Peter Kopp

Northwestern University, Evanston, IL, United States

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Publications (43)178.95 Total impact

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    Thyroid: official journal of the American Thyroid Association 03/2014; · 2.60 Impact Factor
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    ABSTRACT: Associations of vitamin D levels with prospectively measured functional decline and mortality in people with lower extremity peripheral artery disease (PAD) are unknown. We determined whether lower baseline vitamin D levels are associated with a faster decline in functional performance and higher mortality among people with and without PAD. A total of 658 participants (395 with PAD) underwent baseline measurement of 25-hydroxyvitamin D (DiaSorin radioimmunoassay), a 6-minute walk test, 4-meter walking velocity and the Short Physical Performance Battery (SPPB), and were followed annually for up to 4 years. Analyses were adjusted for age, sex, race, body mass index, comorbidities, the ankle-brachial index, and other confounders. Among participants with PAD, lower baseline vitamin D levels were associated with a faster decline in the 6-minute walk (vitamin D < 30 nmol/L: -70.0 feet/year; vitamin D 30 to < 50 nmol/L: -72.3 feet/year; vitamin D 50 to < 75 nmol/L: -35.5 feet/year; vitamin D 75 to < 120 nmol/L: -35.9 feet/year; p trend=0.012). PAD participants with vitamin D < 30 nmol/L had a faster decline in the SPPB and 6-minute walk compared to those with levels of 50 to < 75 (p=0.034 and p=0.04, respectively). Among participants without PAD, lower vitamin D was associated with a faster decline in the fast 4-meter walking velocity (p trend=0.003). There were no significant associations of baseline vitamin D levels with all-cause or cardiovascular disease mortality in PAD or non-PAD participants. In conclusion, among individuals with and without PAD, low vitamin D status was associated with a faster decline in some measures of functional performance but was not related to mortality.
    Vascular Medicine 01/2014; · 1.62 Impact Factor
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    ABSTRACT: Background: An in-depth understanding of the fundamental principles that regulate thyroid hormone homeostasis is critical for the development of new diagnostic and treatment ap-proaches for patients with thyroid disease. Summary: Important clinical practices in use today for the treatment of patients with hypothy-roidism, hyperthyroidism, or thyroid cancer, are the result of laboratory discoveries made by scientists investigating the most basic aspects of thyroid structure and molecular biology. In this document, a panel of experts commissioned by the American Thyroid Association makes a se-ries of recommendations related to the study of thyroid hormone economy and action. These recommendations are intended to promote standardization of study design, which should in turn increase the comparability and reproducibility of experimental findings. Conclusions: It is expected that adherence to these recommendations by investigators in the field will facilitate progress towards a better understanding of the thyroid gland and thyroid hormone dependent processes.
    Thyroid: official journal of the American Thyroid Association 09/2013; · 2.60 Impact Factor
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    ABSTRACT: Context:Postpartum, diabetes insipidus (DI) can be part of Sheehan's syndrome or lymphocytic hypophysitis in combination with anterior pituitary hormone deficiencies. In contrast, acute onset of isolated DI in the postpartum period is unusual.Case Presentation:This patient presented at 33 weeks gestation with placental abruption, prompting a cesarean delivery of twins. Immediately after delivery, she developed severe DI. The DI could be controlled with the vasopressinase-resistant 1-deamino-8-D-arginine vasopressin (DDAVP), but not with arginine vasopressin (AVP), and it resolved within a few weeks.Objective:The aim of this study was to demonstrate that the postpartum DI in this patient was caused by the release of placental vasopressinase into the maternal bloodstream.Methods and Results:Cells were transiently transfected with the AVP receptor 2 (AVPR2) and treated with either AVP or DDAVP in the presence of the patient's serum collected postpartum or 10 weeks after delivery. The response to the different treatments was evaluated by measuring the activity of a cAMP-responsive firefly luciferase reporter construct. The in vitro studies demonstrate that the patient's postpartum serum disrupts activation of the AVPR2 by AVP, but not by the vasopressinase-resistant DDAVP.Conclusions:Placental abruption can rarely be associated with acute postpartum DI caused by release of placental vasopressinase into the bloodstream. This clinical entity must be considered in patients with placental abruption and when evaluating patients presenting with DI after delivery.
