Comparing in-person, blended and virtual training interventions; a real-world evaluation of HIV capacity building programs in 16 countries in sub-Saharan Africa.

We sought to evaluate the impact of transitioning a multi-country HIV training program from in-person to online by comparing digital training approaches implemented during the pandemic with in-person approaches employed before COVID-19. We evaluated mean changes in pre-and post-course knowledge scores and self-reported confidence scores for learners who participated in (1) in-person workshops (between October 2019 and March 2020), (2) entirely asynchronous, Virtual Workshops [VW] (between May 2021 and January 2022), and (3) a blended Online Course [OC] (between May 2021 and January 2022) across 16 SSA countries. Learning objectives and evaluation tools were the same for all three groups. Across 16 SSA countries, 3023 participants enrolled in the in-person course, 2193 learners participated in the virtual workshop, and 527 in the online course. The proportions of women who participated in the VW and OC were greater than the proportion who participated in the in-person course (60.1% and 63.6%, p<0.001). Nursing and midwives constituted the largest learner group overall (1145 [37.9%] vs. 949 [43.3%] vs. 107 [20.5%]). Across all domains of HIV knowledge and self-perceived confidence, there was a mean increase between pre- and post-course assessments, regardless of how training was delivered. The greatest percent increase in knowledge scores was among those participating in the in-person course compared to VW or OC formats (13.6% increase vs. 6.0% and 7.6%, p<0.001). Gains in self-reported confidence were greater among learners who participated in the in-person course compared to VW or OC formats, regardless of training level (p<0.001) or professional cadre (p<0.001). In this multi-country capacity HIV training program, in-person, online synchronous, and blended synchronous/asynchronous strategies were effective means of training learners from diverse clinical settings. Online learning approaches facilitated participation from more women and more diverse cadres. However, gains in knowledge and clinical confidence were greater among those participating in in-person learning programs.

Multiple sclerosis: Executive dysfunction, task switching and the role of attention.

BACKGROUND: It has been suggested that switching ability might not be affected in multiple sclerosis (MS) as previously thought; however, whether this is true under more 'real-world' conditions when asymmetry in task difficulty is present has not been ascertained. OBJECTIVE: The objective of this paper is to examine the impact of task difficulty asymmetry on task switching ability in MS. METHOD: An ocular motor (OM) paradigm that interleaves the simple task of looking towards a target (prosaccade, PS) with the cognitively more difficult task of looking away from a target (antisaccade, PS) was used. Two switching conditions: (1) PS switch cost, switching to a simple task from a difficult task (PS switch), relative to performing two simple tasks concurrently (PS repeat); (2) AS switch cost, switching to a difficult task from a simple task (AS switch) relative to performing two difficult tasks concurrently (AS repeat). Forty-five relapsing-remitting MS patients and 30 control individuals were compared. RESULTS: Controls and patients produced a similar magnitude PS switch cost, suggesting that task difficulty asymmetry does not detrimentally impact MS patients when transitioning from a more difficult task to a simpler task. However, MS patients alone found switching from the simpler PS trial to the more difficult AS trial easier (shorter latency and reduced error) than performing two AS trials consecutively (AS switch benefit). Further, MS patients performed significantly more errors than controls when required to repeat the same trial consecutively. CONCLUSION: MS patients appear to find the maintenance of task-relevant processes difficult not switching per se, with deficits exacerbated under increased attentional demands.

Obesity-induced changes in lipid mediators persist after weight loss.

