Status of phosphatase activities in the liver and kidney of rats treated with isosaline leaf and stem-bark extracts of Harungana madagascariensis (L)

The activities of phosphatases and other biochemical parameters were examined in rats treated with isosaline leaf and stem-bark extracts of Harungana madagascariensis (L). Results show that both the leaf and stem-bark extracts significantly increased the activities of serum and liver alkaline phosphatase, liver acid phosphatase, liver and kidney glucose-6-phosphatase, fructose-1,6-diphosphatase and glycogen in the treated rats. While the stem-bark extract significantly elevated the activities of fructose-1,6-diphosphatase and glycogen in the kidney, these biochemical parameters were not affected by treatment with the leaf extract. The activity of serum acid phosphatase was unaffected by the two extracts. The results obtained clearly show that these extracts caused a marked increase in gluconeogenesis in the liver and kidney of the treated rats. While the stem-bark extract increased gluconeogenesis in both liver and kidney, the leaf extract caused an increase in gluconeogenesis only in the liver. The increased serum alkaline phosphatase activity caused by these extracts may, aside from having other tissues contributing to it, be due to damage caused by these extracts to the hepatocytes. The extent of pathological changes as well as the implications of these findings to folklore medicine requires further investigation.     

Effects of Adenovirus Type 5 E1A Isoforms on Viral Replication in Arrested Human Cells

Human adenovirus has evolved to infect and replicate in terminally differentiated human epithelial cells, predominantly those within the airway, the gut, or the eye. To overcome the block to viral DNA replication present in these cells, the virus expresses the Early 1A proteins (E1A). These immediate early proteins drive cells into S-phase and induce expression of all other viral early genes. During infection, several E1A isoforms are expressed with proteins of 289, 243, 217, 171, and 55 residues being present for human adenovirus type 5. Here we examine the contribution that the two largest E1A isoforms make to the viral life cycle in growth-arrested normal human fibroblasts. Viruses that express E1A289R were found to replicate better than those that do not express this isoform. Importantly, induction of several viral genes was delayed in a virus expressing E1A243R, with several viral structural proteins undetectable by western blot. We also highlight the changes in E1A isoforms detected during the course of viral infection. Furthermore, we show that viral DNA replication occurs more efficiently, leading to higher number of viral genomes in cells infected with viruses that express E1A289R. Finally, induction of S-phase specific genes differs between viruses expressing different E1A isoforms, with those having E1A289R leading to, generally, earlier activation of these genes. Overall, we provide an overview of adenovirus replication using modern molecular biology approaches and further insights into the contribution that E1A isoforms make to the life cycle of human adenovirus in arrested human fibroblasts.     

Doing No Harm? Adverse Events in a Nation-Wide Cohort of Patients with Multidrug-Resistant Tuberculosis in Nigeria

Background

Adverse events (AEs) of second line anti-tuberculosis drugs (SLDs) are relatively well documented. However, the actual burden has rarely been described in detail in programmatic settings. We investigated the occurrence of these events in the national cohort of multidrug-resistant tuberculosis (MDR-TB) patients in Nigeria.

Method

This was a retrospective, observational cohort study, using pharmacovigilance data systematically collected at all MDR-TB treatment centers in Nigeria. Characteristics of AEs during the intensive phase treatment were documented, and risk factors for development of AEs were assessed.

Results

Four hundred and sixty patients were included in the analysis: 62% were male; median age was 33 years [Interquartile Range (IQR):28–42] and median weight was 51 kg (IQR: 45–59). Two hundred and three (44%) patients experienced AEs; four died of conditions associated with SLD AEs. Gastro-intestinal (n = 100), neurological (n = 75), ototoxic (n = 72) and psychiatric (n = 60) AEs were the most commonly reported, whereas ototoxic and psychiatric AEs were the most debilitating. Majority of AEs developed after 1–2 months of therapy, and resolved in less than a month after treatment. Some treatment centers were twice as likely to report AEs compared with others, highlighting significant inconsistencies in reporting at different treatment centers. Patients with a higher body weight had an increased risk of experiencing AEs. No differences were observed in risk of AEs between HIV-infected and uninfected patients. Similarly, age was not significantly associated with AEs.

Conclusion

Patients in the Nigerian MDR-TB cohort experienced a wide range of AEs, some of which were disabling and fatal. Early identification and prompt management as well as standardized reporting of AEs at all levels of healthcare, including the community is urgently needed. Safer regimens for drug-resistant TB with the shortest duration are advocated.     

Surface eroding, liquid injectable polymers based on 5-ethylene ketal ε-caprolactone

Liquid, injectable hydrophobic polymers are potentially useful as depot systems for localized drug delivery. Low molecular weight polymers of 5-ethylene ketal ε-caprolactone and copolymers of this monomer with D,L-lactide were prepared and their properties assessed with respect to their suitability for this purpose. The polymers were amorphous and of low viscosity, and the viscosity was adjustable by choice of initiator and/or by copolymerizing with D,L-lactide. Lower viscosity polymers were attained by using 350 Da methoxy poly(ethylene glycol) as an initiator in comparison to octan-1-ol, while copolymerization with D,L-lactide increased viscosity. The initiator used had no significant effect on the rate of mass loss in vitro, and copolymers with D,L-lactide (DLLA) degraded faster than 5-ethylene ketal ε-caprolactone (EKC) homopolymers. For the EKC-based polymers, a nearly constant degradation rate was observed. This finding was attributed to the hydrolytic susceptibility of the EKC-EKC ester linkage, which was comparable to that of DLLA-DLLA, coupled with a higher molecular weight of the water-soluble degradation product and the low initial molecular weight of the EKC-based polymers. Cytotoxicity of the hydrolyzed EKC monomer to 3T3 fibroblast cells was comparable to that of ε-caprolactone, suggesting that polymers prepared from EKC may be well tolerated upon in vivo implantation.     

