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Biomedical subjects

Catherine M Gordon

Publications and source records attributed to Catherine M Gordon.

At least 19 recordsLinked to original sources
PubMed2026

Convergent IGF2 overexpression in pheochromocytoma/paraganglioma: insights from Beckwith-Wiedemann syndrome.

Beckwith-Wiedemann syndrome (BWS) is an imprinting disorder characterized by overgrowth and tumor predisposition, caused by dysregulated expression of genes on chromosome 11p15.5. An association between BWS and pheochromocytoma/paraganglioma (PPGL) has been suggested in isolated case reports over the past fifty years, but the molecular basis for this link remains unclear. We identified four patients with BWS who developed metastatic PPGL and investigated IGF2 pathway activation in these tumors and in PPGL across various genotypes. Pan-cancer transcriptomic analysis of The Cancer Genome Atlas (TCGA) demonstrated that PPGL overexpresses IGF2, with pseudohypoxic tumors exhibiting higher expression compared to other molecular clusters. Loss of heterozygosity and loss of imprinting at 11p15.5 partially explain this overexpression, with PPGL additionally demonstrating globally elevated expression of imprinted genes compared to most other tumor types, suggesting a broader relaxation of genomic imprinting. Cognate receptor profiling revealed that PPGLs are equipped to respond to IGF2 signaling, with high expression of IGF1R and insulin receptor isoform A (IR-A). Immunohistochemistry confirmed IGF2 protein overexpression in both BWS-associated and genotypically diverse sporadic PPGLs. Our results indicate that IGF2 overexpression is a convergent molecular feature of PPGL across genotypes and suggest the IGF2 pathway as a potential diagnostic and therapeutic target.

Humans↗
PubMed2006

Effects of nutrition, puberty, and gender on bone ultrasound measurements in adolescents and young adults.

PURPOSE: Quantitative ultrasound (QUS) evaluation of bone is attractive for evaluating skeletal status in adolescents, but its use is limited in the United States due to sparse pediatric reference data. This study evaluated associations between radial and tibial speed of sound (SOS) measurements via QUS and demographic, anthropometric and nutritional variables. METHODS: We enrolled 151 healthy participants, aged 11-26 years, during routine visits to an urban adolescent clinic. SOS measurements were obtained using the Omnisense 7000P (Sunlight Medical Ltd., Tel-Aviv, Israel) and correlated with weight, height, gender, race, sexual maturity rating (SMR), and reported nutritional intake. RESULTS: The sample was 53% female; aged 17+/- 2.8 years (mean +/- SD); and 48% African-American, 21% Hispanic, and 21% Caucasian. Seventy percent of males and 91% of females had achieved SMR 5; 96% of females were postmenarchal. Males met the recommended daily allowance for calcium intake, on average; the females did not. Both the girls and boys reported consumption of inadequate vitamin D. Intake of neither calcium nor vitamin D was correlated with SOS. Radial and tibial SOS were significantly higher in those with SMR 5 (p < .001) and were moderately correlated with age in both genders (r = .42-.64, p < .001). In multivariate analyses, age was associated with SOS at both sites (p < .0001). CONCLUSIONS: This study provides QUS measurements of the peripheral skeleton among healthy adolescents. QUS measurements followed similar age and pubertal distributions to dual-energy X-ray absorptiometry (DXA) bone density measurements; other variables did not follow expected trends. Further research is needed to clarify what skeletal properties are assessed by this technique. This study adds to accumulating evidence that many adolescents do not consume adequate vitamin D or calcium.

Adolescent↗
PubMed2006

Adolescent bone health.

Pediatric and adolescent care professionals have increasingly recognized the importance of understanding the skeletal health of their patients. Peak bone mass, the "bone bank" on which an individual will draw for their entire adult life, is likely achieved by late adolescence, with the critical window for accumulation occurring much earlier. This review outlines the known conditions that are associated with impaired bone mineral accrual and clinical settings in which the evaluation of "at-risk" adolescents should be considered. We describe the methods available to the health care professional for evaluating bone density, along with the limitations of each technology. Potential therapeutic options for patients identified to have a low bone mineral density are discussed. Finally, current recommendations regarding physical activity and nutrition, beneficial interventions for all adolescents, are presented.

Absorptiometry, Photon↗
PubMed2006

Bone health in adolescents.

Adolescence is a crucial period for the accrual of bone density and achievement of peak bone mass. Unique situations can arise during adolescence that place an adolescent at risk for bone loss or the failure to attain appropriate bone mass. Clinicians also are challenged by the limitations of currently available measurement tools to evaluate skeletal status in young patients. This article reviews medical approaches to prevent bone loss in patients with eating disorders and the skeletal effects of specific hormonal contraceptive agents. Adolescent medicine specialists and gynecologists caring for teenagers must recognize the potential implications of these clinical settings on bone health to provide appropriate patient guidance and direct management.

