tumors of different origins including rhabdomyosarcoma, a tumor of skeletal muscle origin. To investigate the role of IGFII in tumorigenesis, we have compared the mouse myoblast cell line C2C12-2.7, which was stably transfected with human IGFII cDNA and expressed high and constant amounts of IGFII, to a control cell line C2C12-1.1. A rhabdomyosarcoma cell line, RH30, which expresses high levels of IGFII and contains mutated p53, was also used in these studies. IGFII overexpression in mouse myoblast C2C12 cells causes a reduced cycling time and higher growth rate. After gamma-irradiation treatment, C2C12-1.1 cells were arrested mainly in G0/G1 phase. However, C2C12-2.7 and RH30 cells went through a very short G1 phase and then were arrested in an extended G2/M phase. To verify further the effect of IGFII on the cell cycle, we developed a Chinese hamster ovary (CHO) cell line with tetracycline-controlled IGFII expression. We found that CHO cells with high expression of IGFII have a shortened cycling time and a diminished G1 checkpoint after treatment with methylmethane sulfonate (MMS), a DNA base-damaging agent, when compared with CHO cells with very low IGFII expression. It was also found that IGFII overexpression in C2C12 cells was associated with increases in cyclin D1, p21, and p53 protein levels, as well as mitogen-activated protein kinase activity. These studies suggest that IGFII overexpression shortens cell cycling time and diminishes the G1 checkpoint after DNA damage despite an intact p53/p21 induction. In addition, IGFII overexpression is also associated with multiple changes in the levels and activities of cell cycle regulatory components following gamma-irradiation. Taken together, these changes may contribute to the high growth rate and genetic alterations that occur during tumorigenesis.