BACKGROUND: Obesity induces significant changes in lipid mediators, however, the extent to which these changes persist after weight loss has not been investigated. SUBJECTS/METHODS: We fed C57BL6 mice a high-fat diet to generate obesity and then switched the diet to a lower-fat diet to induce weight loss. We performed a comprehensive metabolic profiling of lipid mediators including oxylipins, endocannabinoids, sphingosines and ceramides in key metabolic tissues (including adipose, liver, muscle and hypothalamus) and plasma. RESULTS: We found that changes induced by obesity were largely reversible in most metabolic tissues but the adipose tissue retained a persistent obese metabolic signature. Prostaglandin signaling was perturbed in the obese state and lasting increases in PGD2, and downstream metabolites 15-deoxy PGJ2 and delta-12-PGJ2 were observed after weight loss. Furthermore expression of the enzyme responsible for PGD2 synthesis (hematopoietic prostaglandin D synthase, HPGDS) was increased in obese adipose tissues and remained high after weight loss. We found that inhibition of HPGDS over the course of 5 days resulted in decreased food intake in mice. Increased HPGDS expression was also observed in human adipose tissues obtained from obese compared with lean individuals. We then measured circulating levels of PGD2 in obese patients before and after weight loss and found that while elevated relative to lean subjects, levels of this metabolite did not decrease after significant weight loss. CONCLUSIONS: These results suggest that lasting changes in lipid mediators induced by obesity, still present after weight loss, may play a role in the biological drive to regain weight.

Omega-3 fatty acids reduce obesity-induced tumor progression independent of GPR120 in a mouse model of postmenopausal breast cancer.

Obesity and inflammation are both risk factors for a variety of cancers, including breast cancer in postmenopausal women. Intake of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) decreases the risk of breast cancer, and also reduces obesity-associated inflammation and insulin resistance, but whether the two effects are related is currently unknown. We tested this hypothesis in a postmenopausal breast cancer model using ovariectomized, immune-competent female mice orthotopically injected with Py230 mammary tumor cells. Obesity, whether triggered genetically or by high-fat diet (HFD) feeding, increased inflammation in the mammary fat pad and promoted mammary tumorigenesis. The presence of tumor cells in the mammary fat pad further enhanced the local inflammatory milieu. Tumor necrosis factor-alpha (TNF-α) was the most highly upregulated cytokine in the obese mammary fat pad, and we observed that TNF-α dose-dependently stimulated Py230 cell growth in vitro. An ω-3 PUFA-enriched HFD (referred to as fish oil diet, FOD) reduced inflammation in the obese mammary fat pad in the absence of tumor cells and inhibited Py230 tumor growth in vivo. Although some anti-inflammatory effects of ω-3 PUFAs were previously shown to be mediated by the G-protein-coupled receptor 120 (GPR120), the FOD reduced Py230 tumor burden in GPR120-deficient mice to a similar degree as observed in wild-type mice, indicating that the effect of FOD to reduce tumor growth does not require GPR120 in the host mouse. Instead, in vitro studies demonstrated that ω-3 PUFAs act directly on tumor cells to activate c-Jun N-terminal kinase, inhibit proliferation and induce apoptosis. Our results show that obesity promotes mammary tumor progression in this model of postmenopausal breast cancer and that ω-3 PUFAs, independent of GPR120, inhibit mammary tumor progression in obese mice.

Functional phosphoproteomic analysis reveals cold-shock domain protein A to be a Bcr-Abl effector-regulating proliferation and transformation in chronic myeloid leukemia.

One proposed strategy to suppress the proliferation of imatinib-resistant cells in chronic myeloid leukemia (CML) is to inhibit key proteins downstream of Bcr-Abl. The PI3K/Akt pathway is activated by Bcr-Abl and is specifically required for the growth of CML cells. To identify targets of this pathway, we undertook a proteomic screen and identified several proteins that differentially bind 14-3-3, dependent on Bcr-Abl kinase activity. An siRNA screen of candidates selected by bioinformatics analysis reveals cold-shock domain protein A (CSDA), shown previously to regulate cell cycle progression in epithelial cells, to be a positive regulator of proliferation in a CML cell line. We show that Akt can phosphorylate the serine 134 residue of CSDA but, downstream of Bcr-Abl activity, this modification is mediated through the activation of MEK/p90 ribosomal S6 kinase (RSK) signaling. Inhibition of RSK, similarly to treatment with imatinib, blocked proliferation specifically in Bcr-Abl-positive leukemia cell lines, as well as cells from CML patients. Furthermore, these primary CML cells showed an increase in CSDA phosphorylation. Expression of a CSDA phospho-deficient mutant resulted in the decrease of Bcr-Abl-dependent transformation in Rat1 cells. Our results support a model whereby phosphorylation of CSDA downstream of Bcr-Abl enhances proliferation in CML cells to drive leukemogenesis.

