Subset-specific regulation of the lymphatic exit of recirculating lymphocytes in vivo

The blood-to-lymph recirculation of lymphocytes is required for the maintenance of immune surveillance and the dissemination of memory. Although the ability of lymph-borne cells to recirculate has been well documented, relatively less is known about the migration capacity of PBLs. We have found a clear preference for PBLs to recirculate through s.c. rather than intestinal lymph nodes. This preference could be directly attributed to the migratory characteristics of gammadelta-T cells. gammadelta-T cells were found to express significantly higher levels of L-selectin than other subsets, suggesting that at least some of this preferential migration could be attributed to their interaction with ligands on vascular endothelium. More detailed experiments showed that gammadelta-T cells migrated through lymph nodes with greater efficiency than alphabeta T cells or B cells, which clearly indicated an enhanced ability of gammadelta-T cells to exit lymph nodes in the efferent lymph independent of entry from the blood. This hypothesis was supported by histological examination, where gammadelta-T cells were found almost exclusively in the interfollicular traffic areas within lymph nodes. These data indicate that gammadelta-T cells are the most active recirculating lymphocyte subset in ruminants and suggest new mechanisms to regulate the traffic of lymphocyte subsets through normal lymph nodes.     

Twenty years of research into medicinal plants: Results and perspectives

Over the years 1981 to 2001 there has been a rapid evolution of research into medicinal plants. The major improvement has been the introduction of simple and predictive bioassays for bioactivity-guided isolation. Radical developments in separation methods have also taken place. Another important addition has been the development of hyphenated techniques involving HPLC: LC/UV, LC/MS, LC/MSⁿ and LC/NMR. These are indispensable nowadays for the early detection and identification of new compounds in crude plant extracts. Hyphenated techniques allow an efficient targeted isolation approach for the discovery of new lead compounds. Other areas of increasing importance include the investigation of toxic constituents of plants and phytomedicines, and the effects of genetic modifications on plant secondary metabolites. This revised version was published online in June 2006 with corrections to the Cover Date.     

Complex Epidemiology of a Zoonotic Disease in a Culturally Diverse Region: Phylogeography of Rabies Virus in the Middle East

The Middle East is a culturally and politically diverse region at the gateway between Europe, Africa and Asia. Spatial dynamics of the fatal zoonotic disease rabies among countries of the Middle East and surrounding regions is poorly understood. An improved understanding of virus distribution is necessary to direct control methods. Previous studies have suggested regular trans-boundary movement, but have been unable to infer direction. Here we address these issues, by investigating the evolution of 183 rabies virus isolates collected from over 20 countries between 1972 and 2014. We have undertaken a discrete phylogeographic analysis on a subset of 139 samples to infer where and when movements of rabies have occurred. We provide evidence for four genetically distinct clades with separate origins currently circulating in the Middle East and surrounding countries. Introductions of these viruses have been followed by regular and multidirectional trans-boundary movements in some parts of the region, but relative isolation in others. There is evidence for minimal regular incursion of rabies from Central and Eastern Asia. These data support current initiatives for regional collaboration that are essential for rabies elimination.     

Benthic Community Structure and Invertebrate Drift in a Pacific Island Stream,Kosrae, Micronesia1

Tropical Pacific island streams have poorly understood communities that deserve scientific attention. We examined benthic macroinvertebrates and fishes of the Inem River on Kosrae, Federated States of Micronesia. Larval chironomids, lepidopterans, odonates, and freshwater shrimps dominated the benthos and drift. Diel periodicity in drift was not evident. Nine fishes, two shrimps, and one snail species were identified. Kosrae's stream fauna appears even more depauperate than other Pacific high islands, possible due to its extreme isolation.     

Establishment of Cohesion at the Pericentromere by the Ctf19 Kinetochore Subcomplex and the Replication Fork-Associated Factor,Csm3

The cohesin complex holds sister chromatids together from the time of their duplication in S phase until their separation during mitosis. Although cohesin is found along the length of chromosomes, it is most abundant at the centromere and surrounding region, the pericentromere. We show here that the budding yeast Ctf19 kinetochore subcomplex and the replication fork-associated factor, Csm3, are both important mediators of pericentromeric cohesion, but they act through distinct mechanisms. We show that components of the Ctf19 complex direct the increased association of cohesin with the pericentromere. In contrast, Csm3 is dispensable for cohesin enrichment in the pericentromere but is essential in ensuring its functionality in holding sister centromeres together. Consistently, cells lacking Csm3 show additive cohesion defects in combination with mutants in the Ctf19 complex. Furthermore, delaying DNA replication rescues the cohesion defect observed in cells lacking Ctf19 complex components, but not Csm3. We propose that the Ctf19 complex ensures additional loading of cohesin at centromeres prior to passage of the replication fork, thereby ensuring its incorporation into functional linkages through a process requiring Csm3.     

