External financial aid to blood transfusion services in sub-Saharan Africa: a need for reflection

Jean-Pierre Allain and colleagues argue that, while unintended, the foreign aid provided for blood transfusion services in sub-Saharan Africa has resulted in serious negative outcomes, which requires reflection and rethinking.

Effects of auditory and physical enrichment on 3 measurements of fear and stress (tonic immobility duration, heterophil to lymphocyte ratio, and fluctuating asymmetry) in several breeds of layer chicks

The purpose of this study was to analyze the effect of auditory enrichment (by means of classical music) or physical enrichment (by means of hanging colored string bunches and barley grains on the floor) on tonic immobility duration, heterophil to lymphocyte ratio, and fluctuating asymmetry (FA) in chicks of several layer breeds. In experiment 1, 192 chicks from 8 Spanish breeds and 1 White Leghorn population were reared in cages with or without music auditory enrichment until 8 wk of age. The effect of music auditory enrichment was significant for heterophil to lymphocyte ratio (P < 0.05). The ratios were higher in chicks reared without music than in those reared with music, suggesting that auditory enrichment from classical music reduces stress in chicks. There were significant differences in morphological trait measurements (relative asymmetry of wing length, leg width, and combined asymmetry; P < 0.05), being greater in chicks reared without music. This result suggests that FA is a good indicator for stress level in chicks, given that it follows the same trend as that found for heterophil to lymphocyte ratio. There was a significant treatment by breed interaction (P < 0.05) for tonic immobility duration, indicating no consistent effect by auditory enrichment on tonic immobility duration across breeds. In experiment 2, 180 chicks from 3 Spanish breeds were housed in pens with or without physical enrichment (colored plastic string bunches and barley grains on the floor) until 6 wk of age. The effect of physical enrichment on tonic immobility duration, heterophil to lymphocyte ratio, and FA was not significant, indicating no effect on fear and stress in layer chicks. In conclusion, auditory enrichment by means of classical music is a reliable method for reducing stress levels in several breeds of layer chicks. However, music auditory enrichment was not effective in reducing fearfulness in any of the layer breeds. Physical enrichment by means of colored plastic string bunches and floor barley grains does not appear to be an effective method for reducing stress and fear in layer chicks.

Determinants of membrane activity from mutational analysis of the HIV fusion peptide

We have synthesized a small library of 38 variants of the 23-residue fusion peptide domain found at the N-terminus of gp41 glycoprotein of HIV. This hydrophobic, glycine-rich sequence is critical for viral infectivity and is thought to be central in the membrane fusion of viral envelope with the host membrane. There has been extensive discussion regarding the origin of fusogenicity in this viral fusion sequence. Our library of fusion peptide variants was designed to address the biophysical importance of secondary structure, peptide flexibility, glycine content, and placement. We assayed each peptide for its ability to induce lipid mixing and membrane permeablization in synthetic vesicles. We find that the viral fusion peptide may be greatly simplified while retaining fusogenic function and minimizing membrane-permeablizing function; to the best of our knowledge, this is the first attempt to optimize fusogenic function of the HIV fusion peptide through sequence variation. Our data show that many flexible, linear, minimally hydrophobic peptides may achieve the biophysical function of fusion; glycine does not appear to be essential. These findings will be useful in the design of synthetic fusogens for cellular delivery.

The low viability of human CD34+ cells under acidic conditions is improved by exposure to thrombopoietin, stem cell factor, interleukin-3, or increased cyclic adenosine monophosphate levels

BACKGROUND

Transplanted hematopoietic progenitor cells (CD34+) have shown great promise in regenerative medicine. However, the therapeutic potential of transplanted cells is limited by their poor viability. It is well known that the microenvironment in which progenitors reside substantially affects their behavior. Because extracellular acidosis is a common feature of injured tissues or the tumor microenvironment and is a critical regulator of cell survival and activation, we evaluated the impact of acidosis on CD34+ cell biology.

STUDY DESIGN AND METHODS

Apoptosis was evaluated by fluorescence microscopy and binding of annexin V, hypodiploid cells, Bcl-xL expression, active caspase-3, and mitochondrial membrane potential was determined by flow cytometry. Colony-forming units were studied by clonogenic assays, and cell cycle was evaluated by flow cytometry.

RESULTS

Exposure of CD34+ cells to low pH (7.0-6.5) caused intracellular acidification, decreased cell proliferation, and triggered apoptosis via the mitochondrial pathway. Whereas exposure to thrombopoietin (TPO), stem cell factor (SCF), interleukin (IL)-3 or increases in cyclic adenosine monophosphate (cAMP) levels prevented CD34+ cell death induced by acidic conditions, granulocyte-macrophage-colony-stimulating factor, FMS-like tyrosine kinase 3-ligand, erythropoietin, and vascular endothelial growth factor had no effect. Despite their cytoprotective effect, CD34+ cell expansion triggered by TPO, SCF, or IL-3 was significantly impaired at low pH. However, a cocktail of these three cytokines synergistically supported proliferation, cell cycle progression, and colony formation.

