Temporal dynamics of the carbon isotope composition in a Pinus sylvestris stand: from newly assimilated organic carbon to respired carbon dioxide.

The (13)C isotopic signature (C stable isotope ratio; delta(13)C) of CO(2) respired from forest ecosystems and their particular compartments are known to be influenced by temporal changes in environmental conditions affecting C isotope fractionation during photosynthesis. Whereas most studies have assessed temporal variation in delta(13)C of ecosystem-respired CO(2) on a day-to-day scale, not much information is available on its diel dynamics. We investigated environmental and physiological controls over potential temporal changes in delta(13)C of respired CO(2) by following the short-term dynamics of the (13)C signature from newly assimilated organic matter pools in the needles, via phloem-transported organic matter in twigs and trunks, to trunk-, soil- and ecosystem-respired CO(2).

Effect of diet and exercise intervention on the growth of prostate epithelial cells.

Epidemiological studies suggest a positive association between nutrient intake, hyperinsulinemia and risk of Benign prostatic hyperplasis (BPH). This study tests the hypothesis that a low-fat, high-fiber diet and daily exercise would lower serum insulin and reduce the growth of serum-stimulated primary prostate epithelial cells in culture. Serum samples were obtained from eight overweight men before and after the Pritikin residential, 2-week diet and exercise intervention and from seven men who were long-term followers of the low-fat, high-fiber diet and regular exercise lifestyle.

Prostate cancer prevention by nutritional means to alleviate metabolic syndrome.

In 1987 when Reaven introduced syndrome X (metabolic syndrome, or MS), we were studying skeletal muscle insulin resistance and found that when rodents were fed a high-fat, refined-sugar (HFS) diet, insulin resistance developed along with aspects of MS, including hyperinsulinemia, hypertension, hypertriglyceridemia, and obesity. MS was controlled in rodents by switching them to a low-fat, starch diet and was controlled in humans with a low-fat starch diet and daily exercise (Pritikin Program). Others reported inverse relations between serum insulin and sex hormone-binding globulin (SHBG).

Universal primers that amplify RNA from all three flavivirus subgroups.

Background: Species within the Flavivirus genus pose public health problems around the world. Increasing cases of Dengue and Japanese encephalitis virus in Asia, frequent outbreaks of Yellow fever virus in Africa and South America, and the ongoing spread of West Nile virus throughout the Americas, show the geographical burden of flavivirus diseases. Flavivirus infections are often indistinct from and confused with other febrile illnesses.

Histamine-induced actin polymerization in human eosinophils: an imaging approach for histamine H4 receptor.

Image-based screening, a new and flexible tool in the drug discovery cascade, is amenable to many different targets. This article describes a particular use of the Cellomics ArrayScan in developing a functional screen for histamine H(4) receptor (H(4)R) antagonists that have potential utility in inflammatory diseases of the airways such as asthma, with H(4)R being expressed on a wide variety of immune cells including eosinophils. Exposure to histamine causes eosinophils to migrate from the bloodstream into the tissue where they contribute to inflammation.

Monitoring the development of non-nucleoside reverse transcriptase inhibitor-associated resistant HIV-1 using an electrochemiluminescence-based reverse transcriptase polymerase assay.

Reverse transcriptase (RT) plays an essential role in the HIV-1 replication process, which converts a single-strand RNA into a double-strand DNA via polymerase and RNase H activities. Therefore, inhibition of RT has been one of the primary therapeutic strategies for suppressing the replication of HIV-1. To facilitate the process of discovering the next generation of antiretroviral agents, this study presents a highly sensitive and nonradioactive RT polymerase assay that is based on electrochemiluminescence (ECL) technology, where a ruthenylated dUTP (Ru-dUTP) is employed as one of the dNTPs.

A mechanism to explain how regular exercise might reduce the risk for clinical prostate cancer.

Epidemiological studies report that regular physical activity can reduce the risk for prostate cancer. This study was conducted to investigate possible mechanisms to explain the epidemiological data. Serum from sedentary controls or men with regular (5 days/week) aerobic exercise was used to stimulate lymph node cancer of the prostate (LNCaP) tumor cells in vitro.

