Laboratory Evaluation of a Point-of-Care Downward-Flow Assay for Simultaneous Detection of Antibodies to Treponema pallidum and Human Immunodeficiency Virus.

Combining the detection of syphilis and HIV antibodies into one point-of-care test integrates syphilis screening into already existing HIV screening programs, which may be particularly beneficial in settings such as antenatal care. Using the INSTI Multiplex downward-flow immunoassay, we tested 200 stored serum samples from high-risk patients enrolled in a longitudinal study on HIV infection and syphilis in Peruvian men who have sex with men and transgender women. This rapid assay detected HIV and Treponema pallidum serum antibodies with sensitivities of 100% (95% confidence interval [CI], 95.9% to 100%) and 87.4% (95% CI, 81.4% to 92.0%), respectively, and specificities of 95.5% (95% CI, 89.9% to 98.5%) and 97.0% (95% CI, 84.2% to 99.9%), respectively (n = 200). The sensitivity for syphilis antibody detection was higher in patients with a rapid plasma reagin titer of ≥1:8 (97.3%) than in those with a titer of ≤1:4 (90%) or a nonreactive titer (66.7%).

Structure and chronology of a star dune at Erg Chebbi, Morocco, reveals why star dunes are rarely recognised in the rock record.

Star dunes are the tallest dunes on Earth and are amongst the larger and more spectacular aeolian landforms. Although they are widespread in modern sandy deserts, star dunes are rarely recognised in the rock record probably due to a lack of suitable sedimentary models. This paper presents a new sedimentary model for the structure of a star dune at Erg Chebbi in Morocco (Sahara Desert) on the basis of ground-penetrating radar (GPR) surveys. Individual sedimentary structures in star dunes are similar to those in linear or barchanoid dunes, likely leading to misidentification in the rock record. However, the suite of features described in this paper will permit identification of star dunes in future studies of the rock record. Optically stimulated luminescence (OSL) dating shows that accumulation of the Erg Chebbi star dune post-dates the end of the African Humid Period (AHP). At the base of the dune, there is an ~ 8000-year hiatus in the record. Since then, the dune has grown rapidly to create a 100 m high dune within the past 1000 years and is migrating towards the west. Changes in the cross-strata support the idea that star dune construction was accompanied by a change in the wind directions.

Treehoppers transfer parental care to ants: a new benefit of mutualism.

Female treehoppers (Publilia reticulata Van Duzee) modify their parental care behavior in the presence of ants. Females with untended young remain with their original brood, but females from ant-tended colonies readily desert their first brood and produce additional clutches. Care by female treehoppers, in the absence of ants, increases the probability that a colony will produce some survivors, but ant attendance greatly increases the number of surviving nymphs.

Oral and vaginal HIV pre-exposure prophylaxis product attribute preferences among female sex workers in the Mexico-US border region.

To assess the potential uptake of HIV pre-exposure prophylaxis (PrEP) products among female sex workers (FSWs) vulnerable to HIV infection, we examined the influence of product attributes on willingness to use products among 271 HIV-negative FSWs in Tijuana and Ciudad Juarez, Mexico (2016-2017). Via five-point Likert scale ratings, participants indicated their willingness to use hypothetical products with six attributes: formulation (pill, gel, liquid, or ring), frequency of use (daily, on-demand, or monthly), cost per use (10 or 200 pesos), effectiveness (40% or 80%), side effects (none or mild), and access point (healthcare clinic or non-governmental organization). Conjoint analysis was used to determine the impact of attributes on product ratings and identify preferred product attributes. Multinomial logistic regression was used to identify factors associated with formulation preferences. In both cities, formulation and frequency of use had the greatest impact on ratings. Participants in Ciudad Juarez indicated a strong preference for oral pills, whereas participants in Tijuana indicated roughly equal preferences for oral pills and vaginal gels. Monthly product use was preferred in both cities. Compared to preferring oral pills (38%), preferring vaginal gels (28%) was associated with practicing vaginal lubrication (adjusted odds ratio = 2.08; 95% confidence interval: 1.07-4.04). Oral PrEP may be acceptable to many FSWs in Tijuana and Ciudad Juarez; however, continued development of behaviorally-congruent vaginal PrEP products may also facilitate uptake and ensure sufficient coverage.

The other side of surveillance: Monitoring, application, and integration of tuberculosis data to guide and evaluate programme activities in South Africa.

