Routine HIV Testing among Hospitalized Patients in Argentina. Is It Time for a Policy Change?

Introduction

The Argentinean AIDS Program estimates that 110,000 persons are living with HIV/AIDS in Argentina. Of those, approximately 40% are unaware of their status, and 30% are diagnosed in advanced stages of immunosuppression. Though studies show that universal HIV screening is cost-effective in settings with HIV prevalence greater than 0.1%, in Argentina, with the exception of antenatal care, HIV testing is always client-initiated.

Objective

We performed a pilot study to assess the acceptability of a universal HIV screening program among inpatients of an urban public hospital in Buenos Aires.

Methods

Over a six-month period, all eligible adult patients admitted to the internal medicine ward were offered HIV testing. Demographics, uptake rates, reasons for refusal and new HIV diagnoses were analyzed.

Results

Of the 350 admissions during this period, 249 were eligible and subsequently enrolled. The enrolled population was relatively old compared to the general population, was balanced on gender, and did not report traditional high risk factors for HIV infection. Only 88 (39%) reported prior HIV testing. One hundred and ninety (76%) patients accepted HIV testing. In multivariable analysis only younger age (OR 1.02; 95%CI 1.003-1.05) was independently associated with test uptake. Three new HIV diagnoses were made (undiagnosed HIV prevalence: 1.58%); none belonged to a most-at-risk population.

Conclusions

Our findings suggest that universal HIV screening in this setting is acceptable and potentially effective in identifying undiagnosed HIV-infected individuals. If confirmed in a larger study, our findings may inform changes in the Argentinean HIV testing policy.     

Is Increased Echogenicity Related to a Decrease in Glomerular Filtration Rate? Objective Measurements in Pediatric Solitary Kidney Patients—A Retrospective Analysis

Quantitative measurements of renal echogenicity using a graphic program show close correlation with renal histology in adult patients, but this has neither been applied in pediatric patients nor correlated with glomerular filtration rate (GFR). To determine the direct relationship between echogenicity and GFR, we retrospectively analyzed 91 patients with a solitary functioning kidney under the age of 10, who underwent ultrasonography and serum cystatin C evaluation on a single day between January 2013 and December 2014. Echogenicity was quantified as previously reported. Echogenicity and kidney length were correlated with age-matched values of serum cystatin C-based GFR. Evaluation was performed at a median age of 17.1 months. GFR was low for age in eight of 54 right solitary kidney patients and four of 37 left solitary kidney patients. The right kidney-liver ratio was significantly elevated in the right decreased GFR group, while the left kidney-spleen ratio was not different in the left decreased GFR group. Age-matched longitudinal kidney length ratios were similar between the decreased and normal GFR groups for both sides. This is the first report to objectively prove the relationship between echogenicity and renal function in patients with a right solitary kidney. The right kidney-liver echogenicity ratio, measured objectively, showed feasibility in clinical practice as it showed a close relationship with decreased renal function when increased. However, absolute kidney echogenicity values, or the left kidney-spleen echogenicity ratio, were not independent markers for decreased renal function.     

Is Structural Equation Modeling Advantageous for the Genetic Improvement of Multiple Traits?

Structural equation models (SEMs) are multivariate specifications capable of conveying causal relationships among traits. Although these models offer insights into how phenotypic traits relate to each other, it is unclear whether and how they can improve multiple-trait selection. Here, we explored concepts involved in SEMs, seeking for benefits that could be brought to breeding programs, relative to the standard multitrait model (MTM) commonly used. Genetic effects pertaining to SEMs and MTMs have distinct meanings. In SEMs, they represent genetic effects acting directly on each trait, without mediation by other traits in the model; in MTMs they express overall genetic effects on each trait, equivalent to lumping together direct and indirect genetic effects discriminated by SEMs. However, in breeding programs the goal is selecting candidates that produce offspring with best phenotypes, regardless of how traits are causally associated, so overall additive genetic effects are the matter. Thus, no information is lost in standard settings by using MTM-based predictions, even if traits are indeed causally associated. Nonetheless, causal information allows predicting effects of external interventions. One may be interested in predictions for scenarios where interventions are performed, e.g., artificially defining the value of a trait, blocking causal associations, or modifying their magnitudes. We demonstrate that with information provided by SEMs, predictions for these scenarios are possible from data recorded under no interventions. Contrariwise, MTMs do not provide information for such predictions. As livestock and crop production involves interventions such as management practices, SEMs may be advantageous in many settings.     