DISCUSSION

Our findings indicate that an acidic milieu is deleterious for CD34+ cells and that a combination of certain cytokines and cAMP donors may improve cell viability and function. These data may be useful to develop new therapeutic strategies or to optimize protocols for regenerative medicine.

Incidence of HIV type 1 infection, antiretroviral drug resistance, and molecular characterization in newly diagnosed individuals in Argentina: A Global Fund Project

An HIV incidence estimation was performed among men who have sex with men (MSM), drug users (DUs), sex workers (SWs), and pregnant women (PW) from Argentina. Volunteers older than 18 years old without a previous HIV-positive diagnosis were included. HIV-positive samples were analyzed by the Serological Testing Algorithm for Recent HIV Seroconversion (STARHS) to estimate incidence. By partial RT-PCR and sequencing of the HIV pol gene, an HIV subtype and resistance profile were determined. A total of 12,192 volunteers were recruited from October 2006 to September 2008. A higher HIV prevalence was detected among trans SWs (33.9%, 38/112), male SWs (10.8%, 12/111), and MSM 10.4% (161/1549). HIV incidence estimates by STARHS was also higher on trans SWs (11.31 per 100 person-years), male SWs (6.06 per 100 person-years), and MSM (6.36 per 100 person-years). Antiretroviral primary resistant mutations were detected in 8.4% of the study group, with a higher frequency in female DUs (33.3%). Phylogenetic analysis showed that 124 (57.9%) samples were subtype B, 84 (39.3%) intersubtype BF recombinants, 5 (2.3%) subtype C, and 1 (0.5%) subtype F in the pol region. Subtype B was most commonly found in MSM and male SWs whereas the intersubtype BF recombinant was more prevalent in female DUs, female SWs, and PW. Given the high HIV prevalence and incidence found in most of these groups, monitoring the continuing spread of the HIV epidemic is essential for determining public health priorities, assessing the impact of interventions, and estimating current and future health care needs.

Evaluation of the trypanocidal, cytotoxic and genotoxic activity of styrylquinoline analogs

Styrylquinolines isolated from Galipea longiflora have shown leishmanicidal, trypanocidal, nematocidal and antimalarial activity. Here, we propose to use analogs of these styrylquinolines to enhance the activity against Trypanosoma cruzi. Three compounds in a reduced and oxidized state were synthesized, and the activity against epimastigotes and trypomastigotes was evaluated. in addition, the cytotoxic activity and genotoxic effect were also determined. The results indicated that epimastigotes from different T. cruzi I stocks were highly sensitive to the three compounds. The PQM4 compound presented promising activity against trypomastigotes and low cytotoxic and genotoxic effects. Finally, we observed that the doublebond reduction of the lateral chain of the three carbons made on these compounds improved the activity and substantially diminished the toxicity of the compounds.

Junín virus infection of human hematopoietic progenitors impairs in vitro proplatelet formation and platelet release via a bystander effect involving type I IFN signaling

Argentine hemorrhagic fever (AHF) is an endemo-epidemic disease caused by Junín virus (JUNV), a member of the arenaviridae family. Although a recently introduced live attenuated vaccine has proven to be effective, AHF remains a potentially lethal infection. Like in other viral hemorrhagic fevers (VHF), AHF patients present with fever and hemorrhagic complications. Although the causes of the bleeding are poorly understood, impaired hemostasis, endothelial cell dysfunction and low platelet counts have been described. Thrombocytopenia is a common feature in VHF syndromes, and it is a major sign for its diagnosis. However, the underlying pathogenic mechanism has not yet been elucidated. We hypothesized that thrombocytopenia results from a viral-triggered alteration of the megakaryo/thrombopoiesis process. Therefore, we evaluated the impact of JUNV on megakaryopoiesis using an in vitro model of human CD34⁺ cells stimulated with thrombopoietin. Our results showed that CD34⁺ cells are infected with JUNV in a restricted fashion. Infection was transferrin receptor 1 (TfR1)-dependent and the surface expression of TfR1 was higher in infected cultures, suggesting a novel arenaviral dissemination strategy in hematopoietic progenitor cells. Although proliferation, survival, and commitment in JUNV-infected cultures were normal, viral infection impaired thrombopoiesis by decreasing in vitro proplatelet formation, platelet release, and P-selectin externalization via a bystander effect. The decrease in platelet release was also TfR1-dependent, mimicked by poly(I:C), and type I interferon (IFN α/β) was implicated as a key paracrine mediator. Among the relevant molecules studied, only the transcription factor NF-E2 showed a moderate decrease in expression in megakaryocytes from either infected cultures or after type I IFN treatment. Moreover, type I IFN-treated megakaryocytes presented ultrastructural abnormalities resembling the reported thrombocytopenic NF-E2^−/− mouse phenotype. Our study introduces a potential mechanism for thrombocytopenia in VHF and other diseases associated with increased bone marrow type I IFN levels.

