11 results on '"Isaac Levy"'
Search Results
2. Witness to Evil: Bergen - Belsen 1945
- Author
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Isaac Levy
- Published
- 2020
3. Insulin-like growth factor 2 (IGF2) expression in adrenocortical disease due to PRKAR1A mutations compared to other benign adrenal tumors
- Author
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Kiran S. Nadella, Constantine A. Stratakis, Fabio R. Faucz, Madson Q. Almeida, Isaac Levy, and Annabel Berthon
- Subjects
Messenger RNA ,animal structures ,endocrine system diseases ,biology ,Endocrinology, Diabetes and Metabolism ,030209 endocrinology & metabolism ,medicine.disease ,female genital diseases and pregnancy complications ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,030220 oncology & carcinogenesis ,Insulin-like growth factor 2 ,Gene expression ,medicine ,biology.protein ,Cancer research ,Benign adrenal tumors ,Gene ,PRKAR1A ,Immunostaining ,Primary pigmented nodular adrenocortical disease - Abstract
Insulin-like growth factor-II (IGF2), a key regulator of cell growth and development, is tightly regulated in its expression by epigenetic control that maintains its monoallelic expression in most tissues. Biallelic expression of IGF2 resulting from loss of imprinting (LOI) has been reported in adrenocortical tumors. In this study, we wanted to check whether adrenocortical lesions due to PRKAR1A mutations lead to increased IGF2 expression from LOI and compare these findings to those in other benign adrenal lesions. We compared the expression of IGF2 by RNA and protein studies in primary pigmented nodular adrenocortical disease (PPNAD) caused by PRKAR1A gene mutations to that in primary macronodular adrenocortical hyperplasia (PMAH) and cortisol-producing adenomas (CPA) that did not have any mutations in known genes. We also checked LOI in all lesions by DNA allelic studies and the expression of other components of IGF2 signaling at the RNA and protein level. We identified cell clusters overexpressing IGF2 in PPNAD; although immunostaining was patchy, overall, by RNA and immunoblotting PPNAD expressed high IGF2 message and protein. However, this was not due to LOI, as there was no correlation between IGF2 expression and the presence of LOI. Our data pointed to over-expression of IGF2 protein in PPNAD compared to other benign adrenocortical lesions, such as PMAH and CPA. However, there was no correlation of IGF2 mRNA levels with LOI of IGF2/H19. The discrepancy between mRNA and protein levels with regards to LOI points, perhaps, to different control of IGF2 gene expression in PPNAD.
- Published
- 2021
- Full Text
- View/download PDF
4. PRKACB variants in skeletal disease or adrenocortical hyperplasia: effects on protein kinase A
- Author
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Edra London, Jérôme Bertherat, Isaac Levy, Ludivine Drougat, Sara Haydar, Davide Calebiro, Fabio R. Faucz, Michael A. Levine, Dong Li, Constantine A. Stratakis, Kerstin Bathon, Stéphanie Espiard, and Nikolaos Settas
- Subjects
Adult ,0301 basic medicine ,Cancer Research ,Adolescent ,Endocrinology, Diabetes and Metabolism ,Adrenal Gland Neoplasms ,Context (language use) ,Biology ,Article ,Germline ,Mice ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,PRKACB Gene ,medicine ,Animals ,Humans ,PRKAR1A ,Carney complex ,Cyclic AMP-Dependent Protein Kinase Catalytic Subunits ,medicine.disease ,Phenotype ,PRKACA ,030104 developmental biology ,Oncology ,030220 oncology & carcinogenesis ,Cancer research ,Female ,Primary pigmented nodular adrenocortical disease - Abstract
Genetic variants in components of the protein kinase A (PKA) enzyme have been associated with various defects and neoplasms in the context of Carney complex (CNC) and in isolated cases, such as in primary pigmented nodular adrenocortical disease (PPNAD), cortisol-producing adrenal adenomas (CPAs), and various cancers. PRKAR1A mutations have been found in subjects with impaired cAMP-dependent signaling and skeletal defects; bone tumors also develop in both humans and mice with PKA abnormalities. We studied the PRKACB gene in 148 subjects with PPNAD and related disorders, who did not have other PKA-related defects and identified two subjects with possibly pathogenic PRKACB gene variants and unusual bone and endocrine phenotypes. The first presented with bone and other abnormalities and carried a de novo c.858_860GAA (p.K286del) variant. The second subject carried the c.899C>T (p.T300M or p.T347M in another isoform) variant and had a PPNAD-like phenotype. Both variants are highly conserved in the PRKACB gene. In functional studies, the p.K286del variant affected PRKACB protein stability and led to increased PKA signaling. The p.T300M variant did not affect protein stability or response to cAMP and its pathogenicity remains uncertain. We conclude that PRKACB germline variants are uncommon but may be associated with phenotypes that resemble those of other PKA-related defects. However, detailed investigation of each variant is needed as PRKACB appears to be only rarely affected in these conditions, and variants such as p.T300M maybe proven to be clinically insignificant, whereas others (such as p.K286del) are clearly pathogenic and may be responsible for a novel syndrome, associated with endocrine and skeletal abnormalities.
