Biomedical subjects

Harry L Malech

Publications and source records attributed to Harry L Malech.

40 records · Page 3Linked to original sources

PubMed2002

CYBB mutation analysis in X-linked chronic granulomatous disease.

Chronic granulomatous disease (CGD) results from mutations of phagocyte NADPH oxidase. Seventy percent are X-linked (X-)CGD with absent or defective gp91(phox) protein encoded by the CYBB gene. A subset of X-CGD patients demonstrates partial oxidase activity and/or varied levels of the gp91(phox) protein. Definitive genotypic diagnosis in these unusual patients requires mutation analysis. Typically, CYBB mutation analysis has relied on initial screening of cDNA by single-stranded conformation polymorphism analysis, followed by selective sequencing. We report a fluorescent, automated method for CYBB mutation analysis using genomic DNA that provides more rapid and reliable results. Moreover, the use of genomic DNA in this approach allows mutation detection in the mRNA coding region, promoter/enhancer region, and intronic sequences flanking splice junctions and does not require mRNA preparation. The PCR conditions were optimized for each exon, including those with A+T-rich regions. We analyzed DNA from two unusual X-CGD patients and established the genetic basis for their phenotype. We also sequenced 100 normal X chromosomes to establish wild-type consensus sequences and identify polymorphisms.

Base Sequence↗

PubMed2002

Characterization of an early dendritic cell precursor derived from murine lineage-negative hematopoietic progenitor cells.

OBJECTIVE: We define characteristics of a dendritic cell (DC) precursor generated from murine lineage-negative (Lin(-)) Sca1(+) hematopoietic progenitor cells (HPC). MATERIALS AND METHODS: Lin(-)Sca1(+) HPC cultured 9 days in 100 ng/mL stem cell factor (SCF), 20 ng/mL interleukin-3 (IL-3), 50 ng/mL monocyte colony-stimulating factor (M-CSF), 5 ng/mL granulocyte-monocyte colony-stimulating factor (GM-CSF), and 25 ng/mL FLT3-ligand (FLT3-L) proliferate 387-fold and differentiate into DC precursors. Switch to > or =100 ng/mL GM-CSF + 1500 U/mL IL-4 or 500 U/mL tumor necrosis factor-alpha (TNF-alpha) for 3 days induces development into immature DC that are responsive to bacterial lipopolysaccharide (LPS)-induced maturation. RESULTS: Lin(-)Sca1(+) HPC in the first 9 days of culture differentiate into DC precursors expressing surface CD11b(bright), CD11c(mod), CD86(low-mod), major histocompatibility class II antigen (MHC) II(low), DEC 205(low), but are surface CD40(-) and contain high levels of intracellular MHC II. Unlike immature DC described by others, these DC precursors are refractory to maturation with LPS and minimally stimulate allogeneic T lymphocytes in mixed leukocyte reactions (MLR). Switch to high-dose GM-CSF alone with IL-4 or TNF-alpha differentiates these DC precursors into immature DC. LPS treatment of the immature DC results in mature DC that express surface CD40(high) and CD86(high), secrete IL-1beta and IL-12, and strongly stimulate MLR. CONCLUSIONS: These studies define a distinct DC precursor derived from murine HPC that precedes development of immature and mature DC.

Analysis of Variance↗

PubMed2002

Hepatic abscess in patients with chronic granulomatous disease.

OBJECTIVE: To evaluate the clinical presentation, diagnostic procedures, and surgical management of hepatic abscesses in patients with chronic granulomatous disease (CGD). SUMMARY BACKGROUND DATA: Chronic granulomatous disease is a rare inherited primary immunodeficiency in which phagocytes cannot destroy catalase-positive bacteria and fungi. Defects in the phagocytic cells' respiratory burst lead to life-threatening infections, including hepatic abscess. These abscesses are recurrent and often multiple and are treated differently from bacterial abscesses in patients without CGD. METHODS: Between 1980 and 2000, 61 cases of hepatic abscess in 22 patients with CGD were treated at the National Institutes of Health. Clinicopathologic features were investigated by retrospective review of the medical records, radiographs, and histopathology. RESULTS: Twelve of the 61 cases were primary hepatic abscesses. Twenty-nine of the cases were recurrent hepatic abscesses, and 20 cases were persistent hepatic abscesses. The median age at the time of initial hepatic abscess presentation was 14 years. Subjective fever was the most frequent presenting symptom, and the erythrocyte sedimentation rate was elevated in 98% of cases. Fifty-two cases were managed surgically and eight cases were managed with percutaneous drainage. One patient refused surgery. The surgical complication rate was 56%; however, there were no deaths directly related to the hepatic abscesses. Staphylococcus aureus was the most frequent organism identified in culture (88% of positive cultures). Aggressive surgery and antibiotics ultimately resulted in successful treatment of all patients. CONCLUSIONS: Hepatic abscesses occurring in patients with CGD represent a difficult diagnostic and treatment challenge. Early excision and treatment with antibiotics directed against S. aureus is necessary. General surgeons should be aware of this rare immunodeficiency and should aggressively manage hepatic abscesses in these patients.

Adolescent↗

PubMedDate not supplied

Cognitive function in patients with chronic granulomatous disease: a preliminary report.

Chronic granulomatous disease is an inherited immunodeficiency in which phagocytes fail to generate superoxide and its metabolites, resulting in severe recurrent infections and frequent hospitalizations. Chronic illness and frequent hospitalizations can affect growth and development as well as social and educational opportunities. Since no data have been reported on cognitive functioning in patients with this illness, the authors sought to examine cognitive function in a group of patients with chronic granulomatous disease. A retrospective chart review of 26 patients seen and followed at the National Institutes of Health who had received cognitive testing at the request of parent or staff was performed. Demographic information including medical, psychiatric, and developmental histories was gathered. Six patients (23%) were found to have an IQ of 70 or below, indicative of cognitive deficits, and all of those patients had defects in the membrane-linked cytochrome b558. The prevalence of cognitive deficits in this selected population of chronic granulomatous disease patients was high. The determination of the true distribution of cognitive functioning in the general chronic granulomatous disease population is important, since cognitive deficits have implications for educational planning and potential therapies such as transplantation and gene therapy in children.

Adolescent↗