Simple and Rapid Method of Microwell Array Fabrication for Drug Testing on 3D Cancer Spheroids.

Three-dimensional (3D) cell culture systems are becoming increasingly popular due to their ability to mimic the complex process of angiogenesis in cancer, providing more accurate and physiologically relevant data than traditional two-dimensional (2D) cell culture systems. Microwell systems are particularly useful in this context as they provide a microenvironment that more closely resembles the in vivo environment than traditional microwells. Poly(ethylene glycol) (PEG) microwells are particularly advantageous due to their bio-inertness and the ability to tailor their material characteristics depending on the PEG molecular weight. Although there are several methods available for microwell fabrication, most of them are time-consuming and expensive. The current study utilizes a low-cost laser etching technique on poly(methyl methacrylate) materials followed by molding with PDMS to produce microwells. The optimal conditions for making concave microwells are an engraving parameter speed of 600 mm/s, power of 20%, and a design diameter of the microwell of 0.4 mm. The artificial tumor achieved its full size after 7 days of cell growth in a microwell system, and the cells developed drugs through a live/dead assay test. The results of the drug testing revealed that the IC50 value of zerumbone-loaded liposomes in HepG2 was 4.53 pM, which is greater than the IC50 value of zerumbone. The HepG2 cancer sphere's 3D platform for medication testing revealed that zerumbone-loaded liposomes were very effective at high doses. These findings generally imply that zerumbone-loaded liposomes have the capacity to target the liver and maintain medication delivery.

Transcriptional response in the peripheral blood of patients infected with Salmonella enterica serovar Typhi.

We used microarrays and transcriptional profiling of peripheral blood to investigate the host response of 29 individuals who contracted typhoid fever in the Mekong Delta region of Vietnam. Samples were taken over a nine month period encompassing acute disease, convalescence, and recovery. We found that typhoid fever induced a distinct and highly reproducible signature in the peripheral blood that changed during treatment and convalescence, returning in the majority of cases to the "normal" profile as measured in healthy uninfected controls. Unexpectedly, there was a strong, distinct signature of convalescence present at day 9 after infection that remained virtually unchanged one month after acute infection and in some cases persisted as long as nine months despite a complete clinical recovery in all patients. Patients who retain the convalescent signature may be genetically or temporarily incapable of developing an effective immune response and may be more susceptible to reinfection, relapse, or the establishment of a carrier state.

Utilizing waste corn-cob in biosynthesis of noble metallic nanoparticles for antibacterial effect and catalytic degradation of contaminants.

In the present study, cost-effective, and environmentally friendly fabrication of silver and gold nanoparticles was performed by using aqueous extract of waste corn-cob. The formation of the metallic nanoparticles (MNPs) was optimized by UV-Vis method. The phytoconstituents were responsible for reduction of silver and gold ions to silver nanoparticles (CC-AgNPs) and gold nanoparticles (CC-AuNPs) which were demonstrated by Fourier-transform infrared (FTIR) spectroscopy while formation of AgCl was attributed to the presence of chloride ions in the aqueous extract. The crystalline nature of the AgNPs, AgCl, and AuNPs was confirmed using the X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns. Morphological studies showed that the synthesized CC-AgNPs existed in spherical shape with the size ranging from 2 to 28 nm possessing an average value of 11 nm while CC-AuNPs were present in the multiple shapes with size ranging from 5 to 50 nm possessing an average value of 35 nm. For studies on bioactive application, the CC-AgNPs exhibited a high antibacterial activity against three bacterial strains including Salmonella typhimurium, Bacillus cereus, and Staphylococcus aureus. In addition, the catalytic efficiency of MNPs was investigated for reduction of o-, m-, p-nitrophenols, and degradation of organic dyes including Eosin Y and Rhodamine 6G. The rate constants calculated from the kinetical data revealed that the biosynthesized nanoparticles are excellent catalysts in potential applications for treatment of wastewater. Graphical abstract .

Serial MRI to determine the effect of dexamethasone on the cerebral pathology of tuberculous meningitis: an observational study.

