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Biomedical subjects

Donald Anderson

Publications and source records attributed to Donald Anderson.

7 recordsLinked to original sources
PubMed2006

Hemithyroidectomy: the optimal initial surgical approach for individuals undergoing surgery for a cytological diagnosis of follicular neoplasm.

BACKGROUND: The primary objective of this study was to determine the true proportion and optimal surgical approach for individuals undergoing thyroid operation for a suspicion of cancer based on a fine-needle aspiration biopsy diagnosis of a follicular neoplasm (FN). A secondary objective of this study was to determine whether patient characteristics could assist the clinician in predicting malignancy in this FN patient cohort. METHODS: A retrospective chart, pathology, and cytology review of 370 consecutive primary thyroid operations was performed over a 4-year period at a tertiary care referral center. Clinical patient data were evaluated as an adjunct for predicting malignancy in the FN patient cohort. Univariate and multivariate analyses were used to investigate the association and the predictability. RESULTS: A total of 80 (22%) of the 370 patients underwent hemithyroidectomy to rule out cancer based on clinical presentation with a fine-needle aspiration biopsy diagnosis of FN. Fifteen (19%) of the FN cases were diagnosed as cancer by histological analysis (4 follicular carcinomas and 11 papillary carcinomas). Hemithyroidectomy was considered adequate treatment for 77 patients (96%). No patient characteristic significantly predicted the presence of cancer by either univariate or multivariate analysis. CONCLUSIONS: Overall, in the FN patient population, five hemithyroidectomies were performed to identify each cancer, and no further operation was required in 96% of patients. New diagnostic tools are needed to reduce the number of operations performed for benign pathology in patients with nodular thyroid disease and a needle biopsy diagnosis of FN.

Adenocarcinoma, Follicular↗
PubMed2006

A randomized controlled trial of telephone calls to young patients with poorly controlled type 1 diabetes.

OBJECTIVE: To determine if scheduled telephone calls from a pediatric diabetes educator to children who have type 1 diabetes improve hemoglobin A1c (HbA1c) level, hospital admissions, diabetes knowledge, compliance, and psychological well-being. RESEARCH DESIGN AND METHODS: A randomized controlled trial of 123 young subjects (mean age 11.9 yr, 69 male) with type 1 diabetes (mean duration 3.65 yr). For 7 months, the intervention group held bimonthly 15-30 min scheduled supportive telephone discussions. The primary outcome was change in the HbA1c level. Admission rates and changes in diabetes knowledge, psychological parameters, compliance, and patient perception were measured. RESULTS: There was no significant difference between the treatment and control groups either before or after the intervention. The mean HbA1c level in the control group increased from 8.32 to 8.82% and in the intervention group from 8.15 to 8.85% (p = 0.24). Both groups showed an increase in admissions of 0.2 per yr (p = 0.57). There was no improvement in diabetes knowledge (p = 0.34), compliance, or psychological function. The intervention group viewed their contact with the clinic as more helpful (p = 0.003). Analysis of family function did not reveal subgroups with statistically significant differences. A mean of 13 calls was made to each subject at a cost of 36 Australian dollars per child per month. CONCLUSIONS: Scheduled bimonthly phone support does not improve the HbA1c level, admission rates, diabetes knowledge, psychological function, or self-management but is perceived by patients as helpful. Further study into the effects of more frequent but shorter periods of support for patients experiencing specific difficulties is needed.

Adolescent↗
PubMed2005

SLC34A3 mutations in patients with hereditary hypophosphatemic rickets with hypercalciuria predict a key role for the sodium-phosphate cotransporter NaPi-IIc in maintaining phosphate homeostasis.

Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is a rare disorder of autosomal recessive inheritance that was first described in a large consanguineous Bedouin kindred. HHRH is characterized by the presence of hypophosphatemia secondary to renal phosphate wasting, radiographic and/or histological evidence of rickets, limb deformities, muscle weakness, and bone pain. HHRH is distinct from other forms of hypophosphatemic rickets in that affected individuals present with hypercalciuria due to increased serum 1,25-dihydroxyvitamin D levels and increased intestinal calcium absorption. We performed a genomewide linkage scan combined with homozygosity mapping, using genomic DNA from a large consanguineous Bedouin kindred that included 10 patients who received the diagnosis of HHRH. The disease mapped to a 1.6-Mbp region on chromosome 9q34, which contains SLC34A3, the gene encoding the renal sodium-phosphate cotransporter NaP(i)-IIc. Nucleotide sequence analysis revealed a homozygous single-nucleotide deletion (c.228delC) in this candidate gene in all individuals affected by HHRH. This mutation is predicted to truncate the NaP(i)-IIc protein in the first membrane-spanning domain and thus likely results in a complete loss of function of this protein in individuals homozygous for c.228delC. In addition, compound heterozygous missense and deletion mutations were found in three additional unrelated HHRH kindreds, which supports the conclusion that this disease is caused by SLC34A3 mutations affecting both alleles. Individuals of the investigated kindreds who were heterozygous for a SLC34A3 mutation frequently showed hypercalciuria, often in association with mild hypophosphatemia and/or elevations in 1,25-dihydroxyvitamin D levels. We conclude that NaP(i)-IIc has a key role in the regulation of phosphate homeostasis.

