Chronic sequelae complicate convalescence from both dengue and acute viral respiratory illness

Long Covid has raised awareness of the potentially disabling chronic sequelae that afflicts patients after acute viral infection. Similar syndromes of post-infectious sequelae have also been observed after other viral infections such as dengue, but their true prevalence and functional impact remain poorly defined. We prospectively enrolled 209 patients with acute dengue (n = 48; one with severe dengue) and other acute viral respiratory infections (ARI) (n = 161), and followed them up for chronic sequelae up to one year post-enrolment, prior to the onset of the Covid-19 pandemic. Baseline demographics and co-morbidities were balanced between both groups except for gender, with more males in the dengue cohort (63% vs 29%, p<0.001). Except for the first visit, data on symptoms were collected remotely using a purpose-built mobile phone application. Mental health outcomes were evaluated using the validated SF-12v2 Health Survey. Almost all patients (95.8% of dengue and 94.4% of ARI patients) experienced at least one symptom of fatigue, somnolence, headache, concentration impairment or memory impairment within the first week of enrolment. Amongst patients with at least 3-months of follow-up, 18.0% in the dengue cohort and 14.6% in the ARI cohort experienced persistent symptoms. The median month-3 SF-12v2 Mental Component Summary Score was lower in patients who remained symptomatic at 3 months and beyond, compared to those whose symptoms fully resolved (47.7 vs. 56.0, p<0.001), indicating that patients who self-reported persistence of symptoms also experienced functionally worse mental health. No statistically significant difference in age, gender distribution or hospitalisation status was observed between those with and without chronic sequelae. Our findings reveal an under-appreciated burden of post-infection chronic sequelae in dengue and ARI patients. They call for studies to define the pathophysiology of this condition, and determine the efficacy of both vaccines as well as antiviral drugs in preventing such sequelae.     

Integration of a multicomponent intervention for hypertension into primary healthcare services in Singapore—A cluster randomized controlled trial

BackgroundDespite availability of clinical practice guidelines for hypertension management, blood pressure (BP) control remains sub-optimal (<30%) even in high-income countries. This study aims to assess the effectiveness of a potentially scalable multicomponent intervention integrated into primary care system compared to usual care on BP control.Methods and findingsA cluster-randomized controlled trial was conducted in 8 government clinics in Singapore. The trial enrolled 916 patients aged ≥40 years with uncontrolled hypertension (systolic BP (SBP) ≥140 mmHg or diastolic BP (DBP) ≥90 mmHg).Multicomponent intervention consisted of physician training in risk-based treatment of hypertension, subsidized losartan-HCTZ single-pill combination (SPC) medications, nurse training in motivational conversations (MCs), and telephone follow-ups. Usual care (controls) comprised of routine care in the clinics, no MC or telephone follow-ups, and no subsidy on SPCs. The primary outcome was mean SBP at 24 months’ post-baseline. Four clinics (447 patients) were randomized to intervention and 4 (469) to usual care. Patient enrolment commenced in January 2017, and follow-up was during December 2018 to September 2020. Analysis used intention-to-treat principles. The primary outcome was SBP at 24 months. BP at baseline, 12 and 24 months was modeled at the patient level in a likelihood-based, linear mixed model repeated measures analysis with treatment group, follow-up, treatment group × follow-up interaction as fixed effects, and random cluster (clinic) effects.A total of 766 (83.6%) patients completed 2-year follow-up. A total of 63 (14.1%) and 87 (18.6%) patients in intervention and in usual care, respectively, were lost to follow-up. At 24 months, the adjusted mean SBP was significantly lower in the intervention group compared to usual care (−3.3 mmHg; 95% CI: −6.34, −0.32; p = 0.03). The intervention led to higher BP control (odds ratio 1.51; 95% CI: 1.10, 2.09; p = 0.01), lower odds of high (>20%) 10-year cardiovascular risk score (OR 0.67; 95% CI: 0.47, 0.97; p = 0.03), and lower mean log albuminuria (−0.22; 95% CI: −0.41, −0.02; p = 0.03). Mean DBP, mortality rates, and serious adverse events including hospitalizations were not different between groups. The main limitation was no masking in the trial.ConclusionsA multicomponent intervention consisting of physicians trained in risk-based treatment, subsidized SPC medications, nurse-delivered motivational conversation, and telephone follow-ups improved BP control and lowered cardiovascular risk. Wide-scale implementation of a multicomponent intervention such as the one in our trial is likely to reduce hypertension-related morbidity and mortality globally.Trial registrationTrial Registration: Clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT02972619","term_id":"NCT02972619"}}NCT02972619.