    The Journal of clinical endocrinology and metabolism 02/2013; · 6.50 Impact Factor
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    ABSTRACT: The clinical implications of low vitamin D in peripheral artery disease (PAD) are unknown. We hypothesized that among individuals with PAD, lower levels of 25-hydroxyvitamin D would be associated with poorer functional performance, more adverse calf muscle characteristics, and poorer peripheral nerve function. Participants were 402 men and women with PAD who underwent measurement of 25-hydroxyvitamin D (DiaSorin radioimmunoassay) along with 6-minute walk testing, measurement of walking velocity at usual and fastest pace, computed tomography-measured calf muscle density, and peripheral nerve conduction velocity (NCV). Among PAD participants, 20.4% had 25-hydroxyvitamin D levels < 30 nmol/L, consistent with deficient vitamin D status. Adjusting for age, sex, and race, lower 25-hydroxyvitamin D levels were associated with poorer 6-minute walk performance (p trend = 0.002), slower usual-paced 4-meter walking velocity (p trend = 0.031), slower fast-paced 4-meter walking velocity (p trend = 0.043), and lower calf muscle density (p trend = 0.031). After additional adjustment for body mass index (BMI) and diabetes, none of these associations remained statistically significant. However, lower levels of 25-hydroxyvitamin D were associated with poorer peroneal NCV (p trend = 0.013) and poorer sural NCV (p trend = 0.039), even after adjusting for age, sex, race, BMI, comorbidities, smoking, physical activity, and other confounders. In conclusion, vitamin D deficiency is common among people with PAD encountered in clinical settings. After adjusting for BMI and diabetes mellitus, we found no significant associations of lower levels of 25-hydroxyvitamin D with poorer functional performance or calf muscle characteristics. Associations of low vitamin D levels with poorer peripheral nerve function require further study.
    Vascular Medicine 07/2012; 17(5):294-302. · 1.62 Impact Factor
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    ABSTRACT: Thyroid hormones are essential for normal development and metabolism. Their synthesis requires transport of iodide into thyroid follicles. The mechanisms involving the apical efflux of iodide into the follicular lumen are poorly elucidated. The discovery of mutations in the SLC26A4 gene in patients with Pendred syndrome (congenital deafness, goiter, and defective iodide organification) suggested a possible role for the encoded protein, pendrin, as an apical iodide transporter. We determined whether TSH regulates pendrin abundance at the plasma membrane and whether this influences iodide efflux. Results of immunoblot and immunofluorescence experiments reveal that TSH and forskolin rapidly increase pendrin abundance at the plasma membrane through the protein kinase A pathway in PCCL-3 rat thyroid cells. The increase in pendrin membrane abundance correlates with a decrease in intracellular iodide as determined by measuring intracellular (125)iodide and can be inhibited by specific blocking of pendrin. Elimination of the putative protein kinase A phosphorylation site T717A results in a diminished translocation to the membrane in response to forskolin. These results demonstrate that pendrin translocates to the membrane in response to TSH and suggest that it may have a physiological role in apical iodide transport and thyroid hormone synthesis.