BACKGROUND: Adjunctive dexamethasone increases survival from tuberculous meningitis, but the underlying mechanism is unclear. We aimed to determine the effect of dexamethasone on cerebral MRI changes and their association with intracerebral inflammatory responses and clinical outcome in adults treated for tuberculous meningitis. METHODS: Cerebral MRI was undertaken, when possible, at diagnosis and after 60 days and 270 days of treatment in adults with tuberculous meningitis admitted to two hospitals in Vietnam. Patients were randomly assigned either dexamethasone (n=24) or placebo (n=19) and received 9 months of treatment with standard first-line antituberculosis drugs. We assessed associations between MRI findings, treatment allocation, and resolution of fever, coma, cerebrospinal fluid inflammation, and neurological outcome. FINDINGS: 83 scans were done for 43 patients: 19 given placebo, 24 given dexamethasone. Basal meningeal enhancement (82%) and hydrocephalus (77%) were the most common presenting findings. Fewer patients had hydrocephalus after 60 days of treatment with dexamethasone than after placebo treatment (p=0.217). Tuberculomas developed in 74% of patients during treatment and in equal proportions in the treatment groups; they were associated with long-term fever, but not relapse or poor clinical outcome. The basal ganglia were the most common site of infarction; the proportion with infarction after 60 days was halved in the dexamethasone group (27%vs 58%, p=0.130). INTERPRETATION: Dexamethasone may affect outcome from tuberculous meningitis by reducing hydrocephalus and preventing infarction. The effect may have been under-estimated because the most severe patients could not be scanned.

Dexamethasone for the treatment of tuberculous meningitis in adolescents and adults.

BACKGROUND: Tuberculous meningitis kills or disables more than half of those affected with the disease. Previous studies have been too small to determine whether adjunctive treatment with corticosteroids can reduce the risk of disability or death among adults with tuberculous meningitis, and the effect of coinfection with the human immunodeficiency virus (HIV) is unclear. METHODS: We performed a randomized, double-blind, placebo-controlled trial in Vietnam in patients over 14 years of age who had tuberculous meningitis, with or without HIV infection, to determine whether adjunctive treatment with dexamethasone reduced the risk of death or severe disability after nine months of follow-up. We conducted prespecified subgroup analyses and intention-to-treat analyses. RESULTS: A total of 545 patients were randomly assigned to groups that received either dexamethasone (274 patients) or placebo (271 patients). Only 10 patients (1.8 percent) had been lost to follow-up at nine months of treatment. Treatment with dexamethasone was associated with a reduced risk of death (relative risk, 0.69; 95 percent confidence interval, 0.52 to 0.92; P=0.01). It was not associated with a significant reduction in the proportion of severely disabled patients (34 of 187 patients [18.2 percent] among survivors in the dexamethasone group vs. 22 of 159 patients [13.8 percent] in the placebo group, P=0.27) or in the proportion of patients who had either died or were severely disabled after nine months (odds ratio, 0.81; 95 percent confidence interval, 0.58 to 1.13; P=0.22). The treatment effect was consistent across subgroups that were defined by disease-severity grade (stratified relative risk of death, 0.68; 95 percent confidence interval, 0.52 to 0.91; P=0.007) and by HIV status (stratified relative risk of death, 0.78; 95 percent confidence interval, 0.59 to 1.04; P=0.08). Significantly fewer serious adverse events occurred in the dexamethasone group than in the placebo group (26 of 274 patients vs. 45 of 271 patients, P=0.02). CONCLUSIONS: Adjunctive treatment with dexamethasone improves survival in patients over 14 years of age with tuberculous meningitis but probably does not prevent severe disability.

Avian influenza A (H5N1) in 10 patients in Vietnam.

