Most preventive care guidelines recommend that women aged 40 and older receive a mammogram every 1-2 years to screen for breast cancer. While much research has focused on the factors that influence a woman's decision to obtain a mammogram, less is known about the factors that influence a woman to return for subsequent mammograms at regular intervals. The vast majority of positive mammograms turn out to be false alarms--meaning that further testing reveals that the woman does not have breast cancer.
View Article and Find Full Text PDFBiochem Soc Trans
February 2003
Leptin regulates energy homoeostasis through central and peripheral mechanisms. Initial steps in leptin action include signalling through a cytokine-like receptor which activates the JAK/STAT pathway. We investigated whether the metabolic effects of leptin in muscle could be mediated by the AMP-activated protein kinase (AMP kinase).
View Article and Find Full Text PDFCaloric restriction has been shown to increase longevity in organisms ranging from yeast to mammals. In some organisms, this has been associated with a decreased fat mass and alterations in insulin/insulin-like growth factor 1 (IGF-1) pathways. To further explore these associations with enhanced longevity, we studied mice with a fat-specific insulin receptor knockout (FIRKO).
View Article and Find Full Text PDFObjective: The purpose of this study was to determine the prevalence of interstitial cystitis in a large number of gynecologic patients with pelvic pain versus control subjects, as indicated by a positive result on a potassium sensitivity test.
Study Design: Gynecologists at four US medical centers administered the potassium sensitivity test to consecutive unselected patients with pelvic pain and control subjects. Before testing, each patient with pelvic pain was given an initial clinical diagnosis on the basis of the chief symptomatic complaint(s) and was surveyed for urologic symptoms.
Objectives: Most individuals with interstitial cystitis (IC) have both pelvic pain and urinary urgency/frequency, and many have dyspareunia. Existing questionnaires designed to assess bladder-origin pelvic pain (IC) give little attention to pelvic pain or dyspareunia, however. On the basis of our clinical experience with more than 5000 patients with IC, we have designed a pelvic pain and urgency/frequency (PUF) symptom scale that gives balanced attention to urinary urgency/frequency, pelvic pain, and symptoms associated with sexual intercourse.
View Article and Find Full Text PDFAdiponectin (Ad) is a hormone secreted by adipocytes that regulates energy homeostasis and glucose and lipid metabolism. However, the signaling pathways that mediate the metabolic effects of Ad remain poorly identified. Here we show that phosphorylation and activation of the 5'-AMP-activated protein kinase (AMPK) are stimulated with globular and full-length Ad in skeletal muscle and only with full-length Ad in the liver.
View Article and Find Full Text PDFAm J Physiol Endocrinol Metab
August 2002
Elevation of plasma lactate levels induces peripheral insulin resistance, but the underlying mechanisms are unclear. We examined whether lactate infusion in rats suppresses glycolysis preceding insulin resistance and whether lactate-induced insulin resistance is accompanied by altered insulin signaling and/or insulin-stimulated glucose transport in skeletal muscle. Hyperinsulinemic euglycemic clamps were conducted for 6 h in conscious, overnight-fasted rats with or without lactate infusion (120 micromol x kg(-1) x min(-1)) during the final 3.
View Article and Find Full Text PDFInsulin signaling in adipose tissue plays an important role in lipid storage and regulation of glucose homeostasis. Using the Cre-loxP system, we created mice with fat-specific disruption of the insulin receptor gene (FIRKO mice). These mice have low fat mass, loss of the normal relationship between plasma leptin and body weight, and are protected against age-related and hypothalamic lesion-induced obesity, and obesity-related glucose intolerance.
View Article and Find Full Text PDFTo determine the mechanism(s) for insulin resistance induced by fatty acids, we measured the ability of insulin to activate phosphoinositide 3-kinase (PI3K) and multiple distal pathways in rats. Following a 5-h infusion of lipid or glycerol (control), rats underwent a euglycemic hyperinsulinemic clamp. Insulin stimulated IRS-1-associated PI3K activity in muscle of glycerol-infused rats 2.
View Article and Find Full Text PDFHigh-resolution infrared nongas absorption spectra derived from the Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment are analyzed for evidence of the presence of cirrus clouds. Several nonspherical ice extinction models based on realistic size distributions and crystal habits along with a stratospheric sulfate aerosol model are fit to the spectra, and comparisons are made with different model combinations. Nonspherical ice models often fit observed transmission spectra better than a spherical Mie ice model, and some discrimination among nonspherical models is noted.
View Article and Find Full Text PDFTo study the relationship between patient weight and perioperative morbidity, 512 total knee arthroplasties performed in 406 patients were reviewed. Patient height, weight, medical history, length of hospital stay, discharge destination (home versus rehabilitation facility), and all complications were recorded. Height and weight were used to calculate a body mass index (BMI) for each patient.
View Article and Find Full Text PDFMice lacking the protein-tyrosine phosphatase PTP1B are hypersensitive to insulin and resistant to obesity. However, the molecular basis for resistance to obesity has been unclear. Here we show that PTP1B regulates leptin signaling.
View Article and Find Full Text PDFBackground: The assessment of vaginal atrophy is central to menopause-related research and clinical practice. However, methods of grading vaginal atrophy have not been subjected to reliability and validity assessments.
Objective: To assess the validity and reproducibility of selected vaginal examination findings proposed to represent vaginal atrophy and inflammation.