    Endocrinology 11/2011; 153(1):512-21. · 4.72 Impact Factor
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    ABSTRACT: Over the past two decades, the genetic and molecular basis of familial forms of diabetes insipidus has been elucidated. Diabetes insipidus is a clinical syndrome characterized by the excretion of abnormally large volumes of diluted urine (polyuria) and increased fluid intake (polydipsia). The most common type of diabetes insipidus is caused by lack of the antidiuretic hormone arginine vasopressin (vasopressin), which is produced in the hypothalamus and secreted by the neurohypophysis. This type of diabetes insipidus is referred to here as neurohypophyseal diabetes insipidus. The syndrome can also result from resistance to the antidiuretic effects of vasopressin on the kidney, either at the level of the vasopressin 2 receptor or the aquaporin 2 water channel (which mediates the re-absorption of water from urine), and is referred to as renal or nephrogenic diabetes insipidus. Differentiation between these two types of diabetes insipidus and primary polydipsia can be difficult owing to the existence of partial as well as complete forms of vasopressin deficiency or resistance. Seven different familial forms of diabetes insipidus are known to exist. The clinical presentation, genetic basis and cellular mechanisms responsible for them vary considerably. This information has led to improved methods of differential diagnosis and could provide the basis of new forms of therapy.
    Nature Reviews Endocrinology 07/2011; 7(12):701-14. · 11.03 Impact Factor
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    ABSTRACT: Copeptin, the C-terminal moiety of provasopressin, is cosecreted with vasopressin. Copeptin may be a useful parameter to characterize disorders of water homeostasis and can be readily measured in plasma or serum. However, it is unknown to date how circulating copeptin and vasopressin levels correlate at different plasma osmolalites. To correlate plasma copeptin with plasma osmolality and vasopressin concentrations in healthy subjects during iso-, hypo-, and hyperosmolar states. Plasma osmolalities, copeptin, and vasopressin levels were measured in 20 volunteers at baseline, after an oral water load, and during and after iv infusion of 3% saline. Correlation coefficients were determined between plasma osmolalites and copeptin and vasopressin concentrations, as well as between vasopressin and copeptin concentrations. Median plasma osmolalities decreased from 290 mOsm/kg (range, 284-302) at baseline to 281 (273-288) mOsm/kg after water load and rose to 301 (298-307) mOsm/kg after hypertonic saline. Median plasma copeptin concentrations decreased from 3.3 (1.1-36.4) pm at baseline to 2.0 (0.9-10.4) pm after water load and increased to 13.6 (3.7-43.3) pm after hypertonic saline. Vasopressin and copeptin concentrations correlated with plasma osmolality (Spearman's rank correlation coefficient 0.49 and 0.77, respectively). There was a close correlation of vasopressin and copeptin concentrations (Spearman's rank correlation coefficient 0.8). Plasma vasopressin and copeptin correlate strongly over a wide range of osmolalities in healthy individuals. Therefore, the measurement of copeptin, which remains stable for several days, is a useful alternative to vasopressin measurements and will likely facilitate the differential diagnosis of disorders of water metabolism.
    The Journal of clinical endocrinology and metabolism 02/2011; 96(4):1046-52. · 6.50 Impact Factor
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    ABSTRACT: Iodide uptake at the basolateral membrane and iodide efflux at the apical membrane of thyrocytes, essential steps in the biosynthesis of thyroid hormone, are stimulated by thyroid stimulating hormone (TSH). Pendrin (SLC26A4) is inserted into the apical membrane of thyrocytes and thought to be involved in mediating iodide efflux. We determined the effects of carboxy-terminal mutations of pendrin on the cellular localization and the ability to transport iodide. After exposure to forskolin, the membrane abundance of wild type pendrin and iodide efflux increase. Truncation mutants lead to complete intracellular retention. Elimination of the distal part of the sulfate transporter and antisigma factor antagonist (STAS) domain with retention of the putative protein kinase A (PKA) phosphorylation site (RKDT 714-717) results in residual membrane insertion and a partial loss of function. Deletion of the PKA site results in decreased basal function and membrane insertion and abolishes the response to forskolin. Pendrin membrane abundance and its ability to mediate iodide efflux increase after activation of the PKA pathway. Elimination of the PKA site abolishes the response to forskolin but partial basal function and membrane insertion are maintained.
