Defective hematopoiesis and hepatic steatosis in mice with combined deficiencies of the genes encoding Fancc and Cu/Zn superoxide dismutase.

Several lines of evidence point to an abnormality in the response of Fanconi anemia cells to reactive oxygen species. To investigate the potential pathologic consequences of an in vivo alteration of redox state in mice lacking one of the Fanconi anemia genes, animals were generated having combined deficiencies of the cytosolic Cu/Zn superoxide dismutase (Sod1) and Fanconi anemia complementation group C (Fancc) genes. Interestingly, hepatocytes of Fancc(-/-)Sod1(-/-) mice exhibited a zonal pattern of microvesicular steatosis, possibly as a result of oxidative stress-induced injury to hepatocyte membranes. Consistent with this idea, freshly explanted Fancc(-/-)Sod1(-/-) hepatocytes demonstrated increased spontaneous production of superoxide in vitro. The second phenotypic feature of Fancc(-/-) Sod1(-/-) mice was that of bone marrow hypocellularity accompanied by significant decreases in peripheral blood erythrocyte and leukocyte numbers as compared with wild-type controls. Although flow cytometry analysis with monoclonal antibodies against cell surface antigens revealed normal numbers of primitive hematopoietic progenitor populations in Fancc(-/-)Sod1(-/-) marrow, lineage-positive progenitor numbers were significantly reduced in these mice. Furthermore, the in vitro clonogenic growth of Fancc(-/-)Sod1(-/-) erythroid, myeloid, and early B-lymphoid colonies in semisolid media was profoundly compromised. These results suggested that the altered redox state likely present in Fancc(-/-) Sod1(-/-) hematopoietic progenitors was responsible for an impairment of cell proliferation or survival. (Blood. 2001;98:1003-1011)

Spectrum of gastritis in celiac disease in childhood.

Celiac disease (CD) may cause changes throughout the gastrointestinal tract. The pathology is best described in the distal duodenum and jejunum. It is also associated with lymphocytic gastritis (LG) and varioliform gastritis in adults and children, but the histologic spectrum in the gastric biopsy and the clinical implications are undefined. In this report we relate our experience with the clinical, endoscopic, and histologic changes in gastric biopsies in CD in childhood. Slides (hematoxylin and eosin stained) were reviewed from 33 celiac children, 5 having had more than 1 gastric biopsy during a 7-year period. Gastric intraepithelial lymphocyte (IEL) counts were compared with those of 10 histologically normal controls (normal range, 1-7 IEL/100 antral or body epithelial cells) and 10 nonceliac chronic gastritis (CG) biopsies without H. pylori (normal range, 1-19 IEL/100 antral cells), noting changes in the epithelium and lamina propria (LP). LG was present in 29/33 initial biopsy sets. Fifteen of 29 showed LG/CG. The IEL number was greater in LG/CG than in LG only (27.2 +/- 9.3, n = 14 vs. 18.6 +/- 13.4, n = 15 in the antrum; 23.5 +/- 2.8, n = 4 vs. 13.0 +/- 8.4 in the body). In CD the difference between these mean values and those of normal and nonceliac CG controls was statistically significant. In CG/LG the inflammatory infiltrate was predominantly diffuse/superficial in the LP; mucin depletion was noted in 11/15. The IELs were in the LG/CG range in two CG controls. The IELs were normal at follow-up in five cases. There were no statistically significant differences between the groups with respect to clinical parameters or gastric endoscopic findings. No child had varioliform gastritis. We conclude that in CD children, the stomach is endoscopically unremarkable but may show LG, or LG/CG with or without mucin depletion, or occasionally appear normal. Gastric histology returned to normal with gluten withdrawal. Normal gastric histology is not typical, but does not exclude CD.

Biliary atresia and cytomegalovirus infection: a DNA study.

The cause of extrahepatic biliary atresia (EHBA) is undetermined in most instances, but an infectious agent is widely suspected. Cytomegalovirus (CMV) infection has been associated with intrahepatic bile duct destruction and paucity, raising the question of its role in EHBA. We identified 12 children in the past 5 years with biliary atresia and examined the bile duct biopsy. These showed acute/chronic inflammation and epithelial degeneration. CMV inclusions were not identified. We used in situ hybridization and the polymerase chain reaction (PCR) for CMV-DNA on formalin-fixed, paraffin-embedded tissue. All samples showed the presence of amplifiable DNA using beta-globin primers. No biopsy tissue showed CMV DNA using specific probes and primers. The absence of demonstrable CMV DNA by in situ hybridization and PCR in EHBA biopsies implies that it is unlikely that this virus has any major role in the pathogenesis of this condition.

