A sticky situation: the unexpected stability of malaria elimination

Malaria eradication involves eliminating malaria from every country where transmission occurs. Current theory suggests that the post-elimination challenges of remaining malaria-free by stopping transmission from imported malaria will have onerous operational and financial requirements. Although resurgent malaria has occurred in a majority of countries that tried but failed to eliminate malaria, a review of resurgence in countries that successfully eliminated finds only four such failures out of 50 successful programmes. Data documenting malaria importation and onwards transmission in these countries suggests malaria transmission potential has declined by more than 50-fold (i.e. more than 98%) since before elimination. These outcomes suggest that elimination is a surprisingly stable state. Elimination''s ‘stickiness’ must be explained either by eliminating countries starting off qualitatively different from non-eliminating countries or becoming different once elimination was achieved. Countries that successfully eliminated were wealthier and had lower baseline endemicity than those that were unsuccessful, but our analysis shows that those same variables were at best incomplete predictors of the patterns of resurgence. Stability is reinforced by the loss of immunity to disease and by the health system''s increasing capacity to control malaria transmission after elimination through routine treatment of cases with antimalarial drugs supplemented by malaria outbreak control. Human travel patterns reinforce these patterns; as malaria recedes, fewer people carry malaria from remote endemic areas to remote areas where transmission potential remains high. Establishment of an international resource with backup capacity to control large outbreaks can make elimination stickier, increase the incentives for countries to eliminate, and ensure steady progress towards global eradication. Although available evidence supports malaria elimination''s stickiness at moderate-to-low transmission in areas with well-developed health systems, it is not yet clear if such patterns will hold in all areas. The sticky endpoint changes the projected costs of maintaining elimination and makes it substantially more attractive for countries acting alone, and it makes spatially progressive elimination a sensible strategy for a malaria eradication endgame.     

On the present situation of vultures in Bulgaria: A review

Abstract

A review of the literature indicated that about 100 pairs of Egyptian Vultures, less than five pairs each of Griffon Vultures and Black Vultures and no more Lammergeiers breed in Bulgaria.     

Actual situation in Fusarium taxonomy

The importance of choosing the proper systematic system in Fusarium taxonomy is stated and a comparative listing of synonyms of the sections Sporotrichiella, Roseum, Liseola, Discolor, Gibbosum, Martiella, as used by various authors in three monographs, is given (2, 4, 9).     

A sticky situation: CCN1 promotes both proliferation and apoptosis of cancer cells

Connective tissue growth factor (CTGF/CCN2) is overexpressed in diabetes. Diabetic rats possess myocardial and cardiomyocyte hypertrophy. In a recent report, Wang and colleagues (Am J Physiol Cell Physiol. 2009 Jul 22. [Epub ahead of print]) show that CCN2 directly mediates cardiomyocyte hypertrophy as well as that induced by high glucose and fatty acid. CCN2 acted via the TrkA receptor. These data are the subject of this commentary, and emphasize that CCN2 may be an excellent target for therapy in diabetes.     

A situation in which a local nontoxic refuge promotes pest resistance to toxic crops

In order to delay the development of pest resistance to genetically engineered insecticidal crop varieties, it is current practice to grow "refugees" of non-toxic plants close to insecticidal crops. We model such a toxic/nontoxic crop complex as an open system with a small stream of toxin-susceptible immigrants. We find that, for intermediate values of the dominance of a pest gene for resistance to the toxin, the local refuge can spoil the benefit that is provided by the immigrant stream. We provide formulas for some important boundaries in parameter space.     

JAB1/CSN5 and the COP9 signalosome. A complex situation

The Jun activating binding protein (JAB1) specifically stabilizes complexes of c-Jun or JunD with AP-1 sites, increasing the specificity of target gene activation by AP-1 proteins. JAB1 is also known as COP9 signalosome subunit 5 (CSN5), which is a component of the COP9 signalosome regulatory complex (CSN). Over the past year, JAB1/CSN5 has been implicated in numerous signaling pathways including those that regulate light signaling in plants, larval development in Drosophila, and integrin signaling, cell cycle control, and steroid hormone signaling in a number of systems. However, the general role of the CSN complex, and the specific role of JAB1/CSN5, still remain obscure. This review attempts to integrate the available data to help explain the role of JAB1/CSN5 and the COP9 signalosome in regulating multiple pathways (in this review, both JAB1 and CSN5 terminologies are used interchangeably, depending on the source material).     

Antioxidants: current situation and perspectives

In the overview one can find analysis medico-biological aspects of free radical theory, clinical experience of antioxidants using, perspectives of new active agents and possible directions of theirs practical use.     

肾小球肾炎动物模型研究概况

肾小球肾炎(glomerulonephritis,GN)是泌尿系统的常见病、多发病,分为急性肾小球肾炎和慢性肾小球肾炎。本文对内源性肾小球肾炎和外源性肾小球肾炎动物模型的造模机理、造模方法等方面进行了归纳和总结。     

Lyme borreliosis situation in North Africa

Many epidemiological studies were conducted for studying Lyme borreliosis (LB) which represents a new global public health problem. It is now the most common vector-borne disease in Europe and North America. The causative agent Borrelia burgdorferi sl is a bacterial species complex comprising 12 delineated and named species. In North Africa, few studies based on clinical and serological features, have suggested that LB could occur. Indeed, recent studies conducted in Tunisia, Algeria and Morocco have showm that Ixodes ricinus is present in cooler and humid area of these regions. These studies also revealed that this species is a vector of B. burgdorferi sl with high prevalence of infection. Using IFI and PCR tests, the mean rate of Borrelia-infection ranged from 50 to 60% in I. ricinus adult collected in Tunisia and Morocco and from 30 to 40% in nymphs; in contrast, the prevalence in larvae is less than 2.5%. Several strains of B. burgdorfer were isolated from adult and nymph I ricinus collected in Tunisia and Morocco. The identification of these strains and DNAs directly extracted from Ixodes was done by PCR-RFLP and sequence analysis. The results showed that B. lusitaniae (genotypes Poti B2 and Poti B3) is the predominant species circulating in I. ricinus in Tunisia and Morocco, B. garinii and B. burgdorferi ss and B lusitaniae were also present but very rare. These results provide the evidence for the existence of B. burgdorferi sl in North Africa; however, the impact of LB in the human population seem to be negligible and the seroprevalence of Borrelia in forest workers (considered as population at high risk) in Tunisia is less than 4%.     

Disease resistance in tomato: practical situation

Tomato crops are parasitised by a large and ever increasing number of pathogens. For tomato, the genetic control of pathogens is very used in practice. The sources of resistance occur monogenic and dominant. Their sources are the wild species closely related to the cultivated form. Many open-pollinated varieties presently cultivated posses genetic resistance to three or four pathogens. With the increasing use of F1 hybrids it is possible to use varieties cumulating four to six resistances. During the last years several new resistances were identified and breeders are introducing these in modern varieties cumulating various resistances and particular qualities now required by specific markets, notably fruit long life and good taste. Some interesting resistances are difficult to select. There are the cases with the oligogenic partial resistances also when the resistance tests are difficult to carry out. In some cases using molecular markers can permit the selection. The wild species of Lycopersicon continue to be the hope to control diseases and pests. Nevertheless, modern varieties derived from interspecific crosses can be sources of new resistances sometimes linked to the expected resistances. New hopes appear with the transgenosis, notably to control various viruses. The present practical situation of the genetic resistance is presented for various cultural conditions.