Risk factors for sessile serrated lesions among Chinese patients undergoing colonoscopy

BACKGROUND AND AIM

Serrated polyps have been recognized as a premalignant lesion accounting for a significant proportion of colorectal cancer. Limited data are available regarding the risk factors for colorectal sessile serrated lesions (SSLs). We aimed to investigate clinical risk factors of SSLs and compared them with colorectal adenomas in a study population of Chinese individuals.

METHODS

A retrospective case-control study was performed in an academic tertiary-referral center in Hong Kong. Subjects with SSLs and adenomas were identified from the hospital pathology database from January 2010 to December 2020, and additional clinical data were retrieved from the electronic patient record system. We compared clinical features and risk factors of SSL patients with those without these lesions.

RESULTS

A total of 2295 subjects were included in the study, including 459 subjects with SSLs, 918 subjects with adenomas, and 918 subjects with normal colonoscopy. By multivariable logistic regression, compared with normal subjects, patients with SSLs only were significantly more likely to have dyslipidemia (adjusted OR: 1.431, 95% CI 1.008-2.030) and diabetes mellitus (adjusted OR: 2.119, 95% CI 1.439-3.122).

CONCLUSIONS

Dyslipidemia and diabetes were independent risk factors for SSLs. Our findings suggest these metabolic factors may be important for the risk of SSLs. The findings may improve our understanding of SSLs and shed light on patient selection for screening and risk stratification.

The E2F1-HOXB9/PBX2-CDK6 axis drives gastric tumorigenesis and serves as a therapeutic target in gastric cancer

Homeobox genes include HOX and non-HOX genes. HOX proteins play fundamental roles during ontogenesis by interacting with other non-HOX gene-encoded partners and performing transcriptional functions, whereas aberrant activation of HOX family members drives tumorigenesis. In this study, gastric cancer (GC) expression microarray data indicated that HOXB9 is a prominent upregulated HOX member in GC samples significantly associated with clinical outcomes and advanced TNM stages. However, the functional role of HOXB9 in GC remains contradictory in previous reports, and the regulatory mechanisms are elusive. By in silico and experimental analyses, we found that HOXB9 was upregulated by a vital cell cycle-related transcription factor, E2F1. Depleting HOXB9 causes G1-phase cell cycle arrest by downregulating CDK6 and a subset of cell cycle-related genes. Meanwhile, HOXB9 contributes to cell division and maintains the cytoskeleton in GC cells. We verified that HOXB9 interacts with PBX2 to form a heterodimer, which transcriptionally upregulates CDK6. Knocking down CDK6 can phenocopy the tumor-suppressive effects caused by HOXB9 depletion. Blocking HOXB9 can enhance the anti-tumor effect of CDK6 inhibitors. In conclusion, we elucidate the oncogenic role of HOXB9 in GC and reveal CDK6 as its potent downstream effector. The E2F1-HOXB9/PBX2-CDK6 axis represents a novel mechanism driving gastric carcinogenesis and conveys prognostic and therapeutic implications. © 2023 The Pathological Society of Great Britain and Ireland.

Cancer-associated fibroblasts potentiate colorectal cancer progression by crosstalk of the IGF2-IGF1R and Hippo-YAP1 signaling pathways

Colorectal cancer (CRC) is one of the most common cancers worldwide. The tumor microenvironment exerts crucial effects in driving CRC progression. Cancer-associated fibroblasts (CAFs) serve as one of the most important tumor microenvironment components promoting CRC progression. This study aimed to elucidate the novel molecular mechanisms of CAF-secreted insulin-like growth factor (IGF) 2 in colorectal carcinogenesis. Our results indicated that IGF2 was a prominent factor upregulated in CAFs compared with normal fibroblasts. CAF-derived conditioned media (CM) promoted tumor growth, migration, and invasion of HCT 116 and DLD-1 cells. IGF1R expression is significantly increased in CRC, serving as a potent receptor in response to IGF2 stimulation and predicting unfavorable outcomes for CRC patients. Apart from the PI3K-AKT pathway, RNA-seq analysis revealed that the YAP1-target signature serves as a prominent downstream effector to mediate the oncogenic signaling of IGF2-IGF1R. By single-cell RNA sequencing (scRNA-seq) and immunohistochemical validation, IGF2 was found to be predominantly secreted by CAFs, whereas IGF1R was expressed mainly by cancer cells. IGF2 triggers the nuclear accumulation of YAP1 and upregulates YAP1 target signatures; however, these effects were abolished by either IGF1R knockdown or inhibition with picropodophyllin (PPP), an IGF1R inhibitor. Using CRC organoid and in vivo studies, we found that cotargeting IGF1R and YAP1 with PPP and verteporfin (VP), a YAP1 inhibitor, enhanced antitumor effects compared with PPP treatment alone. In conclusion, this study revealed a novel molecular mechanism by which CAFs promote CRC progression. The findings highlight the translational potential of the IGF2-IGF1R-YAP1 axis as a prognostic biomarker and therapeutic target for CRC. © 2022 The Pathological Society of Great Britain and Ireland.