Evaluation of MycAssay? Aspergillus for Diagnosis of Invasive Pulmonary Aspergillosis in Patients without Hematological Cancer

Methods based on real-time polymerase chain reaction (PCR) can speed up the diagnosis of invasive aspergillosis but are limited by a lack of standardization. We evaluated the commercially available MycAssay™ Aspergillus test for the diagnosis of invasive aspergillosis in patients without hematological cancer. We prospectively collected 322 lower respiratory tract samples (November 2009–January 2011) from 175 patients with lower respiratory tract infection and the following predisposing conditions: solid cancer (16.8%), cirrhosis (16.8%), corticosteroid therapy (71.7%), HIV infection (15.6%), chronic obstructive pulmonary disease (COPD, 52.6%), solid organ transplantation (kidney [1.2%], heart [3%], liver [4.6%]), or none (3.5%). Specimens were obtained when clinically indicated and analyzed in the microbiology laboratory. Aspergillus DNA was extracted and amplified by means of MycXtra® and MycAssay™ Aspergillus. Aspergillus spp. was isolated from 65 samples (31 patients). According to the European Organization for Research and Treatment of Cancer and Bulpa''s criteria (for patients with COPD), 15 had probable invasive aspergillosis. MycAssay™ Aspergillus results were negative (n = 254), positive (n = 54), or indeterminate (n = 14). The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic odds ratio of the MycAssay™ (first sample/any sample) were 86.7/93, 87.6/82.4, 34.1/34.1, 92.2/100, and 48/68.75. The differences between the proportion of samples with positive PCR determinations (63%) and the proportion of samples with Aspergillus spp. isolation (75%) did not reach statistical significance (P = 0.112). The median time from sample culture to visualization of fungal growth was 3 days, compared with ∼4 hours for MycAssay™ Aspergillus PCR. MycAssay™ Aspergillus showed high sensitivity for the diagnosis of invasive aspergillosis in patients without hematological cancer. Sensitivity increased when multiple samples were used. Compared with fungal culture, PCR significantly reduced the time to diagnosis.     

Bacterial diversity of Escherichia coli in the gut: a reason to re-evaluate probiotic formulations?

Humans and animals are increasingly being subjected to various probiotic formulations with the claim of providing a number of health benefits to the consumer. These formulations usually incorporate bacterial consortia comprising of mostly lactic acid bacteria (LAB). Recent studies have shown that strains found in different regions of the gut are genetically different from each other and may therefore have different abilities to interact with bacteria that they come into contact with. Even LAB show differences in their ability to interact, and further, inhibit growth of pathogenic bacteria in vitro due to individual strain differences. If these results are repeatedly shown to be true in future assessments, an evaluation of bacterial consortia used in probiotic formulations may now be necessary. This may have an impact in the way future probiotic formulations are prepared.     

Is the secret for a successful aging to keep track of cancer pathways?

A successful aging could be gained by life satisfaction, social functioning, or psychological resources and, definitely, by increasing resistance to diverse age‐related pathologies. Nowadays, cancer can be considered an age‐related disease since the incidence of most cancers increases with age, rising more rapidly beginning in midlife. Although adults with extended longevity are less likely to develop cancer, it is now emerging that aging and cancer share common molecular links, and thus targeting these mechanisms may be suitable to treat multiple disorders, for the prolonging of healthy aging. At present, one of the cornerstones of antiaging is hormone‐replacement therapy to treat diseases associated with a state of age‐related sex‐hormone deficiency in women and men; however, many studies question the relationship of hormone replacement to cancer recurrence. Here, we discuss signaling and metabolic molecular crossroad linking aging and cancer. This is useful to argue about the current knowledge of prolongevity and druggable targets and to motivate specific intervention strategies that could modify practices of the aging population, activating multiple longevity pathways but keeping track of cancer pathways, thereby potentially preserving health status.     