Chemically Modified N-Acylated Hyaluronan Fragments Modulate Proinflammatory Cytokine Production by Stimulated Human Macrophages

Low molecular mass hyaluronans are known to induce inflammation. To determine the role of the acetyl groups of low molecular mass hyaluronan in stimulating the production of proinflammatory cytokines, partial N-deacetylation was carried out by hydrazinolysis. This resulted in 19.7 ± 3.5% free NH₂ functional groups, which were then acylated by reacting with an acyl anhydride, including acetic anhydride. Hydrazinolysis resulted in bond cleavage of the hyaluronan chain causing a reduction of the molecular mass to 30–214 kDa. The total NH₂ and N-acetyl moieties in the reacetylated hyaluronan were 0% and 98.7 ± 1.5% respectively, whereas for butyrylated hyaluronan, the total NH₂, N-acetyl, and N-butyryl moieties were 0, 82.2 ± 4.6, and 22.7 ± 3.8%, respectively, based on ¹H NMR. We studied the effect of these polymers on cytokine production by cultured human macrophages (THP-1 cells). The reacetylated hyaluronan stimulated proinflammatory cytokine production to levels similar to LPS, whereas partially deacetylated hyaluronan had no stimulatory effect, indicating the critical role of the N-acetyl groups in the stimulation of proinflammatory cytokine production. Butyrylated hyaluronan significantly reduced the stimulatory effect on cytokine production by the reacetylated hyaluronan or LPS but had no stimulatory effect of its own. The other partially N-acylated hyaluronan derivatives tested showed smaller stimulatory effects than reacetylated hyaluronan. Antibody and antagonist experiments suggest that the acetylated and partially butyrylated lower molecular mass hyaluronans exert their effects through the TLR-4 receptor system. Selectively N-butyrylated lower molecular mass hyaluronan shows promise as an example of a novel semisynthetic anti-inflammatory molecule.     

Citizenship and Resource Competition in Nigeria

This article discusses the growing tension between constitutionally defined citizenship and socially accepted practices of “we–they dichotomies” as a turbulent component of the national question discourse in Nigeria. It examines the adoption of dual citizenship across the country as well as how this generates violent ethnic conflict. Importantly, while citizenship refers to one’s full membership of a sovereign political community acquired either by birth, naturalisation or any other process legitimised and recognised by the supreme law of the state, indigeneship, on the other hand, is a discriminatory policy employed by local or provincial governments for protecting the rights of their so–called indigenous populations to employment, political power and other resources of the regions or states against domination by alien populations and outsiders. It is argued that while such distinctions have been made possible inter alia by Nigeria’s multi–ethnic character, the ensuing struggles and tensions have been driven by the normless competition over resource allocation. These have especially been the case in instances where ethno–territorial cleavages have been the primary beneficiaries and targets of such resource allocation. This article discusses land as a major economic resource over which heated ethnic conflicts have taken place in Nigeria. Drawing on the conflicts between Hausa–Fulani pastoralists and Yoruba farmers in South–Western Nigeria, it examines the question of how disputed access to land and water has underlain an almost permanent basis of conflict in Nigeria as well as their implications for the country’s fledgling democracy. How does the struggle over land affect the articulation of the citizenship question in Nigeria? How have scarcity and competition over resources affected the contest over citizenship and the forging of nationhood among natives and settlers in South–Western Nigeria? How have colonial framings of socially accepted practices of indigeneship entrenched an understanding of the state in Nigeria as a representation of permanently defined subnational conceptions of ethnic citizenship? What role can the state in Nigeria play towards transforming the multiplicities of traditional societies into coherent political societies as a basis for (i) eliciting deference and devotion from the individual to the claims of the state, and ultimately for (ii) increasing cultural homogeneity, political integration and value consensus? Drawing on data generated from an ethnographic study carried out in South–Western Nigeria between October 2009 and March 2015, this study interrogates these questions.     

In vivo degradation and tissue response to poly(5-ethylene ketal ε-caprolactone-co-D,L-lactide)

Low molecular weight poly(5-ethylene ketal ε-caprolactone-co-D,L-lactide) (PEKCDLLA) is being considered as a viscous liquid, injectable depot for localized drug delivery. This polymer degrades in vitro via surface erosion, which is potentially advantageous for the proposed application. However, the in vivo degradation rate and mechanism, and tissue response, to polymers based on 5-ethylene ketal ε-caprolactone have not yet been reported. The purpose of this study was to measure the in vivo weight loss and change in polymer properties and assess the tissue response to PEKCDLLA after subcutaneous injection in rats. The tissue response was assessed histologically using Masson's trichrome staining and immunohistochemically by staining for CD68 positive cells. The polymer lost weight with time in a nearly linear fashion but did not exhibit significant changes in number average molecular weight, polydispersity index, and glass transition temperature or monomer ratio, consistent with a surface erosion process. The tissue response to the polymer was moderate and comparable to that reported in the literature for other degradable polymers used in clinical applications. These findings indicate that PEKCDLLA is a promising candidate for injectable drug delivery.