Use of chimeric antibodies as positive controls in an enzyme-linked immunosorbent assay for diagnosis of scrub typhus (infection by Orientia tsutsugamushi).

The use of human sera collected from individuals of known infected and noninfected status is necessary for the validation of diagnostic assays and for the determination of cutoff values. However, the routine inclusion of pooled human sera from infected individuals for use as positive controls in commercial assay kits has many disadvantages. Sufficient quantities of sera can be difficult to obtain, and there are ethical and safety issues to be considered.

Relationship of dietary protein and soy isoflavones to serum IGF-1 and IGF binding proteins in the Prostate Cancer Lifestyle Trial.

High levels of insulin-like growth factor 1 (IGF-1) are associated with increased risk of prostate cancer, whereas increased levels of some of its binding proteins (IGFBPs) seem to be protective. High intakes of dietary protein, especially animal and soy protein, appear to increase IGF-1. However, soy isoflavones have demonstrated anti-proliferative and apoptotic effects both in vitro and in vivo.

Evaporative enrichment and time lags between delta18O of leaf water and organic pools in a pine stand.

Understanding ecosystem water fluxes has gained increasing attention, as climate scenarios predict a drier environment for many parts of the world. Evaporative enrichment of (18)O (Delta(18)O) of leaf water and subsequent enrichment of plant organic matter can be used to characterize environmental and physiological factors that control evaporation, based on a recently established mechanistic model. In a Pinus sylvestris forest, we measured the dynamics of oxygen isotopic composition (delta(18)O) every 6 h for 4 d in atmospheric water vapour, xylem sap, leaf water and water-soluble organic matter in current (N) and previous year (N-1) needles, phloem sap, together with leaf gas exchange for pooled N and N-1 needles, and relevant micrometeorological variables.

Monosynaptic restriction of transsynaptic tracing from single, genetically targeted neurons.

There has never been a wholesale way of identifying neurons that are monosynaptically connected either to some other cell group or, especially, to a single cell. The best available tools, transsynaptic tracers, are unable to distinguish weak direct connections from strong indirect ones. Furthermore, no tracer has proven potent enough to label any connected neurons whatsoever when starting from a single cell.

Effect of a short-term diet and exercise intervention in youth on atherosclerotic risk factors.

Early stages of atherosclerosis are commonly noted in youth. The present study was designed to examine the effects of lifestyle modification in 19 overweight children (age 8-17) who were placed on a high-fiber, low-fat diet in a 2-week residential program where food was provided ad libitum and daily exercise (2-2.5h) was performed.

Effects of a low-fat, high-fiber diet and exercise program on breast cancer risk factors in vivo and tumor cell growth and apoptosis in vitro.

The present study investigated the effects of a diet and exercise intervention on known breast cancer (BCa) risk factors, including estrogen, obesity, insulin, and insulin-like growth factor-I (IGF-I), in overweight/obese, postmenopausal women. In addition, using the subjects' pre- and postintervention serum in vitro, serum-stimulated growth and apoptosis of three estrogen receptor-positive BCa cell lines were studied. The women where placed on a low-fat (10-15% kcal), high-fiber (30-40 g per 1,000 kcal/day) diet and attended daily exercise classes for 2 wk.

Effect of a short-term diet and exercise intervention on inflammatory/anti-inflammatory properties of HDL in overweight/obese men with cardiovascular risk factors.

There is significant debate regarding high-density lipoprotein cholesterol (HDL-C) and high-fiber, low-fat diets. The present study was designed to examine the effects of lifestyle modification on the inflammatory/anti-inflammatory properties of HDL in obese men (n = 22) with metabolic syndrome factors. Subjects were placed on a high-fiber, low-fat diet in a 3-wk residential program where food was provided ad libitum and daily aerobic exercise was performed.

Effect of altering dietary omega-6/omega-3 fatty acid ratios on prostate cancer membrane composition, cyclooxygenase-2, and prostaglandin E2.

