Biomedical subjects

Hongwei Zhao

Publications and source records attributed to Hongwei Zhao.

11 recordsLinked to original sources

PubMed2021

Spray-induced gene silencing for disease control is dependent on the efficiency of pathogen RNA uptake.

Recent discoveries show that fungi can take up environmental RNA, which can then silence fungal genes through environmental RNA interference. This discovery prompted the development of Spray-Induced Gene Silencing (SIGS) for plant disease management. In this study, we aimed to determine the efficacy of SIGS across a variety of eukaryotic microbes. We first examined the efficiency of RNA uptake in multiple pathogenic and non-pathogenic fungi, and an oomycete pathogen. We observed efficient double-stranded RNA (dsRNA) uptake in the fungal plant pathogens Botrytis cinerea, Sclerotinia sclerotiorum, Rhizoctonia solani, Aspergillus niger and Verticillium dahliae, but no uptake in Colletotrichum gloeosporioides, and weak uptake in a beneficial fungus, Trichoderma virens. For the oomycete plant pathogen, Phytophthora infestans, RNA uptake was limited and varied across different cell types and developmental stages. Topical application of dsRNA targeting virulence-related genes in pathogens with high RNA uptake efficiency significantly inhibited plant disease symptoms, whereas the application of dsRNA in pathogens with low RNA uptake efficiency did not suppress infection. Our results have revealed that dsRNA uptake efficiencies vary across eukaryotic microbe species and cell types. The success of SIGS for plant disease management can largely be determined by the pathogen's RNA uptake efficiency.

Ascomycota↗

PubMed2006

Preparation and characterization of liposomes-in-alginate (LIA) for protein delivery system.

This paper describes the preparation and characterization of a novel drug delivery system for protein, liposomes-in-alginate (LIA) of biodegradable polymers, which is conceived from a combination of the polymer and the lipid-based delivery systems. LIA were prepared by first entrapping bovine serum albumin (BSA), a model protein within multivesicular liposomes (MVLs) by double emulsification process, which are then encapsulated within alginate hydrogel microcapsule, with untrapped BSA which are added during preparation of MVLs. Factors impacting encapsulation efficiency of MVLs are investigated and release of protein from the microcapsules in vitro is studied. At the same time, characterization of MVLs, microcapsules encapsulated protein formulation and integrality analyse of BSA in microcapsules are also studied, with the aim of improving the entrapment efficiency and prolonging release time. It is found that encapsulation efficiency and size of MVLs are affected by the composition and fabrication parameters of LIA. The data also show LIA have high encapsulation efficiency (up to 95%), little chemical change in drug caused by the formulation process, narrow particle size distribution and spherical particle morphology. Drug release assays conducted in vitro indicates that these formulations provide sustained release of encapsulated drug over a period, about 2 weeks.

Alginates↗

PubMed2005

5-Hydroxytryptamine-receptor antagonists versus prochlorperazine for control of delayed nausea caused by doxorubicin: a URCC CCOP randomised controlled trial.

BACKGROUND: Despite widespread use of short-acting antagonists for the 5-hydroxytryptamine (5-HT) receptor, about 50% of patients given moderately emetogenic chemotherapy have delayed nausea. We aimed to assess whether a 5-HT-receptor antagonist was more effective than was prochlorperazine for control of delayed nausea and delayed vomiting caused by doxorubicin. METHODS: 691 patients who previously had not had chemotherapy and who were scheduled to receive doxorubicin were given a short-acting 5-HT-receptor antagonist and dexamethasone before doxorubicin (day 1), and were randomly assigned to one of three regimens for days 2 and 3: 10 mg prochlorperazine taken orally every 8 h; any first-generation 5-HT-receptor antagonist (except palonosetron) taken as standard dose intravenously or orally; or 10 mg prochlorperazine taken as needed. Nausea and vomiting were assessed by use of a home record. The primary endpoint was mean severity of delayed nausea. The secondary endpoint was quality of life. Analyses were done by intention to treat. FINDINGS: 519 (77%) of the 671 evaluable patients had delayed nausea, with a mean severity of 3.33 (95% CI 3.22-3.44). 161 (71%) of 226 patients assigned prochlorperazine every 8 h reported delayed nausea (mean severity 3.37 [3.16-3.58]), as did 179 (79%) of 226 patients assigned 5-HT-receptor antagonists (3.29 [3.09-3.48]) and 179 (82%) of 219 patients assigned prochlorperazine as needed (3.33 [3.15-3.50]); groups did not differ in mean severity (p=0.853, one-way ANOVA). Patients allocated prochlorperazine every 8 h had less delayed nausea than did those allocated 5-HT-receptor antagonists (p=0.05, t test) and those allocated prochlorperazine as needed (p=0.009, t test). INTERPRETATION: Short-acting 5-HT-receptor antagonists are no better than is prochlorperazine in control of delayed nausea caused by doxorubicin. Although fewer patients taking prochlorperazine report delayed nausea, the proportion was unacceptably high.