- Published
- 2020
- Full Text
- View/download PDF
5. Brentuximab vedotin as monotherapy for unresectable breast implant‐associated anaplastic large cell lymphoma
- Author
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Anthony Stack and Isaac Levy
- Subjects
Oncology ,medicine.medical_specialty ,CD30 ,Case Report ,breast implant‐associated anaplastic large cell lymphoma ,lymphoma ,Case Reports ,030204 cardiovascular system & hematology ,Malignancy ,Breast Lymphoma ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,law ,brentuximab vedotin ,Internal medicine ,hemic and lymphatic diseases ,medicine ,Brentuximab vedotin ,Anaplastic large-cell lymphoma ,integumentary system ,business.industry ,breast lymphoma ,General Medicine ,medicine.disease ,ALCL ,Immunoconjugate ,Lymphoma ,030220 oncology & carcinogenesis ,Breast implant ,business ,medicine.drug - Abstract
Key Clinical Message BI‐ALCL is a rare CD30+ T‐cell malignancy, which is known to complicate textured breast implants. The CD30‐targeting immunoconjugate, brentuximab vedotin, has been suggested for invasive BI‐ALCL; however, its efficacy for unresectable BI‐ALCL has not been demonstrated. We present a case of unresectable BI‐ALCL, which was successfully treated with brentuximab vedotin.
- Published
- 2019
6. On the Principles of Gibraltar Taxation
- Author
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Grahame Jackson, Isaac Levy, Grahame Jackson, and Isaac Levy
- Abstract
A series of chapters, each of which describes and discusses a single principle which can be discerned in the design and operation of the Gibraltar taxation system. Not all of these principles will have been in the minds of the drafters of the relevant legislation, some of them may well be what philosophers call'emergent'properties, but nonetheless are there, shaping and guiding the design of new legislation and impacting on the future of our taxation model.
- Published
- 2024
7. Insulin-like growth factor 2 (IGF2) expression in adrenocortical disease due to PRKAR1A mutations compared to other benign adrenal tumors
- Author
-
Kiran S, Nadella, Annabel, Berthon, Madson Q, Almeida, Isaac, Levy, Fabio R, Faucz, and Constantine A, Stratakis
- Subjects
Adrenal Cortex Diseases ,Insulin-Like Growth Factor II ,Cyclic AMP-Dependent Protein Kinase RIalpha Subunit ,Mutation ,Humans ,RNA, Messenger ,Adrenal Cortex Neoplasms ,Transcription Factors - Abstract
Insulin-like growth factor-II (IGF2), a key regulator of cell growth and development, is tightly regulated in its expression by epigenetic control that maintains its monoallelic expression in most tissues. Biallelic expression of IGF2 resulting from loss of imprinting (LOI) has been reported in adrenocortical tumors. In this study, we wanted to check whether adrenocortical lesions due to PRKAR1A mutations lead to increased IGF2 expression from LOI and compare these findings to those in other benign adrenal lesions.We compared the expression of IGF2 by RNA and protein studies in primary pigmented nodular adrenocortical disease (PPNAD) caused by PRKAR1A gene mutations to that in primary macronodular adrenocortical hyperplasia (PMAH) and cortisol-producing adenomas (CPA) that did not have any mutations in known genes. We also checked LOI in all lesions by DNA allelic studies and the expression of other components of IGF2 signaling at the RNA and protein level.We identified cell clusters overexpressing IGF2 in PPNAD; although immunostaining was patchy, overall, by RNA and immunoblotting PPNAD expressed high IGF2 message and protein. However, this was not due to LOI, as there was no correlation between IGF2 expression and the presence of LOI.Our data pointed to over-expression of IGF2 protein in PPNAD compared to other benign adrenocortical lesions, such as PMAH and CPA. However, there was no correlation of IGF2 mRNA levels with LOI of IGF2/H19. The discrepancy between mRNA and protein levels with regards to LOI points, perhaps, to different control of IGF2 gene expression in PPNAD.
