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Biomedical subjects

D Williams

Publications and source records attributed to D Williams.

At least 469 records · Page 26Linked to original sources
PubMed1987

Childhood monosomy 7 syndrome: clinical and in vitro studies.

The clinical and cell growth characteristics of 11 children with monosomy 7 presenting as preleukemia (eight cases) or acute nonlymphoblastic leukemia (three cases) were studied. Anemia was common to all patients, with nine showing leukocytosis, seven thrombocytopenia, and one thrombocytosis. There was a striking predominance of males (M/F ratio, 10:1) and a young median age (3 years). Preleukemia evolved to acute nonlymphoblastic leukemia in five patients and to myelofibrosis in one. In vitro studies of bone marrow progenitor cells cultured in leukocyte feeder-stimulated agar revealed abnormal cell proliferative patterns, most often an increased number of small clusters, for all 11 subjects. The cells of some preleukemic patients showed increased growth even in the absence of an exogenous source of colony-stimulating factor, suggesting autonomous growth or possibly autocrine stimulation. Combination chemotherapy or bone marrow transplantation failed to induce complete remission in the seven patients who were treated. Our findings in these 11 cases confirm the poor prognosis of monosomy 7 presenting as preleukemia in children. The in vitro studies suggest an association between altered cell growth in vitro and clinical evolution to frank leukemia.

Acute Disease↗
PubMed1986

Deletion on the X chromosome detected by direct DNA analysis in one of two unrelated boys with glycerol kinase deficiency, adrenal hypoplasia, and Duchenne muscular dystrophy.

In studies of the X chromosomes of two unrelated boys with adrenal hypoplasia, glycerol kinase deficiency, Duchenne muscular dystrophy, and mental retardation, conventional G banding did not reveal any numerical or structural abnormality, but direct DNA analysis with the X short-arm probes 754, C7, and OCT revealed a deletion in 1 of these patients. It is likely that both boys have a deletion at Xp21 affecting a number of closely linked disease-specific gene loci.

Adrenal Insufficiency↗
PubMed1986

Transmission of hepatitis B with resultant restriction of surgical practice.

Five patients developed acute hepatitis B (HB) within four months after major operations by the same obstetric-gynecologic surgeon. Investigation documented that the surgeon was HB surface antigen and HB e antigen positive; all five patients had an HB subtype matching that of the surgeon and no other identifiable risk factors for HB viral infection. A seroprevalence study comparing exposed surgical and obstetric patients with a control group showed no significant additional subclinical HB transmission. The surgeon resumed his surgical practice but was required to obtain written informed consent from patients, to double-glove, and to employ appropriate surgical techniques to avoid self-injury. Seven months later, acute HB occurred in a patient two months after a cesarean section, resulting in exclusion of the surgeon from major operations. This is the fifth outbreak of nosocomial HB linked to an obstetric-gynecologic surgeon, and it reinforces the need for health care workers to receive preexposure prophylaxis with HB vaccine to prevent such occurrences.

Carrier State↗
PubMed1986

Pericardial abscess: diagnosis using two-dimensional echocardiography and CT.

Two cases of pericardial abscess were identified preoperatively using two-dimensional echocardiography and computed tomography (CT). In one patient the diagnosis was confirmed by needle aspiration of pus under CT guidance. Findings in both cases were similar, which suggests a common pathogenetic mechanism. Because purulent pericardial fluid collections are an uncommon condition associated with a high mortality, early echocardiography and if necessary CT should be performed, as prompt institution of appropriate therapy is the best hope for decreasing mortality.

Abscess↗
PubMed1986

The Overt Aggression Scale for the objective rating of verbal and physical aggression.

The authors describe the design and reliability of a rating scale that measures aggressive behaviors in adults and children. On the Overt Aggression Scale (OAS), aggression is divided into four categories: verbal aggression, physical aggression against objects, physical aggression against self, and physical aggression against others. In addition, specific interventions related to each aggressive event can be recorded on the OAS. The clinical and research applications of this scale are discussed.

Adolescent↗
PubMed1986

Uptake of [3H]vitamin D3 from low and high density lipoproteins by cultured human fibroblasts.

The plasma distribution and cellular uptake of [3H]vitamin D3 was studied in vitro using cultured human fibroblasts. Incubation of [3H]vitamin D3 (cholecalciferol) with plasma followed by sequential ultracentrifugal fractionation of the lipoproteins indicated that 2-4% of the radioactivity associated with the very low density lipoprotein (VLDL), 12% with low density lipoprotein (LDL), and approximately 60% with the high density lipoprotein (HDL). The remaining radioactivity, 25%, was associated with the sedimented plasma fractions. By comparison, an average of 86% of the radioactivity from [3H]1,25-dihydroxycholecalciferol associated with the sedimented plasma fractions. The uptake of [3H]vitamin D3 from plasma, LDL, or HDL was studied in cultured human cells; uptake by normal fibroblasts was greatest from LDL and least from plasma. The cellular association of vitamin D3 was time, concentration, and temperature dependent. At a concentration of 50 micrograms LDL/ml of medium, the uptake of [3H]vitamin D3 from LDL at 37 degrees C was rapid and reached a maximum at approximately 4 hr; it was slower from HDL but continued to increase slowly up to 24 hr. The significance of these in vitro findings is uncertain since much of the vitamin D3 absorbed from the intestine reportedly associates with chylomicrons and is rapidly taken up by the liver.