Is the Vulnerability of Neurons in the Substantia Nigra of Patients with Parkinson's Disease Related to Their Neuromelanin Content?

The contribution of neuromelanin (NM) to the pathogenesis of Parkinson's disease (PD) has long been suspected. In particular, a correlation has been reported between the estimated cell loss in the mesencephalic dopaminergic cell groups and the percentage of NM-pigmented neurons in these cell groups. To test whether the amount of pigment per cell is a critical factor or whether the presence of NM within a neuron is sufficient to account for the degeneration of dopaminergic neurons, the NM content was measured in each neuron from representative sections throughout the ventral mesencephalon of four controls subjects and four patients with PD. Intraneuronal NM was quantified by a densitometric method, using known amounts of synthetic melanin as standards. In control brains, the distribution of melanized neurons in the nigral complex showed a high proportion of lightly melanized neurons in the ventral tegmental area and the pars alpha and gamma of the substantia nigra (SN), whereas heavily melanized neurons were mostly located in the pars beta and lateralis of the SN. An inverse relationship was observed between the percentage of surviving neurons in PD compared with controls and the amount of NM they contain, suggesting that the vulnerability of the dopaminergic neurons is related to their NM content. Factors other than NM may be involved in the differential vulnerability of catecholaminergic neurons in PD. In particular, the constant topography of the cell loss suggests that cell position within the nigral complex is a key factor.     

Is there a place for nuclear medicine in the radioembolization of liver tumors?

This is purposely an ultraprovocative title for the broad nuclear medicine community (including radiophysics and radiopharmacy) which leads us to ask questions about how we should correctly use ⁹⁰Yttrium (MSY90) microspheres in the treatment of liver tumors.     

Is there a role for antibody testing in the diagnosis of invasive candidiasis?

During the last decades, the use of antibody tests for the diagnosis of invasive mycoses has declined as a consequence of the general belief that they are insensitive and non-specific. However, there is a clear evidence that antibodies can be detected in highly immunodeficient patients (such as bone marrow transplant recipients), and that those antibodies are useful for the diagnosis. Antibody tests are currently in use as diagnostic tools for some primary mycoses, such as the endemic mycoses, aspergilloma, allergic bronchopulmonary aspergilosis and sporothrichosis. For invasive candidiasis, diagnostic methods must differentiate Candida colonization of mucous membranes or superficial infection from tissue invasion by this microorganism. Substantial progress has been made in diagnosis of invasive candidiasis with the development of a variety of methods for the detection of antibodies and antigens. However, no single test has found widespread clinical use and there is a consensus that diagnosis based on a single specimen lacks sensitivity. It is necessary to test sequential samples taken while the patient is at greatest risk for developing invasive candidiasis to optimize the diagnosis. Results obtained from a panel of diagnostic tests in association with clinical aspects will likely be the most useful strategy for early diagnosis and therapy.     

Is the additional effort of renesting linked to a hormonal change in the common tern?

The production of and care for a replacement clutch can bear costs in terms of future reproduction or survival. However, renesting is quite common among seabirds and can contribute considerably to individual fitness. Prolactin and corticosterone are two hormones involved in the mediation of breeding behavior and, as they are linked to body condition or effort, it is of interest if these hormone values change during a second demanding breeding phase within a year. We compared baseline prolactin and corticosterone between the first and the renesting attempt in common terns (Sterna hirundo) on individual level. Therefore, in addition to control birds, 37 breeders were sampled during incubation of their first and their replacement clutch in 2008 and 2009. Blood samples were taken non-invasively by blood-sucking bugs. Prolactin level was lower during the renesting period, especially in birds which abandoned their clutch afterwards, whereas corticosterone did not change. Excluding the deserting birds, the reduced prolactin level was not linked to minor success, but could be related to seasonal processes. The control group of late laying common terns showed comparably low prolactin values, but increased corticosterone concentrations. Renesting individuals exhibited higher prolactin during incubation of their first clutch than non-renesting birds, probably indicating their higher quality. The fact that terns still have relatively high prolactin and low corticosterone values during renesting might confirm their higher quality and suggests that they are able to meet the costs of a second demanding breeding period without being considerably stressed.     