- Published
- 2020
8. A phosphodiesterase 11 (Pde11a) knockout mouse expressed functional but reduced Pde11a: Phenotype and impact on adrenocortical function
- Author
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Matthew Starrost, Eva Szarek, Isaac Levy, Fabio R. Faucz, Maria de la Luz Sierra, Constantine A. Stratakis, and Andrea Gutierrez Maria
- Subjects
Male ,0301 basic medicine ,medicine.medical_specialty ,030209 endocrinology & metabolism ,Biochemistry ,Article ,Dexamethasone ,03 medical and health sciences ,chemistry.chemical_compound ,Cushing syndrome ,0302 clinical medicine ,Endocrinology ,Adrenocorticotropic Hormone ,3',5'-Cyclic-GMP Phosphodiesterases ,Corticosterone ,Internal medicine ,Cyclic AMP ,medicine ,Animals ,RNA, Messenger ,Molecular Biology ,Mice, Knockout ,Hyperplasia ,Adrenal cortex ,Phosphodiesterase ,medicine.disease ,Cyclic AMP-Dependent Protein Kinases ,Adenosine ,Phenotype ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,Knockout mouse ,Adrenal Cortex ,Female ,Haploinsufficiency ,Gene Deletion ,medicine.drug - Abstract
Phosphodiesterases catalyze the hydrolysis of cyclic nucleotides and maintain physiologic levels of intracellular concentrations of cyclic adenosine and guanosine mono-phosphate (cAMP and cGMP, respectively). Increased cAMP signaling has been associated with adrenocortical tumors and Cushing syndrome. Genetic defects in phosphodiesterase 11A (PDE11A) may lead to increased cAMP signaling and are found to predispose to the development of adrenocortical, prostate, and testicular tumors. A previously reported Pde11a knockout (Pde11a(−/−)) mouse line was studied and found to express PDE11A mRNA and protein still, albeit at reduced levels; functional studies in various tissues showed increased cAMP levels and reduced PDE11A activity. Since patients with PDE11A defects and Cushing syndrome have PDE11A haploinsufficiency, it was particularly pertinent to study this hypomorphic mouse line. Indeed, Pde11a(−/−) mice failed to suppress corticosterone secretion in response to low dose dexamethasone, and in addition exhibited adrenal subcapsular hyperplasia with predominant fetal-like features in the inner adrenal cortex, mimicking other mouse models of increased cAMP signaling in the adrenal cortex. We conclude that a previously reported Pde11a(−/−) mouse showed continuing expression and function of PDE11A in most tissues. Nevertheless, Pde11a partial inactivation in mice led to an adrenocortical phenotype that was consistent with what we see in patients with PDE11A haploinsufficiency.