Absorptiometry, Photon↗
PubMed2006

Report on the vitamin D status of adult and pediatric patients with inflammatory bowel disease and its significance for bone health and disease.

Vitamin D is a hormone responsible for calcium homeostasis and essential for bone mineralization throughout the lifespan. Recent studies revealed a high prevalence of hypovitaminosis D among healthy adults and children, especially in the northern hemisphere, and a link between this condition and suboptimal bone health. Moreover, maintenance of what are today considered optimal vitamin D stores has not been achieved throughout the year with currently recommended daily intake for vitamin D. The prevalence of hypovitaminosis D is even higher among adults with inflammatory bowel disease (IBD), a situation that may be caused by malabsorption and gastrointestinal losses through an inflamed intestine, among other factors. In children with IBD, existing reports of vitamin D status are scarce. The relationship between vitamin D status and bone health, although well-established in healthy adults and children, has been controversial among adults and children with IBD, and the reasons for this have not been investigated to date. Studies in animal models of colitis and in vitro human studies support a role of vitamin D in the regulation of the immune system of the gut and the potential of vitamin D and its derivatives as therapeutic adjuncts in the treatment of IBD. This role of vitamin D has not been investigated with translational studies to date. Currently, there are no guidelines for monitoring vitamin D status, treating hypovitaminosis D, and maintaining optimal vitamin D stores in patients with IBD. These tasks may prove particularly difficult because of malabsorption and gastrointestinal losses that are associated with IBD.

Adult↗
PubMed2006

Variable deficits of bone mineral despite chronic glucocorticoid therapy in pediatric patients with inflammatory diseases: a Glaser Pediatric Research Network study.

OBJECTIVE: To evaluate the relationship between chronic glucocorticoid (GC) exposure and bone mineral density (BMD) in children with rheumatic diseases and inflammatory bowel disease. STUDY DESIGN: Lumbar spine BMD was measured by DXA in 86 GC-treated children (66% female, age 8-20 years, mixed ethnicity) screened for a multi-center intervention trial. Predictors of spine BMD z-score and vitamin D [25(OH)D] were examined by multivariable linear regression. RESULTS: Mean prior year and lifetime cumulative GC exposure was 77.8 mg/kg and 224.6 mg/kg, respectively. BMD z-scores ranged from -3.7 to 2.2 SD (-1.1 +/- 1.2, mean +/- SD). Lower BMD z-scores were associated with increased prior year average daily GC dose (p = 0.03), decreased height z-score (p = 0.003), and decreased 25(OH)D concentrations (p = 0.03), but explained only a small proportion of BMD variability (adjusted R2 = 0.29). The 25(OH)D levels were <20 ng/ml in 45% of patients, and low 25(OH)D was associated with non-Caucasian ethnicity (p <0.001), increased age (p = 0.004), increased parathyroid hormone (p = 0.03), and residing in the Boston area (p <0.001). CONCLUSIONS: Although GC exposure is significantly associated with BMD z-score, the association is too variable to serve as a consistent predictor of reduced BMD in children. Vitamin D insufficiency is common and may contribute to skeletal deficits in this population.

Adolescent↗
PubMed2006

Vitamin D status in children and young adults with inflammatory bowel disease.

OBJECTIVES: Previous studies of vitamin D status in pediatric patients with inflammatory bowel disease have revealed conflicting results. We sought to report (1) the prevalence of vitamin D deficiency (serum 25-hydroxy-vitamin D concentration < or = 15 ng/mL) in a large population with inflammatory bowel disease, (2) factors predisposing to this problem, and (3) its relationship to bone health and serum parathyroid hormone concentration. PATIENTS AND METHODS: A total of 130 patients (8-22 years of age) with inflammatory bowel disease, 94 with Crohn disease and 36 with ulcerative colitis, had serum 25-hydroxy-vitamin D, intact parathyroid hormone, and lumbar spine bone mineral density (using dual-energy x-ray absorptiometry) measured at Children's Hospital Boston. RESULTS: The prevalence of vitamin D deficiency was 34.6%. Mean serum 25-hydroxy-vitamin D concentration was similar in patients with Crohn disease and ulcerative colitis, 52.6% lower among patients with dark skin complexion, 33.4% lower during the winter months (December 22 to March 21), and 31.5% higher among patients who were taking vitamin D supplements. Serum 25-hydroxy-vitamin D concentration was positively correlated with weight and BMI z score, disease duration, and serum albumin concentration and negatively correlated with erythrocyte sedimentation rate. Patients with Crohn disease and upper gastrointestinal tract involvement were more likely to be vitamin D deficient than those without it. Serum 25-hydroxy-vitamin concentration was not associated with lumbar spine bone mineral density z score or serum parathyroid hormone concentration. CONCLUSIONS: Vitamin D deficiency is highly prevalent among pediatric patients with inflammatory bowel disease. Factors predisposing to the problem include having a dark-skin complexion, winter season, lack of vitamin D supplementation, early stage of disease, more severe disease, and upper gastrointestinal tract involvement in patients with Crohn disease. The long-term significance of hypovitaminosis D for this population is unknown at present and merits additional study.

