ALBERT

Description: Plasma fibronectin augments the clearance of blood-borne foreign and effete complexes by mononuclear phagocytes. The release of a “gelatin- like” ligand into plasma after thermal injury has been reported. We quantified the release of this collagenous debris from thermally injured skin, and its potential interaction with soluble fibronectin in plasma using anesthetized rats. Collagen-like material debris in the plasma was detected by assay of hydroxyproline. Fibronectin was measured by a double antibody enzyme-linked immunosorbent assay (ELISA) technique. Over a 24-hour postburn interval, plasma hydroxyproline increased from 6.7 +/- 0.6 micrograms/mL to a maximum of 19.0 +/- 3.3 micrograms/mL at 60 minutes postburn, and normalized by 6 hours. A direct correlation existed between the magnitude of burn injury and the increase in plasma hydroxyproline. In parallel, plasma fibronectin declined over a 15-minute to 2-hour period postburn, and normalized by 3 to 4 hours with rebound hyperfibronectinemia observed at 24 hours. The elevation in total plasma hydroxyproline was not due to an increase in plasma Clq (zero time, 26.2 +/- 1.4 micrograms/mL; 60 minutes, 23.9 +/- 1.1 micrograms/mL). Tracer studies with 125I-fibronectin showed that the acute decline of plasma fibronectin was due to its uptake by the liver and binding to sites of tissue injury. Total hydroxyproline in extracts of burn skin, used as an index of soluble collagenous material, rose from 15 +/- 3.3 micrograms/g skin at zero time to 129.3 +/- 43.7 micrograms/g skin by 5 minutes postburn, with a decline to 38 +/- 22 micrograms/g skin by 24 hours. The formation of circulating fibronectin-gelatin complexes in vivo was documented by cross- immunoelectrophoresis coupled with autoradiography using 125I-gelatin as a model ligand. Thus, collagenous tissue debris from burned skin may enter the plasma after thermal injury and directly complexes with soluble fibronectin before hepatic phagocytic clearance.

Description: We have analyzed the binding of Sp1, a ubiquitously expressed transactivator, to the promoter region of the gamma genes. Low-affinity Sp1 sites were found at -50 and -200. A high-affinity site was detected at -140, over the CACCC sequence. To analyze the function of these sites, Drosophila SL-2 cells, which lack Sp1, were cotransfected with an Sp1 expression plasmid and gamma globin promoter-CAT constructs. In these assays, the gamma promoter was significantly stronger in the presence than in the absence of Sp1. Thus, the three Sp1 sites in the gamma promoter allow binding as well as transactivation of the promoter. The majority of this transactivation was due to the strong binding site at -140 because introduction of a point mutation at -144 (CACCC----AACCC) reduced Sp1-dependent promoter strength by 57%. Analysis of the -200 region suggested that in the wild-type promoter, Sp1 binding at this site contributes little to promoter strength. However, a point mutation (-198 T----C) associated with hereditary persistence of fetal hemoglobin (HPFH) dramatically increased the affinity of this site for Sp1 and significantly increased Sp1 dependent promoter strength in SL-2 cells. Three other point mutations associated with HPFH did not significantly affect the interaction of Sp1 with the - 200 region.

Description: We have used a single-cell based polymerase chain reaction (PCR) amplification technique to examine the gene expression pattern in single Hodgkin's and Reed-Sternberg (H&RS) cells from seven patients with Hodgkin's disease. Single cells were isolated from lymph nodes obtained at diagnosis (5 of 7 patients) or in first or second relapse (2 of 7 patients). Gene expression was examined by hybridization to a panel of 22 cDNA probes. Forty-nine H&RS cells (and 23 CD3+ or CD20+ lymphocytes as controls) from four patients with nodular sclerosing Hodgkin's disease (HD) and one patient each with lymphocyte predominant and mixed-cellularity HD were successfully analyzed by PCR. This analysis provides evidence that single H&RS cells can coexpress genes characteristic of several hematopoietic lineages (monocytes and lymphocytes). Genes characteristic of activated lymphoid cells are expressed in most H&RS cells. Heterogeneity of expression for certain genes between different cases was found and may eventually define molecular subgroups of HD. These findings indicate that H&RS cells of HD resemble activated hematopoietic cells. Phenotypically similar cells from different cases exhibit characteristic molecular differences. In one patient, 5 of 7 single RS cells showed identical p53 cDNA mutations at codon 246 on specific reverse transcriptase [RT]-PCR and sequencing of exons 5 through 8. The novel experimental approach may provide a valuable tool for understanding the molecular events in newly diagnosed Hodgkin's disease and progression of the disease.

