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Dive into the research topics where Margaret Zacharin is active.

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Featured researches published by Margaret Zacharin.


Neurosurgery | 2001

Transcallosal resection of hypothalamic hamartomas, with control of seizures, in children with gelastic epilepsy.

Jeffrey V. Rosenfeld; A. S. Harvey; Jacquie A. Wrennall; Margaret Zacharin; Samuel F. Berkovic

OBJECTIVE Hypothalamic hamartomas (HHs) are associated with precocious puberty and gelastic epilepsy; the seizures are often refractory to antiepileptic medications and associated with delayed development and disturbed behavior. The current opinion is that surgery to treat intrahypothalamic lesions is formidable and that complete excision is not technically achievable. We report our experience with a transcallosal approach to the resection of HHs. METHODS Five children (age, 4–13 yr) with intractable epilepsy and HHs underwent preoperative clinical, electroencephalographic, and imaging evaluations. Two patients experienced only gelastic seizures, and three patients experienced mixed seizure disorders with drop attacks; all experienced multiple daily seizures. Patients were evaluated with respect to seizures, cognition, behavior, and endocrine status 9 to 37 months (mean, 24 mo) after surgery. The HHs were approached via a transcallosal-interforniceal route to the third ventricle and were resected using a microsurgical technique and frameless stereotaxy. RESULTS Complete or nearly complete (>95%) excision of the HHs was achieved for all patients, with no adverse neurological, psychological, or visual sequelae. Two patients experienced mild transient diabetes insipidus after surgery. Two patients developed appetite stimulation, but no other significant endocrinological sequelae were observed. Three patients are seizure-free and two patients have experienced only occasional, brief, mild gelastic seizures after surgery, all with reduced antiepileptic medications. On the basis of parental reports and our own subjective observations, the children also exhibited marked improvements in behavior, school performance, and quality of life. CONCLUSION Complete or nearly complete resection of HHs can be safely achieved via a transcallosal approach, with the possibility of seizure freedom and neurobehavioral improvements.


The Journal of Clinical Endocrinology and Metabolism | 2009

Induction of spermatogenesis and fertility during gonadotropin treatment of gonadotropin-deficient infertile men: predictors of fertility outcome.

Peter Y. Liu; H. W. Gordon Baker; Veena Jayadev; Margaret Zacharin; Ann J. Conway; David J. Handelsman

BACKGROUND The induction of spermatogenesis and fertility with gonadotropin therapy in gonadotropin-deficient men varies in rate and extent. Understanding the predictors of response would inform clinical practice but requires multivariate analyses in sufficiently large clinical cohorts that are suitably detailed and frequently assessed. DESIGN, SETTING, AND PARTICIPANTS A total of 75 men, with 72 desiring fertility, was treated at two academic andrology centers for a total of 116 courses of therapy from 1981-2008. OUTCOMES Semen analysis and testicular examination were performed every 3 months. RESULTS A total of 38 men became fathers, including five through assisted reproduction. The median time to achieve first sperm was 7.1 months [95% confidence interval (CI) 6.3-10.1]) and for conception was 28.2 months (95% CI 21.6-38.5). The median sperm concentration at conception for unassisted pregnancies was 8.0 m/ml (95% CI 0.2-59.5). Multivariate correlated time-to-event analyses show that larger testis volume, previous treatment with gonadotropins, and no previous androgen use each independently predicts faster induction of spermatogenesis and unassisted pregnancy. CONCLUSIONS Larger testis volume is a useful prognostic indicator of response. The association of slower responses after prior androgen therapy suggests that faster pregnancy rates might be achieved by substituting gonadotropin for androgen therapy for pubertal induction, although a prospective randomized trial will be required to prove this.