BACKGROUND: The importance of using surveillance data to monitor and evaluate programme activities has been emphasised in international policies for tuberculosis (TB) control. OBJECTIVES: A survey was conducted to assess the use of TB surveillance data to monitor and guide TB programme activities in South Africa (SA). METHODS: As part of an evaluation of the SA national TB surveillance system, semi-structured interviews were conducted among TB staff at health facilities and offices in three provinces. At each site, all persons involved with TB care, management and surveillance were invited to participate. RESULTS: At least one person (range 1 - 4) was interviewed at 47/54 health facilities (87.0%), 11/13 subdistrict and district TB offices (84.6%), 2/3 provincial TB offices (66.7%), and at the national level (1/1, 100.0%). Of 119 TB staff, 64.7% recognised the purpose of TB surveillance as guiding programme planning, implementation and evaluation. However, only 16.0% reported using data to measure disease burden, 8.4% to monitor trends, and 9.2% to inform resource allocation. The majority reported using TB management tools provided by the national programme, but 44.5% also described using additional tools. Personnel mentioned the need for dedicated surveillance staff, training on recording and reporting, improved computer access, and methods to apply information from surveillance data to the programme. CONCLUSIONS: The majority of TB staff understood the purpose of surveillance but did not routinely use data to guide programme planning, implementation and evaluation. Training and supporting TB staff to utilise surveillance data will help improve the TB surveillance system.

Identification of a variable region of the African swine fever virus genome that has undergone separate DNA rearrangements leading to expansion of minisatellite-like sequences.

Nucleotide sequencing identified a tandemly repeated sequence array 22 x 10(3) base-pairs from the right-hand DNA terminus of the African swine fever virus (ASFV) genome. The sequence of the repeat array and sequences closely flanking it were compared in the genomes of four groups of ASFV isolates that had very different restriction enzyme site maps. Arrays present in one group of ASFV isolates from East Zambia/Malawi varied in length and contained between 8 and 38 copies of a 17-nucleotide repeat unit. Repeat arrays in a second group of ASFV isolates from Europe were less variable in length but consisted of different types of repeat unit that were divergent in sequence. A third genetically diverse ASFV isolate. LIV 13 from a South Zambia Game Park, contained repeat unit types that were similar to those of European viruses. MFUE6 isolate from an East Zambia Game Park contained a shorter version of the European repeat unit. An eight-base-pair core sequence was conserved between the East Zambia/Malawi and European and LIV 13 repeat units. These tandemly repeated sequence arrays share a number of properties with chromosomal minisatellite DNA. Similar tandem repeat arrays have not been described in poxviruses.

Solid-phase antigen binding by purified immunoproteins from antigen-specific monoclonal T cell hybridomas.

We have developed two distinct solid-phase immunoassays for the detection of antigen binding activity by products of antigen binding T cell hybridomas in the absence of MHC. Two suppressor T cell hybridomas studied (34s-18 and 34s-704) are specific for keyhole limpet hemocyanin, a protein antigen, and the other suppressor T cell hybridoma (51H7D) binds specifically to the arsonate hapten. We have adapted these hybridomas to growth in serum-free medium and have isolated molecules with antigen binding activity both from the cell membranes and from the culture fluid in which the cells had been grown. The antigen binding molecules (ABM) produced by the KLH-specific hybridomas bound best to native hemocyanin; binding was decreased when KLH was denatured by reduction and alkylation and no binding was found to an arthropod (Limulus) hemocyanin. The arsonate binding hybridoma, on the other hand, produced molecules specific for this hapten; they showed no capacity to bind KLH. The antigen binding molecules affinity-purified from all three T hybridomas have intact masses of either 145,000, 67,000 or 48,000 when run in SDS-PAGE under non-reducing conditions. Following reduction, ABM resolve in SDS-PAGE into a complex of polypeptide chains having apparent masses of 65,000, 56,000 and 49,000, with either a pair of bands at 26,000 and 22,000, or with a single band at 32,000, which is consistent with the size of translation products of mRNA previously isolated from these hybridomas. Two of the hybridomas, 34s-18 and 34s-704, used for isolation of antigen binding products in this study, were previously reported to lack detectable rearranged gamma or beta genes and therefore to lack expression of the alpha/beta or gamma/delta heterodimers. The antigen binding molecules react in solid-phase immunoassay with some antibodies specific for variable (first framework) region and joining (J) region peptide sequences predicted from T cell receptor gene sequence. Furthermore, the affinity-purified antigen binding molecules from mouse T cell hybridomas cross-react in ELISA with goat anti-rabbit IgG and not with protein G, thus allowing the use of these commercially available reagents in standard laboratory assays. Interestingly, ABM anchored in intact cell membranes, which could be shown to specifically bind antigen, did not cross-react with goat anti-rabbit IgG, indicating that the cross-reactive moiety is not detectable when the ABM are in this situation.(ABSTRACT TRUNCATED AT 400 WORDS)

