Biomedical subjects

Maria J Henwood

Publications and source records attributed to Maria J Henwood.

4 recordsLinked to original sources

PubMed2006

Pediatric DXA: technique and interpretation.

This article reviews dual X-ray absorptiometry (DXA) technique and interpretation with emphasis on the considerations unique to pediatrics. Specifically, the use of DXA in children requires the radiologist to be a "clinical pathologist" monitoring the technical aspects of the DXA acquisition, a "statistician" knowledgeable in the concepts of Z-scores and least significant changes, and a "bone specialist" providing the referring clinician a meaningful context for the numeric result generated by DXA. The patient factors that most significantly influence bone mineral density are discussed and are reviewed with respect to available normative databases. The effects the growing skeleton has on the DXA result are also presented. Most important, the need for the radiologist to be actively involved in the technical and interpretive aspects of DXA is stressed. Finally, the diagnosis of osteoporosis should not be made on DXA results alone but should take into account other patient factors.

Absorptiometry, Photon↗

PubMed2006

Reconciling diabetes management and the ketogenic diet in a child with pyruvate dehydrogenase deficiency.

A 4-year-old girl with pyruvate dehydrogenase deficiency, static encephalopathy, and seizure disorder treated with the ketogenic diet presented in severe diabetic ketoacidosis. Pyruvate dehydrogenase deficiency is a rare genetic defect of mitochondrial energy metabolism that leads to inefficient glucose use and lactic acidosis. The ketogenic diet provides the brain with an alternate fuel source, but its implementation opposes traditional diabetes management. Faced with this therapeutic dilemma, we aimed to maintain ketosis without compromising safety to optimize neurologic function and quality of life. This is the first report, to our knowledge, of a child simultaneously treated with the ketogenic diet and exogenous insulin. A 28-month follow-up revealed excellent glycemic control, improved activity level, significant developmental achievements, and, perhaps most striking, catch-up linear growth from < 5th percentile to the 50th percentile. Her progress to date indicates that diabetes does not preclude use of the ketogenic diet.

Child, Preschool↗

PubMed2004

Genotype-phenotype correlations in children with congenital hyperinsulinism due to recessive mutations of the adenosine triphosphate-sensitive potassium channel genes.

Congenital hyperinsulinism (HI) is most commonly caused by recessive mutations of the pancreatic beta-cell ATP-sensitive potassium channel (K(ATP)), encoded by two genes on chromosome 11p, SUR1 and Kir6.2. The two mutations that have been best studied, SUR1 g3992-9a and SUR1 delF1388, are null mutations yielding nonfunctional channels and are characterized by nonresponsiveness to diazoxide, a channel agonist, and absence of acute insulin responses (AIRs) to tolbutamide, a channel antagonist, or leucine. To examine phenotypes of other K(ATP) mutations, we measured AIRs to calcium, leucine, glucose, and tolbutamide in infants with recessive SUR1 or Kir6.2 mutations expressed as diffuse HI (n = 8) or focal HI (n = 14). Of the 24 total mutations, at least seven showed evidence of residual K(ATP) channel function. This included positive AIR to both tolbutamide and leucine in diffuse HI cases or positive AIR to leucine in focal HI cases. One patient with partial K(ATP) function also responded to treatment with the channel agonist, diazoxide. Six of the seven patients with partial defects had amino acid substitutions or insertions; whereas, the other patient was compound heterozygous for two premature stop codons. These results indicate that some K(ATP) mutations can yield partially functioning channels, including cases of hyperinsulinism that are fully responsive to diazoxide therapy.

ATP-Binding Cassette Transporters↗

PubMed2002

Expanded spectrum of recombinant human growth hormone therapy.

The efficacy of recombinant human growth hormone in the treatment of growth hormone deficiency is well established. In recent years, the use of recombinant human growth hormone as a therapeutic modality has greatly increased and has expanded beyond the realm of replacement for growth hormone deficiency. Recombinant human growth hormone has been employed to ameliorate growth failure in multiple other disorders. For some, like Turner syndrome, recombinant human growth hormone has become the standard of care. For others, the ultimate benefit of recombinant human growth hormone remains to be determined. Although recent investigations provide encouraging short-term data, it is important to recognize that the impact of recombinant human growth hormone therapy on adult height has not been established in a number of conditions.

Adult↗