[Clinical characteristics and prognosis in papillary thyroid carcinoma patients with recurrent laryngeal nerve invasion]

Objective: To investigate the clinical characteristics and risk factors of postoperative recurrence in papillary thyroid carcinoma (PTC) patients with recurrent laryngeal nerve (RLN) invasion. Methods: The data of PTC patients with recurrent laryngeal nerve invasion treated in Beijing Tongren Hospital, Capital Medical University from January 2006 to December 2019 were retrospectively analyzed. The acoustic parameters were compared between different subgroups. Kaplan-Meier method was used to calculate the overall survival (OS) and the recurrence-free rate (RFS), and univariate and multivariate Cox regression analyses were performed to determine the risk factors for postoperative recurrence. Results: A total of 150 PTC patients were enrolled in the final analysis, including 102 females and 48 males, with an average age of (53.5±13.7) years, and 62 patients (41.3%) aged over 55 years. There were 88 cases with stage Ⅰ, and 62 cases with stage Ⅲ. Fifty-five patients presented with preoperative vocal cord paralysis. There were 75 cases appearing adhesion between tumor or lymph node and recurrent laryngeal nerve while 75 cases presented with direct invasion. The comparisons of acoustic parameters showed that patients with RLN invasion had higher jitter compared with patients without RLN invasion [2.3% (1.4%, 3.2%) vs 1.8% (0.8%, 2.6%), P<0.001]. Moreover, patients with preoperative vocal cord paralysis (VCP) had higher jitter[3.1% (2.2%, 4.6%) vs 2.0% (1.1%, 2.8%), P<0.001] and shimmer [7.1% (4.9%, 9.9%) vs 5.5% (4.2%, 7.3%), P<0.001] and shorter maximum phonation time (MPT) [8.0 (6.0, 10.0) s vs 12.0 (10.0, 15.3) s, P<0.001] compared with patients without preoperative VCP. However, there was no statistical difference in acoustic parameters between cases with RLN adhesion and RLN invasion (all P>0.05). Postoperative follow-up time ranged between 12-196 months, with an average of (65.0±35.9) months. Sixteen patients (10.7%) had recurrence or metastasis, and 8 cases (5.3%) died of recurrence or metastasis. The 5-year OS rate was 95.1%, and the 10-year OS rate was 92.8%. The 5-year RFS rate was 88.9%, and the 10-year RFS rate was 86.2%. Univariate Cox analysis showed that age of onset ≥ 55 years, preoperative recurrent laryngeal nerve palsy, laryngeal, trachea or esophageal invasion were the risk factors for postoperative recurrence of PTC with RLN invasion (all P<0.05). Multivariate Cox analysis showed that age of onset ≥ 55 years (OR=1.060, 95%CI: 1.011-1.110, P=0.015) was an independent risk factor. Conclusions: Age of onset ≥ 55 years is an independent risk factor for postoperative recurrence in PTC patients with RLN invasion. Preoperative acoustic parameters may provide reference for evaluation of RLN function.

[A single-arm prospective study on induction chemotherapy and subsequent comprehensive therapy for advanced hypopharyngeal squamous cell carcinoma: report of 260 cases in a single center]

Objective: To study the significance of induction chemotherapy and subsequent comprehensive therapy for overall survival rate (OS) and larynx dysfunction-free survival rate (LDFS) in patients with advanced hypopharyngeal carcinoma. Methods: Patients who met the inclusion criteria with the diagnoses of advanced hypopharyngeal carcinoma between 2011 and 2017 received 2 or 3 cycles of TPF regimen induction chemotherapy. Patients who attained complete response (CR) received radical chemotherapy. Patients who attained partial response (PR) and the reduction of tumor volume was more than 70% were defined as large PR and received concurrent chemoradiotherapy. When the tumor volume reduction of PR patients was less than 70%, they were defined as small PR. (CR+large PR) group was defined as effective group. Patients who did not reach CR and large PR were defined as uneffective group and underwent radical surgery and received adjuvant radiotherapy as appropriate after the surgery. The end points of the study were OS, progression-free survival (PFS) and LDFS. Chi-square (χ(2)) test was used for correlation analysis. Survival analysis was performed by the Kaplan-Meier method with a Log-rank test. Cox proportional hazards model was used for univariate and multivariate survival analysis. Results: A total of 260 patients were enrolled in the study. The follow-up period ranged from 5 to 83 months, with an average of 24.7 months. The 3-year and 5-year OS rate was 46.0% and 32.6%, respectively. The 3-year and 5-year PFS rate was 41.0% and 26.6%, respectively. The 3-year and 5-year LDFS rate was 37.9% and 24.8%, respectively. Poor outcome of induction chemotherapy, advanced N stage, strong positive Ki-67 immunohistochemistry (all P<0.001) were negative prognostic factors. The advanced clinical stage was positively related to the poor outcome of induction chemotherapy (P=0.015). There was no significant difference in OS and PFS between the large PR group and the small PR group (all P>0.005). Conclusion: TPF regimen induction chemotherapy and subsequent comprehensive therapy for patients with advanced hypopharyngeal carcinoma may improve the quality of life of patients, with high OS rate and LDFS rate.