Argentine hemorrhagic fever (AHF) is an endemo-epidemic disease caused by Junín virus (JUNV). Although a recently introduced live attenuated vaccine has proven to be effective, AHF remains a potentially lethal infection and JUNV is considered to be a potential biological weapon. Like other viral hemorrhagic fevers (VHF), AHF patients present fever with a combination of neurological and bleeding complications. Although the causes of the bleeding are poorly understood, impaired hemostasis and endothelial cell function as well as low platelet counts have been described. In this study, we have examined the impact of JUNV on an in vitro model of platelet production. We found that neither infection of hematopoietic progenitors with JUNV nor poly(I:C) (a double-stranded RNA that mimics viral infection) affected cell survival or megakaryocyte generation. However, these treatments triggered the main anti-viral cytokines produced by host type I IFN (IFN α/β), which acted in a paracrine fashion and led to abnormal platelet formation. Thus, this study identifies type I IFN as a new regulator that selectively affects the last steps of megakaryocyte lifespan, and it suggests a potential mechanism for thrombocytopenia in AHF and other diseases associated with increased bone marrow type I IFN levels.

Lack of association between macrophage migration inhibitory factor-173 gene polymorphism with disease susceptibility and cardiovascular risk in rheumatoid arthritis patients from northwestern Spain

OBJECTIVES

To assess whether the polymorphism of the macrophage migration inhibitory factor (MIF) gene at the position -173 is implicated in the disease susceptibility, risk of cardiovascular (CV) events and presence of subclinical atherosclerosis in patients with rheumatoid arthritis (RA).

PATIENTS AND METHODS

A series of 293 unselected patients fulfilling the 1987 American College of Rheumatology classification criteria for RA seen at the rheumatology outpatient clinic of Hospital Xeral-Calde, Lugo, Spain and 526 matched controls were studied for differences in the MIF-173 G/C gene biallelic polymorphism. A total of 182 consecutive patients that had been periodically followed between March 1996 and September 1996 until patient's death or January 1, 2008 were assessed for the presence of CV events. Moreover, between March and December 2007, a subgroup of unselected RA patients with no history of CV events was studied for the presence of subclinical atherosclerosis by the assessment of the endothelial function (n=107) and the carotid artery intima-media thickness (IMT) (n=91) by ultrasonography studies. Patients and controls were genotyped for the MIF-173 G/C gene polymorphism using a PCR system with pre-developed TaqMan allelic discrimination assay.

RESULTS

No significant differences in allele or genotype frequencies for the MIF-173 gene polymorphism between RA patients and controls were found. Forty-four of the 182 patients followed between 1996 and January 2008 experienced CV events. Although the frequency of MIF-173 GG homozygous was increased in those who had CV events (88.6%) compared to those who did not suffer these complication (73.2%), the difference was not statistically significant. It was also the case when we analyzed the potential influence of MIF-173 genotypes in the presence of endothelial dysfunction or increased carotid IMT of patients with RA.

CONCLUSIONS

Our results do not show that MIF-173 gene polymorphism may infer a direct risk for disease susceptibility or CV disease in patients with RA.

The interleukin 23 receptor gene does not confer risk to systemic sclerosis and is not associated with systemic sclerosis disease phenotype

Objectives:

Multiple studies indicate the role of the interleukin (IL)-17/IL-23 axis in autoimmune diseases, including systemic sclerosis (SSc). The aim of the current study was to investigate the possible implication of the IL23R gene in SSc susceptibility and/or clinical phenotype.

Methods:

An initial case–control study in 143 Dutch patients with SSc and geographically matched healthy individuals (n = 246) was carried out and followed by a replication study in a cohort of 365 Spanish patients with SSc and 515 healthy individuals. Seven single nucleotide polymorphisms (SNPs) spanning the IL23R gene were selected and genotyped using a Taqman assay.

Results:

Using a Dutch cohort of patients with SSc and controls we observed an association between two (rs11209032, rs1495965) of the seven tested SNPs and disease susceptibility (allelic p values: p = 0.02 and p = 0.01 respectively). However, a replication study in an independent Spanish cohort did not confirm these findings and reveal no association of any of the IL23R-tested SNP with disease susceptibility or clinical phenotype. Similarly, a meta-analysis considering both populations did not reveal any significant association. In addition, no association was observed between IL23R genetic variants and SSc clinical phenotypes.