Description: We have analyzed the binding of Sp1, a ubiquitously expressed transactivator, to the promoter region of the gamma genes. Low-affinity Sp1 sites were found at -50 and -200. A high-affinity site was detected at -140, over the CACCC sequence. To analyze the function of these sites, Drosophila SL-2 cells, which lack Sp1, were cotransfected with an Sp1 expression plasmid and gamma globin promoter-CAT constructs. In these assays, the gamma promoter was significantly stronger in the presence than in the absence of Sp1. Thus, the three Sp1 sites in the gamma promoter allow binding as well as transactivation of the promoter. The majority of this transactivation was due to the strong binding site at -140 because introduction of a point mutation at -144 (CACCC----AACCC) reduced Sp1-dependent promoter strength by 57%. Analysis of the -200 region suggested that in the wild-type promoter, Sp1 binding at this site contributes little to promoter strength. However, a point mutation (-198 T----C) associated with hereditary persistence of fetal hemoglobin (HPFH) dramatically increased the affinity of this site for Sp1 and significantly increased Sp1 dependent promoter strength in SL-2 cells. Three other point mutations associated with HPFH did not significantly affect the interaction of Sp1 with the - 200 region.

Description: Numerous independent and interdependent factors are involved in the posttransfusion platelet response. Factors such as ABO match and platelet age are related to circumstances potentially under the control of the blood bank physician and therefore may permit circumvention by an active transfusion service. On the other hand, factors such as fever or sepsis may be unavoidable, being related more to the individual patient or clinical condition. To evaluate which factors could be circumvented, we prospectively followed the 1-hour corrected count increments (CCIs) for 962 single-donor apheresis platelet transfusions to 71 refractory hematologic oncology inpatients, with concomitant recording of implicated factors. Stepwise regression analysis allowed for determination of which concurrent and confounding clinical-, patient-, and blood bank-related factors significantly affected the CCIs. Although many implicated factors proved to be independently associated with an increased or decreased CCI, we found that no single variable consistently explained the CCI variation across the patient population. Each patient appeared sensitive to one or a few particular factors, but because of marked intraindividual variation, it was not possible to identify a priori which factors were important for a given patient. The single exception was a solid-phase red blood cell adherence assay used to cross-match platelets, but only for alloimmunized patients. We also evaluated the utility of requesting HLA- matched platelets from the local suppliers and maintained a clear distinction between platelets simply ordered as HLA matched and actually HLA-identical platelets. Accounting for the confounding clinical-, patient-, and blood bank-related factors, the cross-match assay was a better predictor of an adequate CCI than ordering platelets as HLA matched.