Tazeen H Jafar and colleagues present findings from a cluster-randomized controlled trial conducted to evaluate the effectiveness of an intervention designed to manage hypertension.     

Capture of Bactrocera fruit flies in traps baited with liquid versus solid formulations of male lures in Malaysia

Approximately 70 species of Bactrocera fruit flies (Diptera: Tephritidae) are polyphagous economic pests that attack many important agricultural crops. Several of these Bactrocera species are also highly invasive, and many countries operate continuous, large-scale trapping programs to detect incipient infestations. Detection programs rely heavily on traps baited with male lures, with males of some species responding to raspberry ketone (RK; or its synthetic analogue cue-lure [CL]) and males of other species responding to methyl eugenol (ME). These lures (plus naled, an insecticide) are currently applied as liquids, although this procedure is time-consuming and may expose workers to health risks. Recent field tests, conducted largely in Hawaii, have shown that traps baited with a solid formulation (termed a wafer) that contains both RK and ME (plus dichlorvos, an insecticide) capture as many or more B. dorsalis (Hendel) and B. cucurbitae (Coquillett) males as traps baited with the standard liquid lures. While these results are promising, a more complete evaluation of the solid formulation requires testing in a region with a diverse assemblage of Bactrocera species, since interspecific variation in male response to lures has been reported. The objective of the present investigation was to assess the relative effectiveness of liquid versus solid formulations of male lures in Malaysia, a country known to harbor a large assemblage of Bactrocera species. Based on a 12-week sampling period, we found that, contrary to the Hawaiian results, traps baited with the wafer captured significantly fewer males than traps baited with liquid lures for all five ME-responding taxa analyzed and for one of the three RK/CL-responding species analyzed. Possible explanations for the discrepancy between these and earlier findings are offered.     

Properties and Expression of Na+/K+-ATPase α-Subunit Isoforms in the Brain of the Swamp Eel,Monopterus albus,Which Has Unusually High Brain Ammonia Tolerance

The swamp eel, Monopterus albus, can survive in high concentrations of ammonia (>75 mmol l⁻¹) and accumulate ammonia to high concentrations in its brain (∼4.5 µmol g⁻¹). Na⁺/K⁺-ATPase (Nka) is an essential transporter in brain cells, and since NH₄ ⁺ can substitute for K⁺ to activate Nka, we hypothesized that the brain of M. albus expressed multiple forms of Nka α-subunits, some of which might have high K⁺ specificity. Thus, this study aimed to clone and sequence the nka α-subunits from the brain of M. albus, and to determine the effects of ammonia exposure on their mRNA expression and overall protein abundance. The effectiveness of NH₄ ⁺ to activate brain Nka from M. albus and Mus musculus was also examined by comparing their Na⁺/K⁺-ATPase and Na⁺/NH₄ ⁺-ATPase activities over a range of K⁺/NH₄ ⁺ concentrations. The full length cDNA coding sequences of three nkaα (nkaα1, nkaα3a and nkaα3b) were identified in the brain of M. albus, but nkaα2 expression was undetectable. Exposure to 50 mmol l⁻¹ NH₄Cl for 1 day or 6 days resulted in significant decreases in the mRNA expression of nkaα1, nkaα3a and nkaα3b. The overall Nka protein abundance also decreased significantly after 6 days of ammonia exposure. For M. albus, brain Na⁺/NH₄ ⁺-ATPase activities were significantly lower than the Na⁺/K⁺-ATPase activities assayed at various NH₄ ⁺/K⁺ concentrations. Furthermore, the effectiveness of NH₄ ⁺ to activate Nka from the brain of M. albus was significantly lower than that from the brain of M. musculus, which is ammonia-sensitive. Hence, the (1) lack of nkaα2 expression, (2) high K⁺ specificity of K⁺ binding sites of Nkaα1, Nkaα3a and Nkaα3b, and (3) down-regulation of mRNA expression of all three nkaα isoforms and the overall Nka protein abundance in response to ammonia exposure might be some of the contributing factors to the high brain ammonia tolerance in M. albus.     