Cells, Cultured↗
PubMed1986

Human gamma interferon enhances release from phytohemagglutinin-stimulated T4+ lymphocytes of activities that stimulate colony formation by granulocyte-macrophage, erythroid, and multipotential progenitor cells.

Human gamma interferon (HuIFN gamma) was evaluated for its effects on the release from human peripheral blood T lymphocytes (greater than 98% pure) stimulated by phytohemagglutinin (PHA) of activities that can stimulate granulocyte-macrophage (CFU-GM) colonies and clusters, erythroid (BFU-E) bursts, and mixed (CFU-GEMM) colonies. T lymphocytes did not release these activities in the absence of PHA with or without HuIFN gamma. In the presence of PHA, pure natural HuIFN gamma at concentrations of 0.1 to 100 U/mL significantly enhanced release of these colony-stimulating activities. Although enhanced release of granulocyte-macrophage colony-stimulating activities were noted when T lymphocytes were added to the conditioning medium in the presence of 0.1%, 0.5%, and 1% PHA, enhanced release of burst-promoting and mixed colony activities was seen only in the presence of 0.1% and 0.5% PHA. The enhanced release of colony-stimulating activities was not due to HuIFN gamma-suppression of the release from PHA-stimulated T lymphocytes of suppressor molecules. The enhancing effects of natural HuIFN gamma were neutralized with a monoclonal anti-natural HuIFN gamma, and recombinant HuIFN gamma mimicked the enhancing effects of the natural HuIFN gamma. This enhancing effect was noted only when HuIFN gamma was added with the T lymphocytes and PHA during the first 24 hours of incubation. T lymphocytes were separated into T4+, T8-, T8+, and T4- subsets (greater than 98% pure for the appropriate phenotypes) after incubation with OKT4- and OKT8- monoclonal antibodies and sorting on a fluorescence-activated cell sorter (FACS). All types of colony-stimulating activities were released from each population after stimulation with PHA, but enhanced release of these activities in the presence of HuIFN gamma was only detected with the T4+ or T8- subsets of lymphocytes. It cannot be concluded from these studies whether HuIFN gamma is enhancing the release of one or several types of colony-stimulating activities, but these studies suggest a role for HuIFN gamma and T4+ lymphocyte subsets in the regulation in vitro of the release of colony-stimulating activities.

Colony-Forming Units Assay↗
PubMed1986

Clinical and laboratory characteristics of acute leukemia with the 4;11 translocation.

This report describes the clinical and laboratory features of seven cases of acute leukemia associated with the 4;11 chromosomal translocation. All seven children had acute lymphoblastic leukemia by standard morphologic and cytochemical criteria. Leukemic blasts from six of seven patients were terminal deoxynucleotidyl transferase-positive. Immunologic phenotyping suggested the leukemias were of B cell origin; blasts from five patients expressed HLA-DR and p24 (CD-9 antibody), blasts from three patients expressed B4 (CD-19), and blasts from two patients expressed the common acute lymphoblastic leukemia antigen (CD-10). One patient's leukemic blasts contained cytoplasmic immunoglobulin. Analysis of DNA from four of five patients demonstrated additional evidence of B cell differentiation with heavy-chain immunoglobulin gene rearrangement. When DNA from the four patients with heavy-chain immunoglobulin gene rearrangement was analyzed, one patient's DNA demonstrated light-chain immunoglobulin gene rearrangement. However, flow cytometric analysis of blasts from three patients showed the simultaneous expression of the lymphoid-associated antigen B4 (CD-19) and the myeloid-associated antigen My-1 (X-Hapten). Electron microscopic examination of blasts from one patient that expressed both lymphoid- and myeloid-associated antigens demonstrated ultrastructural characteristics of both lineages. These findings suggest that acute leukemia with the t(4;11) abnormality has mixed lineage characteristics as a result of leukemogenesis in a multipotential progenitor cell or aberrant gene expression later in differentiation. Furthermore, serial analysis of karyotype, immunophenotype, and heavy-chain immunoglobulin genes revealed changes in these biologic markers over time, suggesting continued chromosome rearrangement and gene modulation after the leukemogenic event in cells with the t(4;11).

Acute Disease↗