Neurocognitive function in HIV-infected persons with asymptomatic cryptococcal antigenemia: a comparison of three prospective cohorts.

Background: HIV-infected persons with detectable cryptococcal antigen (CrAg) in blood have increased morbidity and mortality compared with HIV-infected persons who are CrAg-negative. This study examined neurocognitive function among persons with asymptomatic cryptococcal antigenemia.

Methods: Participants from three prospective HIV cohorts underwent neurocognitive testing at the time of antiretroviral therapy (ART) initiation.

Empyema management: A cohort study evaluating antimicrobial therapy.

Objectives: Empyemas require aggressive antimicrobial and surgical management. However, the specifics of antimicrobial therapy have not been studied in clinical trials. The present study examines management and outcomes among a cohort of patients with empyema cared for in a tertiary-care referral hospital over a decade.

Ventricular septal defect and bivalvular endocarditis.

A 63-year-old man presented with generalized fatigue, chills, malaise, dyspnea, intermittent fevers, and 50-pound weight loss of 4 months' duration. Blood cultures were positive for pan-sensitive Streptococcus anginosus. Transesophageal echocardiography showed an 11 mm × 3 mm mobile mass attached to the mitral valve, a 16 mm × 16 mm mobile mass attached to the pulmonary valve, and a small membranous ventricular septal defect.

Predictors of neurocognitive outcomes on antiretroviral therapy after cryptococcal meningitis: a prospective cohort study.

Cryptococcal meningitis is the most common cause of adult meningitis in Africa, yet neurocognitive outcomes are unknown. We investigated the incidence and predictors of neurologic impairment among cryptococcal survivors. HIV-infected, antiretroviral-naive Ugandans with cryptococcal meningitis underwent standardized neuropsychological testing at 1, 3, 6, and 12 months.

Cryptococcal meningitis treatment strategies in resource-limited settings: a cost-effectiveness analysis.

Background: Cryptococcal meningitis (CM) is the most common form of meningitis in Africa. World Health Organization guidelines recommend 14-d amphotericin-based induction therapy; however, this is impractical for many resource-limited settings due to cost and intensive monitoring needs. A cost-effectiveness analysis was performed to guide stakeholders with respect to optimal CM treatment within resource limitations.

Lung manifestations in an autopsy-based series of pulmonary or disseminated nontuberculous mycobacterial disease.

Background: Comparisons of lung manifestations in primary pulmonary vs disseminated nontuberculous mycobacterial disease have not been well described. The clinical, histopathologic, and radiologic disease manifestations of primary pulmonary or disseminated nontuberculous mycobacterial disease were compared in an autopsy series.

Methods: Medical and microbiologic records, autopsy reports, histopathologic slides of the lungs, and chest CT scans were reviewed on patients at the National Institutes of Health with nontuberculous mycobacterial disease who died between 1996 and 2010.

FOXO3a induces differentiation of Bcr-Abl-transformed cells through transcriptional down-regulation of Id1.

Leukemic transformation often requires activation of protein kinase B (PKB/c-Akt) and is characterized by increased proliferation, decreased apoptosis, and a differentiation block. PKB phosphorylates and inactivates members of the FOXO subfamily of Forkhead transcription factors. It has been suggested that hyperactivation of PKB maintains the leukemic phenotype through actively repressing FOXO-mediated regulation of specific genes.

Chronic protein kinase B (PKB/c-akt) activation leads to apoptosis induced by oxidative stress-mediated Foxo3a transcriptional up-regulation.

Increased protein kinase B (PKB; c-Akt) activation is a hallmark of diverse neoplasias providing both proliferative and antiapoptotic survival signals. In this study, we investigated the effect of chronic PKB activation on cellular survival and proliferation using cytokine-dependent bone marrow-derived Ba/F3 cells, in which PKBalpha activation can be directly, and specifically, induced by addition of 4-hydroxytamoxifen (4-OHT). Direct activation of PKB rescued Ba/F3 cells from cytokine withdrawal-induced apoptosis; however, surprisingly, these antiapoptotic effects were short lived, cells only being protected for up to 48 hours.

Cytokine mediated suppression of TF-1 apoptosis requires PI3K activation and inhibition of Bim expression.

Phosphatidylinositol 3-kinase (PI3K) and its effector protein kinase B (PKB/c-akt) have been implicated as critical mediators of cytokine-induced survival signals. In this study, we have utilized an IL-5 dependent hematopoietic cell line (TF-1) to investigate the signaling events involved in cytokine-dependent erythroblast survival. We demonstrate that IL-5 rescues TF-1 cells from apoptosis through a PI3K/PKB-dependent signaling pathway.

