Circulating CD4+ T cells in people with HIV and history of pulmonary tuberculosis have more intact HIV DNA

Background

The primary barrier to curing HIV infection is the pool of intact HIV proviruses integrated into host cell DNA throughout the bodies of people living with HIV (PLHIV), called the HIV reservoir. Reservoir size is impacted by the duration of HIV infection, delay in starting antiretroviral therapy (ART), and breakthrough viremia during ART. The leading infectious cause of death worldwide for PLHIV is TB, but we don't know how TB impacts the HIV reservoir.

Methods

We designed a case-control study to compare HIV provirus-containing CD4 in PLHIV with vs. without a history of active TB disease. Study participants in the pilot and confirmatory cohort were enrolled at GHESKIO Centers in Port au Prince, Haiti. Intact and non-intact proviral DNA were quantified using droplet digital PCR of PBMC-derived CD4 cells. For a subset, Th1 and Th2 cytokines were assayed in plasma. Kruskal-Wallis tests were used to compare medians with tobit regression for censoring.

Results

In the pilot cohort, we found that PLHIV with history of active pulmonary TB (n=20) had higher intact provirus than PLHIV without history of active TB (n=47) (794 vs 117 copies per million CD4, respectively; p<0.0001). In the confirmatory cohort, the quantity of intact provirus was higher in the TB group (n=13) compared with the non-TB group (n=18) (median 102 vs. 0 intact provirus per million CD4, respectively p=0.03). Additionally, we found that the frequencies of CD4+ T cells with any detectable proviral fragment was directly proportional to the levels of IL1B (p= 0.0025) and IL2 (p=0.0002).

Conclusions

This is the first assessment of HIV provirus using IPDA in a clinical cohort from a resource limited setting, and the finding of larger reservoir in PLHIV with history of TB has significant implications for our understanding of TB-HIV coinfection and HIV cure efforts in TB-endemic settings.

The moderating effects of sex, age, and education on the outcome of combined cognitive training and transcranial electrical stimulation in older adults

Computerized cognitive training (CCT) has been shown to improve cognition in older adults via targeted exercises for single or multiple cognitive domains. Combining CCT with non-invasive brain stimulation is thought to be even more effective due to synergistic effects in the targeted brain areas and networks. However, little is known about the moderating effects of sex, age, and education on cognitive outcomes. Here, we investigated these factors in a randomized, double-blind study in which we administered CCT either combined with transcranial direct (tDCS), alternating (tACS) current stimulation or sham stimulation. 59 healthy older participants (mean age 71.7 ± 6.1) received either tDCS (2 mA), tACS (5 Hz), or sham stimulation over the left dorsolateral prefrontal cortex during the first 20 min of a CCT (10 sessions, 50 min, twice weekly). Before and after the complete cognitive intervention, a neuropsychological assessment was performed, and the test scores were summarized in a composite score. Our results showed a significant three-way interaction between age, years of education, and stimulation technique (F(6,52) = 5.53, p = 0.007), indicating that the oldest participants with more years of education particularly benefitted from tDCS compared to the sham group, while in the tACS group the youngest participants with less years of education benefit more from the stimulation. These results emphasize the importance of further investigating and taking into account sex, age, and education as moderating factors in the development of individualized stimulation protocols.

Clinical Trial Registration

ClinicalTrials.gov, identifier NCT03475446.

Investigating Compensatory Brain Activity in Older Adults with Subjective Cognitive Decline

BACKGROUND

Preclinical Alzheimer's disease (AD) is one possible cause of subjective cognitive decline (SCD). Normal task performance despite ongoing neurodegeneration is typically considered as neuronal compensation, which is reflected by greater neuronal activity. Compensatory brain activity has been observed in frontal as well as parietal regions in SCD, but data are scarce, especially outside the memory domain.

OBJECTIVE

To investigate potential compensatory activity in SCD. Such compensatory activity is particularly expected in participants where blood-based biomarkers indicated amyloid positivity as this implies preclinical AD.

METHODS

52 participants with SCD (mean age: 71.00±5.70) underwent structural and functional neuroimaging (fMRI), targeting episodic memory and spatial abilities, and a neuropsychological assessment. The estimation of amyloid positivity was based on plasma amyloid-β and phosphorylated tau (pTau181) measures.

RESULTS

Our fMRI analyses of the spatial abilities task did not indicate compensation, with only three voxels exceeding an uncorrected threshold at p < 0.001. This finding was not replicated in a subset of 23 biomarker positive individuals.

CONCLUSION

Our results do not provide conclusive evidence for compensatory brain activity in SCD. It is possible that neuronal compensation does not manifest at such an early stage as SCD. Alternatively, it is possible that our sample size was too small or that compensatory activity may be too heterogeneous to be detected by group-level statistics. Interventions based on the individual fMRI signal should therefore be explored.