[Analysis for potential targeting genes of TPF regimen induction chemotherapy in hypopharyngeal squamous cell carcinoma]

Objective: To analyze the differentially expressed genes related to the chemosensitivity with the TPF regimen for hypopharyngeal squamous cell carcinoma and to measure potential functional targeting genes expressions. Methods: Twenty-nine patients with primary hypopharyngeal cancer who underwent induction chemotherapy with TPF from January 2013 to December 2017 in Beijing Tongren Hospital were enrolled for microarray analysis, including 28 males and 1 female, aged from 43 to 73 years old. Among them, 16 patients were sensitive to chemotherapy while 13 patients were non-sensitive. Illumina Human HT-12 Bead Chip was applied to analyze the gene expressions and online bioinformatics analysis was used to analyze the differentially expressed genes. Reverse transcription and quantitative real-time PCR (RT-qPCR) was used to measure the mRNA expression of potential functional genes of TPF induction chemotherapy in 43 samples, 29 from original patients and 14 from additional patients. Graphpad prism 7.0 software was used for statistical analysis. Results: A total of 1 381 significantly differentially expressed genes were screened out. By GO analysis, up-regulated genes included sequestering in extracellular matrix, chemokine receptor binding and potassium channel regulator activity; down-regulated genes included regulation of angiogenesis, calcium ion binding and natural killer cell activation involved in immune response. With KEGG database analysis, down-regulated pathways included ECM-receptor interaction and peroxisome and up-regulated pathways included Glutathione metabolism and PPAR signaling pathway. The expressions of CD44 and IL-6R were significantly different and appeared biologically significant. CD44 was significantly upregulated in insensitive tissues (0.54±0.06) compared with sensitive tissues (0.33±0.04)(P<0.01). IL-6R was significantly downregulated in insensitive tissues (0.44±0.03) compared with sensitive tissues. (0.68±0.03) (P<0.01). Conclusion: CD44 and IL-6R may be potentially functional genes of TPF induction chemotherapy in hypopharyngeal squamous cell carcinoma.

Integrated analysis of different mRNA and miRNA profiles in human hypopharyngeal squamous cell carcinoma sensitive and resistant to chemotherapy

The purpose of this study was to identify potential miRNAs and mRNAs involved in chemotherapy insensitivity in hypopharyngeal squamous cell carcinoma (HSCC) and to explore the underlying mechanisms involved to provide diagnostic markers and therapeutic targets for HSCC. We used microarrays to identify differences in both the mRNA and miRNA expression profiles between a group (twelve patients) sensitive to chemotherapy and a resistant group (nine patients). We then employed bioinformatics tools to examine the functions and pathways involved. The genes and miRNAs most related to chemotherapy sensitivity in HSCC were screened. Finally, a miRNA-mRNA-phenotype network was constructed with an integrated analysis based on the identified miRNAs and mRNAs. Nine differentially expressed miRNAs and one hundred differentially expressed mRNAs were identified, and the functions of these genes and miRNAs were predicted. Bioinformatics analysis revealed a regulatory network consisting of eight genes and two miRNAs that influenced HSCC chemosensitivity. According to our analysis, CCL4L1 may be a potential molecular marker for HSCC chemotherapy, and excess CCL4L1 leads to the upregulation of PRAME and the downregulation of miR-375, thus decreasing HSPB8 expression and promoting chemotherapy sensitivity. Our work provides reliable data for further studies investigating the mechanism of HSCC chemotherapy sensitivity.