Mechanisms of human insulin resistance and thiazolidinedione-mediated insulin sensitization.

Cellular and tissue defects associated with insulin resistance are coincident with transcriptional abnormalities and are improved after insulin sensitization with thiazolidinedione (TZD) PPARgamma ligands. We characterized 72 human subjects by relating their clinical phenotypes with functional pathway alterations. We transcriptionally profiled 364 biopsies harvested before and after hyperinsulinemic-euglycemic clamp studies, at baseline and after 3-month TZD treatment. We have identified molecular and functional characteristics of insulin resistant subjects and distinctions between TZD treatment responder and nonresponder subjects. Insulin resistant subjects exhibited alterations in skeletal muscle (e.g., glycolytic flux and intramuscular adipocytes) and adipose tissue (e.g., mitochondrial metabolism and inflammation) that improved relative to TZD-induced insulin sensitization. Pre-TZD treatment expression of MLXIP in muscle and HLA-DRB1 in adipose tissue from insulin resistant subjects was linearly predictive of post-TZD insulin sensitization. We have uniquely characterized coordinated cellular and tissue functional pathways that are characteristic of insulin resistance, TZD-induced insulin sensitization, and potential TZD responsiveness.

Sexual risk behaviour among HIV-positive patients at an urban clinic in Santiago, Dominican Republic.

More than one percent of adults in the Dominican Republic are HIV-infected and most infections are acquired sexually. We studied sexual risk behaviours in a group of HIV-positive patients treated in Santiago, Dominican Republic. Interviews were conducted with 129 participants seen in May 2006 at one of the country's largest public hospital HIV clinics. Questions included demographics, sexual history, condom use and focused on patients' last sexual encounter. Most patients (72.4%) had been sexually active since their HIV diagnosis. Following their diagnosis, 72.8% of sexually active patients used condoms more frequently, 21.7% used condoms with the same frequency and 5.4% used condoms less often. The most common reason cited for not using a condom after HIV diagnosis differed by gender; men cited decreased sexual pleasure (70.0%) and women reported that their partner had refused to use a condom (71.8%). Sexually active patients who believed that their partner did not have HIV were much more likely to report using a condom at their last sexual encounter than those who did not know their partner's HIV status (OR=16.9). HIV-positive patients reported using condoms more frequently following their HIV diagnosis and were more likely to use a condom if they believed their partner did not have HIV. Increased HIV testing may lead to reduced sexual risk behaviour in the Dominican Republic.

Red cell osmotic fragility studies in hemoglobin C-beta thalassemia: osmotically resistant microspherocytes.

Typically certain features of red cell morphology predict the results of osmotic fragility testing. Microspherocytes generally have increased and target cells decreased fragility. Blood smears in homozygous hemoglobin C disease show an interesting admixture of microspherocytes and target cells. Yet osmotic fragility studies generally show only reduced fragility and no population of fragile cells to correspond with the spherocytes. The present study demonstrates that the red cells of patients with hemoglobin C-beta thalassemia share many characteristics with hemoglobin C red cells, including the decreased osmotic fragility of all cells despite the presence of both spherocytes and target cells. These paradoxically osmotically resistant spherocytes probably arise because of cellular dehydration due to a K-Cl transport system which may be activated by binding of hemoglobin C to the red cell membrane.

Concepts and approaches to in situ luminescence dating of Martian sediments.

In this paper we present the concept of a robotic instrument for in situ luminescence dating of near-surface sediments on Mars. The scientific objectives and advantages to be gained from the development of such an instrument are described, and the challenges presented by the Mars surface environment to the design and operation of the instrument are outlined.

Carboxyhemoglobin levels in patients with sickle-cell anemia: relationship to hemolytic and vasoocclusive severity.