Can a serious game-based cognitive training attenuate cognitive decline related to Alzheimer's disease? Protocol for a randomized controlled trial

BACKGROUND

Alzheimer's disease (AD) is a major public health issue. Cognitive interventions such as computerized cognitive trainings (CCT) are effective in attenuating cognitive decline in AD. However, in those at risk of dementia related to AD, results are heterogeneous. Efficacy and feasibility of CCT needs to be explored in depth. Moreover, underlying mechanisms of CCT effects on the three cognitive domains typically affected by AD (episodic memory, semantic memory and spatial abilities) remain poorly understood.

METHODS

In this bi-centric, randomized controlled trial (RCT) with parallel groups, participants (planned N = 162, aged 60-85 years) at risk for AD and with at least subjective cognitive decline will be randomized to one of three groups. We will compare serious game-based CCT against a passive wait list control condition and an active control condition (watching documentaries). Training will consist of daily at-home sessions for 10 weeks (50 sessions) and weekly on-site group meetings. Subsequently, the CCT group will continue at-home training for an additional twenty-weeks including monthly on-site booster sessions. Investigators conducting the cognitive assessments will be blinded. Group leaders will be aware of participants' group allocations. Primarily, we will evaluate change using a compound value derived from the comprehensive cognitive assessment for each of three cognitive domains. Secondary, longitudinal functional and structural magnetic resonance imaging (MRI) and evaluation of blood-based biomarkers will serve to investigate neuronal underpinnings of expected training benefits.

DISCUSSION

The present study will address several shortcomings of previous CCT studies. This entails a comparison of serious game-based CCT with both a passive and an active control condition while including social elements crucial for training success and adherence, the combination of at-home and on-site training, inclusion of booster sessions and assessment of physiological markers. Study outcomes will provide information on feasibility and efficacy of serious game-based CCT in older adults at risk for AD and will potentially generalize to treatment guidelines. Moreover, we set out to investigate physiological underpinnings of CCT induced neuronal changes to form the grounds for future individually tailored interventions and neuro-biologically informed trainings.

TRIAL REGISTRATION

This RCT was registered 1st of July 2020 at clinicaltrials.gov (Identifier NCT04452864).

Detection of in vivo hepatitis B virus surface antigen mutations-A comparison of four routine screening assays

An important requirement for a state-of-the-art hepatitis B surface antigen (HBsAg) screening assay is reliable detection of mutated HBsAg. Currently, there is a striking shortage of data regarding the detection rates of in vivo HBsAg mutations for these clinically important assays. Therefore, we compared the detection rates of four commercial HBsAg screening assays using a global cohort of 1553 patients from four continents with known HBV genotypes. These samples, which represent the broadest spectrum of known and novel HBsAg major hydrophilic region (MHR) mutations to date, were analyzed for the presence of HBsAg using the Roche Elecsys^® HBsAg II Qualitative, Siemens ADVIA Centaur XP HBsAg II, Abbott Architect HBsAg Qualitative II and DiaSorin Liaison^® HBsAg Qualitative assays, respectively. Of the 1553 samples, 1391 samples could be sequenced; of these, 1013 (72.8%) carried at least one of the 345 currently known amino acid substitutions (distinct HBsAg mutation) in the HBsAg MHR. All 1553 patient samples were positive for HBsAg using the Elecsys^® HBsAg II Qual assay, with a sensitivity (95% confidence interval) of 99.94% (99.64%-100%), followed by the Abbott Architect 99.81% (99.44%-99.96%), Siemens ADVIA 99.81% (99.44%-99.96%) and DiaSorin Liaison^® 99.36% (98.82%-99.69%) assays, respectively. Our results indicate that the Elecsys^® HBsAg II Qual assay exhibits the highest sensitivity among the commercial HBsAg screening assays, and demonstrate that its capacity to detect HBV infection is not compromised by HBsAg MHR mutants.

Molecular basis for heterogeneity of the human p53 protein

The human p53 tumor antigen comprises several physically distinct proteins. Two p53 proteins, separable by polyacrylamide gel electrophoresis, are expressed by the human transformed cell line SV-80. The individual cDNAs which code for these proteins were isolated and constructed into the SP6 transcription vector. The proteins encoded by these clones were identified by in vitro transcription with the SP6 vector and translation in a cell-free system. p53-H-1 and p53-H-19 cDNA clones code for the faster- and slower-migrating p53 protein species, respectively, of SV-80. The in vitro-expressed proteins of p53-H-1 and p53-H-19 had the same antigenic determinants and were structurally indistinguishable from their in vivo counterparts. By expressing defined restricted cDNA fragments in vitro, the region of heterogeneity between the respective cDNAs was located at the 5' end of the cDNAs. Exchanging the 5' fragments of interest and expressing the chimeric clones in vitro confirmed that the DNA heterogeneity was responsible for the difference in the electrophoretic mobility of these proteins. The sequences of the two cDNAs revealed a single base pair difference (G versus C) in the coding region of the clones. This sequence difference resulted in an arginine being coded for in clone p53-H-1 and a proline being coded for at the equivalent position in clone p53-H-19. This variation accounted for the change in the electrophoretic mobility of the individual p53 protein species.