Evidence for the binding of human serum amyloid P component to Clq and Fab gamma.

In order to clarify the mechanism of interaction of serum amyloid P component (SAP) with complement, the interaction of SAP with C1q and with IgG was studied. It is known that SAP binds Sepharose in the presence of calcium. When purified 125I-C1q was incubated with SAP prior to Sepharose affinity chromatography, 125I-C1q was retained. However, in the absence of SAP, the 125I-C1q was not retained. To further examine the interaction of SAP with C1q, isolated SAP was incubated at varying ratios with C1q in the presence of 1.5 mM Ca2+. These mixtures were subsequently examined via crossed immunoelectrophoresis against goat anti-SAP. A change in the electrophoretic behavior of SAP was observed in the presence of C1q. In other studies, it was observed that SAP might interact with the collagen-like stem of C1q. In these latter studies, 125I-SAP was incubated with pepsin digests of C1q in a microtitre solid-phase binding assay. In addition, a microtitre solid-phase binding assay was utilized in order to investigate the possible binding of isolated 125I-SAP with IgG. Interestingly in the presence of Ca2+, human IgG and Fab gamma, but not Fc gamma, were found to bind 125I-SAP.

African swine fever virus genome content and variability.

A 55 kilobase pair (kb) region from the right end of the virulent African swine fever virus isolate, Malawi LIL20/1, has been sequenced. The 68 major open reading frames (ORFs) encoded are generally closely spaced and read from both DNA strands across the complete sequence. Comparison of the amino acid sequences of predicted ORFs with sequence databases identified 15 ORFs which encode proteins that are similar to proteins of known function. Two ORFs are homologous to copies of multigene family 360 (MGF360) and one ORF is homologous to copies of multigene family 110 (MGF110). Both of these multigene families have been described previously.

Are ant-aphid associations a tritrophic interaction? Oleander aphids and Argentine ants.

Oleander aphids, (Aphis nerii), which are sporadically tended by ants, were used as a moded system to examine whether host plant factors associated with feeding site influenced the formation of ant-aphid associations. Seasonal patterns of host plant utilization and association with attendant ants were examined through bi-weekly censuses of the aphid population feeding on thirty ornamental oleander plands (Nerium oleander) in northern California in 1985 and 1986. Colonies occurred on both developing and senescing plant terminals, including leaf tips, floral structures, and pods. Aphids preferentially colonized leaf terminals early in the season, but showed no preference for feeding site during later periods. Argentine ants (Iridomyrmex humilis) occasionally tended aphid colonies. Colonies on floral tips were three to four times more likely to attract ants than colonies on leaf tips, even though the latter frequently contained more aphids. Ants showed a positive recruitment response to colonies on floral tips, with a significant correlation between colony size and number of ants. There was no recruitment response to colonies on leaf tips. These patterns were reproducible over two years despite large fluctuations in both aphid population density and ant activity. In a laboratory bioassay of aphid palatability, the generalist predator,Hippodamia convergens, took significantly more aphids reared on floral tips compared to those reared on leaf tips. The patterns reported here support the hypothesis that tritrophic factors may be important in modifying higher level arthropod mutualisms.

Validation of sputum smear results in the Electronic TB Register for the management of tuberculosis, South Africa.

