Comparative evaluation of the binding properties of two species of Khaya gum polymer in a paracetamol tablet formulation

A study was made of the comparative effects of polymers obtained from two species of khaya tree - Khaya senegalensis and Khaya grandifoliola - as binding agents in a paracetamol tablet formulation. The mechanical properties of the tablets were assessed using the tensile strength (T), brittle fracture index (BFI) and friability (F) of the tablets while the drug release properties of the tablets were assessed using disintegration and dissolution times. The tensile strength, disintegration and the dissolution times of tablets increased with the increase in binder concentration while F and BFI decreased. K. senegalensis gum produced tablets with stronger mechanical properties with less tendency to laminate, and longer disintegration and dissolution times than K. grandifoliola gum. The results suggest that the polymer gum from K. senegalensis will be more appropriate as a binding agent than the gum from K. grandifoliola when higher mechanical strength and slower release profiles of tablets are desired.     

Determination of cadmium and lead in urine of some Nigerian subjects

Forty-one urine samples of smokers and non-smokers from Ile-Ife, Nigeria were analyzed for normal cadmium and lead levels after acid digestion. Results of the preliminary study show that concentrations of cadmium obtained were generally low compared with lead. The mean urinary levels from non-smokers ranged from 0.05 - 0.02 to 0.16 - 0.01 wg ml-1 and from 0.02 - 0.03 to 0.88 - 0.04 wg ml-1 for cadmium and lead respectively, whilst, for smokers, urinary levels varied between 0.07 - 0.01 and 0.23 - 0.02 wg ml-1 and between 0.28 - 0.03 and 1.02 - 0.02 wg ml-1 were obtained for cadmium and lead, respectively. Cd levels in urine of smokers and non-smokers are higher than the recommended normal level of 0.0085 wg ml-1, while levels of Pb are above the 0.08-0.15 wg ml-1 exposure range. Results of spiking experiments with urine gave high percentage recoveries for both elements (Cd, 87.9 - 0.40%) and (Pb, 90.40 - 0.12%). Blank determination was done for background correction.     

Permanent Housing Placement and Reentry to Services Among Family Recipients of Homelessness Prevention and Rapid Re-Housing Program (HPRP) Assistance

The Homelessness Prevention and Rapid Re-Housing Program (HPRP) provided individuals and families who were either at-risk or currently experiencing homelessness with time-limited financial and housing support services. Evaluations of HPRP showed a high rate of family placement into permanent housing. However, little research has explored immediate and longitudinal outcomes for families enrolled in HPRP. Using Homeless Management Information System data from Indianapolis, Indiana, we examined demographic and program-related predictors of families entering permanent housing and their risk of reentry into homeless services following HPRP participation. The sample included 511 families who enrolled in the program from 2009 to 2012, with an average follow-up period of 4.5 years. We conducted analyses separately for Homelessness Prevention (HP) recipients (n?=?357) and Rapid Re-Housing (RRH) recipients (n?=?154). Results revealed that HP families were more likely to enter permanent housing if they: included adults who were older in age, were enrolled longer in the program, were provided rental arrear services and utility payments, and did not receive legal services. RRH families receiving rental assistance services had significantly greater odds of entering permanent housing. Among permanently housed families, at least one family member in 10.9% of HP recipients and 18.8% of RRH recipients reentered homeless services. HP families with younger children and one veteran family member were at increased risk of reentry to homelessness services. RRH recipients who did not receive moving cost services and had more children were at greater risk of reentry. Study findings suggest a need for future research on HP and RRH interventions that identify unique service needs among families who are experiencing housing instability or homelessness.     

The peculiarities of protein and RNA syntheses in the hepatic mitochondria of young and old animals: studies without the use of an antibiotic

Pulse-labelling in the presence of antibiotics is so widely used for studying mitochondriogenesis that the shortcomings of the method is usually overlooked. In this article, we present the results of experiments on the biogenesis of mitochondria done without the use of antibiotics. The method of Kitagawa and Sugimoto (1980) for the estimation of in vivo translational activity of rat liver mitochondria without the use of antibiotics was employed. The syntheses of RNA and protein in rat liver mitochondria of young and old animals was investigated. Incorporation of 14C-ATP into the RNA of isolated mitochondria occurs at the same level in both young and old animals. However, the incorporation of 14C-leucine into the two fractions of mitochondria, i.e. mitochondria protein of nucleo-cytoplasmic origin and those of intrinsic mitochondrial origin are at the same level for young animals. In old animals, the incorporation of the tracer into mitochondrial protein of intrinsic mitochondrial origin (which is at the same level as that of young animals) is three times greater than the incorporation of the tracer into mitochondrial protein of nucleo-cytoplasmic origin. These findings suggest that the role of the mitochondrial genome in the biogenesis of mitochondria increases at senesence and that the synthesis of corresponding regulatory proteins which are of nucleo-cytoplasmic origin decreases at senesence.     