Serrated neoplasia in the colorectum: gut microbiota and molecular pathways

Colorectal cancer (CRC) is a heterogeneous disease with different gene expression patterns. There are two major colorectal carcinogenesis pathways: conventional adenoma-carcinoma pathway and alternative serrated neoplasia pathway. Apart from the conventional pathway that is typically initiated by characteristic APC mutation and chromosomal instability, the serrated neoplasia pathway is mainly characterized by mutations of BRAF or KRAS, microsatellite instability (MSI), and CpG island methylator phenotype (CIMP). Despite the malignant potential of serrated lesions, they can be easily overlooked during endoscopy screening and even in pathological assessment due to its anatomical location, morphology, and histological features. It has been shown that environmental factors especially the gut microbial composition play a key role in CRC pathogenesis. Thus, the preferential localization of serrated lesions in specific intestine areas suggest that niche-specific microbiota composition might intertwined with host genetic perturbations during the development of serrated lesions. Although serrated lesions and conventional adenomas are biologically different, most studies have focused on conventional adenomas, while the pathophysiology and role of microorganisms in the development of serrated lesions remain elusive. In this review, we discuss on the role of gut microbiota in the serrated neoplasia pathway of colorectal carcinogenesis and its specific clinical and molecular features, and summarize the potential mechanisms involved.

Characterization of key amino acid substitutions and dynamics of the influenza virus H3N2 hemagglutinin

The annual epidemics of seasonal influenza is partly attributed to the continued virus evolution. It is challenging to evaluate the effect of influenza virus mutations on evading population immunity. In this study, we introduce a novel statistical and computational approach to measure the dynamic molecular determinants underlying epidemics using effective mutations (EMs), and account for the time of waning mutation advantage against herd immunity by measuring the effective mutation periods (EMPs). Extensive analysis is performed on the sequencing and epidemiology data of H3N2 epidemics in ten regions from season to season. We systematically identified 46 EMs in the hemagglutinin (HA) gene, in which the majority were antigenic sites. Eight EMs were located in immunosubdominant stalk domain, an important target for developing broadly reactive antibodies. The EMs might provide timely information on key substitutions for influenza vaccines antigen design. The EMP suggested that major genetic variants of H3N2 circulated in Southeast Asia for an average duration of 4.5 years (SD 2.4) compared to a significantly shorter 2.0 years (SD 1.0) in temperate regions. The proposed method bridges population epidemics and molecular characteristics of infectious diseases, and would find broad applications in various pathogens mutation estimations.

Research Trends on Clinical Helicobacter pylori Eradication: A Bibliometric Analysis from 1983 to 2020

BACKGROUND

Numerous studies related to Helicobacter pylori (H. pylori) eradication have been published since the discovery of H. pylori. This study aimed to use a quantitative method to assess the development of this field.

MATERIALS AND METHODS

We performed a search of related articles from Web of Science published in 1983-2020 using a combination of the search terms "H. pylori" and "eradication". Eligible studies were included after a two-stage screening process, and the following data were extracted: title, author, institution, country, study type, sample size, eradication regimen, publication year, number of citations, journal, and H-index.

RESULTS

A total of 1402 studies were finally identified. The results showed that the period from 1994-2003 was the most influential period in this field. Italy and the USA were dominant countries in this field, while China's publication number increased sharply in the last ten years. Baylor College of Medicine was the most influential institution. Alimentary Pharmacology Therapeutics was the most productive journal. The effects of H. pylori eradication on peptic ulcers and gastric cancer and H. pylori eradication therapy were the most cited topics in this field. After the publish of Maastricht/Florence Ⅳ guideline, the research of quadruple therapy was more than triple therapy. Bismuth-containing quadruple therapy became the most focused regimen after Maastricht/Florence Ⅴ guideline.

CONCLUSIONS

In this study, we summarized the characteristics of the publications; identified the most influential countries, institutions, journals; identified the popular research topics and eradication regimen of clinical H. pylori eradication.

Delay in liver transplantation referral for adolescents with biliary atresia transitioning to adult care: a slippery slope

We compared the waitlist mortality of 114 adolescent (12–17 years) and 217 adult (≥ 18 years) biliary atresia candidates, and the post-transplant survival of 117 adolescent and 160 adult biliary atresia liver transplant recipients using Scientific Registry of Transplant Recipients data (2002-2018). After adjusting for Model for End-stage Liver Disease score (P = 0.001) and ascites, portal vein thrombosis, encephalopathy, life support at listing (all P ≥ 0.09), adults demonstrated 10.9 times higher risk of waitlist mortality vs. adolescents (95 per cent c.i. 1.55 to 76.46; P = 0.02). Adolescents exhibited superior patient (P = 0.007) and graft survival (P = 0.006).