Conclusions:

Our results suggest that the IL23R gene is not associated with SSc susceptibility or clinical phenotype.

Antigenic differentiation of classical swine fever vaccinal strain PAV-250 from other strains, including field strains from Mexico

Twenty-nine classical swine fever virus (CSFv) strains were grown in the PK15 or SK6 cell lines. Antigenic differentiation studies were performed using monoclonal antibodies (McAbs), produced at Lelystad (CDI-DLO), The Netherlands. The monoclonals which were classified numerically as monoclonals 2-13. Epitope map patterns that resulted from the reactivity with McAbs were found to be unrelated to the pathogenicity of the viruses studied. Antigenic determinants were recognized by McAbs 5 and 8, were not detected in some Mexican strains; however, sites for McAb 6 were absent in all strains. The PAV-250 vaccine strain was recognized by all MAbs, except by MAb 6. Furthermore, the Chinese C-S vaccine strain was found to be very similar to the GPE(-) vaccine. None of the studied Mexican vaccines or field strains was found to be similar to the PAV-250 vaccine strain.

Activation of cyclic AMP pathway prevents CD34(+) cell apoptosis

OBJECTIVE

Although cAMP is involved in a number of physiologic functions, its role in hematopoietic cell fate decision remains poorly understood. We have recently demonstrated that in CD34(+)-derived megakaryocytes, cAMP-related agents prevent apoptosis. In this study we addressed the question of whether cAMP also regulates survival of their precursors, CD34(+) cells.

METHODS

Apoptosis was evaluated by fluorescence microscopy, and detection of hypodiploid or annexin V(+) cells by flow cytometry. Mitochondrial membrane potential and bcl-xL or caspase-3 expression were assessed by flow cytometry. Colony-forming units were studied by clonogenic assays in methylcellulose.

RESULTS

We found that two different cAMP analogs such as Dibutiril-cAMP and sp-5,6-DCl-BIMPS (BIMPS) promoted survival of human umbilical cord-derived CD34(+) cells by suppressing apoptosis induced by either nitric oxide (NO) or serum deprivation. Involvement of PKA and PI3K pathway was demonstrated by the ability of their specific inhibitors Rp-cAMP and Wortmannin or LY294002 respectively to reverse the antiapoptotic effect of BIMPS. Treatment of CD34(+) cell with BIMPS not only restrained the bcl-xL downregulation but also suppressed the loss of mitochondrial membrane potential and caspase-3 activation induced by serum starvation. While thrombopoietin (TPO), granulocyte colony-stimulating factor (G-CSF) or stem cell factor (SCF) were not able to increase cAMP levels, the antiapoptotic activity exerted by these growth factors was blocked by inhibition of the adenylate cyclase and synergized by BIMPS. Cyclic AMP analogs suppressed the decreased colony formation in cells exposed to NO or serum deprivation.

CONCLUSION

Altogether, our results strongly suggest that cAMP appears to be not only a key pathway controlling CD34(+) survival, but also a mediator of the TPO-, G-CSF- and SCF-mediated cytoprotection.

Total gastrectomy with or without abdominal drains. A prospective randomized trial

The most common postoperative complications of total gastrectomy are esophagojejunal anastomotic leakage and subphrenic abscess. These complications are a cause of morbidity and mortality, relaparotomy, and longer postoperative stay. The use of abdominal drains is useful for the early diagnosis and management of anastomotic leaks. The aim of this study was to analyze our experience with total gastrectomy for gastric cancer in patients with and without abdominal drains, and to evaluate the results regarding postoperative morbidity, postoperative hospital stay, postoperative days for oral intake, relaparotomy and mortality. This prospective and randomized study examines the results in 60 consecutive patients (43 males and 17 females) with gastric cancer who underwent total gastrectomy in the Regional Clinical Hospital of Concepción, Chile, between 2000 and 2003. Patients were divided into two groups: group I (without drains) and group II (two drains). We found 31 patients in group I and 29 patients in group II. The mean length of postoperative stay was 12.9 days in group I and 18.8 days in group II (p = 0.0242, s.). Morbidity was 9.7% in group I and 37.9% in group II (p = 0.0242, s.). Re-explorations were more frequent in group II (24.1%) versus group I (9.7%) (p = 0.1239, n.s.). Postoperative days for oral intake were 9.4 in group I and 12.8 in group II (p = 0.0514, n.s.) Mortality was 0% in group I and 3.4% in group II (p = 0.4833, n.s.). In our experience, morbidity and postoperative hospital stay were statistically higher in the group of patients with abdominal drains.