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The two main Afrotropical malaria vectors - Anopheles coluzzii and An. gambiae - are genetically distinct and reproductively isolated across West Africa. However, populations at the western extreme of their range are assigned as "intermediate" between the two species by whole genome sequence (WGS) data, and as hybrid forms by conventional molecular diagnostics. By exploiting WGS data from 1,190 specimens collected across west Africa via the Anopheles gambiae 1000 Genomes network, we identify a novel putative taxon in the far-west (provisionally named Bissau molecular form), which did not arise by admixture but rather originated at the same time as the split between An. coluzzii and An. gambiae. Intriguingly, these populations lack insecticide resistance mechanisms commonly observed in the two main species. These findings lead to a change of perspective on malaria vector species in the far-west region with potential for epidemiological implications, and a new challenge for genetic-based mosquito control approaches.
RESUMO
This report is a summary of the first SRS-Africa meeting that was held virtually on the 15th of October 2021, to gain information on the status of radiopharmaceutical sciences in Africa. Registration data included information on participants' qualifications and field of work. An independent survey performed in Africa prior to the meeting elicited details of available staff in different countries, facilities and equipment, radionuclides and radiopharmaceuticals used, research undertaken and difficulties experienced. We present here a brief overview of this meeting's topics of discussion, including ongoing research, gaps and challenges, and local opportunities.
Assuntos
Compostos Radiofarmacêuticos , Humanos , ÁfricaRESUMO
An elemental function of brain dopamine is to coordinate cognitive and motor resources for successful exploitation of environmental energy sources. Dopamine transmission, goal-directed behavior, and glucose homeostasis are altered in schizophrenia patients prior to and after initiation of pharmacological treatment. Thus, we investigated the relationship between blood glucose levels and brain dopamine signaling in drug-naïve patients with first-episode psychosis. We quantified blood glucose levels and binding of the dopamine D2/3 receptor agonist radioligand (+)-[11C]-PHNO in 15 medication-naïve patients and 27 healthy volunteers employing positron emission tomography. Whole-brain voxel-wise linear model analysis identified two clusters of significant interaction between blood glucose levels and diagnosis on (+)-[11C]-PHNO binding-potential values. We observed positive relationships between blood glucose levels and binding-potential values in healthy volunteers but negative ones in patients with first episode psychosis in a cluster surviving rigorous multiple testing correction located in the in the right ventral tegmental area. Another cluster of homologous behavior, however at a lower level of statistical significance, comprised the ventral striatum and pallidum. Extracellular dopamine levels are a major determinant of (+)-[11C]-PHNO binding in the brain. In line with the concept that increased dopamine signaling occurs when goal-directed behavior is needed for restoring energy supply, our data indicate that in healthy volunteers, extracellular dopamine levels are high when blood glucose levels are low and vice-versa. This relationship is reversed in patients with first-episode psychosis, possibly reflecting an underlying pathogenic alteration that links two seemingly unrelated aspects of the illness: altered dopamine signaling and dysfunctional glucose homeostasis.
Assuntos
Dopamina , Esquizofrenia , Glicemia , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Radioisótopos de Carbono , Agonistas de Dopamina , Humanos , Tomografia por Emissão de Pósitrons , Receptores de Dopamina D3/metabolismo , Esquizofrenia/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
The very promising results of Na-trans-[RuCl4(1H-indazole)2] (NKP-1339) in clinical studies have fuelled renewed interest in the research and development of ruthenium(III) coordination compounds for cancer therapy. By applying an improved synthetic approach to this class of coordination compounds, six new examples of the general formula (cation)-trans-[RuCl4(azole)2], where (cation) = tetrabutylammonium (Bu4N)(+) (1, 2), sodium (3, 4), azolium (5, 6), and azole = 1-methyl-indazole (1, 3, 5), 1-ethyl-indazole (2, 4, 6), have been prepared. All compounds have been characterized by elemental analysis, electrospray ionization (ESI) mass spectrometry, UV-vis-, and NMR-spectroscopy and, if possible, X-ray diffraction analysis. Furthermore, the influence of the alkyl substituent at the position N1 of the indazole backbone on the stability in aqueous media as well as on the biological activity in three human cancer cell lines (CH1, A549, and SW480) and on the cellular accumulation in SW480 cells is discussed.
Assuntos
Antineoplásicos/síntese química , Complexos de Coordenação/farmacologia , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Análise Espectral/métodosRESUMO
Explants of mature vigorous donor trees of wych elm ( Ulmus glabra Huds.) that had not been previously exposed to Dutch elm disease were investigated for the influence of phytohormones and media on shoot multiplication rates and organogenic capacity. The regenerates were micropropagated from cultures that originated from 15-year-old progeny of plus trees. Two plus trees aged over 70 years showed recalcitrant responses. Thidiazuron in combination with 6-benzylaminopurine (BAP) induced a significantly higher number of shoots per explant than the most optimal BAP treatment (5.88 vs. 3.05 shoots). Woody plant medium and Dubovský minimal medium had no significant effects on shoot formation and multiplication rates. All plantlets raised in vitro were phenotypically normal and successfully hardened to ex vitro conditions. Two experimental field plots with 3-year-old in vitro-propagated trees were established.
Assuntos
Adenina/análogos & derivados , Brotos de Planta/crescimento & desenvolvimento , Tiadiazóis , Ulmus/crescimento & desenvolvimento , Adenina/farmacologia , Compostos de Benzil , Meios de Cultura/farmacologia , Cinetina , Compostos de Fenilureia/farmacologia , Brotos de Planta/efeitos dos fármacos , PurinasRESUMO
The purpose of this review was to examine published research on basic conditioning factors described in Orem's self-care deficit theory of nursing, in order to identify operational definitions, measurement strategies, and the results of the analyses. Thirty-five research articles published between 1987 and 1997 met the criteria for inclusion in the review. Consensus or lack of consensus in operational definitions for specific factors was determined and successful measurement methods were identified. Recommendations are made for revising conceptual and operational definitions. Suggested measurement strategies for the factors are discussed.