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Biomedical subjects

Donald Zimmerman

Publications and source records attributed to Donald Zimmerman.

13 recordsLinked to original sources
PubMed2006

Surgical management of Graves disease in childhood and adolescence: an institutional experience.

BACKGROUND: Graves disease is the most common cause of hyperthyroidism in children. Medical therapy, radioiodine ablation, and thyroidectomy are all treatment options. To evaluate the safety and efficacy of operative therapy, we updated our operative experience with pediatric Graves disease at a single tertiary care center. METHODS: The medical records of children <18 years old who underwent thyroidectomy for Graves disease between 1986-2003 were reviewed. RESULTS: We identified 78 patients (median age, 13.8 years; 87% female). The most common presenting signs and symptoms included heat intolerance (61%), decreased academic performance (50%), tremor (49%), and ophthalmopathy (43%). All patients had clinical and laboratory evidence of autoimmune thyrotoxicosis. Sixty-nine percent chose operative therapy because of failure of medical therapy or adverse drug reactions. Near-total thyroidectomy was the most common surgical procedure performed (65%). Pathology demonstrated previously unrecognized thyroid malignancies in 4 (5%) patients. Operative morbidities were transient and included hypoparathyroidism (6%) and recurrent laryngeal nerve neuropraxia (1%). Three (4%) patients who underwent subtotal thyroidectomy developed recurrent hyperthyroidism; all were treated successfully with radioiodine ablation. Of patients presenting with ophthalmopathy, 85% noted improvement postoperatively, while 1 (3%) patient experienced worsening of symptoms. Only 5% developed new-onset Graves ophthalmopathy after operation. CONCLUSIONS: Near-total thyroidectomy for Graves disease in children is safe and effective when performed by experienced thyroid surgeons. In addition to relief of systemic symptoms, the majority of patients presenting with Graves ophthalmopathy experienced improvement of their ocular disease after operation. In 5% of patients, surgical management allowed for detection and treatment of clinically occult thyroid malignancies.

Adolescent↗
PubMed2006

Central and gonadal hypogonadism in X-linked lissencephaly.

OBJECTIVE: To directly test gonadal function in a patient with X-linked lissencephaly with ambiguous genitalia (XLAG) in light of lack of previous functional data. STUDY DESIGN AND RESULTS: We studied an infant who failed to increase testosterone levels in response to hCG stimulation. CONCLUSION: In XLAG, the gonads are not only structurally dysgenetic but also functionally abnormal.

Abnormalities, Multiple↗
PubMed2005

Endocrine manifestations of craniopharyngioma.

RATIONALE: Due to the proximity of craniopharyngiomas to the hypothalamus and pituitary gland, most children and adolescents presenting with these tumors will exhibit significant endocrine dysfunction. After treatment, these impairments can become a major cause of morbidity and mortality. METHODS: The postoperative course of children undergoing surgery for craniopharyngioma is reviewed. CONCLUSION: Even if hormone levels seem to be adequate in the short term after treatment, deficiencies may develop over years and need to be monitored closely.

Adrenocorticotropic Hormone↗
PubMed2005

Thyroid nodules and cancers in children.

Thyroid nodules are clinically evident in approximately 1% of children and about 30% of these are malignant. In addition to requiring appropriate surgery, thyroid hormone replacement in and follow-up monitoring of patients who are members of families with tumor syndromes must be studied for other components of these syndromes.

Child↗
PubMed2004

Steroid profiling by tandem mass spectrometry improves the positive predictive value of newborn screening for congenital adrenal hyperplasia.

Congenital adrenal hyperplasia (CAH) is primarily caused by 21-hydroxylase deficiency and leads to an accumulation of 17-hydroxyprogesterone and reduced cortisol levels. Newborn screening for CAH is traditionally based on measuring 17-hydroxyprogesterone by different immunoassays. Despite attempts to adjust cutoff levels for birth weight, gestational age, and stress factors, the positive predictive value for CAH screening remains less than 1%. To improve this situation, we developed a method using liquid chromatography-tandem mass spectrometry to measure 17-hydroxyprogesterone, androstenedione, and cortisol simultaneously in blood spots. A total of 1222 leftover blood spots from six different screening programs using different immunoassays (fluorescent immunoassay and ELISA) were reanalyzed in a blinded fashion by liquid chromatography-tandem mass spectrometry. Thirty-one samples were from babies with CAH, 190 had yielded false-positive results by immunoassay, and the remaining 1001 samples were from babies with normal screening results. Steroid profiling allowed for an elimination of 169 (89%) of the false-positive results and for an improvement of the positive predictive value from the reported 0.5 to 4.7%. Although this method is not suitable for mass screening due to the length of the analysis (12 min), it can be used as a second-tier test of blood spots with positive results for CAH by the conventional methods. This would prevent unnecessary blood draws, medical evaluations, and stress to families.