Species-Specific Bacterial Communities in the Phycosphere of Microalgae?

Specific associations of bacteria with phytoplankton have recently been reported in the literature. In our study, we analyzed bacterial communities of microalgal cultures related to algal growth phases. Seven freshly isolated key diatom and dinoflagellate species from Helgoland Roads, North Sea, were investigated. The community composition of associated bacteria as well as the cell numbers, the photosynthetic efficiency of the algae, and the depletion of inorganic nutrients in the medium were recorded over a period of 8 weeks in batch cultures. Diversity and succession of bacterial communities was analyzed by ribosomal intergenic spacer analysis. Phylogenetic analysis of bacterial populations was performed by denaturing gradient gel electrophoresis of 16S rRNA genes followed by DNA sequence analysis. Members of Alphaproteobacteria and Gammaproteobacteria and the Flavobacteria–Sphingobacteria group within the Bacteroidetes phylum predominated in the cultures. Differences in free-living and attached bacterial populations were observed between the phylogenetic groups. Shifts in the bacterial communities could not be correlated to changes of nutrient levels or algal growth phases. Regarding our results, it should not be generalized that the compositions of the bacterial communities are strictly species specific for microalgae. The importance of factors like the composition of exudates is apparent.     

Is Knowing the Age-Order of Alleles in a Sample Useful in Testing for Selective Neutrality?

The most powerful, and most frequently used, test of selective neutrality, based on data consisting of observed allelic frequencies in a sample of genes at some locus, is the procedure of G. A. Watterson. This procedure uses the sample homozygosity F* as the test statistic, and in effect leads to rejection of the hypothesis of selective neutrality if the observed value of F* differs significantly from neutral theory expectations. The homozygosity statistic is invariant under relabeling of the alleles and thus cannot use any further information on the alleles which might be available. We present results which suggest that information concerning the age order of the alleles cannot be used to provide a more powerful testing procedure than that of Watterson.     

Is the PRC for Dark Pulses in LL a Mirror Image of the PRC for Light Pulses in DD in Mice?

The phase-response curves (PRC) for light pulses in continuous darkness (DD) have been described in many mammals, especially in nocturnal rodents. The PRC for dark pulses in continuous light (LL), however, has been described in a few mammals only, in nocturnal for bat and for hamster and in diurnal for Octodon degus, suggesting that this PRC is mirror imaging the PRC for light pulses. Therefore, the effect of 1-h and 3-h lasting dark pulses on the circadian wheel-running activity rhythm of mice in continuous light was investigated and then the PRC for dark pulses in LL was drawn up. For comparison, the effect of 1-h lasting light pulses on the circadian wheel-running activity rhythm of mice in DD was examined and the PRC for light pulses in DD was constructed. It appeared that the PRC for dark pulses, to a certain degree, represents a mirror image of the PRC for light pulses in mice. However, the advance region of this PRC is longer than that of delay. The mechanism of dark pulses action is discussed.     

Is the PRC for Dark Pulses in LL a Mirror Image of the PRC for Light Pulses in DD in Mice?

The phase-response curves (PRC) for light pulses in continuous darkness (DD) have been described in many mammals, especially in nocturnal rodents. The PRC for dark pulses in continuous light (LL), however, has been described in a few mammals only, in nocturnal for bat and for hamster and in diurnal for Octodon degus, suggesting that this PRC is mirror imaging the PRC for light pulses. Therefore, the effect of 1-h and 3-h lasting dark pulses on the circadian wheel-running activity rhythm of mice in continuous light was investigated and then the PRC for dark pulses in LL was drawn up. For comparison, the effect of 1-h lasting light pulses on the circadian wheel-running activity rhythm of mice in DD was examined and the PRC for light pulses in DD was constructed. It appeared that the PRC for dark pulses, to a certain degree, represents a mirror image of the PRC for light pulses in mice. However, the advance region of this PRC is longer than that of delay. The mechanism of dark pulses action is discussed.