Histopathologic approach to metabolic liver disease: Part 2.

In this, part 2 of the histopathologic approach to the diagnosis of metabolic disease of the liver, the steatotic, cirrhotic, and neoplastic groups are addressed. See the previous issue, Volume 1, Number 3, of Pediatric and Developmental Pathology for part 1 [1]. The perspective concludes with a tabulated assessment of the likelihood of diagnostic ascertainment.

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.

Mucin histochemistry of the developing gastroesophageal junction.

Mucin histochemistry was performed on the squamocolumnar junction (Z-line) of the gastroesophageal region of 49 autopsied previable fetuses, stillbirths, infants, and young children, using alcian blue pH 2.5/periodic acid-Schiff (PAS) and alcian blue pH 1.0/PAS stains. Sialylated and neutral mucins were present in most and sulfated mucin in many cases. In only one fetus was a heterotopic focus of goblet cells found in the distal esophagus. This study confirms that the presence of acidic mucins in columnar epithelium, without goblet cells, at the Z-line and adjacent cardia is common in this age group. Undue reliance on mucin stains to identify metaplastic columnar epithelium, in the absence of goblet cells, may result in overdiagnosis of Barrett's esophagus in children.

A model to begin reengineering the laboratory. How do you change an outmoded laboratory structure?

If a traditionally structured laboratory cannot incorporate new technologies efficiently and can no longer meet its changing service demands, it may require reengineering. A model is presented that can be followed by the laboratory director and a small group of planning colleagues to begin the process. The model was effectively used at British Columbia's Children's and Women's Hospitals (BCCH/WH) to review their laboratory structure and redraft it for the future. The model considers the external and internal pressures facing the laboratory. Technological trends, which have significant impact on laboratory service, are also incorporated into the model. The current list of services, staff expertise, and laboratory specialties is used as the base in the model to formulate the opportunities for improvements and identify the future direction of the laboratory. These opportunities are the context for the vision of the future laboratory. With this vision in mind and a creative planning approach, a new optimum laboratory structure can be outlined. This model begins the reengineering process and can be applied to any laboratory where there is the need for dramatic improvements to accommodate the changes in today's rapidly evolving health-care environment.

Strategies for a successful organizational transition. Identifying staff roles and fulfilling their needs during changing times.

For a successful reorganization of the laboratory, there is a role for each staff member to play during the transition. The role of those in laboratory administration is that of leading change agent. Corporate support staff, such as those in a human resources department, can advise the laboratory director in their areas of expertise. The role of the medical and technical supervisory staff is that of chief implementers of the plan. General laboratory staff has a confusing dual role--not only must they continue to provide laboratory services during the transition, but they also may have to change what they are doing and how they are doing it. Success also depends on meeting the individual personal needs of staff. Laboratory directors and administrators want to make a meaningful contribution to health care. Corporate support staff need to feel that they are a part of the change process. Supervisors' needs vary--coping with the loss of identity, position, or territory will be difficult for some; others will want to be involved in all stages of planning and implementation. The major need of the general laboratory staff is stability. Strategies are listed for each staff grouping to help the laboratory director coordinate staff roles and satisfy staff needs during the transition period.

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.

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.

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.

Rhabdomyosarcoma arising within congenital pulmonary cysts: report of three cases.

Over the past 9 months, three cases of primary pulmonary rhabdomyosarcoma have been treated at British Columbia Children's Hospital. Two patients (aged 24 and 37 months) presented with spontaneous pneumothoraces and had cystic changes in the affected lung on chest radiograph. The third patient (aged 42 months) was evaluated for chronic cough, fever, and failure to thrive. Chest x-ray showed a large mass in the left lower lobe as well as mediastinal adenopathy. All three of these lesions originated within congenital lung cysts, one a peripheral bronchogenic cyst and the others cystic adenomatoid malformations. This report suggests that there is a significant risk for the development of rhabdomyosarcoma within malformed pulmonary tissue.

King syndrome: a genetically heterogenous phenotype due to congenital myopathies.

We report on a patient with myopathy, kyphoscoliosis, joint contractures, and a facial appearance consistent with King syndrome. Unlike other reported cases, our patient had hyperextensible joints, normal stature, and pectus excavatum. The cardiac ventricles, aorta, and pulmonary artery were dilated. Malignant hyperthermia did not occur under anaesthesia although there was a transient increase in CK levels. Muscle bulk and tone were significantly decreased but collagen and elastin fibres were normal. The variable clinical presentation of King syndrome suggests that the manifestations are caused by different congenital myopathies and in all cases there is probably an increased risk of malignant hyperthermia.

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.