Purpose: To determine whether altering the dietary content of omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids affects the growth of androgen-sensitive prostate cancer xenografts, tumor membrane fatty acid composition, and tumor cyclooxygenase-2 and prostaglandin E(2) (PGE(2)) levels.

Experimental Design: Individually caged male severe combined immunodeficiency mice were fed isocaloric 20% kcal fat diets with the fat derived either primarily from n-6 fatty acids (n-6 group) or with the fat consisting of n-6 and n-3 fatty acids in a ratio of 1:1 (n-3 group), and injected s.c.

Phase II study of pomegranate juice for men with rising prostate-specific antigen following surgery or radiation for prostate cancer.

Purpose: Phytochemicals in plants may have cancer preventive benefits through antioxidation and via gene-nutrient interactions. We sought to determine the effects of pomegranate juice (a major source of antioxidants) consumption on prostate-specific antigen (PSA) progression in men with a rising PSA following primary therapy.

Experimental Design: A phase II, Simon two-stage clinical trial for men with rising PSA after surgery or radiotherapy was conducted.

Oxidative stress and dysregulation of NAD(P)H oxidase and antioxidant enzymes in diet-induced metabolic syndrome.

Previously, we have demonstrated that chronic consumption of a high-fat, high-refined sugar (HFS) diet results in metabolic syndrome which is marked by obesity, insulin resistance, hyperlipidemia, and hypertension in Fischer rats. Metabolic syndrome in this model is associated with oxidative stress, avid nitric oxide (NO) inactivation by reactive oxygen species (ROS), diminished NO bioavailability, and dysregulation of NO synthase isotypes. Although occurrence of oxidative stress and its impact on NO metabolism are well established, the molecular source(s) of ROS in this model is unknown.

Effect of a short-term diet and exercise intervention on metabolic syndrome in overweight children.

Overweight and the metabolic syndrome are increasing radically in children. The present study was designed to examine the effects of lifestyle modification in 16 children who were placed on a high-fiber, low-fat diet in a 2-week residential program where food was provided ad libitum and daily aerobic exercise was performed. In each subject, pre- and postintervention fasting blood was drawn.

Kinetochores use a novel mechanism for coordinating the dynamics of individual microtubules.

Chromosome alignment during mitosis is frequently accompanied by a dynamic switching between elongation and shortening of kinetochore fibers (K-fibers) that connect kinetochores and spindle poles . In higher eukaryotes, mature K-fibers consist of 10-30 kinetochore microtubules (kMTs) whose plus ends are embedded in the kinetochore . A critical and long-standing question is how the dynamics of individual kMTs within the K-fiber are coordinated .

Tea polyphenols and theaflavins are present in prostate tissue of humans and mice after green and black tea consumption.

Green and black tea have shown promise in the chemoprevention of prostate cancer. The objective of this study was to determine the bioavailability and bioactivity of tea polyphenols (PP) and theaflavins in human serum and human and mouse tissues. A decaffeinated black tea diet was administered to C57BL/6 mice.

Effect of a diet and exercise intervention on oxidative stress, inflammation and monocyte adhesion in diabetic men.

Diabetes increases the risk of coronary artery disease. We examined the effects of lifestyle modification on key contributing factors to atherogenesis, including oxidative stress, inflammation and cell adhesion. Diabetic men (N=13) were placed on a high-fiber, low-fat diet in a 3-week residential program where food was provided ad libitum and daily aerobic exercise was performed.

Avian sarcoma and leukosis virus-receptor interactions: from classical genetics to novel insights into virus-cell membrane fusion.

For over 40 years, avian sarcoma and leukosis virus (ASLV)-receptor interactions have been employed as a useful model system to study the mechanism of retroviral entry into cells. Pioneering studies on this system focused upon the genetic basis of the differential susceptibilities of different lines of chickens to infection by distinct subgroups of ASLV. These studies led to the definition of three distinct autosomal recessive genes that were predicted to encode cellular receptors for different viral subgroups.