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Biomedical subjects

J E Dimmick

Publications and source records attributed to J E Dimmick.

At least 19 recordsLinked to original sources
PubMed1997

Murine mucopolysaccharidosis type I: targeted disruption of the murine alpha-L-iduronidase gene.

Mucopolysaccharidosis type I (MPS I) is considered to represent the prototypical mucopolysaccharide storage disorder. Although a spectrum of severity is seen within the MPS I subgroup, Hurler syndrome represents the most severe and frequent manifestation of MPS I. We describe here the generation of a murine model for Hurler syndrome by targeted disruption of the murine Idua gene. Homozygous Idua -/- mice have no detectable alpha-L-iduronidase enzyme activity and show increased urinary glycosaminoglycan levels. Although normal appearing at birth, Idua -/- mice develop a flattened facial profile and thickening of the digits discernible by 3 weeks of age. No obvious growth deficiency nor mortality is seen within the first 20 weeks of life. Radiographs reveal anterior flaring of the ribs and thickening of the facial bones as early as 4 weeks of age with more extensive dysostosis detectable by 15 weeks of age. At 4 weeks of age, lysosomal storage is noted primarily within reticuloendothelial cells with abundant lysosomes noted in Kupffer cells, splenic sinusoidal lining cells, and glial cells. More widespread lysosomal storage is noted by 8 weeks of age in hepatocytes, chondrocytes, neurons, as well as renal tubular cells. Thus, targeted disruption of the murine Idua locus has produced a murine strain representative of the severe form of MPS I. This model should permit detailed evaluation of the pathophysiology of lysosomal storage disorders and provide a small animal model for the testing and development of enzyme replacement and gene therapy regimes.

Abnormalities, Multiple↗
PubMed1994

Oral pemphigus vulgaris associated with inflammatory bowel disease and herpetic gingivostomatitis in an 11-year-old girl.

An 11-year-old girl with recently diagnosed oral pemphigus vulgaris developed a severe exacerbation of mouth ulceration due to superinfection with herpes simplex virus type I. A concurrent diagnosis of chronic inflammatory bowel disease was established to explain symptoms of weight loss and intermittent bloody diarrhea that predated the oral ulceration by several years. Herpes simplex infection is a recognized complication of pemphigus vulgaris that may be mistaken for a recrudescence of the disease. The association of pemphigus with chronic inflammatory bowel disease has been documented in a small number of adults. Its relationship to pyostomatitis vegetans, an acknowledged marker for ulcerative colitis and Crohn disease, remains unclear.

Child↗
PubMed1993

Adenocarcinoma in childhood Barrett's esophagus: case documentation and the need for surveillance in children.

A 17-yr-old boy underwent esophagectomy for multifocal high-grade dysplasia and adenocarcinoma complicating Barrett's esophagus (BE). He is believed to be the first child or young adult to have prolonged healthy survival following resection of esophageal adenocarcinoma. Dysplasia in a short retained segment of his Barrett's mucosa appears to have regressed with acid-suppressing therapy. Of nine other reported cases of adenocarcinoma in young people 11-25 yr of age, all died. All had progressive dysphagia and an esophageal mass at presentation, unlike our patient who had only histologic evidence of cancer at presentation. This was found only after repeated and extensive biopsy of the esophagus. We conclude that adenocarcinoma does occur under age 25 yr as a complication of BE arising in childhood, and it may be curable if diagnosed early. Endoscopic surveillance with multiple stepwise biopsies, beginning at age 10 yr, is suggested in those few children who have BE with specialized mucosa and goblet cells.

Adenocarcinoma↗
PubMed1993

Economic analysis of the clinical laboratory: labor implications.

Expenditures on laboratory tests have increased by 468% in real dollars in two decades although the cost per test has remained constant. Cost of labor has doubled over that period, with an approximately similar increase in personnel productivity as the offset. Part of the increased labor cost relates to increased pay for technologist work of apparent increased complexity. We found that technologists perceived less than 20% of all work and less than 4% of all tests performed to be highly complex or of moderately high complexity. Implications of these findings for test complexity analysis and for technologist training are discussed.