17-alpha-Hydroxyprogesterone↗
PubMed2004

Short stature.

These reviews of evaluation and care of patients with short stature should provide a framework for addressing the needs of these patients. Continued study of the mechanisms of short stature may facilitate prediction of the efficacy of growth hormone, growth factor, and perhaps other treatments. In addition, long-term studies should continue to examine the medical and psychological effects of treatment so that treatment decisions are as judicious as possible.

Body Height↗
PubMed2004

Evaluating short stature in children.

A child's growth reflects his or her general state of health. Growth deceleration therefore may result from processes that ultimately threaten much more than height and weight. Accurate height and weight measurements and routine plotting of growth data on standard growth charts are important elements of pediatric practice. A decrease in length of height percentiles may be physiologic in infancy and in puberty. However, in order to distinguish physiologic from pathologic growth deceleration, a careful history and physical examination needs to be obtained. Quite frequently, laboratory and radiographic studies are needed to distinguish with confidence between causes of slow growth in these phases of life. Such studies are always required to evaluate growth deceleration during childhood, because growth deceleration in this phase is virtually always the result of a pathological process. If constitutional growth delay is diagnosed, reassurance is often adequate treatment, though continued monitoring of growth and bone age is indicated. Growth deceleration due to other processes is often treatable. Delineation of the causes of poor growth is particularly important because these disease processes may produce other serious problems.

Adolescent↗
PubMed2004

Idiopathic short stature in children.

Idiopathic short stature represents a group of conditions that are not definable by current biochemical criteria but usually respond to GH therapy. Natural-history studies confirm adult height will be short in untreated ISS individuals. Children and adults with short stature have disadvantages compared with their peers. The evidence for benefit from treatment of children with idiopathic short stature is strong. Numerous studies, now including a placebo-controlled study, have demonstrated the positive effect of GH treatment on final height. The effect of GH treatment is quantitatively similar to results seen in other non-GH-deficient conditions. Although currently very expensive, rhGH treatment is relatively safe. GH treatment of children with idiopathic short stature should not be withheld because of our inability to explain the etiology or because of the inadequacy of our current diagnostic tests. Continued efforts to delineate specific causes of poor growth in ISS individuals may result in our being able to predict subsets of individuals who will respond well to GH and subgroups who may be considered for other treatments, such as IGF-1 or a combination of IGF-1 and IGFBP-3.

Body Height↗
PubMed2004

Managing growth hormone treatment in pediatric patients.

In general, GH is a safe medication. Patients overwhelmingly enjoy its benefits. Infrequently, its side effects produce worrisome problems. Knowledge of these effects may allow families to choose treatment more judiciously and may allow physicians to detect adverse effects at an early stage.

Acute Disease↗
PubMed2004

Coordinating care for children with Turner syndrome.

Turner syndrome is a systemic disease requiring a multi-system management approach. This includes attention to the endocrine system, cardiovascular system, renal system, gastrointestinal system, ears, eyes, skeletal system, and skin, as well as to the psychology of the patient and the family. The primary care physician is central to the care of these patients. In addition to anticipating, diagnosing, and treating the various problems that may arise in patients with Turner syndrome, the primary care physician must coordinate the fairly large healthcare team needed for optimal care.

Adolescent↗
PubMed2003

Recurrent familial hypocalcemia due to germline mosaicism for an activating mutation of the calcium-sensing receptor gene.

De novo activating mutations in the calcium-sensing receptor (CASR) gene are a common cause of sporadic isolated hypoparathyroidism. Here, we describe a family in which two affected siblings were found to be heterozygous for a novel F788L mutation in the fifth transmembrane domain encoded by exon 7 of the CASR. Both parents and the third sibling were clinically unaffected and genotypically normal by direct sequencing of their leukocyte exon 7 PCR amplicons. However, the mother was revealed to be a mosaic for the mutation by sequence analysis of multiple subclones as well as denaturing HPLC of the CASR exon 7 leukocyte PCR product. A functional analysis of the mutation was performed by transiently transfecting wild-type and mutant CASRs tagged with a c-Myc epitope in human embryonic kidney (HEK293) cells. The mutant CASR was expressed at a similar level as the wild type. The F788L mutant produced a significant shift to the left relative to the wild-type CASR in the MAPK response to increasing extracellular calcium concentrations. This is the first report of mosaicism for an activating CASR mutation and suggests that care should be exercised in counseling for risks of recurrence in a situation where a de novo mutation appears likely.

Adolescent↗