Effect of fermentation inhibitors in the presence and absence of activated charcoal on the growth of Saccharomyces cerevisiae

The acidic hydrolysis of biomass generates numerous inhibitors of fermentation, which adversely affect cell growth and metabolism. The goal of the present study was to determine the effects of fermentation inhibitors on growth and glucose consumption by Saccharomyces cerevisiae. We also conducted in situ adsorption during cell cultivation in synthetic broth containing fermentation inhibitors. In order to evaluate the effect of in situ adsorption on cell growth, five inhibitors, namely 5-hydroxymethylfurfural, levulinic acid, furfural, formic acid, and acetic acid, were introduced into synthetic broth. The existence of fermentation inhibitors during cell culture adversely affects cell growth and sugar consumption. Furfural, formic acid, and acetic acid were the most potent inhibitors in our culture system. The in situ adsorption of inhibitors by the addition of activated charcoal to the synthetic broth increased cell growth and sugar consumption. Our results indicate that detoxification of fermentation media by in situ adsorption may be useful for enhancing biofuel production.     

Akt-Induced Phosphorylation of N-CoR at Serine 1450 Contributes to Its Misfolded Conformational Dependent Loss (MCDL) in Acute Myeloid Leukemia of the M5 Subtype

The nuclear receptor co-repressor (N-CoR) is a key component of the generic co-repressor complex that plays an important role in the control of cellular growth and differentiation. As shown by us recently, the growth suppressive function of N-CoR largely relies on its capacity to repress Flt3, a key regulator of cellular gorwth during normal and malignant hematopoesis. We further demonstrated how de-repression of Flt3 due to the misfolded conformation dependent loss (MCDL) of N-CoR contributed to malignant growth in acute myeloid leukemia (AML). However, the molecular mechanism underlying the MCDL of N-CoR and its implication in AML pathogenesis is not fully understood. Here, we report that Akt-induced phosphorylation of N-CoR at the consensus Akt motif is crucial for its misfolding and subsequent loss in AML (AML-M5). N-CoR displayed significantly higher level of serine specific phosphorylation in almost all AML-M5 derived cells and was subjected to processing by AML-M5 specific aberrant protease activity. To identify the kinase linked to N-CoR phosphorylation, a library of activated kinases was screened with the extracts of AML cells; leading to the identification of Akt as the putative kinase linked to N-CoR phosphorylation. Consistent with this finding, a constitutively active Akt consistently phosphorylated N-CoR leading to its misfolding; while the therapeutic and genetic ablation of Akt largely abrogated the MCDL of N-CoR in AML-M5 cells. Site directed mutagenic analysis of N-CoR identified serine 1450 as the crucial residue whose phosphorylation by Akt was essential for the misfolding and loss of N-CoR protein. Moreover, Akt-induced phosphorylation of N-CoR contributed to the de-repression of Flt3, suggesting a cross talk between Akt signaling and N-CoR misfolding pathway in the pathogenesis of AML-M5. The N-CoR misfolding pathway could be the common downstream thread of pleiotropic Akt signaling activated by various oncogenic insults in some subtypes of leukemia and solid tumors.     