Synthesis of a plasmonic AgCl and oxygen-rich Bi24O31Cl10 composite heterogeneous catalyst for enhanced degradation of tetracycline and 2,4-dichlorophenoxy acetic acid

In this study, a AgCl/Bi₂₄O₃₁Cl₁₀ composite heterostructure was constructed. Varying ratios of AgCl nanoparticles were immobilised onto the Bi₂₄O₃₁Cl₁₀ rod-like structure. The physical and optical properties of the synthesised catalysts were characterised using a range of techniques. The photocatalytic activity of the catalysts was investigated by the degradation of 2,4-dichlorophenoxy acetic acid (2,4-D) and tetracycline (TC) under visible light irradiation. The performance of the composite photocatalysts was 18 and 3.4 times better in 2-4,D and TC photodegradation when compared to Bi₂₄O₃₁Cl₁₀ alone. The improved photocatalytic performance was due to the surface plasmon resonance (SPR) effects of the Ag nanoparticles deposited on the surface of the Xwt%AgCl/BOC thereby improving the separation of the electron–hole pair. The effects of the initial contaminant concentration, pH, photocatalyst loading were investigated. Trapping experiments were also carried out to deduce the reactive species responsible for the degradation process and a preliminary mechanism of degradation was proposed. Successful mineralisation of 2,4-D and TC at 65% and 63% efficiency was also measured after 24 h and the potential for reusability of the as-synthesised photocatalyst was established. This work reports a promising heterogeneous photocatalyst for the removal of pollutants such as TC and 2,4-D from wastewater.

Photocatalytic degradation of tetracycline and 2,4-dichlorophenoxy acetic acid using AgCl/Bi₂₄O₃₁Cl₁₀ photocatalyst in visible light.     

Differential gene expression responses distinguish contact and respiratory sensitizers and nonsensitizing irritants in the local lymph node assay

Genomic approaches have the potential to enhance the specificity and predictive accuracy of existing toxicology endpoints, including those for chemical sensitization. The present study was conducted to determine whether gene expression responses can distinguish contact sensitizers (1-chloro-2,4-dinitrobenzene [DNCB] and hexyl cinnamic aldehyde [HCA]), respiratory sensitizers (ortho-phthalaldehyde and trimellitic anhydride [TMA]), and nonsensitizing irritants (methyl salicylate [MS] and nonanoic acid [NA]) in the local lymph node assay (LLNA). Female Balb/c mice received doses of each chemical as per the standard LLNA dosing regimen on days 1, 2, and 3. Auricular lymph nodes were analyzed for tritiated thymidine ((3)HTdR) incorporation on day 6 and for gene expression responses on days 6 and 10. All chemicals induced dose-dependent increases in stimulation index, which correlated strongly with the number of differentially expressed genes. A majority of genes modulated by the irritants were similarly altered by the sensitizers, consistent with the irritating effects of the sensitizers. However, a select number of responses involved with immune-specific functions, such as dendritic cell activation, were unique to the sensitizers and may offer the ability to distinguish sensitizers from irritants. Genes for the mast cell proteases 1 and 8, Lgals7, Tim2, Aicda, Il4, and Akr1c18 were more strongly regulated by respiratory sensitizers compared with contact sensitizers and may represent potential biomarkers for discriminating between contact and respiratory sensitizers. Collectively, these data suggest that gene expression responses may serve as useful biomarkers to distinguish between respiratory and contact sensitizers and nonsensitizing irritants in the LLNA.     

Depression of the Ca(2+)-ATPase activity of the rat liver endoplasmic reticulum by the liver tumour promoters, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)-ethane and phenobarbital.

The effects of a short-term in vivo administration of two liver tumour promoters (phenobarbital and 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane on rat liver endoplasmic reticulum Ca(2+)-ATPase were investigated. The specific activity values of this membrane-bound enzyme significantly decreased (P less than 0.01) by 51% for phenobarbital-treated rats and by 48% for 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane-treated rats compared with control animals. The depression of liver endoplasmic reticulum Ca(2+)-ATPase appears to be a manifestation of the toxicological effect of tumour promoters.     

Postnatal protein malnutrition induces neurochemical alterations leading to behavioral deficits in rats: Prevention by selenium or zinc supplementation

Background/objectives

Protein malnutrition (PM) is a worldwide problem affecting brain development in a large number of children. The present study was aimed at studying the perturbations in antioxidant defense system resulting from protein deficiency and to evaluate the preventive effect of Se and Zn on cortex and cerebellum.

Methods

Well-fed (WF) and PM rats were fed on 16 and 5% protein diet, respectively. After 10 weeks, animals were supplemented with Se and Zn at a concentration of 0.15 and 227 mg/l in drinking water for 3 weeks.

Results

PM rats showed significant increase in lipid peroxidation, nitrite, and protein carbonyl levels. Reduction in the activity of antioxidant enzymes, thiol levels, GSH/GSSG ratio, and neurobehavioral deficits were observed in PM groups. Se and Zn supplementation reduced the levels of lipid peroxidation, nitrite, and protein carbonyl and restored the activity of antioxidant enzymes and thiol levels in the cortex and cerebellum of PM rats along with neurobehavioral deficits.

Discussion

The study showed that Se and Zn supplementation might be beneficial in preventing biochemical alterations and neurobehavioral deficits in PM children.