Description: Plasma fibronectin augments the clearance of blood-borne foreign and effete complexes by mononuclear phagocytes. The release of a “gelatin- like” ligand into plasma after thermal injury has been reported. We quantified the release of this collagenous debris from thermally injured skin, and its potential interaction with soluble fibronectin in plasma using anesthetized rats. Collagen-like material debris in the plasma was detected by assay of hydroxyproline. Fibronectin was measured by a double antibody enzyme-linked immunosorbent assay (ELISA) technique. Over a 24-hour postburn interval, plasma hydroxyproline increased from 6.7 +/- 0.6 micrograms/mL to a maximum of 19.0 +/- 3.3 micrograms/mL at 60 minutes postburn, and normalized by 6 hours. A direct correlation existed between the magnitude of burn injury and the increase in plasma hydroxyproline. In parallel, plasma fibronectin declined over a 15-minute to 2-hour period postburn, and normalized by 3 to 4 hours with rebound hyperfibronectinemia observed at 24 hours. The elevation in total plasma hydroxyproline was not due to an increase in plasma Clq (zero time, 26.2 +/- 1.4 micrograms/mL; 60 minutes, 23.9 +/- 1.1 micrograms/mL). Tracer studies with 125I-fibronectin showed that the acute decline of plasma fibronectin was due to its uptake by the liver and binding to sites of tissue injury. Total hydroxyproline in extracts of burn skin, used as an index of soluble collagenous material, rose from 15 +/- 3.3 micrograms/g skin at zero time to 129.3 +/- 43.7 micrograms/g skin by 5 minutes postburn, with a decline to 38 +/- 22 micrograms/g skin by 24 hours. The formation of circulating fibronectin-gelatin complexes in vivo was documented by cross- immunoelectrophoresis coupled with autoradiography using 125I-gelatin as a model ligand. Thus, collagenous tissue debris from burned skin may enter the plasma after thermal injury and directly complexes with soluble fibronectin before hepatic phagocytic clearance.

Description: We have used a single-cell based polymerase chain reaction (PCR) amplification technique to examine the gene expression pattern in single Hodgkin's and Reed-Sternberg (H&RS) cells from seven patients with Hodgkin's disease. Single cells were isolated from lymph nodes obtained at diagnosis (5 of 7 patients) or in first or second relapse (2 of 7 patients). Gene expression was examined by hybridization to a panel of 22 cDNA probes. Forty-nine H&RS cells (and 23 CD3+ or CD20+ lymphocytes as controls) from four patients with nodular sclerosing Hodgkin's disease (HD) and one patient each with lymphocyte predominant and mixed-cellularity HD were successfully analyzed by PCR. This analysis provides evidence that single H&RS cells can coexpress genes characteristic of several hematopoietic lineages (monocytes and lymphocytes). Genes characteristic of activated lymphoid cells are expressed in most H&RS cells. Heterogeneity of expression for certain genes between different cases was found and may eventually define molecular subgroups of HD. These findings indicate that H&RS cells of HD resemble activated hematopoietic cells. Phenotypically similar cells from different cases exhibit characteristic molecular differences. In one patient, 5 of 7 single RS cells showed identical p53 cDNA mutations at codon 246 on specific reverse transcriptase [RT]-PCR and sequencing of exons 5 through 8. The novel experimental approach may provide a valuable tool for understanding the molecular events in newly diagnosed Hodgkin's disease and progression of the disease.

Description: Numerous independent and interdependent factors are involved in the posttransfusion platelet response. Factors such as ABO match and platelet age are related to circumstances potentially under the control of the blood bank physician and therefore may permit circumvention by an active transfusion service. On the other hand, factors such as fever or sepsis may be unavoidable, being related more to the individual patient or clinical condition. To evaluate which factors could be circumvented, we prospectively followed the 1-hour corrected count increments (CCIs) for 962 single-donor apheresis platelet transfusions to 71 refractory hematologic oncology inpatients, with concomitant recording of implicated factors. Stepwise regression analysis allowed for determination of which concurrent and confounding clinical-, patient-, and blood bank-related factors significantly affected the CCIs. Although many implicated factors proved to be independently associated with an increased or decreased CCI, we found that no single variable consistently explained the CCI variation across the patient population. Each patient appeared sensitive to one or a few particular factors, but because of marked intraindividual variation, it was not possible to identify a priori which factors were important for a given patient. The single exception was a solid-phase red blood cell adherence assay used to cross-match platelets, but only for alloimmunized patients. We also evaluated the utility of requesting HLA- matched platelets from the local suppliers and maintained a clear distinction between platelets simply ordered as HLA matched and actually HLA-identical platelets. Accounting for the confounding clinical-, patient-, and blood bank-related factors, the cross-match assay was a better predictor of an adequate CCI than ordering platelets as HLA matched.