BACKGROUND: The accuracy of tuberculosis (TB) surveillance systems is paramount in TB control. In South Africa, information from the laboratory is not directly linked to the Electronic TB Register (ETR). OBJECTIVE: To validate smear results recorded in the ETR with those recorded in the laboratory. METHODS: A retrospective evaluation was conducted among all sputum smear-positive TB patients recorded in the ETR during the fourth quarter of 2009 in KwaZulu-Natal Province. RESULTS: Of 1036 smear-positive patients recorded in the ETR, 683 (65.9%) had positive results recorded in the laboratory register. Only 364 (53.2%) had their smear results recorded in the ETR at the end of the intensive phase of treatment; of 326 (89.6%) recorded as converted to smear-negative, 224 (61.5%) were confirmed as smear-negative in the laboratory. Of 331 patients with end-of-treatment results in the ETR, 302 (91.2%) were recorded as cured, but only 105 (34.8%) were confirmed in the laboratory. CONCLUSIONS: Over a third of TB patients registered as smear-positive in the ETR could not be confirmed based on laboratory results. Many patients did not have a laboratory record, lending to uncertainty as to the validity of the smear results and treatment outcomes recorded in the ETR.

Scale-up of isoniazid preventive therapy in PEPFAR-assisted clinical sites in South Africa.

We reviewed the implementation of isoniazid preventive therapy (IPT) in South Africa from January 2010 to March 2011. The South African National Department of Health distributed revised IPT guidelines in May 2010 to increase IPT use in eligible human immunodeficiency virus (HIV) infected patients. We found a dramatic increase in the absolute numbers of patients reported to have been initiated on IPT (from 3309 in January-March 2010 to 49 130 in January-March 2011), representing an increase in the proportion (1.0-10.5%) of potentially eligible HIV-infected patients started on IPT.

Description and evaluation of a serious game intervention to engage low secure service users with serious mental illness in the design and refurbishment of their environment.

Service user involvement in all levels of healthcare provision is the expectation of UK government policy. Involvement should not only include participation in the planning and delivery of health care but also the exercise of choice and opinions about that care. In practice, however, service user engagement is most often tokenistic, involving post hoc consultation over plans already committed to by services. This paper explores an Occupational Therapy-led initiative to use the Serious Game format to engage low secure service users with serious mental illness in the design, layout and refurbishment of their unit. Among other things how medication was to be dispensed on the new unit was explored by this game and led to significant replanning in response to service user involvement. The game format was found to be a useful tool in facilitating communication between professionals and a traditionally marginalized and powerless client group. It enabled service users to have a voice, it provided a format for that voice to be heard and made possible service-led change in the planning process.

Systems-level questions in Drosophila oogenesis.

This paper describes computational and experimental work on pattern formation in Drosophila egg development (oogenesis), an established experimental model for studying cell fate diversification in developing tissues. Epidermal growth factor receptor (EGFR) is a key regulator of pattern formation and morphogenesis in Drosophila oogenesis. EGFR signalling in oogenesis can be genetically manipulated and monitored at many levels, leading to large sets of heterogeneous data that enable the formulation of increasingly quantitative models of pattern formation in these systems.

Slow human immunodeficiency virus (HIV) infectivity correlated with low HIV coreceptor levels.

The absolute number of CD4+ lymphocytes in blood is prognostic for disease progression, yet the cell surface density of CD4 receptors or chemokine receptors on a single cell has not previously been found to be predictive of human immunodeficiency virus (HIV) infectivity outcome. It has recently been shown that human leukocyte elastase (HLE) and its ligand alpha(1) proteinase inhibitor (alpha(1)PI; alpha(1)antitrypsin) act as HIV fusion cofactors. The present study shows that decreased HIV infectivity is significantly correlated with decreased cell surface density of HLE but not with decreased CD4 nor chemokine receptors. In vitro HIV infectivity outcome in this study was predicted by the surface density of HLE on mononuclear phagocytes but not on lymphocytes. The set point HLE surface density was in part determined by alpha(1)PI. Decreased circulating alpha(1)PI was correlated with increased cell surface HLE and with increased HIV infectivity. The correlation of HIV infectivity outcome with surface HLE and circulating alpha(1)PI supports the utility of these HIV cofactors in diagnostic analysis and therapeutic intervention.

T cell antigen receptor immune complexes demonstrating biologic and proteolytic activity.

An elastase-like protease, recently recognized as a specific product of murine T cells, may functionally associate with the classical TCR. T cell elastase, found in combination with the natural elastase inhibitor alpha 1-antitrypsin (alpha 1-protease inhibitor, alpha 1-PI), is produced by both CD4+ and CD8+ T lymphocytes. T cell elastase and alpha 1-PI are found chemically associated with the TCR in an antigen-specific complex reminiscent of the Ig-complement 'immune complexes'.