Immunologically distinct p53 molecules generated by alternative splicing

Transfection of a functional cloned p53 gene into an L12 p53 nonproducer cell line efficiently reconstituted p53 expression. The p53 protein synthesized in these clones was indistinguishable from that occurring naturally in tumor cells. When a p53 cDNA clone was used instead, we observed that the L12-derived clones exhibited a distinct immunological profile. In the present experiments we compared the immunological epitopes of p53 proteins encoded by several full-length cDNA clones. Immunoprecipitation of p53 proteins generated by in vitro transcription and translation of the various cDNA clones indicated variations in the content of immunological epitopes. Basically, two p53 protein species were detected. Both species contained the same antigenic determinants except the PAb421-PAb122 site, which was present in proteins encoded by p53-M11 and pcD-p53, but not in the p53 protein encoded by the p53-M8 cDNA clone. Sequence analysis of the various cDNA clones indicated the existence of a 96-base-pair (bp) insert in clone p53-M8 as compared with clone p53-M11 or pCD-p53. The 96-bp insert contained a termination signal which caused the premature termination of the protein, leading to the generation of a p53 product 9 amino acids shorter than usual. The existence of this insert also accounted for the lack of the PAb421-PAb122 epitope which was mapped to the 3' end of the cDNA clone, following the 96-bp insert. This insert shared complete homology with the p53 intron 10 sequences mapping 96 bp upstream of the 5' acceptor splicing site of p53 exon 11. It was therefore concluded that the different cDNA clones represented p53 mRNA species which were generated by an alternative splicing mechanism. Differential hybridization of the mRNA population of transformed fibroblastic or lymphoid cells with either the 96-bp synthetic oligonucleotide or the p53-M11 cDNA indicated that the various mRNA species are expressed in vivo.

Failure of the N-oxodized metabolites of some carcinogenic amines to induce tumors in normal and wounded rat skin

The skin of Osborne-Mendel and Sprague-Dawley rats was treated by repeated topical application of 1- and 2-naphthylamine, 4-biphenylamine and their corresponding N-arylhydroxylamine and nitroso derivatives for 52 weeks. In addition, the possibility of enhancing the susceptibility of the skin to the tumor induction by periodic wounding at the site of compound application was investigated in the Sprague-Dawley strain. The animals were observed for an additional year after which all survivors were sacrificed. No skin tumours were elicited in any of the rats although a small number of systemic tumors at sites distant from the area of application were observed in the Osborne-Mendel strain. No discernable increase in the sensitivity of the skin as a consequence of wounding to the carcinogenic effect of the compounds tested were observed.

Hypotensive activity of sodium nitroprusside and structurally related complexes of sodium pentacyanoamine ferrate with amylnitrite, butylnitrite and n-octylamine

Complexes of sodium pentacyanoamine ferrate (TPF) with amylnitrite and with butylnitrite showed hypotensive activity equal to that of sodium nitroprusside, as tested intravenously, in unanesthetized , instrumented Rhesus, monkeys. The complex with n-octylamine, on the other hand, had significantly lower activity. These complexes produced only marginal hypotensive effects when administered orally in a dose of 10 mg/kg to spontaneously hypertensive rats.

Failure of ascrobic acid to inhibit the metabolic N-oxidation of the bladder carcingen 4-biphenylamine

The effect of L-ascorbic acid on the in vivo metabolic N-oxidation of the bladder carcinogen 4-biphenylamine has been investigated in the dog. Gas chromatographic analysis of the urines of dogs receiving concomitant oral doses of L-ascorbic acid and 4-biphyenylamine showed no significant difference in the N-oxidized metabolites when compared to dogs receiving arylamine alone. The results indicate that pretreatment with large doses of L-ascorbic acid has no effect on the metabolic N-oxidation of 4-biphenylamine or on the urinary concentration of these metabolites. The failure of L-ascrobic acid to lower the urinary concentration of these presumed proximate urinary carcinogens casts doubt on its efficacy in bladder tumor prophylaxis.

The role of dog bladder mucosa in the N-oxidation of arylamines

The in vitro metabolic N-oxidation of 1- and 1-napthylamine, 4-biphenylamine, 2-fluorenylamine and 3-dibenzolfuranylamine has been investigated with intact dog bladder, whole intact bladder mucosa and microsomes prepared from this tissue. Very low levels of metabolic N-oxidation of these carcinogenic amines were detected with these tissue preparations using ferrihemoglobin formation in dog erythrocytes. No N-oxidation by these tissue preparations was observed using gas-liquid chromatography. The concentrations of the N-oxidized metabolites observed in the urine of dogs in vivo exposed to thse amines suggests that N-oxidation takes place predominately in the liver and that the bladder plays, at most, a minor role in the formation of these presumed proximate urinary carcinogens.

Bladder cancer induction by aromatic amines: role of N-hydroxy metabolites

Repeated installation of N-hydroxy-2 naphthylamine into dog bladders produced tumors of this organ. There is a correlation of degree of carcinogenicity of 1-naphthylamine, 2-naphthylamine, and 4-aminobiphenyl with both methemoglobin production in the blood and concentration of N-oxidation products in the urine. Thus, N-hydroxylation appears to be the key to bladder cancer production by aromatic amines.