- Published
- 2021
- Full Text
- View/download PDF
9. POSTTRAUMATIC STRESS SYMPTOMS AND AVERSION TO AMBIGUOUS LOSSES IN COMBAT VETERANS
- Author
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Ilan Harpaz-Rotem, Robert H. Pietrzak, Isaac Levy, Daniel B. Ehrlich, Lital Ruderman, and Alicia Roy
- Subjects
0301 basic medicine ,media_common.quotation_subject ,Human factors and ergonomics ,Poison control ,Ambiguity ,Hypervigilance ,Behavioral economics ,Suicide prevention ,03 medical and health sciences ,Psychiatry and Mental health ,Clinical Psychology ,030104 developmental biology ,0302 clinical medicine ,Injury prevention ,medicine ,medicine.symptom ,Association (psychology) ,Psychology ,030217 neurology & neurosurgery ,media_common ,Clinical psychology - Abstract
BACKGROUND: Psychiatric symptoms typically cut across traditional diagnostic categories. In order to devise individually tailored treatments, there is a need to identify the basic mechanisms that underlie these symptoms. Behavioral economics provides a framework for studying these mechanisms at the behavioral level. Here, we utilized this framework to examine a widely ignored aspect of trauma-related symptomatology-individual uncertainty attitudes-in combat veterans with and without posttraumatic stress disorder (PTSD). METHODS: Fifty-seven combat veterans, including 30 with PTSD and 27 without PTSD, completed a risk and ambiguity decision-making task that characterizes individual uncertainty attitudes, distinguishing between attitudes toward uncertain outcomes with known ("risk") and unknown ("ambiguity") probabilities, and between attitudes toward uncertain gains and uncertain losses. Participants' choices were used to estimate risk and ambiguity attitudes in the gain and loss domains. RESULTS: Veterans with PTSD were more averse to ambiguity, but not risk, compared to veterans without PTSD, when making choices between possible losses, but not gains. The degree of aversion was associated with anxious arousal (e.g., hypervigilance) symptoms, as well as with the degree of combat exposure. Moreover, ambiguity attitudes fully mediated the association between combat exposure and anxious arousal symptoms. CONCLUSIONS: These results provide a foundation for prospective studies of the causal association between ambiguity attitudes and trauma-related symptoms, as well as etiologic studies of the neural underpinnings of these behavioral outcomes. More generally, these results demonstrate the potential of neuroeconomic and behavioral economic techniques for devising objective and incentive-compatible diagnostic tools, and investigating the etiology of psychiatric disorders.© 2016 Wiley Periodicals, Inc. Language: en
- Published
- 2016
- Full Text
- View/download PDF
10. Germline PRKACA amplification causes variable phenotypes that may depend on the extent of the genomic defect: molecular mechanisms and clinical presentations
- Author
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James R. Lupski, J. Aidan Carney, Eva Szarek, Isaac Levy, Fabio R. Faucz, Glenn D. Braunstein, James Gardner, Louise Izatt, Alexander S. Karageorgiadis, Maya Lodish, Caroline Brain, Margarita Raygada, Charalampos Lyssikatos, Elena Belyavskaya, Bo Yuan, Constantine A. Stratakis, Paraskevi Salpea, and Martha Quezado
- Subjects
Adult ,Male ,medicine.medical_specialty ,DNA Copy Number Variations ,Endocrinology, Diabetes and Metabolism ,Clinical Sciences ,Locus (genetics) ,Biology ,Article ,Germline ,Paediatrics and Reproductive Medicine ,Molecular cytogenetics ,Endocrinology & Metabolism ,Young Adult ,Endocrinology ,Clinical Research ,Internal medicine ,Adrenal Glands ,Gene duplication ,Genetics ,medicine ,2.1 Biological and endogenous factors ,Humans ,Aetiology ,Preschool ,Child ,Cushing Syndrome ,Gene ,Pediatric ,Cyclic AMP-Dependent Protein Kinase Catalytic Subunits ,Hyperplasia ,Human Genome ,Gene Amplification ,Chromosome ,Adrenalectomy ,General Medicine ,Phenotype ,PRKACA ,Child, Preschool ,Female ,Biotechnology - Abstract
ObjectiveWe have recently reported five patients with bilateral adrenocortical hyperplasia (BAH) and Cushing's syndrome (CS) caused by constitutive activation of the catalytic subunit of protein kinase A (PRKACA). By doing new in-depth analysis of their cytogenetic abnormality, we attempted a better genotype–phenotype correlation of theirPRKACAamplification.DesignThis study is a case series.MethodsMolecular cytogenetic, genomic, clinical, and histopathological analyses were performed in five patients with CS.ResultsReinvestigation of the defects of previously described patients by state-of-the-art molecular cytogenetics showed complex genomic rearrangements in the chromosome 19p13.2p13.12 locus, resulting in copy number gains encompassing the entirePRKACAgene; three patients (one sporadic case and two related cases) were observed with gains consistent with duplications, while two sporadic patients were observed with gains consistent with triplications. Although all five patients presented with ACTH-independent CS, the three sporadic patients had micronodular BAH and underwent bilateral adrenalectomy in early childhood, whereas the two related patients, a mother and a son, presented with macronodular BAH as adults. In at least one patient,PRKACAtriplication was associated with a more severe phenotype.ConclusionsConstitutional chromosomalPRKACAgene amplification is a recently identified genetic defect associated with CS, a trait that may be inherited in an autosomal dominant manner or occurde novo. Genomic rearrangements can be complex and can result in different copy number states of dosage-sensitive genes, e.g., duplication and triplication.PRKACAamplification can lead to variable phenotypes clinically and pathologically, both micro- and macro-nodular BAH, the latter of which we speculate may depend on the extent of amplification.