[A birth cohort study of the association between prenatal serum bisphenol A concentration and infant neurobehavior development]

Objective: To explore the association between maternal bisphenol A (BPA) exposure during pregnancy and neurobehavioral development in infant. Methods: Participants were from the Ma'anshan Birth Cohort, which was established from October 2008 to October 2010 based on four municipal medical and health institutions in Ma'anshan. High-performance liquid chromatography-tandem mass spectrometry was applied for the determination of serum BPA concentration in 1 783 pregnant women sampled at their first filing, and during 2.97 to 28.1 months age of the infants. Neurobehavioral development were assessed by 0-6-year-old pediatric examination table of neuropsychological development. Generalized linear model was used to analyze the association between serum BPA levels during pregnancy and infants' neurobehavioral development. Results: A total of 931 mother-child pairs had complete data on serum BPA detection during pregnancy and assessment of infants' neurobehavioral development status. The age of pregnant women at their first filing was (26.67±3.45) years old, and the M (P₂₅,P₇₅) of serum BPA concentration (ng/ml) was 0.23 (0.11, 0.52), with a detection rate of 84.1% (783/931). The age of infants was (13.18±5.46) months, and 53.5% (498) were boys. The developmental quotient scores of large motor, fine motor, adaptive ability, language ability and social behaviors of infants were (97.88±16.32), (97.16±15.35), (99.64±15.47), (95.3±16.04) and (98.95±14.76) points, respectively. Generalized linear model showed that after adjusting for factors such as delivery mode, feeding mode, family per capita monthly income, preterm delivery, gender, maternal age, residence, pre-pregnancy body mass index and residence time, serum BPA level in pregnancy was negatively associated with infant's development of social behavior [β (95%CI):-2.42 (-4.71, -0.12)]. The post-stratification analysis by infant age revealed that the serum BPA level in pregnancy was only negatively associated with the development of language and social behavior developmental quotient scores in infants between the ages of 12 and 18 months, with β (95%CI) about -6.66 (-13.06, -0.25) and -7.401 (-12.97, -1.83), respectively. Conclusion: BPA exposure during pregnancy affects language and social behavior development in infants, and the detection window is between 12 and 18 months old of the infant.

Anaesthesia use in catheter ablation for atrial fibrillation: a systematic review and meta-analysis of observational studies

Objectives

This meta-analysis and systematic review seeks to compare both characteristic parameters and procedural outcomes of atrial fibrillation (AF) catheter ablation in patients under general anaesthesia (GA)/deep sedation and mild/moderate sedation.

Background

Catheter ablation has become a widely applied intervention for treating symptomatic AF and arrhythmias that are refractory to medical therapy. It can be conducted through from mild sedation to GA.

Methods

PubMed and Embase were searched up to July 2018 for randomised controlled trials, cohort and observational studies that assessed the outcomes of catheter ablation under GA/deep sedation or mild/moderate sedation. Nine studies were included in this meta-analysis after screening with the inclusion and exclusion criteria. Heterogeneity between studies and publication bias was evaluated by I² index and Egger's regression, respectively.

Results

Our meta-analysis found catheter AF ablation with GA/deep sedation to be associated with reduced risk of recurrence (RR: 0.79, 95% CI 0.56 to 1.13, p=0.20) and complications (RR: 0.95, 95% CI 0.64 to 1.42, p=0.82), though statistically insignificant. In terms of procedural parameters, there was no significant difference between the two groups for both procedural time (SMD: -0.13, 95% CI -0.90 to 0.63, p=0.74) and fluoroscopy time (SMD: -0.41, 95% CI -1.40 to 0.58, p=0.41). Univariate meta-regression did not reveal any covariates as a moderating factor for complication and recurrence risk.

Conclusion

Apart from an increased likelihood of procedural success, ablation by GA/deep sedation was found to be non-significantly different from the mild/moderate sedation approach in both procedural parameters and outcome measures.

[Association between early pregnancy bisphenol A exposure and sleep problems among preschool children]