    Cellular Physiology and Biochemistry 01/2011; 28(3):423-34. · 3.42 Impact Factor
  • Aigerim Bizhanova, Peter Kopp
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    ABSTRACT: Pendred syndrome is an autosomal recessive disorder defined by sensorineural deafness, goiter and a partial organification defect of iodide. It is caused by biallelic mutations in the multifunctional anion transporter pendrin/SLC26A4. In human thyroid tissue, pendrin is localized at the apical membrane of thyroid follicular cells. The clinical phenotype of patients with Pendred syndrome and the fact that pendrin can mediate iodide efflux in transfected cells suggest that this anion exchanger may be involved in mediating iodide efflux into the follicular lumen, a key step in thyroid hormone biosynthesis. This concept has, however, been questioned. This review discusses supporting evidence as well as arguments questioning a role of pendrin in mediating iodide efflux in thyrocytes.
    Cellular Physiology and Biochemistry 01/2011; 28(3):485-90. · 3.42 Impact Factor
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    ABSTRACT: Background: Pendrin is a multifunctional anion transporter that exchanges chloride and iodide in the thyroid, as well as chloride and bicarbonate in the inner ear, kidney and airways. Loss or reduction in the function of pendrin results in both syndromic (Pendred syndrome) and non-syndromic (non-syndromic enlarged vestibular aqueduct (ns-EVA)) hearing loss. Factors inducing an up-regulation of pendrin in the kidney and the lung may have an impact on the pathogenesis of hypertension, chronic obstructive pulmonary disease (COPD) and asthma. Here we characterize the ion transport activity of wild-type (WT) pendrin and seven of its allelic variants selected among those reported in the single nucleotide polymorphisms data base (dbSNPs), some of which were previously identified in a cohort of individuals with normal hearing or deaf patients belonging to the Spanish population. Methods: WT and mutated pendrin allelic variants were functionally characterized in a heterologous over-expression system by means of fluorometric methods evaluating the I-/Cl- and Cl-/OH- exchange and an assay evaluating the efflux of radiolabeled iodide. Results: The transport activity of pendrin P70L, P301L and F667C is completely abolished; pendrin V609G and D687Y allelic variants are functionally impaired but retain significant transport. Pendrin F354S activity is indistinguishable from WT, while pendrin V88I and G740S exhibit a gain of function. Conclusion: Amino acid substitutions involving a proline always result in a severe loss of function of pendrin. Two hyperfunctional allelic variants (V88I, G740S) have been identified, and they may have a contributing role in the pathogenesis of hypertension, COPD and asthma.
    Cellular Physiology and Biochemistry 01/2011; 28(3):467-476. · 3.42 Impact Factor
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    ABSTRACT: Thyroglobulin (Tg) represents one of the largest known self-antigens involved in autoimmunity. Numerous studies have implicated it in triggering and perpetuating the autoimmune response in autoimmune thyroid diseases (AITD). Indeed, traditional models of autoimmune thyroid disease, experimental autoimmune thyroiditis (EAT), are generated by immunizing mice with thyroglobulin protein in conjunction with an adjuvant, or by high repeated doses of Tg alone, without adjuvant. These extant models are limited in their experimental flexibility, i.e. the ability to make modifications to the Tg used in immunizations. In this study, we have immunized mice with a plasmid cDNA encoding the full-length human Tg (hTG) protein, in order to generate a model of Hashimoto's thyroiditis which is closer to the human disease and does not require adjuvants to breakdown tolerance. Human thyroglobulin cDNA was injected and subsequently electroporated into skeletal muscle using a square wave generator. Following hTg cDNA immunizations, the mice developed both B and T cell responses to Tg, albeit with no evidence of lymphocytic infiltration of the thyroid. This novel model will afford investigators the means to test various hypotheses which were unavailable with the previous EAT models, specifically the effects of hTg sequence variations on the induction of thyroiditis.
