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Biomedical subjects

Wei Hua

Publications and source records attributed to Wei Hua.

At least 19 recordsLinked to original sources

Individualized patient tumor organoids faithfully preserve human brain tumor ecosystems and predict patient response to therapy.

Tumor organoids are important tools for cancer research, but current models have drawbacks that limit their applications for predicting response to therapy. Here, we developed a fast, efficient, and complex culture system (IPTO, individualized patient tumor organoid) that accurately recapitulates the cellular and molecular pathology of human brain tumors. Patient-derived tumor explants were cultured in induced pluripotent stem cell (iPSC)-derived cerebral organoids, thus enabling culture of a wide range of human tumors in the central nervous system (CNS), including adult, pediatric, and metastatic brain cancers. Histopathological, genomic, epigenomic, and single-cell RNA sequencing (scRNA-seq) analyses demonstrated that the IPTO model recapitulates cellular heterogeneity and molecular features of original tumors. Crucially, we showed that the IPTO model predicts patient-specific drug responses, including resistance mechanisms, in a prospective patient cohort. Collectively, the IPTO model represents a major breakthrough in preclinical modeling of human cancers, which provides a path toward personalized cancer therapy.

Humans↗

Effect of nifekalant on acute electrical remodelling in rapid atrial pacing canine model.

BACKGROUND: Nifekalant may prevent atrial fibrillation (AF) and possibly be useful in treatment of atrial tachyarrhythmia in patients with severe heart failure. This study investigated the electophysiologic effect of nifekalant on the acute atrial remodeling in rapid atrial pacing (RAP) model of canine. METHODS: Twelve mongrel dogs subjected to rapid stimulation (400 beats/min) at left atrial appendage (LAA) for 24 hours, were randomized into the control group (rapid pacing only, n = 6) and the nifekalant group (intravenous nifekalant therapy immediately after RAP, n = 6). Atrial electrophysiological parameters were measured in right atrium, coronary sinus, LAA, posterior wall of left atrium (PWLA) and left superior pulmonary vein (LSPV), before and after the RAP. RESULTS: In the control group, the effective refractory periods (ERP) were shortened greatly at all sites, paced dogs had substantially shorter ERPs in the high right atrium, LAA, and LSPV, but fewer changes in the PWLA, the coefficient variation of ERP (COV ERP) was increased significantly. After rapid atrial stimulation, the inducibility of AF increased significantly [induction number: pre-RAP vs post-RAP, 1.00 +/- 0.89 vs 8.17 +/- 2.79, P < 0.01; duration of AF: pre-RAP vs post-RAP, (450.34 +/- 362.59) ms vs (9975.77 +/- 4376.99) ms, P < 0.01]. In the nifekalant group, although the ERPs were prolonged at all sites compared with those in pre-RAP state, only the value at LSPV differed significantly from that in pre-RAP state [pre-RAP vs post-RAP, (102.50 +/- 5.24) ms vs (132.51 +/- 5.20) ms, P < 0.01]; the COV ERP did not change statistically in this group. The inducibility of AF slightly increased but insignificantly after pacing [induction number: pre-RAP vs post-RAP, 0.83 +/- 0.75 vs 1.67 +/- 0.82, P = 0.19; duration of AF: pre-RAP vs post-RAP, (378.67 +/- 317.88) ms vs (1124.08 +/- 1109.77) ms, P = 0.06]. Conduction time values did not alter significantly in either of the two groups after RAP. CONCLUSIONS: In canine RAP model, nifekalant inhibited ERP shortening and ERP heterogeneity increasing, decreased AF induction. Nifekalant can reverse acute electrical remodeling effect in this model.

Animals↗

Short-term effect of cardiac resynchronization therapy in patients with ischaemic or nonischaemic cardiomyopathy.