Objective: To analyze the association between maternal bisphenol A exposure during early pregnancy and sleep problems among preschool children. Methods: Research subjects were from one of the sub-cohorts(Ma'anshan Cohort) of the China-Anhui Birth Cohort Study (C-ABCS) in Ma'anshan city. The basic situation of pregnant women and sleep information of preschool children were investigated. We selected preschool children whose mother's maternal serum bisphenol A concentrations of the first trimester had been already detected between December 2012 to Januray 2014. 1 259 pairs of mothers and children were included. The concentrations of bisphenol A exposure during early pregnancy were divided into low, medium and high exposure groups according to 25(th) percentile (P(25)) and 75(th) percentile (P(75)) levels. Multivariate multinomial logistic regression model was used to analyze the association between maternal bisphenol A exposure during early pregnancy and sleep-related problems in preschool children. Results: The P(50) (P(25)-P(75)) of serum bisphenol A exposure level during early pregnancy was 0.231 (0.106-0.512) ng/ml. The sleep-related problems scores of 1 259 preschool children were (16.43±3.82) points. The occasional sleep-related problems were detected about 47.8% (602 cases) and frequent sleep-related problems were detected about 18.3% (230 cases). After the adjustment of the confounding factors such as children's gender, age, BMI, sleep position (lying down, sleeping on one's back), the length of time to sleep and the length of sleep at night, in comparison with bisphenol A low exposure group, the OR (95%CI) value of preschool children with occasional sleep-related problems in maternal bisphenol A high exposure group during early pregnancy was 1.44 (1.01-2.06). After the gender stratification, the results showed that in comparison with bisphenol A low exposure group, the OR (95%CI) value of preschool girls with occasional sleep-related problems in maternal bisphenol A medium and high exposure group during early pregnancy were 1.61 (1.05-2.46) and 2.40 (1.42-4.04), respectively. The OR (95%CI) value of preschool girls with frequent sleep-related problems in maternal bisphenol A high exposure group during early pregnancy was 2.64 (1.34-5.17). However, in boys, there was no statistically significant association between maternal bisphenol A exposure during early pregnancy and sleep-related problems (P>0.05). Conclusion: Maternal bisphenol A exposure during early pregnancy might be related to sleep-related problems in preschool children.

Reduced lysosomal clearance of autophagosomes promotes survival and colonization of Helicobacter pylori

Evasion of autophagy is key for intracellular survival of bacteria in host cells, but its involvement in persistent infection by Helicobacter pylori, a bacterium identified to invade gastric epithelial cells, remains obscure. The aim of this study was to functionally characterize the role of autophagy in H. pylori infection. Autophagy was assayed in H. pylori-infected human gastric epithelium and the functional role of autophagy was determined via genetic or pharmacological ablation of autophagy in mouse and cell line models of H. pylori infection. Here, we showed that H. pylori inhibited lysosomal function and thereby promoted the accumulation of autophagosomes in gastric epithelial cells. Importantly, inhibiting autophagosome formation by pharmacological inhibitors or genetic ablation of BECN1 or ATG5 reduced H. pylori intracellular survival, whereas inhibition of lysosomal functions exerted an opposite effect. Further experiments demonstrated that H. pylori inhibited lysosomal acidification and the retrograde trafficking of mannose-6-phosphate receptors, both of which are known to positively regulate lysosomal function. We conclude that H. pylori subverts autophagy into a pro-survival mechanism through inhibition of lysosomal clearance of autophagosomes. Disruption of autophagosome formation offers a novel strategy to reduce H. pylori colonization in human stomachs. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Long non-coding RNAs in melanoma

Melanoma is the most lethal cutaneous cancer with a highly aggressive and metastatic phenotype. While recent genetic and epigenetic studies have shed new insights into the mechanism of melanoma development, the involvement of regulatory non-coding RNAs remain unclear. Long non-coding RNAs (lncRNAs) are a group of endogenous non-protein-coding RNAs with the capacity to regulate gene expression at multiple levels. Recent evidences have shown that lncRNAs can regulate many cellular processes, such as cell proliferation, differentiation, migration and invasion. In the melanoma, deregulation of a number of lncRNAs, such as HOTAIR, MALAT1, BANCR, ANRIL, SPRY-IT1 and SAMMSON, have been reported. Our review summarizes the functional role of lncRNAs in melanoma and their potential clinical application for diagnosis, prognostication and treatment.

Potential and use of bacterial small RNAs to combat drug resistance: a systematic review

Background

Over the decades, new antibacterial agents have been developed in an attempt to combat drug resistance, but they remain unsuccessful. Recently, a novel class of bacterial gene expression regulators, bacterial small RNAs (sRNAs), has received increasing attention toward their involvement in antibiotic resistance. This systematic review aimed to discuss the potential of these small molecules as antibacterial drug targets.

Methods

Two investigators performed a comprehensive search of MEDLINE, EmBase, and ISI Web of Knowledge from inception to October 2016, without restriction on language. We included all in vitro and in vivo studies investigating the role of bacterial sRNA in antibiotic resistance. Risk of bias of the included studies was assessed by a modified guideline of Systematic Review Center for Laboratory Animal Experimentation (SYRCLE).

Results

Initial search yielded 432 articles. After exclusion of non-original articles, 20 were included in this review. Of these, all studies examined bacterial-type strains only. There were neither relevant in vivo nor clinical studies. The SYRCLE scores ranged from to 5 to 7, with an average of 5.9. This implies a moderate risk of bias. sRNAs influenced the antibiotics susceptibility through modulation of gene expression relevant to efflux pumps, cell wall synthesis, and membrane proteins.

Conclusion

Preclinical studies on bacterial-type strains suggest that modulation of sRNAs could enhance bacterial susceptibility to antibiotics. Further studies on clinical isolates and in vivo models are needed to elucidate the therapeutic value of sRNA modulation on treatment of multidrug-resistant bacterial infection.

