Immunization of cattle with a semi-purified fraction of solubilized membrane-bound antigens extracted from the midgut of the tickRhipicephalus appendiculatus

Boran cattle were immunized with a semi-purified fraction (F₂) of solubilized membrane-bound antigens extracted from the midgut of the tickRhipicephalus appendiculatus. A subsequent challenge with all stages ofR. appendiculatus showed protection of the cattle to a significant degree. There was a decrease in engorgement weight of ticks, the number which fed above critical engorgement weight was considerably reduced, and about 38% of the larvae which fed to repletion did not moult. The major cause of death of adult female ticks was the increased grooming by cattle as a result of increased dermal irritation.     

Somatostatin inhibits neutrophil elastase release in vitro

The influence of the long-acting somatostatin analogue, SMS 201-995, on FMLP-induced neutrophil elastase release in vitro has been investigated. Doses from 150 ng/ml upwards inhibited elastase release, with 100% inhibition by 2500 ng/ml. Inhibition was demonstrated both by an assay measuring elastase immunometrically and by an assay based on its enzyme activity. The demonstration that SMS 201-995 inhibits protease release from polymorphonuclear leukocytes may have implications for the long-term clinical use of this somatostatin analogue.     

Focus: Zoonotic Disease: New Series of Imidazoles Showed Promising Growth Inhibitory and Curative Potential Against Trypanosoma Infection

The Trypanosoma spp. cause animal and human trypanosomiasis characterized with appreciable health and economic burden mostly in developing nations. There is currently no effective therapy for this parasitic disease, due to poor drug efficacy, drug resistance, and unwanted toxicity, etc. Therefore, new anti-Trypanosoma agents are urgently needed. This study explored new series of imidazoles for anti-Trypanosoma properties in vitro and in vivo. The imidazoles showed moderate to strong and specific action against growth of T. congolense. For example, the efficacy of the imidazole compounds to restrict Trypanosoma growth in vitro was ≥ 12-fold specific towards T. congolense relative to the mammalian cells. Additionally, the in vivo study revealed that the imidazoles exhibited promising anti-Trypanosoma efficacy corroborating the in vitro anti-parasite capacity. In particular, three imidazole compounds (C1, C6, and C8) not only cleared the systemic parasite burden but cured infected rats after no death was recorded. On the other hand, the remaining five imidazole compounds (C2, C3, C4, C5, and C7) drastically reduced the systemic parasite load while extending survival time of the infected rats by 14 days as compared with control. Untreated control died 3 days post-infection, while the rats treated with diminazene aceturate were cured comparable to the results obtained for C1, C6, and C8. In conclusion, this is the first study demonstrating the potential of these new series of imidazoles to clear the systemic parasite burden in infected rats. Furthermore, a high selectivity index of imidazoles towards T. congolense in vitro and the oral LD₅₀ in rats support anti-parasite specific action. Together, findings support the anti-parasitic prospects of the new series of imidazole derivatives.     

Modeling population growth and site specific control of the invasive Lantana camara L. (Verbenaceae) under differing fire regimes

It is at the population level that an invasion either fails or succeeds. Lantana camara L. (Verbenaceae) is a weed of great significance in Queensland Australia and globally but its whole life-history ecology is poorly known. Here we used 3 years of field data across four land use types (farm, hoop pine plantation and two open eucalyptus forests, including one with a triennial fire regime) to parameterise the weed’s vital rates and develop size-structured matrix models. Lantana camara in its re-colonization phase, as observed in the recently cleared hoop pine plantation, was projected to increase more rapidly (annual growth rate, λ = 3.80) than at the other three sites (λ 1.88–2.71). Elasticity analyses indicated that growth contributed more (64.6 %) to λ than fecundity (18.5 %) or survival (15.5 %), while across size groups, the contribution was of the order: juvenile (19–27 %) ≥ seed (17–28 %) ≥ seedling (16–25 %) > small adult (4–26 %) ≥ medium adult (7–20 %) > large adult (0–20 %). From a control perspective it is difficult to determine a single weak point in the life cycle of lantana that might be exploited to reduce growth below a sustaining rate. The triennial fire regime applied did not alter the population elasticity structure nor resulted in local control of the weed. However, simulations showed that, except for the farm population, periodic burning could work within 4–10 years for control of the weed, but fire frequency should increase to at least once every 2 years. For the farm, site-specific control may be achieved by 15 years if the biennial fire frequency is tempered with increased burning intensity.     

A risk‐based inventory of invasive plant species of Queensland,Australia: Regional,ecological and floristic insights

Invasive alien plant species threaten agriculture and biodiversity globally and require ongoing management to minimise impacts. However, the large number of invasive species means that a risk‐based approach to prioritisation is needed, taking into account the spatial scale of management decisions and myriad of available information. Here, we developed a risk‐based inventory of invasive plants in Queensland, Australia, using both current species distribution/abundance and the severity of their impacts. Our assessment followed a comprehensive data collection process including a scoping of local government pest management plans, herbarium records, the published literature and structured elicitation of expert knowledge during a series of regional stakeholder workshops. From ~300 plant species that were identified as established and/or emerging invaders in the State, only one‐third were considered by practitioners to pose significant risks across regions to be considered management priorities. We aggregated regional species lists into a statewide priority list and analysed the data set (107 species) for historical, geographical, floristic and ecological patterns. Regions on the mainland eastern seaboard of the State share similar invasive plant communities, suggesting that these regions may form a single management unit, unlike the western/inland and the extreme far north (Torres Strait Islands) regions, which share fewer invasive plant species. Positive correlations were detected between invasiveness and time since introduction for some but not all plant life forms. Stakeholders identified research and management priorities for the invasive plant list, including biological control options, public awareness/education, effective herbicide use, ecology/taxonomy and risk analysis. In the course of the exercise, a statewide invasive plant priority list of high‐, medium‐ and low‐impact scores for policy, research and management was compiled. Finally, our approach to invasive plant species prioritisation highlighted that planning and policy documents are not necessarily reflected at the grass‐root level in terms of species identity and management priorities.     