BACKGROUND: Patients with heart failure were candidates for cardiac resynchronization therapy (CRT) regardless of underlying aetiology. This study observed the effect of CRT in patients with ischaemic or nonischaemic cardiomyopathy. METHODS: One hundred and forty-two patients with refractory chronic heart failure and left bundle branch block received cardiac resynchronization therapy, 91 men and 51 women, average age 60 years. Left ventricular ejection fraction (LVEF) was severely depressed (mean 29%), left ventricular end diastolic diameter (LVEDD) enlarged (mean 72 mm) and QRS width was lengthened (mean 147 ms). Ninety-eight had nonischaemic cardiomyopathy and 44 had ischaemic cardiomyopathy. RESULTS: After cardiac resynchronization therapy, the heart function was significantly improved. The mean LVEF increased from 29% to 36% after pacing. In patients with nonischaemic cardiomyopathy, the LVEF was improved from 28% to 37%, and in patients with ischaemic cardiomyopathy, the LVEF was improved from 30% to 36%. No significant difference of the improvement was found between the two groups (P > 0.05). CONCLUSIONS: Cardiac resynchronization therapy could significantly improve cardiac function in patients with chronic heart failure regardless of the underlying heart disease.

Bundle-Branch Block↗

The association between change in social network characteristics and non-fatal overdose: results from the SHIELD study in Baltimore, MD, USA.

BACKGROUND: Social network factors have been reported to be associated with non-fatal overdose. Yet, few studies have examined how changes in social network characteristics may influence overdose risk. The purpose of this study was to examine the relationship between changes in social network and non-fatal overdose. METHODS: Data for this study came from 659 participants enrolled in the Self-Help in Eliminating Life-Threatening Diseases (SHIELD) study, who reported details about their non-fatal overdose experience between enrollment and a follow-up visit. Social network characteristics were described at both time points and net change in network composition was calculated. RESULTS: The sample was predominately male (56%), African-American (96%) and unemployed (78%). Experience of non-fatal overdose between time points was reported by 15%. Older age was associated with non-fatal overdose. Interaction between incarceration status and drug use was statistically significant. Protective factors were having a denser network at baseline and a network that became denser after adjusting for gender, homelessness, incarceration, drug use and total network size. CONCLUSIONS: Drug users' social networks are an important target for overdose prevention interventions. Further research on overdose risk and movement of specific network members in and out of networks is warranted.

Adult↗

Characterization of PM(2.5) in the ambient air of Shanghai City by analyzing individual particles.

PM(2.5) samples were collected simultaneously at three representative areas (central city, industrial area and clean air suburban) of Shanghai City. Their morphologies and elemental compositions were determined by scanning electron microscopy coupled with energy analysis (SEM-EDX). The particles were classified into four groups based on morphology and elemental composition. Soot aggregates and spherical fly ash particles were the two dominant types and they were identified as originating from automobile exhaust, metallurgical industry and coal combustion. The size distribution of the particles showed that most had diameters in the range of 0.2-1.4 microm. Individual particles were measured by synchrotron radiation micro-beam X-ray fluorescence (micro-SXRF) and the micro-SXRF spectra were obtained. Pattern recognition techniques, which took the micro-SXRF spectrum of a single aerosol particle as its fingerprint, were used to identify the origins of the particles. Seven source types were identified. They were: metallurgical industry, vehicle exhaust, soil dust, coal combustion, diesel exhaust, oil combustion and motorcycle exhaust. Metallurgical industry, automobile exhaust, and coal combustion were recognized to be the main pollution sources of PM(2.5) in the air of Shanghai City.

Air Pollutants↗

Impact of automatic threshold capture on pulse generator longevity.