Adolescent↗
PubMed2005

Influence of bone density results on adolescents with anorexia nervosa.

OBJECTIVE: Not reaching an optimal peak bone mass during adolescence puts young patients with anorexia nervosa (AN) at risk for osteoporosis. Qualitative techniques were employed to determine whether having a bone mineral density (BMD) measurement affected the attitudes and behaviors of young women with AN. METHODS: Nineteen adolescents with AN who had undergone BMD measurements were questioned about the experience of having the test and reactions to the results. Themes were identified and statistical analyses were performed. RESULTS: Participants perceived a normal or low BMD in healthy and unhealthy ways. Although not all healthy feelings led to behavioral change, they appeared to serve as driving forces later in their illness. DISCUSSION: Providing young women with BMD results is not always enough to change unhealthy behaviors and may generate some unhealthy thoughts. However, the experience may lead to positive behavioral changes and result in long-term improvement. Clinicians must be careful and sensitive when presenting these results.

Absorptiometry, Photon↗
PubMed2005

Correlates of stress fractures among preadolescent and adolescent girls.

OBJECTIVE: Although stress fractures are a source of significant morbidity in active populations, particularly among young female athletes, the causes of stress fractures have not been explored among females <17 years of age or in the general population. The purpose of this study was to examine correlates of stress fractures in a large, population-based, national, cohort study of preadolescent and adolescent girls. METHODS: A cross-sectional analysis of data from 5461 girls, 11 to 17 years of age, in the Growing Up Today Study, an ongoing longitudinal study of the children of registered female nurses participating in Nurses' Health Study II, was performed. Mothers self-reported information regarding their children's histories of stress fractures on their 1998 annual questionnaire. Growing Up Today Study participants self-reported their weight and height, menarcheal status, physical activity, dietary intake, and disordered eating habits on annual surveys. RESULTS: In 1998, the mean age of the participants was 13.9 years. Approximately 2.7% of the girls had a history of stress fracture, 3% engaged in disordered eating (using fasting, diet pills, laxatives, or vomiting to control weight), and 16% participated in > or =16 hours per week of moderate to vigorous activity. Age at menarche, z score of BMI in 1998, calcium intake, vitamin D intake, and daily dairy intake were all unrelated to stress fractures after controlling for age. Independent of age and BMI, girls who participated in > or =16 hours per week of activity in 1998 had 1.88 greater odds of a history of stress fracture than did girls who participated in <4 hours per week (95% confidence interval [CI]: 1.18-3.30). Girls who participated in > or =16 hours per week of activity were also more likely than their peers to engage in disordered eating (4.6% vs 2.8%); however, disordered eating did not have an independent association with stress fractures (odds ratio [OR]: 1.33; 95% CI: 0.61-2.89). Independent of age and BMI, each hour per week of high-impact activity significantly increased the risk of stress fracture (OR: 1.05; 95% CI: 1.02-1.09). Among the high-impact physical activities, only running (OR: 1.13; 95% CI: 1.05-1.22) and cheerleading/gymnastics (OR: 1.10; 95% CI: 1.01-1.21) were independently associated with greater odds of stress fracture. CONCLUSIONS: These findings suggest that, although activity can be beneficial for bone health, there is a threshold over which the risk of stress fracture increases significantly among adolescent girls. High-impact activities, particularly running, cheerleading, and gymnastics, appear to be higher risk than other activities. Prospective studies are needed to explore the directionality of these relationships, as well as the role of menstrual history. In the meantime, clinicians should remain vigilant in identifying and treating disordered eating and menstrual irregularities among their highly active, young, female patients.

Adolescent↗
PubMed2004

Prevalence of vitamin D deficiency among healthy adolescents.