Combinatorial epigenetic deregulation by Helicobacter pylori and Epstein-Barr virus infections in gastric tumourigenesis

Epigenetic mechanisms, including DNA methylation, histone modifications, chromatin remodelling and microRNAs, convert environmental signals to transcriptional outputs but are commonly hijacked by pathogenic microorganisms. Recent advances in cancer epigenomics have shed new light on the importance of epigenetic deregulation in Helicobacter pylori- and Epstein-Barr virus (EBV)-driven gastric tumourigenesis. Moreover, it is becoming apparent that epigenetic mechanisms interact through crosstalk and feedback loops, which modify global gene expression patterns. The SWI/SNF remodelling complexes are commonly involved in gastric cancers associated with H. pylori or EBV through different mechanisms, including microRNA-mediated deregulation and genetic mutations. While H. pylori causes epigenetic silencing of tumour-suppressor genes to deregulate cellular pathways, EBV-positive tumours exhibit a widespread and distinctive DNA hypermethylation profile. Given the early successes of epigenetic drugs in haematological malignancies, further studies are mandated to enrich and translate our understanding of combinatorial epigenetic deregulation in gastric cancers into interventional strategies in the clinic. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

MEMS-based flow cytometry: microfluidics-based cell identification system by fluorescent imaging

This study utilizes MEMS technology to realize a novel low-cost microfluidics-based biochip system for flow-type cell handling. Powered by vacuum pump, the microfluidic driving system enables cells to move in order one by one in the biochip by an effect of sheath flow prefocus. Then, cells are guided to a fluorescent inspection region where two detection tasks such as cell image identification and cell counting are conducted. Currently, the glass-based biochip has been manufactured and all the related devices have been well set up in our laboratory. With this proposed prototype system, typical results about cell separation of yeast cell and PC-3 cell are available and their separated images are also presented, respectively.

Cloning and characterization of the Cu/Zn superoxide dismutase of Trichinella pseudospiralis

Copper/zinc (Cu/Zn) superoxide dismutase (SOD) activity was identified for the first time in both crude somatic extracts (CE) and excretory/secretory (E/S) products of Trichinella pseudospiralis. It was the dominant SOD in infective-stage larvae. Native polyacrylamide gel electrophoresis of CE and E/S products yielded a prominent band, which was cyanide-sensitive and was partly inhibited by hydrogen peroxide in SOD assay. Cytosolic Cu/Zn SOD was cloned. The 471-bp full-length cDNA sequence contained an open reading frame of 157 amino acids. The gene contained three introns. Quantitative reverse transcription-polymerase chain reaction indicated that the expression of cytosolic Cu/Zn SOD was substantially higher in infective-stage larvae than in adult worms. Cluster analysis showed that the sequence of the Cu/Zn SOD of T. pseudospiralis, an adenophorean nematode, is related to those of Brugia pahangi, Acanthocheilonema viteae, Onchocerca volvulus, and Haemonchus contortus (all belonging to the sercenentean group).

Descemet Membrane Detachment Caused by Hydrogen Peroxide Injury

OBJECTIVE

To describe a patient who developed a Descemet membrane detachment after hydrogen peroxide injury with successful reattachment by intracameral injection of sulfur hexafluoride gas.

METHODS

Case report.

RESULTS

The right eye of a 40-year-old man was exposed to 35% hydrogen peroxide. This resulted in a central corneal epithelial defect, corneal edema, a localized detachment of Descemet membrane, and a gas bubble between the posterior corneal stroma and Descemet membrane. The Descemet membrane detachment persisted after reabsorption of the gas bubble. Successful reattachment of Descemet membrane was achieved with injection of 0.15 mL of 20% sulfur hexafluoride gas into the anterior chamber.

CONCLUSION

Hydrogen peroxide ocular injury may cause Descemet membrane detachment, and successful reattachment may be achieved with intracameral injection of 20% sulfur hexafluoride gas.

Hepatoprotective action of an oleanolic acid-enriched extract of Ligustrum lucidum fruits is mediated through an enhancement on hepatic glutathione regeneration capacity in mice

The fruits of Ligustrum lucidum Ait. (FLL) were fractionated into petroleum ether (FLL-Pe), chloroform (FLL-Ch), butanol (FLL-Bu) and aqueous (FLL-Aq) fractions, of which FLL-Ch and FLL-Bu were found to be enriched with oleanolic acid (OLA). The in vivo antioxidant activities of various FLL fractions and OLA were assessed by examining the effect on carbon tetrachloride (CCl(4))-induced hepatotoxicity in mice. Pretreatment of animals with various FLL fractions could protect against CCl(4)-induced hepatotoxicity to a varying degree, with OLA-enriched FLL-Bu and FLL-Ch being more potent. However, a mortality rate of 60% was observed in the FLL-Ch pretreated and CCl(4)-intoxicated mice. OLA pretreatment also produced a dose-dependent protection against CCl(4) hepatotoxicity. The hepatoprotection afforded by FLL-Bu or OLA pretreatment was associated with an enhancement of hepatic-glutathione regeneration capacity (GRC). In contrast, the inability of FLL-Aq pretreatment to enhance hepatic GRC resulted in a failure to prevent CCl(4)-induced hepatic injury. The results suggest that the hepatoprotective action afforded by OLA-enriched FLL-Bu or OLA pretreatment may be mainly mediated by the enhancement of hepatic GRC, particularly under conditions of CCl(4)-induced oxidative stress.