BACKGROUND: The automatic, threshold tracking, pacing algorithm developed by St. Jude Medical, verifies ventricular capture beat by beat by recognizing the evoked response following each pacemaker stimulus. This function was assumed to be not only energy saving but safe. This study estimated the extension in longevity obtained by AutoCapture (AC) compared with pacemakers programmed to manually optimized, nominal output. METHODS: Thirty-four patients who received the St. Jude Affinity series pacemaker were included in the study. The following measurements were taken: stimulation and sensing threshold, impedance of leads, evoked response and polarization signals by 3501 programmer during followup, battery current and battery impedance under different conditions. For longevity comparison, ventricular output was programmed under three different conditions: (1) AC on; (2) AC off with nominal output, and (3) AC off with pacing output set at twice the pacing threshold with a minimum of 2.0 V. Patients were divided into two groups: chronic threshold is higher or lower than 1 V. The efficacy of AC was evaluated. RESULTS: Current drain in the AC on group, AC off with optimized programming or nominal output was (14.33 +/- 2.84) mA, (16.74 +/- 2.75) mA and (18.4 +/- 2.44) mA, respectively (AC on or AC off with optimized programming vs. nominal output, P < 0.01). Estimated longevity was significantly extended by AC on when compared with nominal setting [(103 +/- 27) months, (80 +/- 24) months, P < 0.01). Furthermore, compared with the optimized programming, AC extends the longevity when the pacing threshold is higher than 1 V. CONCLUSION: AC could significantly prolong pacemaker longevity; especially in the patient with high pacing threshold.

Aged↗

Assessment of cardiac function and synchronicity in subjects with isolated bundle branch block using Doppler imaging.

BACKGROUND: Using tissue Doppler imaging and conventional echocardiographic technique, we examined the cardiac function and synchronicity in individuals with isolated right bundle branch block (RBBB) or left bundle branch block (LBBB) and assessed the relationship between QRS duration and synchronicity. METHODS: Subjects with isolated RBBB (n = 20), LBBB (n = 10) and normal controls (n = 20) were studied with conventional echocardiography and tissue Doppler imaging. The difference between aortic and pulmonary preejection intervals was defined as interventricular delay. Parameters in septum and lateral wall were measured using tissue Doppler imaging, including peak sustained systolic velocity (S(M)), peak early (E(M)) and late (A(M)) diastolic velocities as well as time to peak velocities (T(S), T(E) and T(A)). RESULTS: Subjects with LBBB had lower S(M) and longer T(S) than did the RBBB and control groups (P < 0.05, P < 0.001 respectively). A significant difference was observed in E(M), being the lowest in the LBBB and the highest in the control group (P < 0.05). Moreover, T(E) was longer in the LBBB group compared with the other two groups (P < 0.001). Both A(M) and T(A) were similar among three groups (P > 0.05). In the bundle branch block groups, one ventricle lagged about 40 ms behind the other. A significant correlation was found between interventricular delay and QRS duration (r = 0.713, P < 0.001). CONCLUSIONS: Cardiac ventricles were not well synchronized with one ventricle lagging about 40 ms behind the other in subjects with LBBB or RBBB, even though only LBBB group showed barely perceptible, impaired cardiac function. In addition, QRS duration and cardiac asynchronicity were positively correlated.

Adult↗

Incidence and causes of inappropriate detection and therapy by implantable defibrillators of cardioversion in patients with ventricular tachyarrhythmia.