How Do Different Watering Regimes Affect the Growth,Chlorophyll Fluorescence,Phytohormone, and Phenolic Acid Content of Greenhouse-Grown Ceratotheca triloba?

We evaluated the effect of different watering regimes on the growth, chlorophyll fluorescence, phytohormones, and phenolic acids in Ceratotheca triloba (Bernh.) Hook.f., a commonly consumed African indigenous leafy vegetable. The study was conducted in the greenhouse under different watering regimes [seven (daily); three (thrice); two (twice); one (once) day(s) per week] for a period of 2 and 4-months. In each pot (7.5 cm diameter; 150 ml volume), 50 ml of water was applied per treatment. At the end of the experiment, plant growth, chlorophyll fluorescence, phytohormones, and phenolic acids were determined. A decrease in water availability resulted in a consistent decline in plant growth after a 4-month growth period. The severity of reduced water availability was more noticeable in plants watered once a week with a 1.4-fold reduction in growth and quantum efficiency of PSII (Fv/Fm) value of 0.80. The significant decline in growth and chlorophyll fluorescence was probably due to the increased production of abscisic acid (ABA) and cytokinin (CK) content together with the detected phytohormones in plants with restricted water supply. Furthermore, plants watered once a week had a trade-off between growth and phenolic acid production, with significantly higher (threefolds) concentrations of vanillic, ferulic, caffeic, and 4-coumaric acids in 4-month-old plants. Even though C. triloba grew best in well-watered soil, the plant had the potential to adapt and survive in soils with limited water supply for longer periods of growth. These findings suggest that regulation of phytohormones and phenolic acids played an important role in improving the growth of C. triloba under limited water conditions.

     

Ticks and Tick-Borne Diseases of Livestock Belonging to Resource-poor Farmers in the Eastern Free State of South Africa

The paper provides a summary of three studies conducted in the eastern Free State of South Africa between 1998 and 2000. In a questionnaire-based study approximately 21% of interviewed resource-poor farmers (n = 150) indicated that they experienced problems with ticks and tick-borne diseases. About 56% of farmers indicated that tick-related problems were most severe in summer, while 32% indicated that the most problems were encountered in winter. About 12% indicated that the tick problems were experienced throughout the year. Farmers also indicated that the highest tick burdens were experienced between spring and early winter. The principal ticks infesting cattle (n = 30) were found to be Boophilus decoloratus (53.1%), Rhipicephalus evertsi evertsi (44.7%), Rhipicephalus follis (1.0%), Rhipicephalus gertrudae (0.7%) and Rhipicephalus warburtoni (0.4%). On small stock (n = 188), R. evertsi evertsi (68%) and B. decoloratus (32%) were recorded as the main ticks in the study area. A sero-epidemiological survey of cattle (n = 386) showed that 94% of cattle were sero-positive for Babesia bigemina by IFAT, while 87% were sero-positive for Anaplasma by indirect ELISA. All the animals were sero-negative for Babesia bovis and this is probably because the tick vector, Boophilus microplus, is not present in the study area. All sheep and goats were sero-positive for Theileria species by IFAT while 85% of sheep and 100% of goats tested positive for Anaplasma species by competition inhibition ELISA. The high incidence of positive serological results for B. bigemina and Anaplasma in cattle, and Theileria and Anaplasma in sheep and goats and the absence of clinical cases would indicate that this area is endemically stable for these diseases. This revised version was published online in July 2006 with corrections to the Cover Date.     

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.     

Lead Exposure: A Contributing Cause of the Current Breast Cancer Epidemic in Nigerian Women

The paper discusses various approaches used to investigate biocompatibility by the analysis of metals release by the materials of which orthodontic appliances are made. Analysis of various biomarkers of exposure: saliva, serum, mucosa cells, or urine is used in in vivo tests. In this work, the techniques, results, and conclusions of original papers were compared by the implementation of the concept of a systematic review. The aim of the present work was to report the state-of-the-art in the research on methods used to assess exposure to trace metals from orthodontic appliances. The PubMed search identified 35 studies, among which nine met the selection criteria. The general conclusion in the studies was that metal ions were released mostly in the initial stage of the treatment. However, the majority of studies included 1–2 months long period and did not reflect long-term changes nor the impact of the complete treatment, the duration of which is several years, on the whole organism and the overall accumulation of metals from orthodontic appliances. In studies which evaluated nickel concentrations in blood and urine, long-term metal release was detected and significant differences were found. It leads to the conclusion that nickel ions are released from orthodontic appliances in measurable amounts to human organism.