Antiemetics↗

PubMed2005

Factors affecting protein release from microcapsule prepared by liposome in alginate.

A new type of drug delivery system that microcapsule was prepared by liposome in alginate on this paper, bovine serum albumin (BSA) as an model drug. Influences of liposomes composition and multivalent cations on morphology, enveloped rate, integrality and release in vitro from microcapsule were investigated. The results are showed that Ca2+ and Ba2+ made hydrogels form easier than Al3+ and particle size were uniform, circular, but microcapsule prepared by Al3+ was flat circular and easily adhere to each other. Particle size of all microcapsules was 200-300 microm after dryness, measured by vernier calliper. BSA enveloped rate prepared by PC/PG/Chol and Ba2+ was highest, 77.65%, and also correlative to concentration of lipid. At the other hand, Ba2+ microcapsule prepared by liposome in alginate has not an initial burst and have a good performance on delivering protein. Integrality of protein was not destroyed after encapsulated.

Alginates↗

PubMed2005

Microencapsulation peptide and protein drugs delivery system.

Many methods were used to devise peptide and protein drugs delivery system (DDS). Because of their relatively large size, they have low transdermal bioavailabilities. In systemic delivery of proteins, biodegradable material as parenteral depot formulation occupy an important place because of several aspects like protection of sensitive proteins from degradation, prolonged or modified release, pulsatile release patterns. The main objective in developing controlled release protein injectables is avoidance of regular invasive doses which in turn provide patient compliance, comfort as well as control over blood levels. This review article presents the outstanding contributions in field of microencapsulation as protein delivery systems and different approaches of protein delivery are described. Then discusses how these advances may be applied to resolve the challenges face the development of microcapsule for the controllable delivery of protein drugs.

Alginates↗

PubMed2005

Interrater agreement in the assessment of motor manifestations of Huntington's disease.

With prospects improving for experimental therapeutics aimed at postponing the onset of illness in preclinical carriers of the Huntington's disease (HD) gene, we assessed agreement among experienced clinicians with respect to the motor manifestations of HD, a relevant outcome measure for preventive trials in this population. Seventy-five clinicians experienced in the evaluation of patients with early HD and six non-clinicians were shown a videotape compiled from the film archives of the United States-Venezuela Collaborative HD Research Project. Observers were asked to rate a 2-3-minute segment of the motor examination for each of 17 at-risk subjects. The rating scale ranged from 0 (normal) to 4 (unequivocal extrapyramidal movement disorder characteristic of HD). As measured by a weighted kappa statistic, there was substantial agreement among the 75 clinicians in the judgment of unequivocal motor abnormalities comparing scale ratings of 4 with ratings that were not 4 (weighted kappa = 0.67; standard error (SE) = 0.09). Agreement among the non-clinicians was only fair (weighted kappa = 0.28; SE = 0.10). Even under the artificial conditions of a videotape study, experienced clinicians show substantial agreement about the signs that constitute the motor manifestations of illness in subjects at risk for HD. We expect these findings to translate to a similar level of interobserver agreement in the clinical trial setting involving experienced investigators examining live patients.

Basal Ganglia Diseases↗

PubMed2005

Variations in jail sentences and the probability of re-arrest for driving while intoxicated.

OBJECTIVE: The probability of re-arrest for driving while intoxicated (DWI) is compared for four different groups of individuals classified by whether the individual was convicted and, if so, the type of sentence received. METHOD: Subsequent re-arrests for DWI were examined for all individuals whose index arrest for DWI had occurred between 1994 and 2001 in a county in New Mexico. The groups included (1) those convicted as a result of the index arrest and sentenced to a 28-day jail/treatment program (N (#)=(#) 2,703); (2) all those not convicted as a result of the index arrest (N = 709); (3) those who were convicted but not sentenced to jail (N = 1,047); and (4) those convicted and sentenced to jail (N = 1,290). RESULTS: Adjusting for covariates of BAC, number of prior arrests, ethnicity, age, and sex, the probability of not being re-arrested was greatest among those sentenced to the jail/treatment program (Group 1), next highest in the two groups convicted but not sentenced to jail/treatment (Groups 3 and 4), and lowest in the group that was not convicted (Group 2). Length of jail sentence among people convicted but not sentenced to the jail/treatment program was unrelated to the probability of re-arrest. CONCLUSION: Conviction for DWI, regardless of the sentence, appears to reduce the probability of re-arrest, and being sentenced to a multi-modal treatment/incarceration program further reduces the probability of re-arrest. However, the other types of sentences do not appear to differ in their impact on probability of re-arrest.

Adult↗

PubMed2004

The prevention paradox, traffic safety, and driving-while-intoxicated treatment.