Cost-Benefit Analysis↗
PubMed1992

Pasteurella multocida chorioamnionitis from vaginal transmission.

A 21 year old primigravida with a twin pregnancy developed Pasteurella multocida chorioamnionitis. Infection occurred at 27 weeks gestational age after prolonged rupture of membranes. The twin in the separate sac presenting proximal to the cervix suffered infection and died shortly after birth whereas the other twin was not infected. The bacterium is believed to have caused ascending infection from asymptomatic colonization of the vaginal tract.

Adult↗
PubMed1992

Primary hemochromatosis in children: report of three newly diagnosed cases and review of the pediatric literature.

Hereditary hemochromatosis was diagnosed in three asymptomatic siblings following the unexpected finding of elevated serum iron concentrations. This diagnosis was confirmed by hepatic biopsy. Repeated phlebotomies resulted in a significant decline of serum iron and ferritin concentrations and a decrease of hepatic iron content. This report and a review of the literature indicate that the diagnosis of hereditary hemochromatosis must be considered more frequently in childhood. Organ dysfunction from iron overload may be minimized in children by the early commencement of regular phlebotomy.

Child↗
PubMed1991

Hepatic dysfunction in Alström disease.

Alström disease is a rare disorder; less than 20 cases have been reported. An 11-year-old girl is described with this condition. She has pigmentary retinopathy, sensory neural deafness, obesity, Type II diabetes mellitus, hyperlipidemia, and acanthosis nigricans. However, in addition she developed hepatic dysfunction, pathologically similar to chronic active hepatitis. This may be a further, previously undescribed systemic manifestation of Alström disease.

Acanthosis Nigricans↗
PubMed1991

Unique features of Helicobacter pylori disease in children.

In a six-year period, 41 children had endoscopically documented duodenal ulcer disease or primary H. pylori antral gastritis without duodenal ulcer. Of 37 children with H. pylori gastritis, group 1 comprised 23 patients with duodenal ulcer disease and group 2 had 14 patients without ulcers (primary H. pylori gastritis). Group 3 comprised four children with duodenal ulcer disease and H. pylori-negative antral biopsies. During the study period, all primary chronic ulcer disease was duodenal; no primary chronic gastric ulcer was present. Two distinct types of duodenal ulcer disease were identified; the majority (85%) was always associated with significant active H. pylori antral gastritis (group 1). The minority (15%) had virtually absent gastritis and no H. pylori (group 3). Native Indian children were represented in group 1 quite out of proportion to the referral population and had the most severe disease. While it is established that a higher prevalence of asymptomatic H. pylori infection exists in non-Caucasians, this appears to be the first demonstration of a higher prevalence of symptomatic ulcer disease in non-Caucasian children or adults. Caucasian children tended to have primary H. pylori gastritis (group 2) or duodenal ulcer without H. pylori (group 3). Antral nodularity was found to be an important specific endoscopic sign, unique to those children with H. pylori disease. It has not been described in adult H. pylori disease. Non-Caucasian children, especially Native Indians, in British Columbia have more prevalent and more severe H. pylori disease than Caucasians. Endoscopy with gastric antral biopsies is necessary to distinguish different types of duodenal ulcer disease and to diagnose primary H. pylori gastritis.

Adolescent↗
PubMed1991

Severe perinatal liver disease and Down syndrome: an apparent relationship.

Down syndrome (DS) is not usually thought of in association with significant infantile liver disease. We present clinical and histopathologic data from 10 patients with DS who presented with severe liver disease at birth or within the first few weeks of life, and summarize the findings of eight previously reported cases. The liver disease was fatal in all but one case. Diffuse lobular fibrosis surrounding proliferating ductular elements and residual hepatocytes characterized the pathologic findings in the liver in all patients. A large number of megakaryocytes were present in the liver in nine of 12 patients. The phenotype of "perinatal hemochromatosis" was documented in eight of nine cases in which the presence of iron was investigated. Since only a fraction of the patients with this phenotype have DS, the patients we describe seem to represent a relatively well-defined subset of the perinatal hemochromatosis phenotype. The existence of such a subset suggests that the perinatal hemochromatosis phenotype does not represent a single etiopathogenetic disorder. The association between DS, megakaryocytic infiltrates in the liver, and fatal subacute/chronic liver disease gives rise to the speculation that fibrosis-promoting factors and/or metabolic abnormalities, such as those resulting from a gene dosage effect, may play a role in the genesis of the liver disease, perhaps due to a particular susceptibility of fetal liver.