    PLoS ONE 01/2011; 6(4):e19200. · 3.73 Impact Factor
  • Aigerim Bizhanova, Peter Kopp
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    ABSTRACT: Pendred syndrome is an autosomal recessive disorder characterized by sensorineural deafness, goiter and a partial defect in iodide organification. Goiter development and hypothyroidism vary and appear to depend on nutritional iodide intake. Pendred syndrome is caused by biallelic mutations in the SLC26A4 gene, which encodes pendrin, a multifunctional anion exchanger. Pendrin is mainly expressed in the thyroid, the inner ear, and the kidney. In the thyroid, pendrin localizes to the apical membrane of thyrocytes, where it may be involved in mediating iodide efflux. Loss-of-function mutations in the SLC26A4 gene are associated with a partial iodide organification defect, presumably because of a reduced iodide efflux into the follicular lumen. In the kidney, pendrin functions as a chloride/bicarbonate exchanger. In the inner ear, pendrin is important in the maintenance of a normal anion transport and the endocochlear potential. Elucidation of the function of pendrin has provided unexpected novel insights into the pathophysiology of thyroid hormone biosynthesis, chloride retention in the kidney, and composition of the endolymph.
    Molecular and Cellular Endocrinology 03/2010; 322(1-2):83-90. · 4.04 Impact Factor
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    ABSTRACT: To study the case of a 2 10/12-year-old boy who had growth failure and delayed bone maturation. We reviewed the history, which revealed that he had had polyuria, polydipsia, lack of weight gain, and frequent vomiting since the age of 5 months. On physical examination, his height was 86 cm (-1.93 standard deviation [SD]), his weight 10.5 kg (-2.67 SD), and he had motor and mental retardation. His maternal great-grandfather also had polyuria and polydipsia (but not diabetes mellitus), suggesting X-linked nephrogenic diabetes insipidus as the underlying cause. The patient underwent a water deprivation-desmopressin test. The coding region of the AVPR2 gene was amplified by polymerase chain reaction and submitted to direct sequence analysis. The water deprivation test confirmed the diagnosis of diabetes insipidus, and administration of desmopressin did not diminish his water secretion. Direct sequencing of the AVPR2 gene revealed a novel deletion of adenine at position 222 (222delA) in exon 2. This mutation is predicted to lead to a frameshift beginning at amino acid 75 and a premature stop codon at position 115 (FS75>115X). His height and weight, as well as his motor skills, improved after initiation of therapy with hydrochlorothiazide and amiloride. Growth delay can be associated with diabetes insipidus. The X-linked nephrogenic diabetes insipidus in this boy is caused by a novel mutation in the AVPR2 gene that is predicted to truncate the receptor protein.
    Endocrine Practice 08/2009; 16(2):231-6. · 2.49 Impact Factor
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    ABSTRACT: Thyroglobulin (TG) is a large glycoprotein and functions as a matrix for thyroid hormone synthesis. TG gene mutations give rise to goitrous congenital hypothyroidism (CH) with considerable phenotype variation. The aim of the study was to report the genetic screening of 15 patients with CH due to TG gene mutations and to perform functional analysis of the p.A2215D mutation. Clinical evaluation and DNA sequencing of the TG gene were performed in all patients. TG expression was analyzed in the goitrous tissue of one patient. Human cells were transfected with expression vectors containing mutated and wild-type human TG cDNA. All patients had an absent rise of serum TG after stimulation with recombinant human TSH. Sequence analysis revealed three previously described mutations (p.A2215D, p.R277X, and g.IVS30+1G>T), and two novel mutations (p.Q2142X and g.IVS46-1G>A). Two known (g.IVS30+1G/p.A2215D and p.A2215D/p.R277X) and one novel (p.R277X/g.IVS46-1G>A) compound heterozygous constellations were also identified. Functional analysis indicated deficiency in TG synthesis, reduction of TG secretion, and retention of the mutant TG within the cell, leading to an endoplasmic reticulum storage disease, whereas small amounts of mutant TG were still secreted within the cell system. All studied patients were either homozygous or heterozygous for TG gene mutations. Two novel mutations have been detected, and we show that TG mutation p.A2215D promotes the retention of TG within the endoplasmic reticulum and reduces TG synthesis and secretion, causing mild hypothyroidism. In the presence of sufficient iodine supply, some patients with TG mutations are able to compensate the impaired hormonogenesis and generate thyroid hormone.