BACKGROUND: Implantable cardioverter defibrillator (ICD) is the only effective therapy in patients with life threatening ventricular arrhythmias. Inappropriate detection and therapy by ICDs are the most common causes of side effects that affect the quality of life in ICD recipients. This study evaluated the incidence and causes of inappropriate detection and therapy by ICDs in patients in our hospital. METHODS: From January 2000 to December 2005, fifty patients who received ICD implantation for ventricular arrhythmias for prevention of sudden cardiac death were evaluated in this study. Each ICD was programmed using clinical arrhythmic and cardiac data of the patient before discharge. Patients were followed up by standard schedule after implantation and all data retrieved from each device were collected and saved for further analysis. RESULTS: No arrhythmic event was detected in 12/50 (24%) patients during the period of follow-up. Among the remaining patients, 11 (22%) experienced inappropriate detections and therapies during follow-up in this study. ICD detected 383 ventricular tachyarrhythmia (VT) and 108 ventricular fibrillation (VF) episodes and delivered 678 therapies. In VT group, ICD delivered 413 antitachycardiac pacings (ATPs) and 118 shocks, among which 78 ATPs and 9 shocks were initiated by 55/383 (14.3%) inappropriate detections. In VF group ICD delivered 147 shocks, among which 56 shocks were initiated by 28/108 (26.9%) inappropriate detections. Overall, more than 50% of these episodes were caused by atrial fibrillation (AF) with rapid ventricular response, followed by electromagnetic or myopotential interference. In addition, most inappropriate therapies occurred within one year after ICD implantation. CONCLUSIONS: About one fifth of patients experienced ICD inappropriate detection and therapy after implantation. The main cause was AF with rapid ventricular response, followed by electromagnetic or myopotential interference.

Adult↗

Identification of differentially expressed genes in seeds of two near-isogenic Brassica napus lines with different oil content.

The regulation of seed oil synthesis in rapeseed is largely unknown. In this study, we compared the gene expression during seed development between two lines of Brassica napus with a 10% difference in oil content. We isolated the immature seeds 15 and 25 days after flowering at periods preceding and including the major accumulation of storage oils and proteins. The differentially expressed gene clones between the two rape lines were isolated by subtractive suppression hybridization (SSH). All SSH clones were arrayed and screened by dot blot hybridization, followed by RT-PCR analysis for selected clones. A total of 217 cDNA clones corresponding to 30 genes were found to have a high expression in seeds with high oil content. Six genes were highly expressed in seeds with low oil content. Northern blot and enzyme activity analysis demonstrated a change in expression pattern of several genes. The results provide information on gene-encoding factors responsible for the regulation of oil synthesis. The possible role of these genes in seeds is discussed. The genes in this study may be suitable as novel targets for genetic improvement of seed oil content and may also provide molecular markers for studies of rape breeding.

Brassica napus↗

Vectorial insertion of apical and basolateral membrane proteins in polarized epithelial cells revealed by quantitative 3D live cell imaging.

Although epithelial cells are known to exhibit a polarized distribution of membrane components, the pathways responsible for delivering membrane proteins to their appropriate domains remain unclear. Using an optimized approach to three-dimensional live cell imaging, we have visualized the transport of newly synthesized apical and basolateral membrane proteins in fully polarized filter-grown Madin-Darby canine kidney cells. We performed a detailed quantitative kinetic analysis of trans-Golgi network (TGN) exit, passage through transport intermediates, and arrival at the plasma membrane using cyan/yellow fluorescent protein-tagged glycosylphosphatidylinositol-anchored protein and vesicular stomatitis virus glycoprotein as apical and basolateral reporters, respectively. For both pathways, exit from the TGN was rate limiting. Furthermore, apical and basolateral proteins were targeted directly to their respective membranes, resolving current confusion as to whether sorting occurs on the secretory pathway or only after endocytosis. However, a transcytotic protein did reach the apical surface after a prior appearance basolaterally. Finally, newly synthesized proteins appeared to be delivered to the entire lateral or apical surface, suggesting-contrary to expectations-that there is not a restricted site for vesicle docking or fusion adjacent to the junctional complex.

Animals↗

Complications of cardiac resynchronization therapy in patients with congestive heart failure.

BACKGROUND: Previous clinical studies have suggested that patients with congestive heart failure and intraventricular conduction delay could benefit from cardiac resynchronization therapy (CRT). Implantation of left ventricular lead is a complex procedure with some potential for complications. This study was conducted to analyse the complications of CRT in patients with congestive heart failure. METHODS: Totally 117 patients, 86 males and 31 females, mean age of 53 years, with congestive heart failure and intraventricular conduction delay were enrolled in this study. Venography was performed on all patients. Different types of coronary sinus leads were used to pace the left ventricle. RESULTS: Left ventricular lead was attempted to implant through coronary sinus for all the 117 patients and was successfully implanted in 111 patients. The success rate was 94.9%. Main complications rate was 6.8%, including coronary sinus dissection in 4 patients, phrenic nerve stimulation required lead repositioning in 2 patients and lead dislodgement in 2 patients. CONCLUSIONS: It is feasible and safe to pace left ventricle through coronary sinus. However, there are some procedural complications.

