ABSTRACT
Silica nanoparticles (SiO2 NPs) synthesized by the Stober method were used as drug delivery vehicles. Doxorubicin hydrochloride (DOX·HCl) is a chemo-drug absorbed onto the SiO2 NPs surfaces. The DOX·HCl loading onto and release from the SiO2 NPs was monitored via UV-VIS and fluorescence spectra. Alternatively, the zeta potential was also used to monitor and evaluate the DOX·HCl loading process. The results showed that nearly 98% of DOX·HCl was effectively loaded onto the SiO2 NPs' surfaces by electrostatic interaction. The pH-dependence of the process wherein DOX·HCl release out of DOX·HCl-SiO2 NPs was investigated as well. For comparison, both the free DOX·HCl molecules and DOX·HCl-SiO2 NPs were used as the labels for cultured cancer cells. Confocal laser scanning microscopy images showed that the DOX·HCl-SiO2 NPs were better delivered to cancer cells which are more acidic than healthy cells. We propose that engineered DOX·HCl-SiO2 systems are good candidates for drug delivery and clinical applications.
Subject(s)
Antineoplastic Agents , Doxorubicin , Drug Carriers , Nanoparticles , Neoplasms , Silicon Dioxide , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Doxorubicin/chemistry , Doxorubicin/pharmacokinetics , Doxorubicin/pharmacology , Drug Carriers/chemistry , Drug Carriers/pharmacokinetics , Drug Carriers/pharmacology , Humans , MCF-7 Cells , Microscopy, Confocal , Nanoparticles/chemistry , Nanoparticles/therapeutic use , Neoplasms/drug therapy , Neoplasms/metabolism , Neoplasms/pathology , Silicon Dioxide/chemistry , Silicon Dioxide/pharmacokinetics , Silicon Dioxide/pharmacologyABSTRACT
BACKGROUND: This study assesses the prevalence of Vietnamese children receiving the hepatitis B (HepB) vaccine birth dose and explores its associated socioeconomic factors. METHODS: We used the data of the Multiple Indicator Cluster Survey, 2014. We estimated the overall percentage of HepB birth dose vaccination among 0-23-month-old children and its percentages according to selected characteristics. Multiple logistic regression was applied. RESULTS: 62.8% of children received the HepB vaccine birth dose. The prevalence rates by selected factors ranged from 35.3% to 76.7%. The categories with the lowest prevalence rates were children who had low birth weight (41.6%), had a mother aged less than 20 years (35.3%), had a mother with primary or less education (42.7%), belonged to ethnic minorities (30.3%), resided in rural areas (59.9%), and were in the 1st quintile of mother's socioeconomic status (38.6%). Receiving HepB vaccine birth dose was associated with child's birth weight, mother's age, mother's education, socioeconomic status, and ethnicity. CONCLUSIONS: This study identified vulnerable groups, upon which policy-makers should focus their efforts to equitably and sustainably tackle birth dose HepB vaccine coverage as well as the full vaccination coverage, thereby promoting long-lasting herd immunity in this country.
Subject(s)
Hepatitis B Vaccines/therapeutic use , Hepatitis B/prevention & control , Immunization Programs , Adult , Dose-Response Relationship, Drug , Female , Hepatitis B/epidemiology , Hepatitis B/immunology , Hepatitis B/virology , Hepatitis B Vaccines/immunology , Humans , Infant , Infant, Newborn , Male , Middle Aged , Mothers , Parturition/immunology , Pregnancy , Social Class , Vaccination , Vietnam/epidemiologyABSTRACT
Four Trichoderma strains (CH2, SH16, PQ34, and TN42) were isolated from soil samples collected from Quang Tri and Thua Thien Hue provinces in Vietnam. The strains exhibited high chitinolytic secretion. Strain PQ34 formed the largest zone of chitinase-mediated clearance (> 4 cm in diameter) in agar containing 1% (w/v) colloidal chitin. Analysis of the internal transcribed spacer regions of these strains indicated that they were Trichoderma asperellum. The molecular weights of the chitinases were approximately 42 kDa. Chitinase genes (chi42) of T. asperellum strains TN42, CH2, SH16, and PQ34 were 98~99% homologous to the ech42 gene of T. harzianum CB-Pin-01 (accession No. DQ166036). The deduced amino acid sequences of both T. asperellum strains SH16 and TN42 shared 100% similarity.
Subject(s)
Agar , Amino Acid Sequence , Chitin , Chitinases , Colloids , Molecular Weight , Soil , Sprains and Strains , Trichoderma , VietnamABSTRACT
BACKGROUND: Vietnam has an emerging HIV epidemic, particularly in male drug injectors. Data on HIV infections in women in the general population, and their risk factors, are scanty. METHODS: A case-control study was performed in a large gynaeco-obstetric hospital in Haiphong city in 1998-2001. The sample was 22000 attendees. The medical records of 58 HIV-seropositive cases were compared with 422 randomly chosen HIV-seronegative controls for potential risk factors. RESULTS: A multivariate analysis found that HIV infection was associated with young age, past/current history of sexually transmitted infections (STI) and being unemployed. Patients aged 21-30 years were 10-fold less likely to be infected than women aged <20 years (OR 0.11, 95% CI 0.04-0.33). Women with a past/current history of STI had over 20 times the risk of those who did not (95% CI 6.7-62.3). Unemployed women had at least twice the risk of infection of any other occupational group. CONCLUSIONS: We have identified risk factors in women that have not been highlighted previously in Vietnam. Our study suggests that all antenatal women, especially those who are young or unemployed (or, with a current/past history of STI), should be offered free HIV tests, counselling and management.