    The Journal of clinical endocrinology and metabolism 06/2009; 94(8):2938-44. · 6.50 Impact Factor
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    ABSTRACT: To assess associations of sex hormones with impaired fasting glucose (IFG) and type 2 diabetes in men. A total of 3,156 African American, Non-Hispanic white, Hispanic, and Chinese-American men aged 45-84 years who participated in the baseline visit of the Multi-Ethnic Study of Atherosclerosis (MESA) were included. Odd sratios and 95% CIs for type 2 diabetes and IFG compared with normal fasting glucose for quartiles of hormones were estimated. After adjusting for age, ethnicity, BMI, and waist circumference, IFG and diabetes were associated inversely with total testosterone and sex hormone-binding globulin (SHBG) and positively with estradiol (E2). Dehydroepiandrosterone was positively associated with IFG but not with diabetes. Associations did not differ across ethnic groups. Regardless of obesity, total testosterone and SHBG were associated inversely and E2 was associated positively with IFG and diabetes in men. Further research is warranted to better understand the underlying biological mechanisms.
    Diabetes care 04/2009; 32(6):1049-51. · 7.74 Impact Factor
  • Aigerim Bizhanova, Peter Kopp
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    ABSTRACT: Thyroid hormones are essential for normal development and metabolism. Thyroid hormone biosynthesis requires iodide uptake into the thyrocytes and efflux into the follicular lumen, where it is organified on selected tyrosyls of thyroglobulin. Uptake of iodide into the thyrocytes is mediated by an intrinsic membrane glycoprotein, the sodium-iodide symporter (NIS), which actively cotransports two sodium cations per each iodide anion. NIS-mediated transport of iodide is driven by the electrochemical sodium gradient generated by the Na(+)/K(+)-ATPase. NIS is expressed in the thyroid, the salivary glands, gastric mucosa, and the lactating mammary gland. TSH and iodide regulate iodide accumulation by modulating NIS activity via transcriptional and posttranscriptional mechanisms. Biallelic mutations in the NIS gene lead to a congenital iodide transport defect, an autosomal recessive condition characterized by hypothyroidism, goiter, low thyroid iodide uptake, and a low saliva/plasma iodide ratio. Pendrin is an anion transporter that is predominantly expressed in the inner ear, the thyroid, and the kidney. Biallelic mutations in the SLC26A4 gene lead to Pendred syndrome, an autosomal recessive disorder characterized by sensorineural deafness, goiter, and impaired iodide organification. In thyroid follicular cells, pendrin is expressed at the apical membrane. Functional in vitro data and the impaired iodide organification observed in patients with Pendred syndrome support a role of pendrin as an apical iodide transporter.
    Endocrinology 03/2009; 150(3):1084-90. · 4.72 Impact Factor
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    ABSTRACT: Animal and human studies suggest that C-reactive protein (CRP) may be inversely associated with serum insulin-like growth factor-I (IGF-I) concentrations. However, most human studies have not controlled adequately for confounding factors, particularly nutritional intake. This population-based study examined whether CRP is inversely associated with IGF-I and IGFBP-3 concentrations. In cross-sectional analysis, multivariable linear regression with adjustment for age, BMI, smoking status, alcohol intake, and nutritional factors was used to relate log CRP, the independent variable, to IGF-I and IGFBP-3 in a sample of black (n=364) and white men (n=486) separately by race. Only black men had positive findings: log CRP was significantly associated with IGF-I (beta=-13.1 ng/ml, p=0.02) and the difference in mean IGF-I concentrations between the highest and lowest quartiles of CRP was 26 ng/ml. There was a statistically significant interaction between log CRP and smoking status (p=0.02); the regression coefficient for IGF-I predicted from log CRP was significant in smokers (beta=-39.8 ng/ml, p=0.0001), but not in non-smokers. The difference in mean IGF-I concentrations between highest and lowest quartiles of CRP was 100 ng/ml for black smokers. There were no associations for IGFBP-3. In our study, CRP levels are inversely associated with IGF-I concentrations in black male smokers; however, the causal nature of the association is unclear and should be studied further.