Angioplasty, Balloon, Coronary↗

Arabidopsis cytosolic glutamine synthetase AtGLN1;1 is a potential substrate of AtCRK3 involved in leaf senescence.

While considerable progress has been achieved in plant CDPK studies in the past decade, there is relatively no information about the potential substrates of CRKs. In this report, a yeast two-hybrid screen was performed with truncated form of AtCRK3 as bait to identify its interacting proteins in an effort to dissect its physiological roles. One gene encoding cytosolic glutamine synthetase AtGLN1;1 was isolated. Further analyses indicated that AtGLN1;1 could interact specifically with AtCRK3 and the kinase domain of AtCRK3 and the catalytic domain of AtGLN1;1 were responsible for such interaction, respectively. Furthermore, in vitro and in vivo co-immunoprecipitation results strongly supported that they could physically interact with each other. Phosphorylation assays revealed that AtGLN1;1 could be specifically phosphorylated by AtCRK3 in vitro. All the results demonstrate that AtGLN1;1 may be a substrate of AtCRK3. In addition, both AtGLN1;1 and AtCRK3 could be induced by natural or artificially induced leaf senescence, implying that such interaction may be involved in the regulation of nitrogen remobilization during leaf senescence.

Arabidopsis↗

Social context of needle selling in Baltimore, Maryland.

Although much of the debate surrounding the distribution of sterile syringes to injection drug users (IDUs) has focused on needle exchange programs (NEPs), IDUs acquire their syringes from three major sources: NEPs, pharmacies, and secondary exchangers or needle sellers. The purpose of the present study is to examine types and frequencies of social interactions among drug injectors who sell needles, most of which come from NEPs, compared with individuals who do not sell needles. Specifically, we compared engagement in drug-related behaviors, roles in the drug economy, and social network membership. Data were collected as part of the SHIELD study, an HIV prevention intervention targeted at drug users and their social networks (n=910) from February 2001 through September 2003 in Baltimore, Maryland (USA). In this sample, 56 participants reported selling needles. Needle sellers had higher levels of engagement in drug-related social interactions, including using drugs with others, giving or receiving drugs from others, and buying drugs with other users. Participants who sold needles had a significantly higher number of roles in the drug economy. Also, they had more social network members who were injectors, with whom they talked about risky drug behaviors, gave needles to, and shared cookers and bleach with. Compared with nonselling injectors, needle sellers engage in HIV risk-related behaviors, such as injecting daily and sharing injection equipment, more frequently. The study's findings may be useful to determine whether secondary exchangers should be targeted for HIV prevention activities both to reduce their own risk and to diffuse risk reduction information throughout the drug using community.

Acquired Immunodeficiency Syndrome↗

Needle exchange program utilization and entry into drug user treatment: is there a long-term connection in Baltimore, Maryland?

This study examined the relationship between Needle Exchange Program (NEP) utilization and treatment entry in Baltimore, Maryland. The sample was composed of 440 drug injectors with disadvantaged backgrounds. Face-to-face interviews, focusing on HIV risk behaviors, drug use, and health, were conducted between June 1997 and June 2002. Multivariate logistic analyses revealed that entering treatment was associated with NEP utilization, being female, and being HIV-positive. Cocaine sniffers/snorters were less likely to enter treatment. These findings highlight the importance of NEPs in linking injectors to treatment. These data also suggest that treatment needs to address co-occurring problems, like HIV and mental illness. Study limitations are noted.