Journal of Clinical Oncology | 2011

Metastatic Pheochromocytoma/Paraganglioma Related to Primary Tumor Development in Childhood or Adolescence: Significant Link to SDHB Mutations

Kathryn S. King; Tamara Prodanov; Vitaly Kantorovich; Tito Fojo; Jacqueline K. Hewitt; Margaret Zacharin; Robert Wesley; Maya Lodish; Margarita Raygada; Anne Paule Gimenez-Roqueplo; Shana E. McCormack; Graeme Eisenhofer; Dragana Milosevic; Electron Kebebew; Constantine A. Stratakis; Karel Pacak

PURPOSE To present data on the high rate of SDHB mutations in patients with metastatic pheochromocytoma/paraganglioma whose initial tumor presentation began in childhood or adolescence. PATIENTS AND METHODS From 2000 to 2010, 263 patients with pheochromocytoma/paraganglioma were evaluated through the National Institutes of Health (NIH), Bethesda, MD. Of the 263 patients, 125 patients were found to have metastatic disease; of these 125 patients, 32 patients presented with a tumor before 20 years of age. An additional 17 patients presented with a tumor before 20 years of age but demonstrated no development of metastatic disease. Genetic testing for mutations in the VHL, MEN, and SDHB/C/D genes was performed on patients without previously identified genetic mutations. RESULTS Of the 32 patients who presented with metastatic disease and had their primary tumor in childhood or adolescence, sequence analysis of germline DNA showed SDHB mutations in 23 patients (71.9%), SDHD mutations in three patients (9.4%), VHL mutations in two patients (6.3%), and an absence of a known mutation in four patients (12.5%). The majority of these 32 patients (78.1%) presented with primary tumors in an extra-adrenal location. CONCLUSION The majority of patients with metastatic pheochromocytoma/paraganglioma who presented with a primary tumor in childhood/adolescence had primary extra-adrenal tumors and harbored SDHB mutations. Except for primary tumors located in the head and neck where SDHD genetic testing is advised, we recommend that patients who present with metastatic pheochromocytoma/paraganglioma with primary tumor development in childhood or adolescence undergo SDHB genetic testing before they undergo testing for other gene mutations, unless clinical presentation or family history suggests a different mutation.


Journal of Paediatrics and Child Health | 2003

Use of bisphosphonate therapy for osteoporosis in childhood and adolescence

Ja Batch; Jj Couper; Christine Rodda; Christopher T. Cowell; Margaret Zacharin

Abstract:  Congenital and acquired forms of osteoporosis in childhood and adolescence can result in morbidity from fracture and pain in childhood, and place an individual at significant risk for problems in adult life. A range of therapies exist for the prevention and treatment of osteoporosis, including optimization of daily calcium intake, adequate vitamin D status, weight‐bearing exercise, treatment with sex steroids where delayed puberty is a problem and, more recently, use of bisphosphonate therapy. Intravenous pamidronate therapy (a bisphosphonate) has been shown to reduce fractures and improve bone density in children with osteogenesis imperfecta, and might prove to be of benefit in other osteoporotic conditions in childhood. However, a number of issues regarding the optimal use of bisphosphonate therapy in children and adolescents remain to be resolved, including total annual dose and frequency and duration of administration. Bisphosphonate therapy should, therefore, be used only in the context of a well‐run clinical programme with specialist knowledge in the management of osteopenic disorders in childhood.


Archives of Disease in Childhood | 2004

Effect of gluten-free diet and adherence on growth and diabetic control in diabetics with coeliac disease.

Saadah Oi; Margaret Zacharin; O'Callaghan A; Mark R. Oliver; Anthony G. Catto-Smith

Aims: To study the effect of gluten-free diet on growth and diabetic control of children with type 1 diabetes mellitus and coeliac disease. Methods: Twenty one children (mean age 7.5 years, range 1.6–12.9) with type 1 diabetes, primarily initially identified on the basis of symptoms and consecutively diagnosed with coeliac disease by biopsy over a 10 year period, were matched by sex, age at onset, and duration of diabetes with two diabetic controls without coeliac disease. Weight, height, haemoglobin A1c, and insulin requirements were measured before and for 12 months after the diagnosis and treatment of coeliac disease. Dietary awareness and adherence were assessed by structured questionnaire. Results: A gluten-free diet resulted in a significant increase in weight-for-age z scores at 12 months after diagnosis (mean increase in z score 0.33) and in BMI (mean increase in z score 0.32). Increases in height did not achieve statistical significance. Controls showed no significant changes in weight, height, or BMI over the same period. Insulin dosage at diagnosis was less in coeliacs than in controls (mean difference 0.16 units/kg/day), but was similar to controls once a gluten-free diet had been established. Questionnaires were obtained in 20 patients. There appeared to be a relation between dietary awareness/adherence and growth parameters, but the small number of patients with “poor/fair” dietary adherence prevented meaningful analysis of this group. Conclusion: Identification and dietary treatment of coeliac disease in children with diabetes improved growth and influenced diabetic control. Evaluation of the outcome of treatment of coeliac disease in diabetics should include assessments of gluten intake.