[Clinical observation of isolated immunoglobulin G4-related sclerosing cholangitis and immunoglobulin G4 sclerosing cholangitis combined autoimmune pancreatitis]

Objective: To compare and analyze patient's general condition, laboratory testing and therapeutic responses of isolated immunoglobulin G4- related sclerosing cholangitis (IgG4-SC) and immunoglobulin G4 sclerosing cholangitis combined autoimmune pancreatitis (IgG4-SC/AIP). Methods: A retrospective study was conducted on IgG4-SC patients who attended outpatient and inpatients department of our hospital from April 2014 to March 2018 and their demographic characteristics, laboratory testing, and therapeutic responses were statistically analyzed. Normal distribution of continuous variables was compared with t-test, non-normal distribution of continuous variables was compared using the Mann-Whitney U test, and the categorical variables were compared with χ (2) test. Results: 29 IgG4-SC patients were included, including 19-isolated IgG4-SC and 10 IgG4-SC combined AIP (IgG4-SC/AIP). The average age of onset in the isolated IgG4-SC group was (46.06±19.03) years which was lower than IgG4-SC/AIP group (62.60±15.11), t = -2.360, P < 0.05. The median IgG4 in IgG4-SC/AIP patients is higher than that in isolated IgG4-SC, respectively 10.87 (3.73 ~ 20.13) and 3.14 (2.37 ~ 4.78)g/L(U = 159.000, P < 0.05). IgG4/IgG ratio is higher in IgG4-SC/AIP, than that in isolated IgG4-SC, respectively 0.62(0.23 ~ 0.86) and 0.16(0.10 ~ 0.21), U = 130.000, P < 0.05. Liver cirrhosis was more common in isolated IgG4-SC group (47%) than the IgG4-SC/AIP group (0), χ (2) = 9.637, P < 0.05. The median biochemical response time of isolated IgG4-SC group was 3.00 (2.00 to 4.00) months, which was longer than 1.00 (1.00 to 1.25) months of IgG4-SC/AIP group, U = 30.000, P < 0.05. The biochemical recurrence rate of isolated IgG4-SC group was 32%, which was lower than that of IgG4-SC/AIP (χ (2) = 6.461, P < 0.05). Conclusion: Serum IgG4 level and IgG4/IgG ratio were higher in patients with IgG4-SC/AIP group, and therapeutic responses in isolated IgG4-SC patients were worse than that of IgG4-SC/AIP patients. The efficacy of glucocorticoid monotherapy and immunosuppressive agents combined with glucocorticoid therapy demonstrated no considerable difference in IgG4-SC patients.

[A preliminary analysis on potentially targeted genes of induced chemotherapy in supraglottic laryngeal squamous cell carcinoma]

OBJECTIVE

To analyze the differentially expressed genes produced by paclitaxel, cisplatin and 5-fluorouracil(TPF) regimen induction chemotherapy and the potentially functionally targeted genes of the induced chemotherapy in supraglottic laryngeal squamous cell carcinoma.

METHODS

A total of 11 tissue samples from patients diagnosed as supraglottic carcinoma who didn't receive any treatment before were analyzed with microarray. The patients were divided into two groups based on their responses to the induction chemotherapy: 7 were sensitive to chemotherapy and 4 were non-sensitive. Gene expressions were detected by Illumina Human HT-12 BeadChip. The bioinformatics analysis online was used to analyze the differentially expressed genes.

RESULTS

A total of 1 554 differentially expressed genes related to chemosensitivity were found. Analyzed with GO database, the up-regulated genes included the functional sets of biological adhesion, immune system development and stem cell proliferation, and the down-regulated genes included the functional sets of cell junction organization, phosphorus metabolic process and cell morphogenesis involved in differentiation. Analyzed with KEGG database, the up-regulated pathways included p53, cell adhesion and Ras signaling pathways, and the down-regulated pathways included focal adhesion, endocytosis and ErbB signaling pathways. There were statistically significant differences in the expressions of MAPK10, PIK3R5 and JUN genes, which had biological significance, between sensitive patients and non-sensitive patients.

CONCLUSION

MAPK10, PIK3R5 and JUN may be considered as potentially functional genes of the induced chemotherapy in supraglottic carcinoma.