Insulin stimulation of phosphatidylinositol (PI) 3-kinase activity is defective in skeletal muscle of type 2 diabetic individuals. We studied the impact of antidiabetic therapy on this defect in type 2 diabetic subjects who failed glyburide treatment by the addition of troglitazone (600 mg/day) or metformin (2,550 mg/day) therapy for 3-4 months. Improvement in glycemic control was similar for the two groups, as indicated by changes in fasting glucose and HbA(1c) levels.
View Article and Find Full Text PDFLeptin is a hormone secreted by adipocytes that plays a pivotal role in regulating food intake, energy expenditure and neuroendocrine function. Leptin stimulates the oxidation of fatty acids and the uptake of glucose, and prevents the accumulation of lipids in nonadipose tissues, which can lead to functional impairments known as "lipotoxicity". The signalling pathways that mediate the metabolic effects of leptin remain undefined.
View Article and Find Full Text PDFAm J Physiol Endocrinol Metab
January 2002
The purpose of this study was to determine whether the improved insulin action with short-term exercise training in middle-aged individuals is associated with enhanced phosphatidylinositol (PI) 3-kinase activity in skeletal muscle. Nine men of ages 50-70 yr were studied before and after 7 consecutive days of supervised exercise (60 min/day, 70% peak O2 consumption). Insulin sensitivity was measured with a euglycemic hyperinsulinemic glucose clamp in the sedentary condition and 15-17 h after the final exercise session.
View Article and Find Full Text PDFFor regulatory oversight and quality control of Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) actions, fish, mussels, and sediments were analyzed from the Peconic River system on Long Island, NY, downstream of the Brookhaven National Laboratory, as well as from control locations. The analyses were for photon-emitting radionuclides (notably 60Co and 137Cs), uranium, plutonium, and americium. Sediments were cored in 4 sections to 0.
View Article and Find Full Text PDFThis study investigated the metabolic changes with age in the Fischer 344 x Brown Norway rat and its suitability as an animal model of postmaturational insulin resistance. Specifically, we determined whether an age-associated decrease in glucose disposal is associated with diminished whole body insulin responsiveness and/or a decrease in glucose transporter (GLUT-4) protein and mRNA content in medial gastrocnemius muscle of male Fischer 344 x Brown Norway rats of ages 8, 18, and 28 months. Fasting plasma glucose was unchanged with age.
View Article and Find Full Text PDFBackground: The growing number of cancer survivors has created an increased need for survivorship research; however, the identification and recruitment of cancer survivors present some challenges. This report describes how two hospital cancer registries were used to recruit a large sample of breast cancer survivors (BCS) for a study examining the late reproductive effects of breast cancer treatments. Limitations and opportunities associated with this type of recruitment strategy are described, and the overall success of recruitment using this approach is presented.
View Article and Find Full Text PDFUsing cre/loxP gene targeting, transgenic mice with muscle-specific inactivation of the GLUT4 gene (muscle GLUT4 KO) were generated and shown to develop a diabetes phenotype. To determine the mechanism, we examined insulin-stimulated glucose uptake and metabolism during hyperinsulinemic-euglycemic clamp in control and muscle GLUT4 KO mice before and after development of diabetes. Insulin-stimulated whole body glucose uptake was decreased by 55% in muscle GLUT4 KO mice, an effect that could be attributed to a 92% decrease in insulin-stimulated muscle glucose uptake.
View Article and Find Full Text PDFObjective: To document the initial clinical diagnoses, determine the prevalence of urinary symptoms, and test for intravesical potassium sensitivity in gynecologic patients with chronic pelvic pain.
Methods: Gynecologists at three United States medical centers administered the Potassium Sensitivity Test to consecutive unselected pelvic pain patients. Before testing, each patient was given an initial clinical diagnosis based on the patient's chief symptomatic complaint(s) and surveyed for urologic symptoms.
Two field trials at Stillwater and Bixby, OK, evaluated the efficacy of solid matrix priming techniques, alone or in combination with fungicide seed treatment on seedling emergence and reduction of damping-off of okra in field soil naturally infested with Pythium ultimum. The following treatments were evaluated: thiram + carboxin (chemo-primed) (commercially applied), biological seed treatment (bio-primed) (Trichoderma harzianum isolate OK-110, 1 g suspended in 1% carboxymethylcellulose [CMC]), untreated seed (control), and a 1% CMC control. Chemo-primed seeds had a more uniform and faster emergence compared with untreated seeds at both field sites.
View Article and Find Full Text PDFA peer-verified gas chromatographic (GC) method is presented for the weight percent (wt %) determination of acetochlor herbicide in technical and formulated products. During method development, the method was found to be rugged by the Youden Ruggedness Test. Two laboratories with experience in the wt % determination of acetochlor in various matrixes participated in this study.
View Article and Find Full Text PDFPrevious reports indicate that the expression and/or activity of the protein-tyrosine phosphatase (PTP) LAR are increased in insulin-responsive tissues of obese, insulin-resistant humans and rodents, but it is not known whether these alterations contribute to the pathogenesis of insulin resistance. To address this question, we generated transgenic mice that overexpress human LAR, specifically in muscle, to levels comparable to those reported in insulin-resistant humans. In LAR-transgenic mice, fasting plasma insulin was increased 2.
View Article and Find Full Text PDFUCP3 is a mitochondrial membrane protein expressed in humans selectively in skeletal muscle. To determine the mechanisms by which UCP3 plays a role in regulating glucose metabolism, we expressed human UCP3 in L6 myotubes by adenovirus-mediated gene transfer and in H(9)C(2) cardiomyoblasts by stable transfection with a tetracycline-repressible UCP3 construct. Expression of UCP3 in L6 myotubes increased 2-deoxyglucose uptake 2-fold and cell surface GLUT4 2.
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