The Journal of Pediatrics | 2008

Bisphosphonate Treatment in Chronic Recurrent Multifocal Osteomyelitis

Peter J Simm; Roger Allen; Margaret Zacharin

OBJECTIVE To test the safety and efficacy of biphosphonates in chronic recurrent multifocal osteomyelitis (CRMO). STUDY DESIGN Five patients with CRMO, all of whom had ongoing pain and loss of function despite conventional treatment with non-steroidal anti-inflammatory agents, were treated with pamidronate (1 mg/kg/dose with a dosing frequency of 2 to 4 monthly for a total treatment duration of 12 to 42 months). RESULTS Pain decreased after the first infusion for 4 of 5 patients, with symptomatic improvement maintained with time. Significant improvement was seen in radiological lesions for these 4 patients. CONCLUSION Bisphosphonates appear to be a useful and safe adjunctive treatment in CRMO when simple therapies such as anti-inflammatory agents fail to control symptoms or cases in which lesion expansion continues.


Journal of Pediatric Endocrinology and Metabolism | 2002

Pamidronate treatment of osteogenesis imperfecta--lack of correlation between clinical severity, age at onset of treatment, predicted collagen mutation and treatment response.

Margaret Zacharin; John F. Bateman

UNLABELLED Severe forms of osteogenesis imperfecta (OI) are characterised by osteoporosis with multiple fractures, deformity, progressive loss of mobility and chronic bone pain. Bisphosphonates, as osteoclast inhibitors, reduce bone turnover and improve osteoporosis. OBJECTIVE To investigate the effect of pamidronate treatment of severe OI in children, and find any correlation between clinical severity, age at start of treatment, type of predicted collagen mutation and treatment response. DESIGN Open, observational trial. PATIENTS A two-year study of pamidronate treatment was undertaken in a cohort of 18 children, (1.4-14.5 years) with OI types III and IV. INTERVENTIONS Disodium pamidronate, 1 mg/kg/day for 3 days every 4 months, by i.v. infusion with measurement of bone turnover, bone density, vertebral morphology and skin biopsies to assess collagen mutation. RESULTS Eleven children have completed 2 years of treatment and three more have completed 20 months. Sustained cessation of bone pain, improved mobility and decreased fracture rate were seen in all patients. Bone turnover decreased slightly but was not statistically significant. Bone mineral density (BMD) of lumbar spine increased by a mean of 124.7 +/- 75.7% over 2 years (Z score mean -5.08 +/- 1.27, to -3.30 +/- 1.71, p <0.001); the greatest change in BMD was seen in the most severely affected patients: 138 +/- 50.6% (severe), 62.47 +/- 22.9% (mild). There was a mean increase in vertebral height at L4 of 68.5% and in vertebral area of 85.4%. The majority of patients had slow electrophoretic migration of type I collagen alpha chains or reduced secretion of type I collagen, indicative of structural, helix-breaking mutations. There was no correlation between phenotypic severity, age at start of treatment and treatment response (r2 = 0.14) CONCLUSIONS Pamidronate treatment of severe forms of OI is an effective therapeutic modality to increase bone density, decrease fracture rate, increase mobility and improve quality of life, irrespective of the severity of the mutation or clinical phenotype. It has a good short-term safety profile.


