Relative significance of different pathways of immune reconstitution in HIV type 1 infection as estimated by mathematical modeling

A major goal of antiretroviral HIV-1 therapy is the reversal of HIV-1-associated immunological dysfunction. However, the pathogenetic mechanisms involved and their significance are largely unknown. On the basis of the life cycle of naive, activated, and memory CD4(+) T cell subsets, a mathematical model of immune reconstitution was developed and applied to data for T cell subsets in individuals with acute or chronic HIV-1 infection receiving antiretroviral therapy. The final model that most accurately fitted the data, and resulted in realistic estimates for CD4(+) T cell turnover, considered three pathways of immune reconstitution for naive cells, including thymic production, peripheral expansion, and redistribution of naive cells from lymphoid tissue. The reconstitution of the memory compartment was fitted through differentiation and expansion of naive cells and peripheral expansion of memory cells as well as redistribution of memory cells trapped in the lymphoid tissue. Estimated median half-lives for naive and memory CD4(+) T cells were 114 and 21 days, while total production rates were 9.1 x 10(7) and 2.4 x 10(9) cells/day, respectively. Peripheral expansion and thymic production contributed equally to the regeneration of naive cells, but peripheral expansion of memory cells was larger than production of these cells by differentiation of naive cells. A comparison of immune reconstitution in acute and chronic HIV-1 infection revealed that, after adjustment for age, the main difference was the more rapid release of a larger number of naive cells in treated acute HIV-1 infection. Thymic function and peripheral expansion rates, however, were similar in both cohorts.     

Instituting a Sugar-Sweetened Beverage Ban: Experience From a Children’s Hospital

Sugar-sweetened beverage (SSB) consumption is linked to increased weight and obesity in children and remains the major source of added sugar in the typical US diet across all age groups. In an effort to improve the nutritional offerings for patients and employees within our institution, Nationwide Children’s Hospital in Columbus, Ohio, implemented an SSB ban in 2011 in all food establishments within the hospital. In this report, we describe how the ban was implemented. We found that an institutional SSB ban altered beverage sales without revenue loss at nonvending food locations. From a process perspective, we found that successful implementation requires excellent communication and bold leadership at several levels throughout the hospital environment.Sugar-sweetened beverage (SSB) consumption is linked to increased weight and obesity in children and remains the major source of added sugar in the typical US diet across all age groups.1 For the purposes of this report, we define SSBs as soft drinks (soda or pop), fruit drinks, sports drinks, energy drinks, and any other beverages to which sugar, typically high fructose corn syrup or sucrose (table sugar), has been added.2 Although recent studies indicate an overall trending down of SSB intake, higher rates of consumption occur among low-income and minority children.1In 2010 the Ohio legislature passed the Healthy Choices for Healthy Children Act to help schools play an active role in decreasing the high childhood obesity rates.3 A component of this law includes an SSB ban in schools. In an effort to recognize the importance of and support this statewide initiative, Nationwide Children’s Hospital (NCH) partnered with leaders in the business community to gain bipartisan support for this legislation. To further emphasize support, NCH decided to lead by example and expand the hospital’s already existing Wellness Initiative to improve the nutritional offerings for patients and employees through implementation of an SSB ban in all food establishments within the hospital and approved catering companies. Such a ban would not only impact the food environment for children but also their families as well as hospital staff. In this report, we describe our implementation of an organizational SSB ban and report the beverage consumption and sales revenue for the years preceding and following the ban, as well as key steps to implementation.     

The HIV-1 proviral landscape reveals that Nef contributes to HIV-1 persistence in effector memory CD4+ T cells

Despite long-term antiretroviral therapy (ART), HIV-1 persists within a reservoir of CD4⁺ T cells that contribute to viral rebound if treatment is interrupted. Identifying the cellular populations that contribute to the HIV-1 reservoir and understanding the mechanisms of viral persistence are necessary to achieve an effective cure. In this regard, through Full-Length Individual Proviral Sequencing, we observed that the HIV-1 proviral landscape was different and changed with time on ART across naive and memory CD4⁺ T cell subsets isolated from 24 participants. We found that the proportion of genetically intact HIV-1 proviruses was higher and persisted over time in effector memory CD4⁺ T cells when compared with naive, central, and transitional memory CD4⁺ T cells. Interestingly, we found that escape mutations remained stable over time within effector memory T cells during therapy. Finally, we provided evidence that Nef plays a role in the persistence of genetically intact HIV-1. These findings posit effector memory T cells as a key component of the HIV-1 reservoir and suggest Nef as an attractive therapeutic target.     

Identification of circulating antigen-specific CD4+ T lymphocytes with a CCR5+, cytotoxic phenotype in an HIV-1 long-term nonprogressor and in CMV infection

Antigen-specific CD4+ effector T cells primarily provide help for B-cell antibody responses and CD8+ cytotoxic T-lymphocyte (CTL) responses. We have found an expanded population of HIV-1 p24-specific, T-cell receptor V beta 17+, CD4+ T lymphocytes, defined by in vitro proliferative and interferon-gamma responses to a 15-mer Gag peptide, in the peripheral blood of an individual with long-term nonprogressive HIV-1 infection. Ex vivo, these cells were CCR5+ and CCR7-, consistent with an effector/memory function. Surprisingly, these cells highly expressed several proteins characteristic of cytotoxic lymphocytes, including TIA-1 (T-cell intracellular antigen 1; GMP-17/NKG7), granzymes A and B, CD161 (NKRP-1), and CD244 (C1.7/2B4). Following in vitro peptide stimulation, these cells produced interleukin 2 (IL-2) and intracellular CD40L, suggesting possible helper function, in addition to induction of perforin and cytotoxicity. A subset of cytomegalovirus (CMV)-specific CD4+ T cells in healthy adults similarly expressed these CTL markers and CCR5, ex vivo. Furthermore, this distinct subset of CD4+ T cells was significantly elevated in healthy CMV-seropositive adults, compared with CMV-seronegative individuals. These results suggest that CCR5+ CD4+ CTL may be a major effector mechanism of the immune response to viral infections in humans. Moreover, expression of CCR5 may render them particularly susceptible to cytopathic effects during progressive HIV-1 infection.     