[Establishment and characterization of a laryngeal squamous cell carcinoma cell line]

Objective: To establish a laryngeal squamous cell carcinoma (LSCC) cell line through primary cell culture and observe its biological characteristics. Methods: Tissue block culture method was used for primary cell culture. After LSCC cells passed 25 times in vitro, the morphology of cells was observed, keratin was stained histochemically, cell cycle was tested by PI-FACS, and the specie of cells was detected by PCR and short tandem repeat(STR) typing. Results: This newly established LSCC cell line was named as TR-LCC-1, most of the cancer cells were polygonal shape, like the cobblestone, loss of contact inhibition and with overlapping growth. Cell size was large and cell pleomorphism was very obvious. Cytokeratin staining was positive. After 6 months of continuous culture in vitro, the TR-LCC-1 cells passed more than 30 times, and cell doubling time was 201.2h. Cell cycle assay indicated that G1 phase accounted for 51.71%, S phase was 44.56%, and G2 phase was 2.28%. Mycoplasma test showed no mycoplasma contamination. Cell species identification identified TR-LCC-1 was human-derived cells. STR detection showed P26 and P6 were same, and they were different from the STR typing of disclosed cells. Conclusion: The establish ment of the new laryngeal squamous carcinoma cell line TR-LCC-1 can be helpful to the research for laryngeal squamous cell cancer.

Emerging technologies to measure neighborhood conditions in public health: implications for interventions and next steps

Adverse neighborhood conditions play an important role beyond individual characteristics. There is increasing interest in identifying specific characteristics of the social and built environments adversely affecting health outcomes. Most research has assessed aspects of such exposures via self-reported instruments or census data. Potential threats in the local environment may be subject to short-term changes that can only be measured with more nimble technology. The advent of new technologies may offer new opportunities to obtain geospatial data about neighborhoods that may circumvent the limitations of traditional data sources. This overview describes the utility, validity and reliability of selected emerging technologies to measure neighborhood conditions for public health applications. It also describes next steps for future research and opportunities for interventions. The paper presents an overview of the literature on measurement of the built and social environment in public health (Google Street View, webcams, crowdsourcing, remote sensing, social media, unmanned aerial vehicles, and lifespace) and location-based interventions. Emerging technologies such as Google Street View, social media, drones, webcams, and crowdsourcing may serve as effective and inexpensive tools to measure the ever-changing environment. Georeferenced social media responses may help identify where to target intervention activities, but also to passively evaluate their effectiveness. Future studies should measure exposure across key time points during the life-course as part of the exposome paradigm and integrate various types of data sources to measure environmental contexts. By harnessing these technologies, public health research can not only monitor populations and the environment, but intervene using novel strategies to improve the public health.

Neighborhood Socioeconomic Deprivation and Geographic Heterogeneity of Tobacco Environment in Missouri

Purpose: To examine neighborhood characteristics associated with geographic distribution of tobacco sale outlets in Missouri. Methods: We obtained the addresses of tobacco outlets in Missouri from the Missouri Department of Mental Health. We geocoded these addresses and computed the outlet density by 5-digit ZIP codes. Using the data from the 2008–2012 American Community Survey, we developed a ZIP Code Tabulation Area (ZCTA)-level socioeconomic deprivation (SED) index. We analyzed the relationships of tobacco outlet density with neighborhood SED index and five separate socioeconomic indicators (%population with less than high school, %population unemployed, %households below the poverty, % population under the poverty, and %African Americans). Results: There were more than 5,000 tobacco retailers within Missouri in January, 2014. The number of tobacco retailers ranged from 0 to 56 (median = 2) per ZIP code, while tobacco outlet density ranged from 0 to 29 per 1,000 persons age 18+ (median: 1.18). Tobacco outlet density was significantly correlated with neighborhood SED (rho = 0.21, P &lt; 0.001). The consistency of quartiles of both variables was also statistically significant (weighted Kappa = 0.11, P &lt; 0.001). Logistic regression analysis indicated that neighborhood SED was associated with more than 3 times higher odds of denser tobacco outlets (&gt;median density) (the most vs. least deprived quartile: odd ratio = 3.24, 95% confidence interval = 2.26–4.65). Similar results were also found for each of the five individual socioeconomic indicators. Conclusion: Geographic distribution of tobacco retailing outlets was strongly associated with neighborhood SED environment. Neighborhoods with greater SED condition were also more likely to have a higher density of tobacco retailing outlets in Missouri. Our finding implies that higher accessibility to tobacco retailing outlets might play an important role in geographic SED disparity in smoking. Future studies should examine the degree to which neighborhood SED effect on smoking behaviors is mediated by higher accessibility to tobacco retailing outlets. This insight can help policy-makers develop appropriate geographic priority to effectively allocate tobacco control programs to reduce cigarette smoking in Missouri.