BACKGROUND: When carbon monoxide binds to hemoglobin, it increases the affinity of hemoglobin for oxygen and shifts the oxygen dissociation curve to the left. The resulting decrease in sickling tendency could have clinical benefit, and carbon monoxide has been suggested as a treatment for sickle-cell disease. Furthermore, in sickle-cell disease, as in other hemolytic diseases, endogenous carbon monoxide production is increased because of increased heme catabolism. METHODS: In the present study, we measured carboxyhemoglobin levels in sickle-cell patients and compared them with estimates of the hemolytic and the vasoocclusive severity of the disease. RESULTS: Significant correlation was found between carboxyhemoglobin (HbCO) levels and hematocrit, reticulocyte count, unconjugated bilirubin level, and percentage of irreversibly sickled cells. However, there was no significant correlation between carboxyhemoglobin levels and measures of the vaso-occlusive severity of the disease. CONCLUSIONS: The correlations between HbCO levels and measures of hemolytic severity are best explained by the known relationship between hemoglobin catabolism and CO production. The lack of correlation with vaso-occlusive severity may be due to the complex changes involved and the difficulty of quantifying vasoocclusive severity.

Donor cell leukemia: report of a case occurring 11 years after allogeneic bone marrow transplantation and review of the literature.

We report the case of a man with chronic myelocytic leukemia (CML) and a 46,XY,t(5;9;22) karyotype who developed acute myelocytic leukemia (AML) with a 45,X,t(8;21) karyotype 11 years after bone marrow transplantation (BMT) from his HLA-matched sister. Fluorescent in situ hybridization (FISH) studies and molecular analysis using short tandem repeat (STR) sequences proved the new leukemia to be of donor cell origin. Donor cell leukemia (DCL) after BMT is rare. Our review of the literature found 15 cases following BMT for leukemia and 2 cases after BMT for benign hematological disorders. In fewer than half the reported cases were molecular studies available to confirm the cytogenetic evidence for DCL, and the longest previously reported interval between BMT and DCL was 6 years.

Serum soluble transferrin receptor and the prediction of marrow aspirate iron results in a heterogeneous group of patients.

Serum soluble transferrin receptor (sTfR) concentration has been evaluated in the diagnosis of iron deficiency in otherwise healthy individuals and in patients with rheumatoid arthritis, but has not been studied in a general population of patients with complicated clinical presentations. In this study, 145 anaemic patients with a variety of medical conditions undergoing diagnostic bone marrow aspiration for any reason were tested by a complete blood count, a panel of biochemical tests to evaluate iron status, bone-marrow aspirate iron stain, and serum sTfR concentration. Sixteen per cent lacked stainable iron in the marrow aspirate. All biochemical parameters differed significantly between patients with or without stainable marrow iron. The sTfR assay was significantly more sensitive but less specific than other iron status assays in identifying the absence of stainable iron. Logistic regression analysis demonstrated that only sTfR and ferritin contributed independently to the prediction of marrow iron status. Serum ferritin alone was highly specific but insensitive. A decision algorithm combining serum ferritin and sTfR was as sensitive as TfR and as specific as serum ferritin. The measurement of serum sTfR, especially in conjunction with serum ferritin, is a valuable addition to the existing methods for predicting the results of marrow aspirate iron stains.

Increased instability of human CTG repeat tracts on yeast artificial chromosomes during gametogenesis.

Expansion of trinucleotide repeat tracts has been shown to be associated with numerous human diseases. The mechanism and timing of the expansion events are poorly understood, however. We show that CTG repeats, associated with the human DMPK gene and implanted in two homologous yeast artificial chromosomes (YACs), are very unstable. The instability is 6 to 10 times more pronounced in meiosis than during mitotic division. The influence of meiosis on instability is 4.4 times greater when the second YAC with a repeat tract is not present. Most of the changes we observed in trinucleotide repeat tracts are large contractions of 21 to 50 repeats. The orientation of the insert with the repeats has no effect on the frequency and distribution of the contractions. In our experiments, expansions were found almost exclusively during gametogenesis. Genetic analysis of segregating markers among meiotic progeny excluded unequal crossover as the mechanism for instability. These unique patterns have novel implications for possible mechanisms of repeat instability.