- Published
- 2015
- Full Text
- View/download PDF
11. The Impact of Hypoparathyroidism Treatment on the Kidney in Children: Long-Term Retrospective Follow-Up Study
- Author
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Jennifer Harrington, Christoph Licht, Isaac Levy, Etienne Sochett, and Alan Daneman
- Subjects
Male ,medicine.medical_specialty ,Adolescent ,Hypoparathyroidism ,Endocrinology, Diabetes and Metabolism ,Clinical Biochemistry ,Renal function ,Context (language use) ,Kidney ,Biochemistry ,Phosphates ,Cohort Studies ,Hyperphosphatemia ,Endocrinology ,Calcitriol ,Internal medicine ,medicine ,Prevalence ,Humans ,Child ,Retrospective Studies ,Ultrasonography ,business.industry ,Biochemistry (medical) ,Infant, Newborn ,Infant ,Retrospective cohort study ,medicine.disease ,Calcium Channel Agonists ,Nephrocalcinosis ,medicine.anatomical_structure ,Child, Preschool ,Hypercalcemia ,Calcium ,Female ,Kidney Diseases ,business ,Cohort study ,Follow-Up Studies ,Glomerular Filtration Rate - Abstract
Adults with hypoparathyroidism have significant rates of nephrocalcinosis and impaired renal function. Little is known about the impact of hypoparathyroidism treatment on renal function in children.To determine the prevalence and predictors for renal abnormalities (nephrocalcinosis and decreased estimated glomerular filtration rate [eGFR]) in children with treated hypoparathyroidism.A retrospective chart review of patients with permanent hypoparathyroidism at the Hospital for Sick Children, Toronto, between 1996 and 2013.Data of 29 patients (15 males) followed for at least 1 year with documented hypoparathyroidism were analyzed. Mean duration of follow up was 7.4 ± 5 years.The presence or absence of nephrocalcinosis as detected on ultrasound and eGFR were evaluated.Time-weighted average serum measurements were calculated for all biochemical variables. Mean total and ionized serum calcium were 8.9 ± 0.8 and 4.6 ± 0.5 mg/dL, respectively. Nephrocalcinosis was observed in 38% of the subjects, with the most significant predictors being the degree of relative hypercalcemia and hyperphosphatemia (R(2) = 0.47, P.01). Although all patients had an eGFR greater than 60, in 45% of the children, the eGRF was between 60 and 90 mL/min per 1.73 m(2). Higher calcium concentrations (r = -0.42, P = .02) and a greater proportion of time with relative hypercalcemia (r = -0.41, P = .03) were associated with lower eGFR.Our results establish that children with hypoparathyroidism treated with calcitriol and calcium supplements are at risk for nephrocalcinosis and decreased eGFR. Because hypoparathyroidism is most commonly a life-long condition, careful monitoring and management of calcium abnormalities has important future implications.
- Published
- 2015
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