[Clinical study on effect of sini decoction on ischemia/reperfusion injury by Holter monitoring in patients with acute myocardial infarction treated with thrombolytic therapy]

OBJECTIVE

To observe the clinical effect of Sini Decoction (SND) on ischemia/reperfusion injury in acute myocardial infarction (AMI).

METHODS

Randomized case-control clinical trial was conducted to observe the change of Holter monitoring in 22 cases of AMI treated with thrombolytic therapy before and after treatment.

RESULTS

The lasting time of acute ST segment, total burden of myocardial infarction, QRS score, QT dispersion and occurrence of reperfusion arrhythmia in patients received SND treatment were lower than those untreated with SND (P < 0.05).

CONCLUSION

SND is helpful in improving reperfusion injury of thrombolytic therapy in AMI patients.

[Mechanism of sini decoction in regulating beta-adrenergic receptor signal transduction in rats with myocardial ischemia]

OBJECTIVE

To investigate the effect of Sini Decoction (SND) on beta-adrenergic receptor (beta-AR) signal transduction in rats with myocardial ischemia.

METHODS

After beta-AR had been blocked by propranolol, the myocardial ischemia rats were established by pituitrin injection. The density of beta-AR in myocardial cell membrane was determined by radioligand binding assay, cAMP level in plasma and myocardial tissue was detected by radioimmunoassay (RIA), and the mRNA expression of beta 1-AR and beta 1-AR kinase (beta ARK-1) was measured by quantitative reverse transcriptase polymerase chain reaction (RT-PCR) amplifying assay.

RESULTS

In myocardial ischemia group, the density of beta 1-AR was up-regulated and the mRNA expression of beta ARK-1 increased (P < 0.01), but the cAMP level in plasma and myocardium was lower than that in the normal group (P < 0.01 and P < 0.05). SND could promote beta 1-AR mRNA expression and inhibit beta ARK-1 mRNA expression so as to increase the density of beta-AR and cause significant raising of cAMP level in plasma and myocardium.

CONCLUSION

SND could reduce the desensitization of beta 1-AR during myocardial ischemia and improve signal transduction of beta-AR.

Myocardial protection against ischaemia-reperfusion injury by a Polygonum multiflorum extract supplemented 'Dang-Gui decoction for enriching blood', a compound formulation, ex vivo

'Dang-Gui Decoction for Enriching the Blood' (BE), a traditional Chinese formulation comprising Angelica sinensis and Astragalus membranaceus, is used for stimulating red blood cell production as well as enhancing cardiovascular function. In the present study, we have demonstrated the myocardial protection afforded by BE pretreatment against ischaemia-reperfusion (IR) injury in isolated-perfused rat hearts. A more complete and potent myocardial protection against IR injury was also shown by a Polygonum multiflorum extract supplemented BE preparation (BEA). The results suggest that the more potent cardioprotective action of BEA may be related to its ability to sustain the myocardial glutathione antioxidant status under conditions of IR-induced oxidative stress, which may possibly in turn result from the synergistic interaction between the BE and Polygonum extract.

Myocardial protective effect of an anthraquinone-containing extract of Polygonum multiflorum ex vivo

An ethyl acetate extract of Polygonum multiflorum Thunb. (PME) was fractionated into an anthraquinone-containing (PME-I) and a non-anthraquinone-containing (PME-II) fraction. The effects of PME and its related extracts pretreatment on myocardial ischemia-reperfusion (IR) injury in isolated perfused rat hearts were examined. Pretreatment with PME extract or its anthraquinone-containing fraction produced a dose-dependent protection against myocardial IR injury, as evidenced by a significant decrease in the extent of LDH leakage as well as an improvement in contractile force recovery. The myocardial protection was found to be associated with an enhancement in myocardial glutathione antioxidant status, as indicated by significant reductions in both the extent of IR-induced reduced glutathione (GSH) depletion and inhibition of Se-glutathione peroxidase (GPX) and glutathione reductase (GRD) activities. Both alpha-tocopherol acetate (VE) and emodin (EMD) pretreatments protected against IR-induced myocardial injury as assessed by the decrease in the extent of LDH leakage. But the contractile force recovery of the ischemic-reperfused hearts prepared from VE or EMD pretreated animals was not improved. The more complete myocardial protection afforded by the anthraquinone-containing fraction of PME extract may be related to its ability to sustain the glutathione antioxidant status under the condition of IR-induced oxidative stress.