BACKGROUND: In San Juan County, New Mexico, a 28-day jail/treatment program for first-time driving-while-intoxicated (DWI) offenders was established in 1994 to reduce both DWI recidivism and alcohol-related crashes. This paper assesses the impact of the program on both outcomes. METHODS: The data are composed of driving records of all people arrested for DWI in San Juan County from August 1994 through December 2001. Subsequent re-arrests and crashes were analyzed to compare people who had been sentenced to the jail/treatment program and those who had not. Kaplan-Meier survival curves and Cox proportional hazards regression analyses were used. Covariates included age, gender, blood alcohol content (BAC), number of prior arrests, and ethnicity (Native American, non-Hispanic white, and Hispanic). RESULTS: Re-arrest rates were significantly lower for the treatment than the nontreatment group. Each of the three major ethnic groups showed similar effects. This was not observed for subsequent alcohol-related crashes, possibly as a result of insufficient numbers. BAC and number of previous arrests were, however, significant risk factors for subsequent crashes. Finally, although BAC and previous arrests were important risk factors for subsequent crashes, the vast majority of subsequent alcohol-related crashes occurred among people in the intermediate risk ranges. CONCLUSIONS: The jail/treatment program is effective in reducing the probability of DWI re-arrests. The evidence with respect to crashes is equivocal. That most crashes occur to people in the intermediate risk range exemplifies the prevention paradox, and means that the courts, which deal most severely with high-risk individuals, cannot be expected to have a major impact on alcohol-related crashes.

Accidents, Traffic↗

PubMed2003

Using local correlation in kernel-based smoothers for dependent data.

We consider the general problem of smoothing correlated data to estimate the nonparametric mean function when a random, but bounded, number of measurements is available for each independent subject. We propose a simple extension to the local polynomial regression smoother that retains the asymptotic properties of the working independence estimator, while typically reducing both the conditional bias and variance for practical sample sizes, as demonstrated by exact calculations for some particular models. We illustrate our method by smoothing longitudinal functional decline data for 100 patients with Huntington's disease. The class of local polynomial kernel-based estimating equations previously considered in the literature is shown to use the global correlation structure in an apparently detrimental way, which explains why some previous attempts to incorporate correlation were found to be asymptotically inferior to the working independence estimator.

Biometry↗

PubMed2002

Rearrest rates after incarceration for DWI: a comparative study in a southwestern US county.

OBJECTIVES: This study was undertaken to assess a 28-day detention and treatment program's effect, in a multiethnic county with high rates of alcohol-related arrests and crashes, on first-time offenders sentenced for driving while impaired (DWI). METHODS: We used comparison of baseline characteristics, survival curves of subsequent arrest, and Cox proportional hazards regression to examine probability of rearrest of those sentenced and those not sentenced to the program. RESULTS: Probability of not being rearrested was significantly higher for the treatment group after adjustment for covariates. At 5 years, probability of not being rearrested for the treatment vs the nontreatment group was 76.6% vs 59.9%. CONCLUSIONS: Results suggest that this county's program has significantly affected rearrest rates for Native Americans, Hispanics, and non-Hispanic Whites.

Accidents, Traffic↗

PubMedDate not supplied

Gabapentin for hot flashes in 420 women with breast cancer: a randomised double-blind placebo-controlled trial.

BACKGROUND: Most women receiving systemic therapy for breast cancer experience hot flashes. We undertook a randomised, double-blind, placebo-controlled, multi-institutional trial to assess the efficacy of gabapentin in controlling hot flashes in women with breast cancer. METHODS: 420 women with breast cancer who were having two or more hot flashes per day were randomly assigned placebo, gabapentin 300 mg/day, or gabapentin 900 mg/day by mouth in three divided doses for 8 weeks. Each patient kept a 1-week, self-report diary on the frequency, severity, and duration of hot flashes before the start of the study and during weeks 4 and 8 of treatment. Analyses were by intention to treat. FINDINGS: Evaluable data were available on 371 participants at 4 weeks (119 placebo, 123 gabapentin 300 mg, and 129 gabapentin 900 mg) and 347 at 8 weeks (113 placebo, 114 gabapentin 300 mg, and 120 gabapentin 900 mg). The percentage decreases in hot-flash severity score between baseline and weeks 4 and 8, respectively were: 21% (95% CI 12 to 30) and 15% (1 to 29) in the placebo group; 33% (23 to 43) and 31% (16 to 46) in the group assigned gabapentin 300 mg; and 49% (42 to 56) and 46% (34 to 58) in the group assigned gabapentin 900 mg. The differences between the groups were significant (p=0.0001 at 4 weeks and p=0.007 at 8 weeks by ANCOVA for overall treatment effect, adjusted for baseline values); only the higher dose of gabapentin was associated with significant decreases in hot-flash frequency and severity. INTERPRETATION: Gabapentin is effective in the control of hot flashes at a dose of 900 mg/day, but not at a dose of 300 mg/day. This drug should be considered for treatment of hot flashes in women with breast cancer.

Amines↗