BACKGROUND: Recent outbreaks of avian influenza A (H5N1) in poultry throughout Asia have had major economic and health repercussions. Human infections with this virus were identified in Vietnam in January 2004. METHODS: We report the clinical features and preliminary epidemiologic findings among 10 patients with confirmed cases of avian influenza A (H5N1) who presented to hospitals in Ho Chi Minh City and Hanoi, Vietnam, in December 2003 and January 2004. RESULTS: In all 10 cases, the diagnosis of influenza A (H5N1) was confirmed by means of viral culture or reverse transcriptase-polymerase chain reaction with primers specific for H5 and N1. None of the 10 patients (mean age, 13.7 years) had preexisting medical conditions. Nine of them had a clear history of direct contact with poultry (median time before onset of illness, three days). All patients presented with fever (temperature, 38.5 to 40.0 degrees C), respiratory symptoms, and clinically significant lymphopenia (median lymphocyte count, 700 per cubic millimeter). The median platelet count was 75,500 per cubic millimeter. Seven patients had diarrhea. In all patients, there were marked abnormalities on chest radiography. There was no definitive evidence of human-to-human transmission. Eight patients died, one patient has recovered, and one is recovering. CONCLUSIONS: Influenza A (H5N1) infection, characterized by fever, respiratory symptoms, and lymphopenia, carries a high risk of death. Although in all 10 cases the infection appears to have been acquired directly from infected poultry, the potential exists for genetic reassortment with human influenzaviruses and the evolution of human-to-human transmission. Containment of influenza A (H5N1) in poultry throughout Asia is therefore urgently required.

Dihydroartemisinin-piperaquine against multidrug-resistant Plasmodium falciparum malaria in Vietnam: randomised clinical trial.

BACKGROUND: Southeast Asia has the most resistant malaria parasites in the world, which severely limits treatment options. There is general acceptance that to combat resistance, combinations of antimalarial drugs that include an artemisinin derivative should be used, and, if possible, these should be formulated in a single tablet. METHODS: We did a pilot randomised study in a tertiary referral hospital in Vietnam to compare the efficacy of 3-day regimens of dihydroartemisinin-trimethoprim-piperaquine (DHA-TP total dose 4.8/13.6/48 mg/kg, respectively) with the standard antimalarial regimen in Vietnam, artesunate-mefloquine (A3M total dose 12/25 mg/kg, respectively) in non-immune patients with uncomplicated Plasmodium falciparum malaria. 114 patients were randomised, 76 to DHA-TP and 38 to A3M. The subsequent open randomised trial at a Provincial Health Station compared DHA-TP, dihydroartemisinin-piperaquine, and A3M in 400 patients. In both studies all patients received directly observed therapy and were followed up for 56 days. The primary endpoint was reappearance of P falciparum malaria within 56 days of treatment. Analysis was by intention to treat. FINDINGS: The 56-day cure rate in the pilot study, adjusted for reinfections identified by PCR genotyping, was 97.4% (74/76) in the DHA-TP group and 100% (38/38) in the A3M group. In the second study, cure rates were similar in the three groups; DHA-TP 97.4% (153/157), dihydroartemisinin-piperaquine 98.7% (164/166), and A3M 98.7% (76/77). The DHA-TP and dihydroartemisinin-piperaquine regimens were well tolerated; fewer than 3% of patients had side-effects that might have been related to treatment, compared with 16% of A3M patients (p<0.001). No patients were lost to follow-up. INTERPRETATION: Dihydroartemisinin-piperaquine is an inexpensive, safe, highly efficacious fixed-dose antimalarial combination treatment that could make an important contribution to the control of multidrug-resistant falciparum malaria.

Magnetic Fe(2)MO(4) (M:Fe, Mn) activated carbons: fabrication, characterization and heterogeneous Fenton oxidation of methyl orange.

We present a simple and efficient method for the fabrication of magnetic Fe(2)MO(4) (M:Fe and Mn) activated carbons (Fe(2)MO(4)/AC-H, M:Fe and Mn) by impregnating the activated carbon with simultaneous magnetic precursor and carbon modifying agent followed by calcination. The obtained samples were characterized by nitrogen adsorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM), and the catalytic activity in heterogeneous Fenton oxidation of methyl orange (MO) was evaluated. The resulting Fe(2)MnO(4)/AC-H showed higher catalytic activity in the methyl orange oxidation than Fe(3)O(4)/AC-H. The effect of operational parameters (pH, catalyst loading H(2)O(2) dosage and initial MO concentration) on degradation performance of the oxidation process was investigated. Stability and reusability of selected catalyst were also tested.

