Publications by authors named "Scarbrough K"

Human papillomavirus (HPV) is the most common sexually transmitted infection and plays a significant role in cervical, penile, anal, vaginal, vulvar, and oropharyngeal cancers as well as non-cancerous genital warts and genital dysplasia. In the United States, there are approximately 46,000 new HPV-related cancers a year. There is an effective vaccine to prevent over 90% of these cancers and other HPV-related diseases; however, those that are aged 18-26 have the lowest vaccine rates among eligible age groups.

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Introduction: Colorectal cancer is the second most common cause of cancer-related death in the U.S. Lower SES and lack of health insurance coverage are 2 known risk factors for lower colorectal cancer survival.

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Purpose: The aims of this investigation were to evaluate racial disparities in prostate cancer among men living in a relatively affluent community with access to high quality healthcare.

Patients And Methods: This retrospective study included 1363 cases with prostate cancer entered into the Stony Brook Cancer Center registry between 2010 and 2020. Demographic and other factors, including the Distressed Community Index (DCI) which provides an indicator of socioeconomic status by zip code, were analyzed as predictors of later stage disease using logistic regression.

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Perturbation analysis has been crucial in the study of biological rhythms. Antisense technology provides investigators with new means to alter the internal milieu of the circadian clock itself. Practical aspects of the method and the theoretical background are presented in sufficient detail to enable others to design appropriate antisense oligodeoxynucleotides and use them for research purposes.

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Time of day has proven to be a source of variability in diverse behavioral measures. Knowledge of the pattern of this temporal effect as well as its origin (exogenous or endogenous) is essential for a precise description of any behavior. This study analyzed the effect of the external light-dark cycle and the internal rest-activity rhythm on the response of C57BL/6J mice to a novel environment.

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We present a model for the generation of precise, long term rhythms from a collection of imprecise, short term oscillators. The model uses variability between oscillators in conjunction with simple coupling rules to produce long term rhythms that are independent of rate equations (e.g.

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Serotonin (5-HT) has been implicated in the phase adjustment of the circadian system during the subjective day in response to nonphotic stimuli. Two components of the circadian system, the suprachiasmatic nucleus (SCN) (site of the circadian clock) and the intergeniculate leaflet (IGL), receive serotonergic projections from the median raphe nucleus and the dorsal raphe nucleus, respectively. Experiment 1, performed in golden hamsters housed in constant darkness, compared the effects of bilateral microinjections of the 5-HT1A/7 receptor agonist, 8-hydroxydipropylaminotetralin (8-OH-DPAT; 0.

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To determine whether changes in gonadotropin-releasing hormone (GnRH) neurons are early indicators of photostimulation, Siberian hamsters were placed in short days (6:18-h light-dark) at 3 (experiment 1) or 6 (experiment 2) wk of age where they were held for 3 (experiment 1) or 4 (experiment 2) wk. Hamsters were then moved to long photoperiod (16:8-h light-dark). In experiment 1, brains were collected 1-21 days after transfer from short to long days.

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The effects of age on the circadian clock system have been extensively studied, mainly in two rodent species, the laboratory rat and the golden hamster. However, less information is available on how aging alters circadian rhythmicity in a commonly studied rodent animal model, the mouse. Therefore, in the present study we compared the rhythm of wheel-running activity in adult (6-9 mo) and old (19-22 mo) C57BL/6J mice maintained under different lighting conditions for a period of 4 mo.

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We assessed whether fetal tissue containing the suprachiasmatic nuclei (SCN) can restore age-related changes in the diurnal rhythm of hypothalamic corticotropin-releasing hormone (CRH) and anterior pituitary proopiomelanocortin (POMC) mRNA. Young, middle-aged, and middle-aged SCN-transplanted rats were killed at seven times of day. In young rats, CRH mRNA exhibited a diurnal rhythm in the dorsomedial paraventricular nuclei but not in other subdivisions of the nuclei.