FoxO3a and BCR-ABL regulate cyclin D2 transcription through a STAT5/BCL6-dependent mechanism.

Cell cycle arrest by FoxO transcription factors involves transcriptional repression of cyclin D, although the exact mechanism remains unclear. In this study, we used the BCR-ABL-expressing cell line BV173 as a model system to investigate the mechanisms whereby FoxO3a regulates cyclin D2 expression. Inhibition of BCR-ABL by STI571 results in down-regulation of cyclin D2 expression, activation of FoxO3a activity, and up-regulation of BCL6 expression.

Bcl-2 prevents loss of mitochondria in CCCP-induced apoptosis.

Bcl-2 family proteins regulate apoptosis at the level of mitochondria. To examine the mechanism of Bcl-2 function, we investigated the effects of the protonophore carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on two hematopoietic cell lines and Bcl-2 overexpressing transfectants. CCCP directly interferes with mitochondrial function and induces apoptosis.

Constitutive NF-kappaB DNA-binding activity in AML is frequently mediated by a Ras/PI3-K/PKB-dependent pathway.

In the present study, we aimed to elucidate the mechanism responsible for constitutive NF-kappaB DNA-binding activity in AML cells. Intervening in aberrant signaling pathway provides a rational approach for in vivo targeting of AML cells. Constitutive NF-kappaB DNA-binding activity was observed in 16 of 22 (73%) investigated AML cases and was, in general, associated with resistance to spontaneous apoptosis.

FOXO transcription factors as regulators of immune homeostasis: molecules to die for?

Regulation of phosphatidylinositol 3-kinase (PI3K) activity has been demonstrated to be critical for correct lymphocyte function. The molecular targets of this lipid kinase have been the subject of extensive research, and many functional effects of PI3K activation are thought to be mediated by the serine-threonine kinase protein kinase B (PKB/c-akt). Genetic analyses in the nematode worm Caenorhabditis elegans have identified a novel PI3K-regulated signaling pathway that regulates organism lifespan through inhibition of a Forkhead (FOX) transcription factor, DAF-16.

Regulation of cell survival and proliferation by the FOXO (Forkhead box, class O) subfamily of Forkhead transcription factors.

Recently, the FOXO (Forkhead box, class O) subfamily of Forkhead transcription factors has been identified as direct targets of phosphoinositide 3-kinase-mediated signal transduction. The AFX (acute-lymphocytic-leukaemia-1 fused gene from chromosome X), FKHR (Forkhead in rhabdomyosarcoma) and FKHR-L1 (FKHR-like 1) transcription factors are directly phosphorylated by protein kinase B, resulting in nuclear export and inhibition of transcription. This signalling pathway was first identified in the nematode worm Caenorhabditis elegans, where it has a role in regulation of the life span of the organism.

FKHR-L1 can act as a critical effector of cell death induced by cytokine withdrawal: protein kinase B-enhanced cell survival through maintenance of mitochondrial integrity.

Survival signals elicited by cytokines include the activation of phosphatidylinositol 3-kinase (PI3K), which in turn promotes the activation of protein kinase B (PKB). Recently, PKB has been demonstrated to phosphorylate and inactivate forkhead transcription factor FKHR-L1, a potent inducer of apoptosis. To explore the mechanisms underlying the induction of apoptosis after cytokine withdrawal or FKHR-L1 activation, we used a cell line in which FKHR-L1 activity could be specifically induced.

Regulation of constitutive STAT5 phosphorylation in acute myeloid leukemia blasts.

In the present study, we examined the underlying mechanism, which causes the constitutive tyrosine phosphorylation of signal transducer and activator of transcription 5 (STAT5) in acute myeloid leukemia (AML) blasts. Constitutive STAT5 phosphorylation was observed in 18 of 26 (69%) patients with AML. The constitutive STAT5 phosphorylation was caused by different mechanisms.

[Multi-rotation CT and acute respiratory distress syndrome. Animal experiment studies].

Purpose: Aim of the study was to investigate alveolar inspiration and expiration using multiscan CT. Results of a visual assessment using a scoring system were compared with density ranges known to represent alveolar ventilation best.

Method: Pigs were examined before and after lavage-induced ARDS.

An inhibitor of PI3-K differentially affects proliferation and IL-6 protein secretion in normal and leukemic myeloid cells depending on the stage of differentiation.

In this study, we examined the involvement of the phosphatidylinositol 3-kinase (PI3-K) and p70S6 kinase signal transduction pathway in the interleukin-1(IL-1)-mediated proliferation and cytokine production by normal and leukemic myeloid cells. Total AML blast populations, early progenitor (CD34(+)/CD36(-)) cells, and more differentiated (CD34(-)/CD36(+)) cells were treated with the PI3-K inhibitor Ly294002 and p70S6K inhibitor rapamycin. The effects on proliferation, IL-6 protein secretion, and intracellular signaling cascades were determined and compared with normal CD34(+) cells and monocytes.