Hospital and geographic variability in two colorectal cancer surgery outcomes: complications and mortality after complications

BACKGROUND

The purpose of this study was to describe hospital and geographic variation in 30-day risk of surgical complications and death among colorectal cancer (CRC) patients and the extent to which patient-, hospital-, and census-tract-level characteristics increased risk of these outcomes.

METHODS

We included patients at least 66 years old with first primary stage I-III CRC from the 2000-2005 National Cancer Institute's Surveillance, Epidemiology, and End Results data linked with 1999-2005 Medicare claims. A multilevel, cross-classified logistic model was used to account for nesting of patients within hospitals and within residential census tracts. Outcomes were risk of complications and death after a complication within 30 days of surgery.

RESULTS

Data were analyzed for 35,946 patients undergoing surgery at 1,222 hospitals and residing in 12,187 census tracts; 27.2 % of patients developed complications, and of these 13.4 % died. Risk-adjusted variability in complications across hospitals and census tracts was similar. Variability in mortality was larger than variability in complications, across hospitals and across census tracts. Specific characteristics increased risk of complications (e.g., census-tract-poverty rate, emergency surgery, and being African-American). No hospital characteristics increased complication risk. Specific characteristics increased risk of death (e.g. census-tract-poverty rate, being diagnosed with colon (versus rectal) cancer, and emergency surgery), while hospitals with at least 500 beds showed reduced death risk.

CONCLUSIONS

Large, unexplained variations exist in mortality after surgical complications in CRC across hospitals and geographic areas. The potential exists for quality improvement efforts targeted at the hospital and/or census-tract levels to prevent complications and augment hospitals' ability to reduce mortality risk.

Are neighborhood conditions associated with HIV management?

OBJECTIVES

HIV infection has become a manageable chronic disease as a result of treatment advances. Secondary prevention efforts have proved inadequate to reduce the estimated incidence of new HIV infections. Epidemiological data suggest that geographical clustering of new HIV infections is a common phenomenon, particularly in urban areas among populations of low socioeconomic status. This study aimed to assess the relationship between neighbourhood conditions and HIV management and engagement in high-risk behaviours.

METHODS

During routine out-patient HIV clinic visits, 762 individuals from the St Louis metropolitan area completed behavioural assessments in 2008. Biomedical markers were abstracted from their medical records. Multi-level analyses were conducted based on individuals' census tracts.

RESULTS

The majority of the sample were male and African American. In the adjusted models, individuals residing in neighbourhoods with higher poverty rates were more likely to have lower CD4 cell counts and be current smokers. In neighbourhoods with higher rates of unemployment, individuals were less likely to have a current antiretroviral prescription. In more racially segregated neighbourhoods, individuals reported more depressive symptoms.

CONCLUSIONS

Despite the advances in HIV disease management, neighbourhood characteristics contribute to disparities in HIV care. Interventions that address neighbourhood conditions as barriers to HIV management may provide improved health outcomes.

AC electrothermal manipulation of conductive fluids and particles for lab-chip applications

AC electrokinetics has shown great potential for microfluidic functions such as pumping, mixing and concentrating particles. So far, electrokinetics are typically applied on fluids that are not too conductive (<0.02 S/m), which excludes most biofluidic applications. To solve this problem, this paper seeks to apply AC electrothermal (ACET) effect to manipulate conductive fluids and particles within. ACET generates temperature gradients in the fluids, and consequently induces space charges that move in electric fields and produce microflows. This paper reports two new ACET devices, a parallel plate particle trap and an asymmetric electrode micropump. Preliminary experiments were performed on fluids with conductivity at 0.224 S/m. Particle trapping and micropumping were demonstrated at low voltages, reaching approximately 100 microm/s for no more than 8 Vrms at 200 kHz. The fluid velocity was found to depend on the applied voltage as V(4), and the maxima were observed to be approximately 20 microm above the electrodes.

