Historically, DENV-4 has been rarely associated with epidemics and has been less well-studied than DENV-1 to -3. Epidemic dengue struck several South and Central American countries in 2022, with Nicaragua reporting the highest incidence. In an acute febrile illness (AFI) cohort enrolled from June to September 2022, 58 (34%) of 172 patients had PCR-confirmed dengue, of which 46 (79%) were serotyped as DENV-4.
View Article and Find Full Text PDFAm J Trop Med Hyg
April 2024
Since the Zika virus (ZIKV) pandemic in 2015-2017, there has been a near absence of reported cases in the Americas outside of Brazil. However, the conditions for Aedes-borne transmission persist in Latin America, and the threat of ZIKV transmission is increasing as population immunity wanes. Mexico has reported only 70 cases of laboratory-confirmed ZIKV infection since 2020, with no cases recorded in the Yucatán peninsula.
View Article and Find Full Text PDFTo understand the dynamics of Zika virus (ZIKV)-specific antibody immunity in children born to mothers in a flavivirus-endemic region during and after the emergence of ZIKV in the Americas. We performed serologic testing for ZIKV cross-reactive and type-specific IgG in two longitudinal cohorts, which enrolled pregnant women and their children (PW1 and PW2) after the beginning of the ZIKV epidemic in Nicaragua. Quarterly samples from children over their first two years of life and maternal blood samples at birth and at the end of the two-year follow-up period were studied.
View Article and Find Full Text PDFAcute febrile illness is a common problem managed by clinicians and health systems globally, particularly in the Tropics. In many regions, malaria is a leading and potentially deadly cause of fever; however, myriad alternative etiologies exist. Identifying the cause of fever allows optimal management, but this depends on many factors including thorough knowledge of circulating infections.
View Article and Find Full Text PDFInfect Control Hosp Epidemiol
November 2022
Objectives: To determine the incidence of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection among healthcare personnel (HCP) and to assess occupational risks for SARS-CoV-2 infection.
Design: Prospective cohort of healthcare personnel (HCP) followed for 6 months from May through December 2020.
Setting: Large academic healthcare system including 4 hospitals and affiliated clinics in Atlanta, Georgia.
Infect Control Hosp Epidemiol
March 2022
Among 353 healthcare personnel in a longitudinal cohort in 4 hospitals in Atlanta, Georgia (May-June 2020), 23 (6.5%) had severe acute respiratory coronavirus virus 2 (SARS-CoV-2) antibodies. Spending >50% of a typical shift at the bedside (OR, 3.
View Article and Find Full Text PDFObjective: Cyclosporine A (CsA) and sirolimus (SRL) are immunosuppressive agents (IA) associated with new onset diabetes after transplantation and dyslipidemia. We aim to evaluate the molecular effects of CsA (5mg/kg/day) and SRL (1mg/kg/day) treatment for 3 and 9weeks on lipid metabolism, in Wistar rats.
Materials/methods: Lipolysis was evaluated in isolated adipocytes, while triglycerides (TG) and non-esterified fatty acid (NEFA) were measured in serum.
Body weight is regulated by coordinating energy intake and energy expenditure. Transforming growth factor β (TGFβ)/bone morphogenetic protein (BMP) signaling has been shown to regulate energy balance in lower organisms, but whether a similar pathway exists in mammals is unknown. We have previously demonstrated that BMP7 can regulate brown adipogenesis and energy expenditure.
View Article and Find Full Text PDFBrown adipose tissue plays an important role in obesity, insulin resistance, and diabetes. We have previously shown that the transition from brown preadipocytes to mature adipocytes is mediated in part by insulin receptor substrate (IRS)-1 and the cell cycle regulator protein necdin. In this study, we used pharmacological inhibitors and adenoviral dominant negative constructs to demonstrate that this transition involves IRS-1 activation of Ras and ERK1/2, resulting in phosphorylation of cAMP response element-binding protein (CREB) and suppression of necdin expression.
View Article and Find Full Text PDFEnvironmental factors, such as the macronutrient composition of the diet, can have a profound impact on risk of diabetes and metabolic syndrome. In the present study we demonstrate how a single, simple dietary factor--leucine--can modify insulin resistance by acting on multiple tissues and at multiple levels of metabolism. Mice were placed on a normal or high fat diet (HFD).
View Article and Find Full Text PDFBackground: Tripeptidyl aminopeptidase I (TPPI) is a crucial lysosomal enzyme that is deficient in the fatal neurodegenerative disorder called classic late-infantile neuronal ceroid lipofuscinosis (LINCL). It is involved in the catabolism of proteins in the lysosomes. Recent X-ray crystallographic studies have provided insights into the structural/functional aspects of TPPI catalysis, and indicated presence of an octahedrally coordinated Ca(2+).
View Article and Find Full Text PDFBoth insulin and bone morphogenetic protein (BMP) signaling systems are important for adipocyte differentiation. Analysis of gene expression in BMP7-treated fibroblasts revealed a coordinated change in insulin signaling components by BMP7. To further investigate the cross talk between insulin and BMP signaling systems in brown adipogenesis, we examined the effect of BMP7 in insulin receptor substrate 1 (IRS-1)-deficient brown preadipocytes, which exhibit a severe defect in differentiation.
View Article and Find Full Text PDFThe peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1) family is a key regulator of mitochondrial function, and reduced mRNA expression may contribute to muscle lipid accumulation in obesity and type 2 diabetes. To characterize the effects of PGC-1 on lipid metabolism, we overexpressed PGC-1alpha and PGC-1beta in C2C12 myotubes using adenoviral vectors. Both PGC-1alpha and -1beta increased palmitate oxidation [31% (P<0.
View Article and Find Full Text PDFAdipose tissue is central to the regulation of energy balance. Two functionally different types of fat are present in mammals: white adipose tissue, the primary site of triglyceride storage, and brown adipose tissue, which is specialized in energy expenditure and can counteract obesity. Factors that specify the developmental fate and function of white and brown adipose tissue remain poorly understood.
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