Cohesin-Dependent Association of Scc2/4 with the Centromere Initiates Pericentromeric Cohesion Establishment

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Highlights? Cohesin is required for the association of its loader, Scc2/4, with centromeres ? The Ctf19 kinetochore subcomplex targets the loader to centromeres ? Centromere-loaded cohesin ensures pericentromeric cohesion establishment ? Cohesin ring formation triggers cohesin loading via Scc2/4     

Evolutionary History and Phylogeography of Rabies Viruses Associated with Outbreaks in Trinidad

Bat rabies is an emerging disease of public health significance in the Americas. The Caribbean island of Trinidad experiences periodic outbreaks within the livestock population. We performed molecular characterisation of Trinidad rabies virus (RABV) and used a Bayesian phylogeographic approach to investigate the extent to which outbreaks are a result of in situ evolution versus importation of virus from the nearby South American mainland. Trinidadian RABV sequences were confirmed as bat variant and clustered with Desmodus rotundus (vampire bat) related sequences. They fell into two largely temporally defined lineages designated Trinidad I and II. The Trinidad I lineage which included sequences from 1997–2000 (all but two of which were from the northeast of the island) was most closely related to RABV from Ecuador (2005, 2007), French Guiana (1990) and Venezuela (1993, 1994). Trinidad II comprised sequences from the southwest of the island, which clustered into two groups: Trinidad IIa, which included one sequence each from 2000 and 2007, and Trinidad IIb including all 2010 sequences. The Trinidad II sequences were most closely related to sequences from Brazil (1999, 2004) and Uruguay (2007, 2008). Phylogeographic analyses support three separate RABV introductions from the mainland from which each of the three Trinidadian lineages arose. The estimated dates for the introductions and subsequent lineage expansions suggest periods of in situ evolution within Trinidad following each introduction. These data also indicate co-circulation of Trinidad lineage I and IIa during 2000. In light of these findings and the likely vampire bat origin of Trinidadian RABV, further studies should be conducted to investigate the relationship between RABV spatiotemporal dynamics and vampire bat population ecology, in particular any movement between the mainland and Trinidad.     

Intensive agriculture and land use at Roman Gordion,central Turkey

Few archaeobotanical studies of Roman agricultural practices and their environmental impact in Anatolia (modern Turkey) have been published. New data from Roman levels at Gordion, a multi-period urban centre in central Anatolia, indicate that free-threshing wheat, most likely Triticum aestivum (bread wheat), was the focus of agricultural practice, in contrast to earlier periods when a more diverse agricultural system included greater amounts of barley and pulses. Evidence for increased levels of irrigation and wood fuel use relative to dung, along with regional overgrazing, provide further evidence for significant change in land-use practices during the Roman period. The emphasis on T. aestivum cultivation coupled with extensive grazing had significant environmental implications, leading to severe overgrazing and soil erosion on a regional scale. Historical sources and limited data from other Roman period sites suggest that similar patterns of agriculture may have been practiced across central Anatolia during the Roman period. We propose that this may have been due to externally imposed demands for taxation or military tribute in the form of wheat, and conclude that these demands led to the adoption of an unsustainable agricultural system at Gordion.     

Insemination timing affects pregnancy rates in beef cows treated with CO-Synch protocol including an intravaginal progesterone insert

Our objective was to determine the optimal time to artificially inseminate lactating beef cows (Bos taurus typicus) after using the standard CO-Synch protocol that also included a progesterone-releasing, intravaginal controlled internal drug release (CIDR) insert. Cows (N = 605) at three locations were inseminated at four different times after CIDR insert removal and the prostaglandin F_2α administration of the CO-Synch + CIDR protocol: 48, 56, 64, or 72 h. Blood samples were collected 9 to 10 d before and on the day of CIDR insertion. Based on elevated (>1 ng/mL) serum progesterone concentrations, 60% of 605 cows had previously ovulated (were cycling) at the initiation of the study, with a range of 39.6% to 67.9% among locations (P < 0.05). Age of cow, body condition score, and days postpartum affected (P ≤ 0.05) cycling status before ovulation was synchronized. Averaged across treatments, pregnancy rate to artificial insemination (AI) at Day 32 was affected (P ≤ 0.05) by pretreatment cycling status and body condition. Younger cows (≤3 yr) tended to have greater AI pregnancy rates when inseminated at 56 h, whereas older cows had similar pregnancy rates when inseminated at 56 h or later (timing of AI by age interaction; P = 0.085). Pregnancy loss between Days 32 and 63 was greatest (quadratic effect; P < 0.05) when cows were inseminated at 48 and 72 h. In summary, insemination times at or after 56 h improved AI pregnancy rates when using the CO-Synch + CIDR program. Further work is warranted to examine age effects on timing of AI in the CO-Synch + CIDR program.