BACKGROUND: Although vitamin D deficiency has been documented as a frequent problem in studies of young adults, elderly persons, and children in other countries, there are limited data on the prevalence of this nutritional deficiency among healthy US teenagers. OBJECTIVE: To determine the prevalence of vitamin D deficiency in healthy adolescents presenting for primary care. DESIGN: A cross-sectional clinic-based sample. SETTING: An urban hospital in Boston. PARTICIPANTS: Three hundred seven adolescents recruited at an annual physical examination to undergo a blood test and nutritional and activity assessments. MAIN OUTCOME MEASURES: Serum levels of 25-hydroxyvitamin D (25OHD) and parathyroid hormone, anthropometric data, nutritional intake, and weekly physical activity and lifestyle variables that were potential risk factors for hypovitaminosis D. RESULTS: Seventy-four patients (24.1%) were vitamin D deficient (serum 25OHD level, </=15 ng/mL [</=37.5 nmol/L]), of whom 14 (4.6%) were severely vitamin D deficient (25OHD level, </=8 ng/mL [</=20 nmol/L]). By using a broader definition (25OHD level, </=20 ng/mL [</=50 nmol/L]), 129 patients (42.0%) were vitamin D insufficient. Serum 25OHD levels were inversely correlated with parathyroid hormone levels (r = -0.29), and were 24% lower during winter compared with summer. In a final multivariate model, season, ethnicity, milk and juice consumption, body mass index, and physical activity were significant independent predictors of hypovitaminosis D. CONCLUSIONS: Vitamin D deficiency was present in many US adolescents in this urban clinic-based sample. The prevalence was highest in African American teenagers and during winter, although the problem seems to be common across sex, season, and ethnicity.

Adolescent↗
PubMed2003

Clinical uses and misuses of dehydroepiandrosterone.

Dehydroepiandrosterone is the most abundant adrenal androgen and also functions as a neurosteroid. Serum concentrations decline with age and can serve as a prognostic factor in both critical illnesses and breast cancer progression. Evidence is accruing in support of dehydroepiandrosterone supplementation in adrenal insufficiency, hypopituitarism, osteoporosis, systemic lupus erythematosus, depression and schizophrenia. Research is ongoing at both the basic and the clinical level to elucidate mechanisms of action and establish efficacy and safety, as well as to expand new areas of potential application for this multi-faceted hormone.

Adjuvants, Immunologic↗
PubMed2003

Fertility concerns and sexual behavior in adolescent girls with polycystic ovary syndrome: implications for quality of life.

OBJECTIVE: To examine the fertility concerns and sexual behavior of adolescent girls with polycystic ovary syndrome (PCOS) as compared to healthy adolescent girls and the effect of these concerns on health-related quality of life. DESIGN AND SETTING: A cross-sectional study of adolescent girls with PCOS (n = 97) and healthy comparisons (n = 186) was conducted at an urban, hospital-based adolescent medicine practice. Participants completed the Child Health Questionnaire Version CF-87 as a measure of health-related quality of life and a general health history questionnaire that included items regarding sexual activity, contraception, fertility concerns, and severity of illness. Findings were evaluated using multivariate logistic and linear regression models. RESULTS: Healthy subjects were 2.8 times more likely to have had sexual intercourse than PCOS participants, though the mean age at initiation of sexual intercourse among sexually active girls was not significantly different between the two groups. Severity of illness and the worry about fertility were not associated with odds of being sexually active. Girls with PCOS were 3.4 times more likely to be worried about their ability to become pregnant than comparisons and concern about future fertility was associated with significant reductions in quality of life. CONCLUSION: Adolescents with PCOS are more concerned about fertility than their healthy peers and this concern may affect their overall quality of life. The finding that more than a third of the adolescents with PCOS in this study were sexually active underscores the importance of providing ongoing counseling on fertility issues, contraception, and STD prevention in the care of adolescent girls with PCOS.

Adolescent↗
PubMed2003

Normal bone accretion and effects of nutritional disorders in childhood.

Although osteoporosis is usually considered to be a health concern of the elderly, increased attention is being paid to children and adolescents who are at risk for developing this devastating disease. As osteoporosis is a preventable condition with no identified cure, focus has been placed on modifiable areas in a young person's life that may prevent the development of the disease. A child or adolescent's nutrition is an example of such an area. This review examines factors influencing normal bone development and emphasizes the importance of the adolescent years as a time for peak bone accretion. Current methods to evaluate skeletal status are examined, including the challenges that arise in interpreting bone densities in children who have growing bones. Children and adolescents who are at high risk for osteoporosis are discussed, with an emphasis on groups in whom poor nutrition likely mediates bone loss. Two models of malnutrition, anorexia nervosa and the female athlete triad, are discussed, with emphasis on the way in which each has deleterious effects on the adolescent skeleton. The promotion of skeletal health is ultimately the encouragement of good general health principles for all young people. Approaches for working with children and adolescents are reviewed, including literature supporting each strategy.