Down Syndrome↗
PubMed1990

Neuroblastoma in a child with Wiedemann-Beckwith syndrome.

We report on a patient with Wiedemann-Beckwith syndrome (WBS) who developed abdominal neuroblastoma. Although WBS patients are known to have a higher incidence of embryonal tumors, this is only the 4th known case of neuroblastoma associated with this syndrome. Chromosomes on peripheral lymphocytes and tumor cells were normal. Children with WBS should be screened for a variety of embryonal neoplasms, not only Wilms tumor.

Abdominal Neoplasms↗
PubMed1990

Postoperative intussusception in a premature infant.

Intussusception occurs most commonly between the fifth and ninth month of life. Affected infants are usually healthy and born at full gestation age. We describe a case of intussusception occurring in a 10-day-old, 700-g neonate born at 28 weeks' gestation. The diagnosis was made at laparotomy 7 days after colostomy for imperforate anus. There were three associated bowel perforations. This case demonstrates that postoperative intussusception can occur in the premature infant. It also serves to illustrate the difficulty in making the diagnosis preoperatively.

Anus, Imperforate↗
PubMed1990

Acute aluminum toxicity after continuous intravesical alum irrigation for hemorrhagic cystitis.

An encephalopathy and cardiomyopathy developed in a seventeen-year-old girl with chemotherapy-induced renal failure while receiving an intravesical aluminum infusion for hemorrhagic cystitis. Premortem serum and postmortem tissue aluminum levels were markedly elevated. It is likely that her inability to excrete absorbed aluminum contributed to her death. Aluminum infusions should be used with caution in patients with renal failure.

Administration, Intravesical↗
PubMed1990

Congenital rubella syndrome associated with calcific epiphyseal stippling and peroxisomal dysfunction.

An infant girl had the clinical and immunologic findings of congenital rubella syndrome but also had arthrogryposis multiplex and calcific epiphyseal stippling. Spastic quadriparesis developed, and both physical and behavioral development were slow. Increased spasticity of the legs at 5 1/2 years was related not to progressive rubella encephalomyelopathy but to spinal cord compression by abnormal cartilaginous tissue. The presence of a peroxisomal disorder was demonstrated by a greatly increased level of phytanic acid and slightly increased levels of hexacosanoate in serum and by reduced activity of peroxisomal dihydroxyacetone phosphate acyltransferase and a slightly increased ratio of cytosolic to peroxisomal catalase activity in cultured fibroblasts. A reduction in the number and size of peroxisomes was demonstrated in cultured fibroblasts, and a needle biopsy specimen of the liver also showed the peroxisomes to have a smaller diameter than usual. We recommend that any child with epiphyseal stippling be assessed for peroxisomal disease and that the potential for spinal cord compression by dysplastic bone or cartilage be recognized. The association of peroxisomal dysfunction with congenital rubella has not been described previously. The interaction between rubella virus infection and peroxisomal function may need further investigation.

Calcinosis↗
PubMed1990

The high incidence of valproate hepatotoxicity in infants may relate to familial metabolic defects.

The incidence of fatal hepatic failure associated with valproic acid (VPA) therapy is highest in children under the age of three years, particularly in those with developmental delay. The pathogenesis of VPA hepatotoxicity is unclear but may relate to the accumulation of a toxic metabolite of VPA which impairs fatty-acid oxidation. We describe two unrelated infants with developmental delay who developed hepatic failure while receiving VPA. Siblings of both children subsequently developed hepatic steatosis and intractable seizures without being exposed to VPA. This suggests that the two children who developed liver failure when receiving VPA may have had a familial metabolic disorder. Familial metabolic disorders may account partly for the higher incidence of fatal hepatotoxicity described in infants receiving VPA.

Chemical and Drug Induced Liver Injury↗