[Study on platelet-derived growth factor mRNA and copper-zinc superoxide dismutase mRNA expression changes of aortic artery endothelium with restenosis after aortic artery dilatation treated with buyang huanwu decoction]

OBJECTIVE

To study on dynamic mechanism of restenosis after PTCA treated with Buyang Huanwu Decoction (BYHWD).

METHODS

Twenty-eight male New Zealand rabbits with mimic restenosis after aortic artery dilatation were detected by prime in situ labeling in aortic endothelium. The items included gene expression of copper zinc superoxide dismutase (SOD-1) and platelet-derived growth factor receptor (PDGFR) mRNA to analyse dynamic mechanism of restenosis.

RESULTS

Seven days after aortic artery dilatation, PDGFR mRNA of aortic endothelium decreased clearly. The comparison between experimental and the control group showed significant difference (P < 0.05). By the same condition, the gene expression of SOD-1 was increasing, which showed a significant difference with the control group (P < 0.05).

CONCLUSIONS

BYHWD increased SOD-1 gene expression of artery endothelium, to improve oxygen feed for ischemia reperfusion in the same way, BYHWD suppressed PDGFR mRNA expression to control cellular pathological proliferation.

[Improvement of sini decoction on hemorheology following percutaneous transluminal coronary angioplasty]

OBJECTIVE

To study the hemorheological effects of Sini decoction on patients following percutaneous transluminal coronary angioplasty (PTCA).

METHODS

Forty-six patients were randomly divided into Sini decoction and control groups. The hemorheologic variables were determined before and after Sini decoction treatment.

RESULTS

No hemorheologic changes were observed in the patients (n = 23) only with PTCA, but the patients (n = 23) with Sini decoction were found to be significantly decreased in whole blood viscosity and red cell aggregation and dredging the blood of microcirculation as post-PTCA compared to pre-PTCA.

CONCLUSION

Sini decoction could improve the patient's hemorheology.

Isolation and characterization of a unique group of slowly growing mycobacteria: description of Mycobacterium lentiflavum sp. nov

A distinct group of slowly growing mycobacteria was identified on the basis of growth characteristics, biochemical and lipid profiles, and nucleic acid analyses. The isolates showed growth at 22 to 37 degrees C, yellow pigmentation, and negative tests for Tween 80 hydrolysis, nicotinic acid, nitrate reductase, and urease; tests for arylsulfatase, pyrazinamidase, and heat-stable catalase were variable. Analysis of cellular fatty acids by gas-liquid chromatography and mycolic acids by thin-layer chromatography and high-performance liquid chromatography indicated a distinctive pattern which was unlike those of other species. Determination of the 16S rRNA gene sequence showed a unique sequence closely related to Mycobacterium simiae and M. genavense. On the basis of DNA homology studies, we suggest that these organisms are representatives of a novel species, for which the name M. lentiflavum sp. nov. is proposed.

Studies on the agronomic characteristics, yield, and saikosaponin content of two Bupleurum species in Taiwan

Two Bupleurum species (Bupleurums spp.), i.e., B. falcatum L. cv. Tainung No. 1 and B. kaoi Liu, Chao, et Chuang, were compared for their differences in seed germination, plant characteristics and root yield, and saikosaponin content. Experimental data showed that the most suitable temperature for seed germination of the two species was 16 degrees C. Two treatments, cold stratification at 4 degrees C for 8 weeks and presoaking by running water for 2 days, resulted in higher germination rates. Tainung No. 1 possessed a higher 1,000-seed weight than B. kaoi. However, field survival rate was higher for B. kaoi than for Tainung No.1. Results from field experiments also revealed that stem diameter, leaf width and fresh weight of various plant parts except the root were superior for Tainung No. 1 to B. kaoi. On the contrary, tiller number and root diameter and weight of B. kaoi were higher than those of Tainung No. 1. Harvest data and elevation had significant effects on the agronomic performance of the two Bupleurum spp. Measurements of most traits of the 6 month-old plants were superior to those of the 3 and 10 month-old plants. Cultivation at higher elevation (850 m) favored the development of leaf weight and root length, while cultivation at lower elevation (85 m) facilitated the development of plant height, root diameter, and root weight. Analysis of saikosaponin concentration in the root tissue revealed that average contents of 3.19 and 3.80 mg/g, respectively, for plants grown at the elevations of 850 m and 85 m. Comparison between the two species showed no significant difference in saikosaponin content, ranging from 3.45 to 3.55 mg/g.