Adolescent↗
PubMed2003

Amenorrhea and bone health in adolescents and young women.

PURPOSE OF REVIEW: We present an update on amenorrhea in adolescent girls and young women. Amenorrhea may herald the onset of estrogen deficiency, which can adversely affect peak bone mass and ultimate risk of osteoporosis. RECENT FINDINGS: Adolescence is a critical period for bone accretion. Important modifiable factors that optimize bone accretion during this time are calcium intake, vitamin D, nutrition, and exercise. Another modifiable factor in the hands of the clinician is the prompt recognition and therapy of amenorrhea associated with estrogen deficient states, caused by conditions such as hyperprolactinemia and ovarian failure. An important recent observation is that adolescents with amenorrhea who diet, but who do not meet diagnostic criteria for anorexia nervosa, are nonetheless at significant risk for low bone density. Also, multiple factors contribute to the bone loss experienced by patients with anorexia nervosa, and the associated estrogen deficiency may not be the major contributor. Recent evidence also suggests that the contraceptive depot medroxyprogesterone acetate may contribute to impaired bone accretion. While estrogen/progestin replacement therapy has a clear role in the management of girls and young women with primary ovarian insufficiency, the exact role of this therapy in the amenorrhea associated with anorexia nervosa or exercise remains controversial. SUMMARY: Increasingly, osteoporosis prevention is recognized as an important role for health care providers of adolescent girls and young women. Viewed from this perspective, there is a need for more aggressive evaluation and management of amenorrhea, and research is needed to define sound and cost effective strategies.

Adolescent↗
PubMed2002

Quality of life in adolescent girls with polycystic ovary syndrome.

OBJECTIVES: To examine health-related quality of life (HRQL) in adolescents with polycystic ovary syndrome (PCOS), compared with healthy adolescents, and to determine whether clinically observed or self-perceived severity of illness affects their HRQL. DESIGN AND SETTING: Cross-sectional study of female adolescents conducted at an urban, hospital-based adolescent medicine clinical practice. PARTICIPANTS: Ninety-seven adolescent patients with PCOS and 186 healthy patients who were seen for care between October 15, 1999, and March 2, 2001. MAIN OUTCOME MEASURES: Health-related quality-of-life scores as determined by the Child Health Questionnaire-Child Self-Report Form. RESULTS: Adolescents with PCOS scored lower on subscales measuring general health perceptions, physical functioning, general behavior, and limitations in family activities because of illness. Patients scored higher on the change in health in the last year subscale, and most had been diagnosed and initiated treatment for PCOS in the last year. Patients who had higher self-perceived severity of illness also scored lower on the general health perceptions subscale, but clinical severity was not associated with differences in HRQL. CONCLUSIONS: Adolescents with PCOS experience lower HRQL compared with healthy adolescents. Polycystic ovary syndrome and perceived severity of illness negatively affect HRQL in adolescents. This study suggests a need to develop interventions to reduce the distress that patients with PCOS may face as adolescents and young adults.

Adolescent↗
PubMed2002

Physiologic regulators of bone turnover in young women with anorexia nervosa.

OBJECTIVE: To clarify the role of physiologic regulators of bone turnover in patients with anorexia nervosa (AN). STUDY DESIGN: Adolescent girls with AN (n = 61) had anthropometric, nutrition, and exercise data acquired, and bone mineral density (BMD) and body composition measured by dual energy x-ray absorptiometry. Serum samples were obtained for hormones, proresorptive cytokines, and bone formation markers, and urine for bone resorption markers. RESULTS: In bivariate correlation analyses, significant (P <.05) predictors of lumbar BMD included height, weight, and exercise. In multiple regression models, these significant relationships held, even after controlling for the duration of amenorrhea and AN. For total body BMD, the same positive predictors were found and percentage of body fat was a negative correlate. For hip BMD, exercise and weight were found to be positive predictors. Dehydroepiandrosterone sulfate (DHEAS) was inversely correlated with N-telopeptides (NTx), and insulin-like growth factor I (IGF-I) was directly correlated with osteocalcin. Proresorptive cytokine levels were low or undetectable. CONCLUSIONS: Exercise and weight were positive predictors of BMD. These data are the first to suggest a relationship between DHEAS and increased bone resorption in AN. IGF-I was correlated with bone formation indices. Low cytokine levels suggest that these factors do not mediate the increased bone resorption of AN.

Adolescent↗