Neuropsychology (journal) | 2000

Cerebral Lateralization and Cognitive Functioning in Patients With Congenital Adrenal Hyperplasia

Wendy Kelso; Michael E. R. Nicholls; Garry L. Warne; Margaret Zacharin

A battery of tests was administered to 17 patients with congenital adrenal hyperplasia (CAH) and 17 normal controls to investigate the effect of prenatal androgen exposure on cerebral lateralization and cognitive performance. Individuals were compared on measures of hand preference, verbal and performance IQ, and temporal processing asymmetry. A higher incidence of left-handedness was found among CAH participants. CAH individuals exhibited higher performance IQs as opposed to verbal IQs. Temporal processing asymmetries were investigated using an auditory gap detection task. Measures of reaction time and response error revealed a right-ear, therefore left-hemisphere, advantage for gap detection. This right-ear advantage did not differ between CAH individuals and controls. Results partially support the hypothesis that prenatal androgen exposure causes a shift in cerebral lateralization toward right-hemisphere dominance.


Endocrine-related Cancer | 2015

X-linked acrogigantism syndrome: clinical profile and therapeutic responses.

Albert Beckers; Maya Lodish; Giampaolo Trivellin; Liliya Rostomyan; Misu Lee; Fabio R. Faucz; Bo Yuan; Catherine S. Choong; Jean-Hubert Caberg; Elisa Verrua; Luciana A. Naves; Tim Cheetham; Jacques Young; Philippe A. Lysy; Patrick Petrossians; Andrew Cotterill; Nalini S. Shah; Daniel Metzger; Emilie Castermans; Maria Rosaria Ambrosio; Chiara Villa; Natalia Strebkova; Nadia Mazerkina; Stephan Gaillard; Gustavo Barcelos Barra; Luis Augusto Casulari; Sebastian Neggers; Roberto Salvatori; Marie Lise Jaffrain-Rea; Margaret Zacharin

X-linked acrogigantism (X-LAG) is a new syndrome of pituitary gigantism, caused by microduplications on chromosome Xq26.3, encompassing the gene GPR101, which is highly upregulated in pituitary tumors. We conducted this study to explore the clinical, radiological, and hormonal phenotype and responses to therapy in patients with X-LAG syndrome. The study included 18 patients (13 sporadic) with X-LAG and microduplication of chromosome Xq26.3. All sporadic cases had unique duplications and the inheritance pattern in two families was dominant, with all Xq26.3 duplication carriers being affected. Patients began to grow rapidly as early as 2-3 months of age (median 12 months). At diagnosis (median delay 27 months), patients had a median height and weight standard deviation scores (SDS) of >+3.9 SDS. Apart from the increased overall body size, the children had acromegalic symptoms including acral enlargement and facial coarsening. More than a third of cases had increased appetite. Patients had marked hypersecretion of GH/IGF1 and usually prolactin, due to a pituitary macroadenoma or hyperplasia. Primary neurosurgical control was achieved with extensive anterior pituitary resection, but postoperative hypopituitarism was frequent. Control with somatostatin analogs was not readily achieved despite moderate to high levels of expression of somatostatin receptor subtype-2 in tumor tissue. Postoperative use of adjuvant pegvisomant resulted in control of IGF1 in all five cases where it was employed. X-LAG is a new infant-onset gigantism syndrome that has a severe clinical phenotype leading to challenging disease management.


The Medical Journal of Australia | 2012

Incidence of vitamin D deficiency rickets among Australian children: an Australian Paediatric surveillance unit study

Craig Munns; Peter J Simm; Christine Rodda; Margaret Zacharin; Leanne M. Ward; Janet Geddes; Sarah Cherian; Yvonne Zurynski; Christopher T. Cowell

Objective: To determine the incidence of and factors associated with vitamin D deficiency rickets in Australian children.

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Peter J Simm

Royal Children's Hospital

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Sonia Grover

University of Melbourne

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Sze Choong Wong

Royal Hospital for Sick Children

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Ciara McDonnell

Royal Children's Hospital

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Garry L. Warne

Royal Children's Hospital

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Mary White

Royal Children's Hospital

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