Boston Children's Hospital

About: Boston Children's Hospital is a healthcare organization based out in Boston, Massachusetts, United States. It is known for research contribution in the topics: Population & Medicine. The organization has 165409 authors who have published 215589 publications receiving 6885627 citations.

Regulation of autophagy by cytoplasmic p53

Abstract: Multiple cellular stressors, including activation of the tumour suppressor p53, can stimulate autophagy. Here we show that deletion, depletion or inhibition of p53 can induce autophagy in human, mouse and nematode cells subjected to knockout, knockdown or pharmacological inhibition of p53. Enhanced autophagy improved the survival of p53-deficient cancer cells under conditions of hypoxia and nutrient depletion, allowing them to maintain high ATP levels. Inhibition of p53 led to autophagy in enucleated cells, and cytoplasmic, not nuclear, p53 was able to repress the enhanced autophagy of p53(-/-) cells. Many different inducers of autophagy (for example, starvation, rapamycin and toxins affecting the endoplasmic reticulum) stimulated proteasome-mediated degradation of p53 through a pathway relying on the E3 ubiquitin ligase HDM2. Inhibition of p53 degradation prevented the activation of autophagy in several cell lines, in response to several distinct stimuli. These results provide evidence of a key signalling pathway that links autophagy to the cancer-associated dysregulation of p53.

Prevalence of the metabolic syndrome in American adolescents: findings from the Third National Health and Nutrition Examination Survey.

Abstract: Background— Metabolic syndrome (MetS) is defined by the Third Report of the Adult Treatment Panel (ATP III) using criteria easily applied by clinicians and researchers. There is no standard pediatric definition. Methods and Results— We defined pediatric MetS using criteria analogous to ATP III as ≥3 of the following: (1) fasting triglycerides ≥1.1 mmol/L (100 mg/dL); (2) HDL 75th percentile for age and gender; and (5) systolic blood pressure >90th percentile for gender, age, and height. MetS prevalence in US adolescents was estimated with the Third National Health and Nutritional Survey 1988 to 1994. Among 1960 children aged ≥12 years who fasted ≥8 hours, two thirds had at least 1 metabolic abnormality, and nearly 1 in 10 had MetS. The racial/ethnic distribution was similar to adults: Mexican-Americans, followed by non-Hispanic w...

Adenoma-linked barrier defects and microbial products drive IL-23/IL-17-mediated tumour growth.

Abstract: Approximately 2% of colorectal cancer is linked to pre-existing inflammation known as colitis-associated cancer, but most develops in patients without underlying inflammatory bowel disease. Colorectal cancer often follows a genetic pathway whereby loss of the adenomatous polyposis coli (APC) tumour suppressor and activation of β-catenin are followed by mutations in K-Ras, PIK3CA and TP53, as the tumour emerges and progresses. Curiously, however, 'inflammatory signature' genes characteristic of colitis-associated cancer are also upregulated in colorectal cancer. Further, like most solid tumours, colorectal cancer exhibits immune/inflammatory infiltrates, referred to as 'tumour-elicited inflammation'. Although infiltrating CD4(+) T(H)1 cells and CD8(+) cytotoxic T cells constitute a positive prognostic sign in colorectal cancer, myeloid cells and T-helper interleukin (IL)-17-producing (T(H)17) cells promote tumorigenesis, and a 'T(H)17 expression signature' in stage I/II colorectal cancer is associated with a drastic decrease in disease-free survival. Despite its pathogenic importance, the mechanisms responsible for the appearance of tumour-elicited inflammation are poorly understood. Many epithelial cancers develop proximally to microbial communities, which are physically separated from immune cells by an epithelial barrier. We investigated mechanisms responsible for tumour-elicited inflammation in a mouse model of colorectal tumorigenesis, which, like human colorectal cancer, exhibits upregulation of IL-23 and IL-17. Here we show that IL-23 signalling promotes tumour growth and progression, and development of a tumoural IL-17 response. IL-23 is mainly produced by tumour-associated myeloid cells that are likely to be activated by microbial products, which penetrate the tumours but not adjacent tissue. Both early and late colorectal neoplasms exhibit defective expression of several barrier proteins. We propose that barrier deterioration induced by colorectal-cancer-initiating genetic lesions results in adenoma invasion by microbial products that trigger tumour-elicited inflammation, which in turn drives tumour growth.

Bad Bugs Need Drugs: An Update on the Development Pipeline from the Antimicrobial Availability Task Force of the Infectious Diseases Society of America

Abstract: The Antimicrobial Availability Task Force (AATF) of the Infectious Diseases Society of America (IDSA) has viewed with concern the decreasing investment by major pharmaceutical companies in antimicrobial research and development. Although smaller companies are stepping forward to address this gap, their success is uncertain. The IDSA proposed legislative and other federal solutions to this emerging public health problem in its July 2004 policy report "Bad Bugs, No Drugs: As Antibiotic R&D Stagnates, a Public Health Crisis Brews." At this time, the legislative response cannot be predicted. To emphasize further the urgency of the problem for the benefit of legislators and policy makers and to capture the ongoing frustration our clinician colleagues experience in their frequent return to an inadequate medicine cabinet, the AATF has prepared this review to highlight pathogens that are frequently resistant to licensed antimicrobials and for which few, if any, potentially effective drugs are identifiable in the late-stage development pipeline.

Angiogenesis in vitro

Abstract: Cloned capillary endothelial cells, cultured in tumour-conditioned medium, form capillary tubes. By light and electron microscopy these tubes resemble capillaries in vivo. This first demonstration of angiogenesis in vitro: (1) shows that all the information necessary to develop an entire capillary network in vitro is expressed by one cell type; (2) suggests a mechanism for lumen formation; and (3) offers a possibility of distinguishing between direct and indirect angiogenesis factors.