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Biomedical subjects

C H Packman

Publications and source records attributed to C H Packman.

At least 37 records · Page 2Linked to original sources
PubMed1993

One hundred autotransplants for relapsed or refractory Hodgkin's disease and lymphoma: value of pretransplant disease status for predicting outcome.

PURPOSE: One hundred autotransplants for Hodgkin's disease (HD) or non-Hodgkin's lymphoma (NHL) were examined prospectively to identify variables with prognostic significance. PATIENTS AND METHODS: Ninety-six patients with relapsed or refractory HD or NHL underwent 100 autotransplants. Patients received high-dose carmustine (BCNU), etoposide, cytarabine, and cyclophosphamide (BEAC) followed by unpurged autologous stem-cell rescue. RESULTS: The 3-year actuarial event-free survival (EFS) rate for the 47 HD patients is 49%, with a median followup duration of 2 years. For the 53 NHL patients, the 3-year actuarial EFS rate is 40%, with a median follow-up duration of 19 months. By multivariate analysis, minimal disease on admission (all areas < or = 2 cm) is associated with improved EFS (HD, P = .003, NHL, P = .03). The projected EFS rate for HD patients entering with minimal disease is 70% versus 15% for patients with bulky disease (P = .0001). The projected EFS rate for NHL patients with minimal disease is 48% versus 25% for patients with bulky disease (P = .04). Posttransplant involved-field radiotherapy, administered to 26 of the last 61 patients, was associated with an improved EFS rate for NHL patients (P = .015). The BEAC regimen was well tolerated by patients who entered the study with minimal disease (mortality rate, < 5%), but caused significant toxicity in patients with bulky disease (mortality rate, 25%). CONCLUSION: Disease burden before autotransplantation is an important predictor of regimen-related toxicity and EFS. Posttransplant involved-field radiotherapy may improve outcomes in select patients with NHL. The BEAC regimen is safe and effective, particularly for patients with minimal disease.

Actuarial Analysis↗
PubMed1991

Signal transduction and the regulation of actin conformation during myeloid maturation: studies in HL60 cells.

Maturation of human myeloid cells is associated with quantitative and qualitative changes in protein kinase C (PKC) and increases in N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) receptors, actin, and actin regulatory proteins. We have studied the actin responses and cell shape changes caused by FMLP and its second messenger pathways in HL60 cells undergoing neutrophilic maturation. In uninduced cells, the PKC activators 12-O-tetradecanoyl phorbol-13-acetate (TPA), bryostatin, and 1-oleyl-2-acetylglycerol (OAG) resulted in 15% to 30% decreases in F-actin, whereas FMLP had no effect. Ionomycin had no effect on actin but did cause a 10-fold increase in intracellular calcium. Cells grown for 24 hours in 1% dimethyl sulfoxide (DMSO) acquired the ability to polymerize actin in response to FMLP and ionomycin. TPA continued to cause a decrease in F-actin at 24 hours, but caused an increase in F-actin at 48 to 72 hours of maturation. The PKC inhibitor 1-5-isoquinolinesulfonyl 2-methylpiperazine (H7) partially blocked the F-actin increase caused by TPA in induced cells, but had no effect on the decrease in F-actin caused by TPA in uninduced cells or the increase in F-actin seen in FMLP-treated neutrophils. F-actin rich pseudopods developed following TPA or FMLP stimulation of induced HL60 cells; in uninduced cells neither agent caused pseudopod formation but TPA caused a dramatic loss of surface ruffles. The ability of FMLP and ionomycin to elicit a neutrophil-like actin response in HL60 cells within 24 hours after DMSO treatment shows that the actin regulatory mechanism is mature by that time. The inability of ionomycin to increase F-actin in uninduced cells supports the view that calcium increases alone are insufficient for actin polymerization. The longer maturation time required for HL60 cells to develop an actin polymerization response to TPA compared with FMLP, coupled with the inability of H7 to block the FMLP-mediated F-actin increase in neutrophils, suggests that the F-actin increase caused by FMLP is not mediated solely by PKC. Lastly, the TPA-induced F-actin decrease and shape changes in uninduced HL60 cells, and the longer time required for a "mature" response to TPA, may reflect immaturity in the PKC isoenzyme pattern rather than immaturity of the actin regulatory mechanism.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1991

Acute cell volume changes in anisotonic media affect F-actin content of HL-60 cells.