Society of Gynecologic Oncologists Education Committee statement on risk assessment for inherited gynecologic cancer predispositions

Women with germline mutations in the cancer susceptibility genes, BRCA1 or BRCA2, associated with Hereditary Breast/Ovarian Cancer syndrome, have up to an 85% lifetime risk of breast cancer and up to a 46% lifetime risk ovarian cancer. Similarly, women with mutations in the DNA mismatch repair genes, MLH1, MSH2 or MSH6, associated with the Lynch/Hereditary Non-Polyposis Colorectal Cancer (HNPCC) syndrome, have up to a 40-60% lifetime risk of both endometrial and colorectal cancer as well as a 9-12% lifetime risk of ovarian cancer. Genetic risk assessment enables physicians to provide individualized evaluation of the likelihood of having one of these gynecologic cancer predisposition syndromes, as well the opportunity to provide tailored screening and prevention strategies such as surveillance, chemoprevention, and prophylactic surgery that may reduce the morbidity and mortality associated with these syndromes. Hereditary cancer risk assessment is a process that includes assessment of risk, education and counseling conducted by a provider with expertise in cancer genetics, and may include genetic testing after appropriate consent is obtained. This commentary provides guidance on identification of patients who may benefit from hereditary cancer risk assessment for Hereditary Breast/Ovarian Cancer and the Lynch/Hereditary Non-Polyposis Colorectal Cancer syndrome.     

Tertiary cytoreductive surgery in recurrent ovarian cancer: selection criteria and survival outcome

OBJECTIVES: Studies of tertiary cytoreductive surgery (TCS) in recurrent epithelial ovarian cancer are limited, and appropriate patient selection remains a clinical challenge. We sought to evaluate the impact of TCS on survival and to determine predictors of optimal tertiary resection. METHODS: Between January 1997 and July 2004, 47 women with recurrent epithelial ovarian cancer underwent TCS at two institutions. All patients received initial platinum and taxane-based chemotherapy following primary cytoreductive surgery. Clinico-pathologic factors and survival were retrospectively abstracted from medical records. Optimal TCS was defined as microscopic residual disease. RESULTS: Thirty of 47 (64%) patients underwent optimal TCS. Size of tumor implants<5 cm on preoperative imaging was the only significant predictor of achieving optimal TCS. Overall survival after TCS was statistically longer in patients with microscopic versus macroscopic residual disease (24 versus 16 months, p=0.03). After controlling for age, time to progression and optimal TCS, only the presence of diffuse disease at tertiary exploration remained a significant poor predictor of survival. However, in a cohort of patients with limited disease implants, multivariate analysis indicated that optimal TCS retained prognostic significance as a positive predictor of survival. Twelve patients (26%) experienced severe postoperative complications, including six with pulmonary embolism, four with fistulae and two with postoperative myocardial infarctions. CONCLUSIONS: Size of disease implants on preoperative imaging may guide the selection of candidates for TCS. In those patients with limited disease implants at laparotomy, optimal TCS is associated with improved survival.     

Loss of leucine-rich repeat kinase 2 causes impairment of protein degradation pathways,accumulation of α-synuclein,and apoptotic cell death in aged mice

Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common genetic cause of Parkinson''s disease. LRRK2 is a large protein containing a small GTPase domain and a kinase domain, but its physiological role is unknown. To identify the normal function of LRRK2 in vivo, we generated two independent lines of germ-line deletion mice. The dopaminergic system of LRRK2^−/− mice appears normal, and numbers of dopaminergic neurons and levels of striatal dopamine are unchanged. However, LRRK2^−/− kidneys, which suffer the greatest loss of LRRK compared with other organs, develop striking accumulation and aggregation of α-synuclein and ubiquitinated proteins at 20 months of age. The autophagy–lysosomal pathway is also impaired in the absence of LRRK2, as indicated by accumulation of lipofuscin granules as well as altered levels of LC3-II and p62. Furthermore, loss of LRRK2 dramatically increases apoptotic cell death, inflammatory responses, and oxidative damage. Collectively, our findings show that LRRK2 plays an essential and unexpected role in the regulation of protein homeostasis during aging, and suggest that LRRK2 mutations may cause Parkinson''s disease and cell death via impairment of protein degradation pathways, leading to α-synuclein accumulation and aggregation over time.     

Glucose sensors: a review of current and emerging technology

Glucose monitoring technology has been used in the management of diabetes for three decades. Traditional devices use enzymatic methods to measure glucose concentration and provide point sample information. More recently continuous glucose monitoring devices have become available providing more detailed data on glucose excursions. In future applications the continuous glucose sensor may become a critical component of the closed loop insulin delivery system and, as such, must be selective, rapid, predictable and acceptable for continuous patient use. Many potential sensing modalities are being pursued including optical and transdermal techniques. This review aims to summarize existing technology, the methods for assessing glucose sensing devices and provide an overview of emergent sensing modalities.