    Growth hormone & IGF research: official journal of the Growth Hormone Research Society and the International IGF Research Society 02/2009; 19(5):420-5. · 2.35 Impact Factor
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    ABSTRACT: We present an unusual case of primary central nervous system (CNS) lymphoma presenting with bilateral symmetric hypothalamic lesions causing diabetes insipidus and hypopituitarism. A 50-year-old male presented initially with mental status changes, polyuria and polydipsia. The patient was determined to have diabetes insipidus (DI) and significant anterior pituitary deficiencies resulting in symptomatic pleural and pericardial effusions. Brain MRI with contrast demonstrated bilateral enhancement of his hypothalamus extending to the optic tract. The extensive diagnostic workup that ensued on his initial presentation was non-diagnostic as he had no obvious site of involvement that was easily accessible to biopsy. With close follow-up, the patient had rapid radiographic progression of his disease to his cerebral hemispheres. He therefore underwent brain biopsy and was diagnosed with primary CNS large B cell lymphoma. Chemotherapy has resulted in disease remission with resolution of MRI findings, but the patient has not had resolution of the hypopituitarism or DI. This case highlights the unique diagnostic challenge of patients with isolated hypothalamic lesions.
    Pituitary 02/2009; 14(2):194-7. · 2.67 Impact Factor
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    ABSTRACT: We examined cross-sectional associations between sex hormones and carotid artery intimal-medial thickness (cIMT) and coronary artery calcium in women in the Multi-Ethnic Study of Atherosclerosis. Serum testosterone, estradiol, sex hormone binding globulin (SHBG), and dehydroepiandrosterone levels were measured in 1947 postmenopausal women aged 45-84 years (30% White, 14% Chinese-American, 31% Black, and 25% Hispanic) and not on hormone therapy. Using multiple linear regression we evaluated associations between log(sex hormone) levels and log(cIMT) adjusted for age, ethnicity, body mass index (BMI) and cardiac risk factors. Associations between sex hormone levels and the presence and extent of coronary calcium were evaluated. Total and bioavailable testosterone were positively associated with common cIMT independent of age, BMI, hypertension, smoking, HDL-cholesterol, LDL-cholesterol and insulin sensitivity (p=0.009 and p=0.002, respectively). SHBG was negatively associated with common cIMT (p=0.001) but further adjustment for BMI, cardiovascular risk factors, and LDL- and HDL-cholesterol removed significance. Estradiol and dehydroepiandrosterone were not associated with common cIMT. Sex hormones were not associated with presence of coronary calcium. Among women with measurable coronary calcium, higher SHBG (p=0.012) and lower bioavailable testosterone (p=0.007) were associated with greater coronary calcium score. No heterogeneity by ethnicity was found. In postmenopausal women, testosterone is independently associated with greater common cIMT. SHBG is negatively associated and this may be mediated by LDL- and HDL-cholesterol. In contrast, SHBG and testosterone were associated with extent of coronary calcium but in the opposite direction compared to carotid intimal-medial thickness. These differences warrant further evaluation.
    Atherosclerosis 10/2008; 204(1):255-61. · 3.71 Impact Factor

Publication Stats

556 Citations
178.95 Total Impact Points

Institutions

  • 1999–2013
    • Northwestern University
      • • Division of Endocrinology, Metabolism and Molecular Medicine
      • • Feinberg School of Medicine
      • • Department of Preventive Medicine
      Evanston, IL, United States
  • 2008–2009
    • Johns Hopkins University
      • Department of Medicine
      Baltimore, MD, United States
    • Columbia University
      • Department of Medicine
      New York City, NY, United States
  • 2001–2007
    • Ann & Robert H. Lurie Children's Hospital of Chicago
      Chicago, Illinois, United States