Adolescent↗
PubMed2004

An application of meta-analysis in food safety consumer research to evaluate consumer behaviors and practices.

Meta-analysis provides a structured method for combining results from several studies and accounting for and differentiating between study variables. Numerous food safety consumer research studies often focus on specific behaviors among different subpopulations but fail to provide a holistic picture of consumer behavior. Combining information from several studies provides a broader understanding of differences and trends among demographic subpopulations, and thus, helps in developing effective risk communication messages. In the illustrated example, raw/undercooked ground beef consumption and hygienic practices were evaluated according to gender, ethnicity, and age. Percentages of people engaging in each of the above behaviors (referred to as effect sizes) were combined using weighted averages of these percentages. Several measures, including sampling errors, random variance between studies, sample sizes of studies, and homogeneity of findings across studies, were used in the meta-analysis. The statistical significance of differences in behaviors across demographic segments was evaluated using analysis of variance. The meta-analysis identified considerable variability in effect sizes for raw/undercooked ground beef consumption and poor hygienic practices. More males, African Americans, and adults between 30 and 54 years (mid-age) consumed raw/undercooked ground beef than other demographic segments. Males, Caucasians, and Hispanics and young adults between 18 and 29 years were more likely to engage in poor hygienic practices. Compared to traditional qualitative review methods, meta-analysis quantitatively accounts for interstudy differences, allows greater consideration of data from studies with smaller sample sizes, and offers ease of analysis as newer data become available, and thus, merits consideration for its application in food safety consumer research.

Adult↗
PubMed2003

A new method for assessing arteriolar diameter and hemodynamic resistance using image analysis of vessel lumen.

To characterize the nonuniform diameter response in a blood vessel after a given stimulus (e.g., arteriolar conducted response), frequent serial diameter measurements along the vessel length are required. We used an advanced image analysis algorithm (the "discrete dynamic contour") to develop a quick, reliable method for serial luminal diameter measurements along the arteriole visualized by intravital video microscopy. With the use of digitized images of the arteriole and computer graphics, the method required an operator to mark the image of the two inner edges of the arteriole at several places along the arteriolar length. The algorithm then "filled in" these marks to generate two continuous contours that "hugged" these edges. A computer routine used these contours to determine luminal diameters every 20 microm. Based on these diameters and on Poiseuille's law, the routine also estimated the hemodynamic resistance of the blood vessel. To demonstrate the usefulness of the method, we examined the character of spatial decay of KCl-induced conducted constriction along approximately 500-microm-long arteriolar segments and the KCl-induced increase in hemodynamic resistance computed for these segments. The decay was only modestly fitted by a simple exponential, and the computed increase in resistance (i.e., 5- to 70-fold) was only modestly predicted by resistance increase based on our mathematical model involving measurements at two arteriolar sites (Tyml K, Wang X, Lidington D, and Oullette Y. Am J Physiol Heart Circ Physiol 281: H1397-H1406, 2001). We conclude that our method provides quick, reliable serial diameter measurements. Because the change in hemodynamic resistance could serve as a sensitive index of conducted response, use of this index in studies of conducted response may lead to new mechanistic insights on the response.

Animals↗
PubMed2001

Hereditary hypophosphatemic rickets with hypercalciuria is not caused by mutations in the Na/Pi cotransporter NPT2 gene.

Hereditary hypophosphatemic rickets with hypercalciuria (HHRH), a renal phosphate (Pi) wasting disease first described in an extended Bedouin kindred, is characterized by hypophosphatemia, elevated serum 1,25-dihydroxyvitamin D levels, hypercalciuria, rickets, and osteomalacia. Correction of all abnormalities, except for renal Pi wasting, can be achieved by oral Pi supplementation. These findings and the demonstration that mice that are homozygous for the disrupted Na/Pi cotransporter gene Npt2 exhibit many of the biochemical features of HHRH suggested that mutations in the human orthologue NPT2 might be responsible for HHRH. The NPT2 gene in affected individuals from the Bedouin kindred and four small families was screened for mutations to test this hypothesis. No putative disease-causing mutation was found. Two single nucleotide polymorphisms (SNP), a silent substitution in exon 7 and a nucleotide substitution in intron 4, were identified, and neither consistently segregated with HHRH in the Bedouin kindred. Linkage analysis indicated that the two NPT2 intragenic SNP as well as five microsatellite markers in the NPT2 gene region were not linked to HHRH in the Bedouin kindred. Therefore, this is evidence to exclude NPT2 as a candidate gene for HHRH in the families that were studied.

Base Sequence↗