Singular value decomposition with self-modeling applied to determine bacteriorhodopsin intermediate spectra: analysis of simulated data.

An a priori model-independent method for the determination of accurate spectra of photocycle intermediates is developed. The method, singular value decomposition with self-modeling (SVD-SM), is tested on simulated difference spectra designed to mimic the photocycle of the Asp-96 --> Asn mutant of bacteriorhodopsin. Stoichiometric constraints, valid until the onset of the recovery of bleached bacteriorhodopsin at the end of the photocycle, guide the self-modeling procedure. The difference spectra of the intermediates are determined in eigenvector space by confining the search for their coordinates to a stoichiometric plane. In the absence of random noise, SVD-SM recovers the intermediate spectra and their time evolution nearly exactly. The recovery of input spectra and kinetics is excellent although somewhat less exact when realistic random noise is included in the input spectra. The difference between recovered and input kinetics is now visually discernible, but the same reaction scheme with nearly identical rate constants to those assumed in the simulation fits the output kinetics well. SVD-SM relegates the selection of a photocycle model to the late stage of the analysis. It thus avoids derivation of erroneous model-specific spectra that result from global model-fitting approaches that assume a model at the outset.

Intermediate spectra and photocycle kinetics of the Asp96 --> asn mutant bacteriorhodopsin determined by singular value decomposition with self-modeling.

Singular value decomposition with self-modeling is applied to resolve the intermediate spectra and kinetics of the Asp96 --> Asn mutant bacteriorhodopsin. The search for the difference spectra of the intermediates is performed in eigenvector space on the stoichiometric plane. The analysis of data at pH values ranging from 4 to 8 and temperatures between 5 and 25 degrees C reveals significant, early partial recovery of the initial state after photoexcitation. The derived spectra are not biased by assumed photocycles. The intermediate spectra derived in the initial step differ from spectra determined in prior analyses, which results in intermediate concentrations with improved stoichiometric properties. Increasingly more accurate photocycles follow with increasing assumed complexity, of which parallel models are favored, consistent with recent, independent experimental evidence.

Martian "microfossils" in lunar meteorites?

One of the five lines of evidence used by McKay et al. (1996) for relic life in the Martian meteorite Allan Hills (ALH) 84001 was the presence of objects thought to be microfossils. These ovoid and elongated forms are similar to structures found in terrestrial rocks and described as "nanobacteria" (Folk, 1993; McBride et al., 1994). Using the same procedures and apparatus as McKay et al. (1996), we have found structures on internal fracture surfaces of lunar meteorites that cannot be distinguished from the objects described on similar surfaces in ALH 84001. The lunar surface is currently a sterile environment and probably always has been. However, the lunar and Martian meteorites share a common terrestrial history, which includes many thousands of years of exposure to Antarctic weathering. Although we do not know the origin of these ovoid and elongated forms, we suggest that their presence on lunar meteorites indicates that the objects described by McKay et al. (1996) are not of Martian biological origin.

Pure red cell aplasia associated with hepatitis C infection.

We report the case of a 34-year-old woman with recurrent pure red cell aplasia and evidence of hepatitis B and C infection. Review of the English literature identified 19 prior cases in which pure red cell aplasia was associated with hepatitis. This case is the first in which serologic evidence of hepatitis C infection was documented. This patient also had porphyria cutanea tarda and marked hepatic siderosis but no active hepatitis or cirrhosis. Treatment with cyclophosphamide and prednisone produced complete remission of the pure red cell aplasia. Erythroid colony formation (colony-forming unit-erythroid and erythroid burst-forming unit) was reduced in cultures of bone marrow obtained during relapse but was normal in remission marrow. However, addition of the patient serum, whether collected during relapse or remission, inhibited erythroid colony formation by her bone marrow. These observations, and the known extrahepatic immunologic manifestations of hepatitis C infection, suggest that the pure red cell aplasia occurred because of autoimmune mechanism provoked by the infection.