The p38 MAP kinase inhibitor SB203580 enhances nuclear factor-kappa B transcriptional activity by a non-specific effect upon the ERK pathway.

In the present study we investigated a possible role for the p38 mitogen-activated protein (MAP) kinase pathway in mediating nuclear factor-kappa B (NF-kappaB) transcriptional activity in the erythroleukaemic cell line TF-1. TF-1 cells stimulated with the phosphatase inhibitor okadaic acid (OA) demonstrated enhanced NF-kappaB and GAL4p65-regulated transcriptional activity which was associated with elevated p38 phosphorylation. However, pretreatment with the p38 MAPK specific inhibitor SB203580 (1 microM) or overexpression of kinase-deficient mutants of MKK3 or MKK6 did not affect OA-enhanced NF-kappaB transcriptional potency, as determined in transient transfection assays.

Differential effects of interleukin-3 and interleukin-1 on the proliferation and interleukin-6 protein secretion of acute myeloid leukemic cells; the involvement of ERK, p38 and STAT5.

In the present study we examined whether the p38 and extracellular signal-regulated kinase (ERK) signal transduction pathways are involved in the interleukin-3 (IL-3)- or interleukin-1 (IL-1)-mediated proliferation and cytokine production of acute myeloid leukemic (AML) cells. The IL-3- and IL-1-mediated proliferation were both inhibited by the specific p38 and MEK1 inhibitors SB203580 and PD98059, respectively. Specificity of these inhibitors was demonstrated by in vitro kinase assays.

[Multi-rotation CT during continuous ventilation: comparison of different density areas in healthy lungs and in the ARDS lavage model].

Purpose: In this animal study, density ranges for CT-based quantification of ventilated lung area were determined. Healthy lungs and ARDS lungs were compared during artificial respiration.

Material And Methods: CT-scans were performed in 5 anesthetized pigs using a dynamic multiscan CT option on a predefined transverse slice (slice thickness 1 mm; effective temporal resolution, 250 ms).

A dual function for p38 MAP kinase in hematopoietic cells: involvement in apoptosis and cell activation.

In the present study we examined in more detail the dual role of the c-JUN N-terminal kinase (JNK) and p38 stress-activated protein kinase pathways in mediating apoptosis or cellular activation in hematopoietic cells. Growth factor deprivation of the erythroleukemic cell line TF-1 led to apoptosis which was associated with an enhanced activity of JNK and p38 and immediate dephosphorylation of the extracellular signal-regulated kinases (ERKs). Enhanced activity of p38 and JNK was not only observed during apoptosis but also in TF-1 cells stimulated with IL-1.

Extracellular-regulated kinase 1/2, Jun N-terminal kinase, and c-Jun are involved in NF-kappa B-dependent IL-6 expression in human monocytes.

In the present study we investigated the possible involvement of the mitogen-activated protein kinase family members extracellular-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK) in mediating IL-6 gene expression in human monocytes, in particular their role in enhancing NF-kappa B activity. Freshly isolated monocytes treated with the protein phosphatase inhibitor okadaic acid secreted high levels of IL-6 protein, which coincided with enhanced binding activity of NF-kappa B as well as with phosphorylation and activation of the ERK1/2 and JNK proteins. The ERK pathway-specific inhibitor PD98059 inhibited IL-6 secretion from monocytes.

Bacteriophage T4 strand transfer protein UvsX tolerates symmetric and asymmetric heterologies in short double-stranded oligonucleotides.

The UvsX protein of bacteriophage T4 catalyzes strand transfer from double-stranded DNA to homologous single-stranded DNA to generate both paranemic and plectonemic joints. We demonstrate here that UvsX mediates strand transfer efficiently from synthetic double-stranded donor oligonucleotides of 30 to 117 bp in length to circular single-stranded recipient M13mp19 DNA. Recovery of a diagnostic BamHI-restriction site, activated in the recipient after strand transfer, demonstrates that recipient and donated strands are perfectly base-paired after the exchange reaction has taken place.

In vitro processing of heteroduplex loops and mismatches by endonuclease VII.

Endonuclease VII is a Holliday-structure resolving enzyme of phage T4 which cleaves at junctions of branched DNAs and at mispairings. In extension of these findings we report the following: i) Endonuclease VII can discriminate between a large heteroduplex loop and a TT mismatch arranged in tandem, 6 nt distant from each other, in the same heteroduplex molecule. The enzyme cleaves two nucleotides 3' from the base of the loop or the TT mismatch.