η-Allyl-cobalt (II) complexes

(η³-Cyclooctenyl)Co(bisphosphine) compounds react with HBF₄ in the presence of alkenes with oxidation of the metal to give the novel, paramagnetic organocobalt(II) species [(η³-cyclooctenyl)Co(bisphosphine)]⁺BF₄⁻, (η³-2-RC₃H₄)Co(bisphosphine) complexes react similarly. The Co(II) compounds form adducts with CO and NO (the latter being diamagnetic) and undergo facile chemical and electrochemical reduction.     

Critical Reexamination of Palynological Characters Used to Delimit Asclepiadaceae in Comparison to the Molecular Phylogeny Obtained from PlastidmatK Sequences

The family Asclepiadaceae (Dicotyledones) was created by Brown in 1810 by splitting in two the family Apocynaceae of Jussieu established in 1789. The morphological characters used to make this distinction were mainly palynological, such as presence of tetrads or pollinia and number and orientation of pollinia. Those characters, still used in higher taxonomic delimitation (families, subfamilies, and tribes), are here critically reexamined and compared to a molecular phylogeny obtained with one of the more variable plastid genes (matK) of 46 species in the order Gentianales. In this molecular phylogeny, Asclepiadaceae form a monophyletic group derived from within Apocynaceae. Each of the subfamilies of Asclepiadaceae is monophyletic and based on reliable palynological characters, but palynological characters are not useful to delimit tribes of the subfamily Asclepiadoideae. Based on the molecular data, these tribes have undergone parallelisms in several reproductive traits.     

Evaluation of two new commercial tests for the diagnosis of acute dengue virus infection using NS1 antigen detection in human serum

Background

We compared the performance of two new commercial tests for the detection of dengue NS1 protein during the clinical phase of dengue virus (DENV) infection—an immunochromatographic test allowing rapid detection of the NS1 antigen, Dengue NS1 Ag STRIP (Bio-Rad Laboratories - Marnes La Coquette, France), and a two-step sandwich-format microplate enzyme-linked immunosorbent assay (ELISA), pan-E Dengue Early ELISA (Panbio - Brisbane, Australia)—with a one-step sandwich-format microplate ELISA, the Platelia Dengue NS1 Ag test (Bio-Rad).

Methods

We tested 272 serum samples from patients with dengue disease. Of these, 222 were from patients with acute infection of one of the four dengue serotypes, detected by RT-PCR and/or virus isolation. Forty-eight acute-phase serum samples from patients not infected with dengue virus were also included.

Results

The sensitivity of the Platelia Dengue NS1 Ag test on acute serum samples (n = 222) was 87.4% (95% confidence interval: 82.3% to 91.5%); that of Dengue NS1 Ag STRIP was 81.5% (95% CI: 75.8% to 86.4%) after 15 minutes and 82.4% (95% CI: 76.8% to 87.2%) after 30 minutes. Both tests had a specificity of 100% (97.5% CI, one-sided test: 92.6% to 100.0%). The pan-E Dengue Early ELISA had a sensitivity of 60.4% (95% CI: 53.4% to 66.8%) and a specificity of 97.9% (95% CI: 88.9% to 99.9%).

Conclusion

Our findings support the use of diagnostic tools based on the NS1 antigen detection for the diagnosis of acute DENV infection. The immunochromatographic test, Dengue NS1 Ag STRIP—the first rapid diagnostic test for DENV infection—was highly sensitive and specific, and would therefore be a suitable first-line test in the field. The pan-E Dengue Early ELISA was less sensitive than the Platelia test; this two-step ELISA should be combined with DENV IgM antibody detection for the diagnosis of DENV infection.     

Analysis of the Escherichia coli Tol-Pal and TonB systems by periplasmic production of Tol,TonB, colicin,or phage capsid soluble domains

The aim of this review is to describe an in vivo assay of the interactions taking place in the Tol-Pal or TonB-ExbB-ExbD envelope complexes in the periplasm of Escherichia coli and between them and colicins or g3p protein of filamentous bacteriophages. Domains of colicins or periplasmic soluble domains of Tol or TonB proteins can be artificially addressed to the periplasm of bacteria by fusing them to a signal sequence from an exported protein. These domains interact specifically in the periplasm with the Tol or TonB complexes and disturb their function, which can be directly detected by the appearance of specific tol or tonB phenotypes. This technique can be used to detect new interactions, to characterize them biochemically and to map them or to induce tol or tonB phenotypes to study the functions of these two complexes.     

Frailty Markers and Treatment Decisions in Patients Seen in Oncogeriatric Clinics: Results from the ASRO Pilot Study

Background

Comprehensive Geriatric Assessment (CGA) is the gold standard to help oncologists select the best cancer treatment for their older patients. Some authors have suggested that the concept of frailty could be a more useful approach in this population. We investigated whether frailty markers are associated with treatment recommendations in an oncogeriatric clinic.