[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.

Factors affecting broadband ultrasound attenuation results of the calcaneus using a gel-coupled quantitative ultrasound scanning system

This study aimed to assess the factors that may influence the distribution and description of broadband ultrasound attenuation (BUA) and to identify specific criteria for diagnostic consideration when collecting BUA reference data. Two hundred Caucasian women (aged 20-79 years) without a history of atraumatic fractures or medicines known to affect bone metabolism were selected for this study. Medical and menstrual history, medication usage, family history of osteoporosis (FHO), physical activity, activities of daily living (ADL), dietary calcium intake, as well as smoking and alcohol consumption were obtained. Broadband ultrasound attenuation (BUA, dB/MHz) was determined in the right foot using a new gel-coupled ultrasound system. BUA was significantly associated with age (p<0.001), body weight (p<0.001), level of physical activity (p = 0.024) and dietary calcium intake (p = 0.023). Smoking, alcohol and coffee consumption and ADL were not associated with BUA (p>0.05). There were no differences in BUA (p>0.05) between those women who reported taking medications or had diseases (known to not affect bone metabolism), were using contraceptives, taking vitamin/mineral supplements and/or had traumatic fractures and their counterparts who did not report these characteristics. Premenopausal women with a FHO had significantly lower BUA values compared with those without a FHO (p = 0.013). When those participants with a FHO were removed from the sample, the peak BUA value was 1.1-4.4% higher and the variability (SD) was reduced by about 3.3-9.3% depending on which age range was used to define the peak BUA value. Consequently, an additional 4.5% of the population were classified as having a T-score <-2. Our results suggest that the impact on BUA of risk factors such as a FHO, body weight, physical activity and dietary calcium intake is similar to that on bone mineral density obtained by dual-energy X-ray absorptiometry (DXA), and thus provides further information on the comparability of quantitative ultrasound and DXA for assessment of risk of fracture. The criteria for calculating the T-score need further study to determine whether young adults with FHO should be included and what cutoff age range should be used in collecting peak values of quantitative ultrasound parameters.

The influence of stress on edentulous maxillary bone with different artificial anterior tooth arrangements by three-dimensional photoelasticity

OBJECTIVE

To investigate the influence of stress on edentulous maxillary bone different artificial anterior tooth arrangements, with the goal to establish theoretical evidence for optimal anterior tooth arrangements in complete denture restoration.

MATERIALS AND METHODS

Three-dimensional photoelasticity experimental stress analysis was conducted. Shear stresses were measured and principal stresses were separated into six different models of maxillary central incisor arrangements.

RESULTS

The value of maximum stresses and the absolute values of principal stresses and positive stresses were obtained. The distribution curve of shear stresses and principal stresses was also shown.

CONCLUSIONS

The horizontal distance between the incisive papilla center and the incisal margin of the maxillary central incisor should be no more than 8 mm, if the anterior mandibular arch is larger than the maxillary arch. The principal stress is a better indicator of stress on edentulous maxillary bone when load is applied at the protrusive occlusal position.

Effects of thrombolytic therapy on recanalization in different starting time of treatment after acute myocardial infarction

OBJECTIVE

To investigate the effects of thrombolytic therapy on recanalization in different starting time of treatment after acute myocardial infarction.

METHODS

172 cases with intravenous thrombolytic agents were divided into 4 groups: < or = 2 hours, > 2-4 hours, > 4-6 hours and > 6-12 hours, according to the different starting time of therapy after onset of symptoms.

RESULTS

The recanalization rates were 78.6%, 74%, 39. 6% and 14.3% in < or = 2 hours, > 2-4 hours, > 4-6 hours and > 6-12 hours, respectively. The recanalization rate within 4 hours was significantly higher than those in the groups of > 4-6 hours AND > 6-12 hours. The time interval from the initiation of thrombolytic therapy to reperfusion was increased as the starting time of thrombolysis after onset of symptoms was delayed.

CONCLUSIONS

Starting time of thrombolysis within 4 hours after onset of acute myocardial infarction is of the best effect on recanalization.