[Mechanisms responsible for protective effect of Sini decoction on ischemic myocardium in mice]

The possible mechanisms responsible for the protective effect of Sini decoction (SND) on the ischemic myocardium were studied on the mice model of pituitrin-induced myocardial ischemia in terms of free radical. Results indicated that SND significantly decreased the concentration of oxygen free radical and the content of malondialdehyde (MDA), increased nutritional blood flow and the activity of superoxide dismutase (SOD) in ischemic myocardium. These results suggested that three mechanisms whereby SND exerted its protective effects existed; improving the perfusion of ischemic myocardium, attenuating the injurious action of free radical and strengthening the free radical defense.

Effects of media, atmosphere, and incubation time on colonial morphology of Arcanobacterium haemolyticum

Arcanobacterium haemolyticum causes pharyngitis as well as skin and other wound infections. Although it is a beta-hemolytic organism, the hemolysis is less well defined than that of beta-hemolytic streptococci and may be overlooked in cultures with heavy growth of commensal throat flora. To determine whether routine throat culture conditions are sufficient to produce recognizable colonies of A. haemolyticum, the morphology of six distinct strains was studied after various combinations of incubation time, medium, and atmosphere. The agar media, containing 5% sheep blood, were Trypticase soy agar, Columbia agar, and heart infusion agar. Cultures were incubated in ambient air, 6 to 8% CO2, or an anaerobic atmosphere. Cultures were compared after 24, 48, and 72 h of incubation for colony size, clarity and size of hemolytic zone, and macroscopic evidence of agar pitting. A minimum of 48 h was needed for expression of beta-hemolysis and pitting. Trypticase soy agar was the superior medium and CO2 was the superior atmosphere for beta-hemolysis. Agar pitting was not significantly affected by variations in medium or atmosphere. Strains differed in their expression of hemolysis and production of pits at 48 h. After 72 h of incubation, beta-hemolysis and pitting were visible in over 96% of culture observations.

Midgut basal lamina thickness and dengue-1 virus dissemination rates in laboratory strains of Aedes albopictus (Diptera: Culicidae)

Strain differences in midgut basal lamina thickness, assessed by measurement in transmission electron micrographs, and disseminated infection rates of dengue-1 virus were compared among three laboratory strains of Aedes albopictus (Skuse). Mean basal lamina thickness for the New Orleans and Houston strains were significantly greater than those for the Oahu strain, which exhibits a higher disseminated infection rate than the former two. Although basal lamina thickness among the F1 progeny of reciprocal crosses of the Oahu and Houston strains were intermediate between the parental strains, they were too variable to be useful as markers in genetic studies. Measurements of basal laminae among individuals of the New Orleans strain, with disseminated or nondisseminated infections, failed to demonstrate a role for basal lamina thickness as a modulator of dengue-1 virus dissemination across the midgut epithelium of Ae. albopictus.

Genetic factors controlling susceptibility to Leishmania major infection in the sand fly Phlebotomus papatasi (Diptera: Psychodidae)

Studies of the genetic factors controlling Leishmania major infection in Phlebotomus papatasi were carried out using 2 different sand fly lines: one highly susceptible and the other refractory to the parasite. L. major infection rates in both F1 and F2 generations from reciprocal crosses and in backcrosses between the parent lines showed that susceptibility and refractoriness of Ph. papatasi to infection with L. major are controlled by less than 1 gene. Neither susceptibility nor refractoriness is dominant over the other.

Selection of Phlebotomus papatasi (Diptera: Psychodidae) lines susceptible and refractory to Leishmania major infection

Variation in susceptibility to infection with cultured promastigotes of Leishmania major was detected among 3 different geographic strains (ISRAEL, EGYPT, and INDIA) of the sand fly Phlebotomus papatasi. The ISRAEL strain showed the greatest susceptibility and was chosen for subsequent genetic selection experiments. After 13 generations of genetic selection in this strain, a stable refractory line was obtained in which only 7.5% of the insects could be infected. A highly susceptible line was also obtained in 5 generations of selection. Infection rates in the susceptible line were stabilized at about 94%. A description of the selection process and characteristics of the 2 lines are given.

De novo formation of immune complexes in human kidney allografts

Cryostat sections of 11 rejected human renal grafts were selected for positive results in immunofluorescence tests. Immune complexes were detected in glomerular basement membrane (9 cases), tubular basement membrane (3 cases), and vessels (5 cases). Preincubation of the sections with FII of pooled human serum, but not of rabbit serum, prevented the staining of immune complexes for human IgG. These findings were interpreted by the assumption that most complexes under study were produced by reaction of the patient's altered IgG with the rheumatoid-like factor of IgG variety.

Spontaneous rupture of a metastatic brain tumor into the ventricular system. Report of two cases

✓ Two cases are reported in which spontaneous rupture of a metastatic brain tumor occurred into the ventricular system, leading to the dissemination of the tumor contents in the cerebrospinal fluid. The site of rupture was demonstrated by ventriculography in the first case and by surgical exposure in the second. These cases support the assumption that metastatic neoplasms within the brain may rupture into the ventricular system and spread via the cerebrospinal fluid pathways.