Adult↗

Exploring the role of needle selling in a drug-using community in Baltimore, Maryland.

Needle exchange programs (NEPs) play a critical role in reducing the spread of HIV in injection drug users (IDUs). However, many IDUs do not access NEPs and rely on needle sellers. This study examined differences between needle sellers and others in a drug-using community and assessed sources and quantity of needles sold by needle sellers. The study also explored factors associated with needle selling. Compared with nonsellers, needle sellers were more likely to be homeless, HIV-positive, and unemployed. The NEP was the most frequent source of needles for needle sellers. Needle sellers were more likely to share their needles with sex partners and strangers than were nonsellers. Within the whole sample, needle selling was associated with injecting drugs and the number of roles in the drug economy. For injectors, needle selling was associated with obtaining needles from the NEP and having >1 role in the drug economy. Because needle sellers frequently interact with IDUs, training needle sellers may be an effective strategy for risk reduction and HIV prevention. However, because some needle sellers disseminate used needles, all injectors need to be educated about proper disposal techniques.

Adult↗

[Gene expression and activity regulation of two calmodulin binding protein kinases in tobacco seedling].

Two different calmodulin-binding protein kinase cDNAs (NtCBK1/2) have been isolated from tobacco. To understand the CBK protein activity regulation, we compared the activity regulation of NtCBK1 and NtCBK2 by pH, Mg(2+) concentration and Na(+) concentration. We found the autophosphorylation of NtCBK1/2 reached the maximum in pH 7.5 and 8 respectively; Mg(2+) and Na(+) shown different effects on the activity of NtCBKs, high and low Mg(2+) concentrations both inhibited the activity of NtCBKs, but Na+ had little effect on the kinase activity. In addition, to obtain further insight about the physiological roles of individual NtCBKs, we detected the expression profiles of CBKs. The results revealed different patterns of expression of NtCBK1 and NtCBK2. Both are largely expressed in leaf and flower; but in stem and root, NtCBK1 gene had stronger expression than NtCBK2. NtCBK2 expression was induced by GA treatment, while NtCBK1 expression remained unchanged under GA treatment. Expression of both NtCBK1 and NtCBK2 increased in response to salt stress, the former to a greater extent, and both expressions did not change under high/low temperature, drought, NAA and ABA treatments.

Blotting, Northern↗

[Clinical study on 29 pacemaker and defibrillator lead fractures].

OBJECTIVE: To analyze major probable causes, locations and remedies of lead fractures in implanted pacemaker and implanted cardioverter defibrillator (ICD) . METHODS: From January 1982 to November 2004, on all the pacemakers and ICDs implanted at this hospital, lead fractures were detected timely by regular telemetric programmed testing, chest radiography and electrocardiography. Appropriate remedial actions were given and follow up visits were done to verify the results. RESULTS: Of all the 4698 pacemakers and 161 ICDs, there were 29 lead fractures on 31 leads with an incidence rate of 0.6%. The incidence rate of lead fracture was 0.9% for pacemakers/defibrillators implanted by subclavian venipuncture, while it was 0.4% for pacemakers/defibrillators implanted by cephalic venotomy (P = 0.04). Fracture locations: 22 cases at the sub clavicle, 6 cases in the pacemaker pocket, and 1 case in the right ventricle. Among the 29 cases, 24 were implanted with additional new leads, 3 cases whose atrial leads were fractured were switched from DDD mode to VVI. All the patients were followed up for an average of 5.6 months +/- 16.1 months. In one patient, the lead was removed through thoracotomy due to infection of exposed lead. CONCLUSIONS: Cephalic venotomy is the first choice for pacemaker and ICD implantation, and the second choice is subclavian venipuncture in the outer part of subclavian vein, which has a higher incidence rate of lead fracture. Most lead fractures are detected at the region of medial subclavian. Regular follow-up can help timely detect fractures, so that the cases can be dealt with properly.

Adult↗