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Aging affects the regulation of diurnal and circadian rhythmicity. We tested the hypothesis that the age-related difference in the phase angle of entrainment of the locomotor activity rhythm to a light-dark (LD) cycle would be greater under LD 6:18 than LD 14:10. We also analyzed changes in quantitative aspects of wheel-running behavior according to age group.

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Background: Several lines of evidence indicate a two-stage failure mode for the Björk-Shiley convexo-concave (C/C) heart valve, in which one of the two outlet strut legs separates from the flange before the other, potentially providing an opportunity to identify and prophylactically replace failure-prone valves. Radiographic single leg separation (SLS) detection, although successful, is subjective and skill intensive, implying a need for both an objective preliminary screen and subsequent corroboration of the radiographic findings.

Methods And Results: We developed a time-windowed, power density analysis of C/C valve closing sounds to detect the vibrational resonance that characterizes the presence of an intact outlet strut in clinically functioning, 29-mm-flange size C/C valves.

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The menopause marks the permanent end of fertility in women. It was once thought that the exhaustion of ovarian follicles was the single, most important explanation for the transition to the menopause. Over the past decade, this perception has gradually changed with the realization that there are multiple pacemakers of reproductive senescence.

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The activity profiles of homozygous tau mutant hamsters bred in our colony exhibit several differences when compared to wildtype golden hamsters. In addition, tau mutant hamsters respond to saturating white light pulses presented between circadian time (CT) 11 and CT 16 with extremely large phase shifts (type 0 resetting) after prolonged time in constant darkness. We measured five parameters of the activity rhythm early during exposure to constant darkness (DD) (cycles 5-9), and after 44-48 cycles in DD, and we confirmed the tau mutants' unusual phase shifting response to light.

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In mammals, the suprachiasmatic nuclei (SCN) regulate the timing of LH surges. Recent evidence suggests that vasoactive intestinal peptide (VIP), an abundantly expressed neuropeptide of the SCN, communicates time of day information from the SCN to GnRH neurons. VIP levels in the SCN decrease with age and may be responsible for alterations in LH surges that become apparent in middle-aged rats.

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The circadian clock that resides in the suprachiasmatic nucleus (SCN) of the hypothalamus is the major neural pacemaker driving most 24-h rhythms in mammals. Several neurotransmitter peptides are synthesized within this nucleus and communicate rhythmically with other cells in the SCN as well as with cells in other regions of the brain. At the present time, little is known about their role in regulating outputs of the clock.

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Reproductive activity in the Djungarian hamster is controlled by seasonal variations in day length. Exposure to long days stimulates testis development, while exposure to short days induces testis regression. We recently found that testis regression after gonadotropin deprivation in rats is associated with increases in apoptosis.

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Depletion of ovarian follicles is often thought to be the determining factor in female reproductive aging. However, increasing evidence suggests that neural and neuroendocrine changes play important causative roles in the decline of regular reproductive cycles leading to the menopause. A blunting or suppression in the daily pattern of secretion of several neuroendocrine hormones has been documented in aging laboratory animals and humans.

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Several lines of evidence from different laboratories suggest that hypothalamic beta-endorphinergic activity decreases around the time of initiation of the LH surge and may increase on estrus to extinguish the expression of the daily neuronal signal for the surge. In several hormone systems, factors that stimulate or suppress hormone release also stimulate or repress transcription of the hormone gene and translation of the messenger RNA encoding the hormone. Therefore, information about neurohormone activity may be inferred from data on changes in the levels of RNA species encoding these neurohormones.

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We have developed an assay that allows one to monitor gene expression in and peptide secretion from individual cells. By combining the reverse hemolytic plaque with in situ hybridization, investigators can quantitate simultaneously the level of gene expression and the level of secretion of a peptide. The method can be used in any system in which an appropriate antibody for the reverse hemolytic plaque assay and probes complementary to the mRNA of interest are available.

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The diurnal rhythms of many physiological functions are disrupted during aging. Underlying these disruptions are age-related alterations in the activity of neurotransmitters and/or their receptors. Estradiol has a significant influence on the pattern of the diurnal rhythms in neurotransmitter function, and responsiveness to estradiol changes with age.

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