Activated carbon/Fe(3)O(4) nanoparticle composite: fabrication, methyl orange removal and regeneration by hydrogen peroxide.

In the water treatment field, activated carbons (ACs) have wide applications in adsorptions. However, the applications are limited by difficulties encountered in separation and regeneration processes. Here, activated carbon/Fe(3)O(4) nanoparticle composites, which combine the adsorption features of powdered activated carbon (PAC) with the magnetic and excellent catalytic properties of Fe(3)O(4) nanoparticles, were fabricated by a modified impregnation method using HNO(3) as the carbon modifying agent. The obtained composites were characterized by X-ray diffraction, scanning and transmission electron microscopy, nitrogen adsorption isotherms and vibrating sample magnetometer. Their performance for methyl orange (MO) removal by adsorption was evaluated. The regeneration of the composite and PAC-HNO(3) (powdered activated carbon modified by HNO(3)) adsorbed MO by hydrogen peroxide was investigated. The composites had a high specific surface area and porosity and a superparamagnetic property that shows they can be manipulated by an external magnetic field. Adsorption experiments showed that the MO sorption process on the composites followed pseudo-second order kinetic model and the adsorption isotherm date could be simulated with both the Freundlich and Langmuir models. The regeneration indicated that the presence of the Fe(3)O(4) nanoparticles is important for a achieving high regeneration efficiency by hydrogen peroxide.

A randomised trial evaluating the safety and immunogenicity of the novel single oral dose typhoid vaccine M01ZH09 in healthy Vietnamese children.

BACKGROUND: The emergence of drug resistant typhoid fever is a major public health problem, especially in Asia. An oral single dose typhoid vaccine would have major advantages. M01ZH09 is a live oral single dose candidate typhoid vaccine containing Salmonella enterica serovar Typhi (Ty2 aroC(-)ssaV(-)) ZH9 with two independently attenuating deletions. Studies in healthy adults demonstrated immunogenicity and an acceptable safety profile. OBJECTIVES: We conducted a randomised placebo controlled, single-blind trial to evaluate the safety and immunogenicity of M01ZH09 in healthy Vietnamese children aged 5 to 14 years. METHODS: Subjects were randomly assigned to receive either a nominal dose of 5x10(9) CFU of M01ZH09 or placebo and were followed up for 28 days. The primary safety outcome was the proportion of subjects with any adverse event attributed to M01ZH09. The primary immunogenicity endpoint was the proportion of subjects who showed a positive immune response to M01ZH09 in the Salmonella Typhi lipopolysaccharide (LPS) specific serum IgA and IgG ELISA. PRINCIPAL FINDINGS: One hundred and fifty-one children were enrolled, 101 subjects received M01ZH09 and 50 subjects received placebo. An intention to treat analysis was conducted. There were no serious adverse events and no bacteraemias. In the M01ZH09 group, 26 (26%; 95% CI, 18-5%) of 101 subjects experienced adverse events compared to 11 (22%; 95% CI, 12-36%) of 50 subjects in the placebo group (odds ratio (OR) [95%CI] = 1.23 [0.550-2.747]; p = 0.691). Faecal shedding of S. Typhi (Ty2 aroC(-)ssaV(-)) ZH9 was detected in 51 (51%; 95% CI, 41-61%) of 100 M01ZH09 subjects. No shedding was detected beyond day 3. A positive immune response, defined as 70% increase (1.7 fold change) in LPS specific serum IgG (day 14 or 28) and/or 50% increase (1.5 fold change) in LPS specific serum IgA (day 7 or 14) from baseline was detected in 98 (97%; 95% CI, 92-99%) of 101 M01ZH09 recipients and 8 (16%; 95% CI, 7-29%) of 50 placebo recipients. Twenty-eight (100%; 95% CI, 88-100%) of 28 vaccine recipients who were evaluated in the LPS specific IgA ELISPOT assay showed a positive response compared to none of the 14 placebo recipients tested. CONCLUSIONS: This was the first phase II trial of a novel oral candidate typhoid vaccine in children in an endemic country. M01ZH09 had an appropriate safety profile and was immunogenic in children. TRIAL REGISTRATION: Controlled-trials.com ISRCTN91111837.