Rapid and repeatable host plant shifts drive reproductive isolation following a recent human-mediated introduction of the apple maggot fly,Rhagoletis pomonella

Ecological speciation via host-shifting is often invoked as a mechanism for insect diversification, but the relative importance of this process is poorly understood. The shift of Rhagoletis pomonella in the 1850s from the native downy hawthorn, Crataegus mollis, to introduced apple, Malus pumila, is a classic example of sympatric host race formation, a hypothesized early stage of ecological speciation. The accidental human-mediated introduction of R. pomonella into the Pacific Northwest (PNW) in the late 1970s allows us to investigate how novel ecological opportunities may trigger divergent adaptation and host race formation on a rapid timescale. Since the introduction, the fly has spread in the PNW, where in addition to apple, it now infests native black hawthorn, Crataegus douglasii, and introduced ornamental hawthorn, Crataegus monogyna. We use this “natural experiment” to test for genetic differentiation among apple, black, and ornamental hawthorn flies co-occurring at three sympatric sites. We report evidence that populations of all three host-associations are genetically differentiated at the local level, indicating that partial reproductive isolation has evolved in this novel habitat. Our results suggest that conditions suitable for initiating host-associated divergence may be common in nature, allowing for the rapid evolution of new host races when ecological opportunity arises.     

Inhibition of neuronal nitric oxide synthase activity promotes migration of human‐induced pluripotent stem cell‐derived neural stem cells toward cancer cells

The breakthrough in derivation of human‐induced pluripotent stem cells (hiPSCs) provides an approach that may help overcome ethical and allergenic challenges posed in numerous medical applications involving human cells, including neural stem/progenitor cells (NSCs). Considering the great potential of NSCs in targeted cancer gene therapy, we investigated in this study the tumor tropism of hiPSC‐derived NSCs and attempted to enhance the tropism by manipulation of biological activities of proteins that are involved in regulating the migration of NSCs toward cancer cells. We first demonstrated that hiPSC‐NSCs displayed tropism for both glioblastoma cells and breast cancer cells in vitro and in vivo. We then compared gene expression profiles between migratory and non‐migratory hiPSC‐NSCs toward these cancer cells and observed that the gene encoding neuronal nitric oxide synthase (nNOS) was down‐regulated in migratory hiPSC‐NSCs. Using nNOS inhibitors and nNOS siRNAs, we demonstrated that this protein is a relevant regulator in controlling migration of hiPSC‐NSCs toward cancer cells, and that inhibition of its activity or down‐regulation of its expression can sensitize poorly migratory NSCs and be used to improve their tumor tropism. These findings suggest a novel application of nNOS inhibitors in neural stem cell‐mediated cancer therapy.     

Epigallocatechin-3-gallate prevents systemic inflammation-induced memory deficiency and amyloidogenesis via its anti-neuroinflammatory properties

Neuroinflammation has been known to play a critical role in the pathogenesis of Alzheimer's disease (AD) through amyloidogenesis. In a previous study, we found that systemic inflammation by intraperitoneal (ip) injection of lipopolysaccharide (LPS) induces neuroinflammation and triggers memory impairment. In this present study, we investigated the inhibitory effects of epigallocatechin-3-gallate (EGCG) on the systemic inflammation-induced neuroinflammation and amyloidogenesis as well as memory impairment. ICR mice were orally administered with EGCG (1.5 and 3 mg/kg) for 3 weeks, and then the mice were treated by ip injection of LPS (250 μg/kg) for 7 days. We found that treatment of LPS induced memory-deficiency-like behavior and that EGCG treatment prevented LPS-induced memory impairment and apoptotic neuronal cell death. EGCG also suppressed LPS-induced increase of the amyloid beta-peptide level and the expression of the amyloid precursor protein (APP), β-site APP cleaving enzyme 1 and its product C99. In addition, we found that EGCG prevented LPS-induced activation of astrocytes and elevation of cytokines including tumor necrosis factor-α, interleukin (IL)-1β, macrophage colony-stimulating factor, soluble intercellular adhesion molecule-1 and IL-16, and the increase of inflammatory proteins, such as inducible nitric oxide synthase and cyclooxygenase-2, which are known factors responsible for not only activation of astrocytes but also amyloidogenesis. In the cultured astrocytes, EGCG also inhibited LPS-induced cytokine release and amyloidogenesis. Thus, this study shows that EGCG prevents memory impairment as well as amyloidogenesis via inhibition of neuroinflammatory-related cytokines released from astrocytes and suggests that EGCG might be a useful intervention for neuroinflammation-associated AD.