Effects of early human immunodeficiency virus infection on cerebral white matter blood flow autoregulation.

Blood flow autoregulation in cerebral white matter was measured before and after acute nicardipine-induced changes in mean arterial pressure of 10-21% in 21 treatment naïve HIV-positive adults and 32 controls. The autoregulatory index (-% cerebral blood flow change/% mean arterial pressure change) was not different at baseline ( P  = 0.71) or after 1 year of treatment ( n  = 11, P  = 0.

A longitudinal study of olfactory dysfunction and parosmia in mild COVID-19 cases.

Background: COVID-19-related olfactory dysfunction (OD) can persist long after patients recover from acute infection, yet few studies have investigated the long-term progression of this complication. Moreover, existing studies are focused on hyposmia/anosmia but parosmia is becoming an increasingly recognized long-term symptom.

Methods: We completed a longitudinal study about OD in individuals with mild cases of COVID-19.

Reduction in cerebral oxygen metabolism in subcortical regions may be a biomarker of cognitive decline in people living with human immunodeficiency virus.

Background And Purpose: Regional cerebral blood flow (rCBF) and oxygen metabolism (rCMRO ) in whole brain, white matter, gray matter and lenticular nuclei were studied in people living with human immunodeficiency virus (PLHIV) as well as HIV-associated neurocognitive disorder (HAND).

Methods: Treatment-naïve PLHIV underwent neurocognitive assessment and magnetic resonance (MR) measurement of rCBF and rCMRO with repeat after 12 months of antiretroviral therapy (ART). Age- and sex-matched controls underwent single MR measurements.

COVID-19 related olfactory dysfunction prevalence and natural history in ambulatory patients.

Background: Evidence regarding prevalence of COVID-19 related Olfactory dysfunction (OD) among ambulatory patients is highly variable due to heterogeneity in study population and measurement methods. Relatively few studies have longitudinally investigated OD in ambulatory patients with objective methods.

Methods: We performed a longitudinal study to investigate OD among COVID-19 ambulatory patients compared to symptomatic controls who test negative.

Autoregulation of White Matter Cerebral Blood Flow to Arterial Pressure Changes in Normal Subjects.

Endothelial dysfunction causing impaired cerebrovascular vasodilatory capacity in response to reduced blood pressure has been proposed as a mechanism of white matter (WM) disease development. This study investigated autoregulation of CBF to blood pressure reduction in WM and gray matter (GM) in normal subjects recruited as controls for a study of cerebrovascular function in human immunodeficiency virus positive subjects. They underwent baseline CBF and oxygen extraction fraction measurement by MRI before and after mean arterial pressure (MAP) reduction.

Reduced homeobox protein MSX1 in human endometrial tissue is linked to infertility.

Study Question: Is protein expression of the muscle segment homeobox gene family member MSX1 altered in the human secretory endometrium by cell type, developmental stage or fertility?

Summary Answer: MSX1 protein levels, normally elevated in the secretory phase endometrium, were significantly reduced in endometrial biopsies obtained from women of infertile couples.

What Is Known Already: Molecular changes in the endometrium are important for fertility in both animals and humans. Msx1 is expressed in the preimplantation mouse uterus and regulates uterine receptivity for implantation.

Increased Cortical Cerebral Blood Flow in Asymptomatic Human Immunodeficiency Virus-Infected Subjects.

Background: Human immunodeficiency virus (HIV)-infected individuals are at high risk for ischemic stroke. To investigate the physiological basis for this risk, we used magnetic resonance imaging (MRI) to measure oxygen extraction fraction (OEF) and cerebral blood flow (CBF) in treatment-naive asymptomatic HIV-infected subjects and controls.

Methods: In treatment-naive asymptomatic HIV-infected subjects and age-, gender-, and race-matched controls, OEF was measured by MRI asymmetric spin-echo echo-planar imaging sequences and CBF was measured by MRI pseudocontinuous arterial spin labeling.

A Comprehensive Analysis of Replicative Lifespan in 4,698 Single-Gene Deletion Strains Uncovers Conserved Mechanisms of Aging.

Many genes that affect replicative lifespan (RLS) in the budding yeast Saccharomyces cerevisiae also affect aging in other organisms such as C. elegans and M. musculus.

Yeast life span extension by depletion of 60s ribosomal subunits is mediated by Gcn4.

In nearly every organism studied, reduced caloric intake extends life span. In yeast, span extension from dietary restriction is thought to be mediated by the highly conserved, nutrient-responsive target of rapamycin (TOR), protein kinase A (PKA), and Sch9 kinases. These kinases coordinately regulate various cellular processes including stress responses, protein turnover, cell growth, and ribosome biogenesis.

Sirtuin-independent effects of nicotinamide on lifespan extension from calorie restriction in yeast.

Two models have been proposed for how calorie restriction (CR) enhances replicative longevity in yeast: (i) suppression of rDNA recombination through activation of the sirtuin protein deacetylase Sir2 or (ii) decreased activity of the nutrient-responsive kinases Sch9 and TOR. We report here that CR increases lifespan independently of all Sir2-family proteins in yeast. Furthermore, we demonstrate that nicotinamide, an inhibitor of Sir2-mediated deacetylation, interferes with lifespan extension from CR, but does so independent of Sir2, Hst1, Hst2, and Hst4.