Methods

This prospective study included 70 years and older patients with solid tumors and referred for an oncogeriatric assessment. The CGA included nine domains: autonomy, comorbidities, medication, cognition, nutrition, mood, neurosensory deficits, falls, and social status. Five frailty markers were assessed (nutrition, physical activity, energy, mobility, and strength). Patients were categorized as Frail (three or more frailty markers), pre-frail (one or two frailty markers), or not-frail (no frailty marker). Treatment recommendations were classified into two categories: standard treatment with and without any changes and supportive/palliative care. Multiple logistic regression models were used to analyze factors associated with treatment recommendations.

Results

217 patients, mean age 83 years (± Standard deviation (SD) 5.3), were included. In the univariate analysis, number of frailty markers, grip strength, physical activity, mobility, nutrition, energy, autonomy, depression, Eastern Cooperative Oncology Group Scale of Performance Status (ECOG-PS), and falls were significantly associated with final treatment recommendations. In the multivariate analysis, the number of frailty markers and basic Activities of Daily Living (ADL) were significantly associated with final treatment recommendations (p<0.001 and p = 0.010, respectively).

Conclusion

Frailty markers are associated with final treatment recommendations in older cancer patients. Longitudinal studies are warranted to better determine their use in a geriatric oncology setting.     

Human immunodeficiency virus type 1 assembly, budding, and cell-cell spread in T cells take place in tetraspanin-enriched plasma membrane domains

Human immunodeficiency virus type-1 (HIV-1) egress from infected CD4+ T cells is thought to be via assembly and budding at the plasma membrane and may involve components of the T-cell secretory apparatus, including tetraspanins. However, many studies on HIV-1 assembly have examined the trafficking of viral proteins in isolation, and most have used immortalized epithelial, fibroblastic, or hematopoietic cell lines that may not necessarily reflect natural infection of susceptible T cells. Here we have used immunofluorescence and cryoimmunoelectron microscopy (CEM) to examine protein transport during HIV-1 assembly in productively infected Jurkat CD4+ T cells and primary CD4+ T cells. The HIV-1 envelope glycoprotein (Env) and the core protein (Gag) colocalize strongly with CD63 and CD81 and less strongly with CD9, whereas no colocalization was seen between Env or Gag and the late endosome/lysosomal marker Lamp2. CEM revealed incorporation of CD63 and CD81 but not Lamp2 into virions budding at the plasma membrane, and this was supported by immunoprecipitation studies, confirming that HIV-1 egress in T cells is trafficked via tetraspanin-enriched membrane domains (TEMs) that are distinct from lysosomal compartments. CD63, CD81, and, to a lesser extent, CD9 were recruited to the virological synapse (VS), and antibodies against these tetraspanins reduced VS formation. We propose that HIV-1 promotes virus assembly and cell-cell transfer in T cells by targeting plasma membrane TEMs.     

Coat condition of ringtailed lemurs,Lemur catta,at Berenty Reserve,Madagascar: II. Coat and tail alopecia associated with Leucaena leucocepahala, 2001–2006

Fur condition in wild ringtailed lemurs, Lemur catta, was recorded during September–November birth seasons 2001–2006 at Berenty Reserve, Madagascar. Body coat condition was scored on a scale from BS 0: full, smooth coat with guard hairs, to BS5: half or more of back and limbs hairless. Tail condition was scored from TS 0: full, to TS 5: half or more hairless. Where troop core areas included stands of Leucaena leucocephala, alopecia was dramatically more frequent than in similar areas without leucaena, including many animals with score BS5 or TS5, “bald lemur syndrome.” Female coats were worse than males,' possibly related to female dominance and access to this preferred food. Tails in non‐leucaena‐feeding females tend to remain full, even if coats deteriorate, but with leucaena‐feeding female tails are highly correlated with coat condition and equally bare. Coat and tail condition in L. catta reflected not only the dietary toxin but individual differences as well as differences between adjacent troops that may result from territorially mediated access to the environment. Leucaena contains the non‐protein amino acid mimosine, a known cause of alopecia, wasting, and organ damage in livestock, although the effects are usually reversible. This is the first case of its effect in wildlife. Leucaena is an agroforestry tree introduced throughout the tropics. In high dietary concentrations leucaena might potentially affect any browsing mammal. Am. J. Primatol. 71:199–205, 2009. © 2008 Wiley‐Liss, Inc.     

Distinguishing between convergence and parallelism is central to comparative biology: a reply to Williams and Ebach

The definitions of character similarity, homology, homoplasy, heterology, parallelism and convergence are clarified in the framework of current phylogenetic methodology. They are all associated with definite patterns of character change and can consequently be tested by phylogeny building. Their crucial significance in comparative biology is illustrated using demonstrative examples. © The Willi Hennig Society 2006.