To investigate the possible role of the cytoskeleton in volume regulatory responses of human promyelocytic leukemic (HL-60) cells, we monitored and modulated the F-actin content of these cells undergoing volume regulation in anisotonic media. Initial volume changes of HL-60 cells suspended in hypertonic media followed a Van't Hoff relationship, and intracellular F-actin content during volume regulatory responses in anisotonic media changed concomitantly as an inverse function of the volume shifts. These F-actin changes were shown to be an explicit function of cell volume and not tonicity of the medium. The data fit with the idea that changes in affinity of actin-binding proteins (ABPs) for actin and/or changes in the overall effective critical concentration of actin occur during acute cell volume changes, producing shifts in the relative amounts of G- and F-actin. Treatment of HL-60 cells with dihydrocytochalasin B (DHB), which perturbs cellular actin assembly, lowered resting levels of intracellular F-actin but did not prevent volume-associated F-actin changes in anisotonic media. Despite the lowered F-actin levels, HL-60 cells in the presence of DHB still undergo normal volume regulatory responses. Thus the absolute amount of intracellular F-actin does not appear to be critical for volume regulation in HL-60 cells.

Actins↗
PubMed1991

Cardiac arrest after autologous marrow infusion.

A 27-year-old woman undergoing autologous bone marrow transplantation for relapsed, refractory Hodgkin's disease developed acute non-cardiogenic pulmonary edema immediately after transfusion of autologous bone marrow. A few similar cases in the literature are identified. Although the precise mechanisms for these rare reactions are not clear, several possibilities including anaphylaxis due to dimethylsulfoxide, leukoagglutination, complement activation, and transient left ventricular dysfunction are proposed and discussed. Features which might allow patients at risk for similar events to be identified include the presence of active pulmonary tumor, and a history of dyspnea and pulmonary infiltrates following transfusion of homologous blood products.

Adult↗
PubMed1990

Control of actin conformation in AML myeloblasts: the effects of bryostatin and TPA.

Protein kinase C (PKC), an enzyme involved in signal transduction, is the receptor for both the tumor-promoting phorbol esters and the anti-neoplastic bryostatins. In many cells, phorbol esters and bryostatins cause similar effects; we have found that both agents increase actin polymerization in neutrophils. In some cells, however, the two agents result in different cell processes; we have found consistently different effects of these agents on actin conformation in myeloblasts obtained from leukemic patients. The patients tested all had increases in F-actin in response to 12-O-tetradecanoylphorbol-13-acetate (TPA) and most had decreases in F-actin in response to bryostatin. The data suggests that leukemic myeloblasts have a different cytoskeletal response to a tumor promoter and an antineoplastic agent despite their common receptor.

Actins↗
PubMed1990

Activation of neutrophils: measurement of actin conformational changes by flow cytometry.

Actin, which comprises approximately 10% of the weight of cytoplasmic protein of neutrophils, is the principal component of the cytoplasmic microfilament lattice. It can exist in either of two physical states, G-actin, which is monomeric, or F-actin, which is polymeric or filamentous. Actin microfilaments support many forms of cell movement. Continuous remodeling of the microfilament lattice, which seems integral to sustained movement, is possible in part because of the ability of actin to change rapidly between its monomeric G-state and its filamentous F-state. Changes in the G- and F-actin equilibrium may be studied by flow analysis using a fluorescent probe which is specific for F-actin, 7-nitrobenz-2-oxa-1,3-diazole-(NBD)-phallacidin. Alterations in neutrophil F-actin have been measured in response to chemotactic agents (e.g., formyl peptides and leukotriene B4), inhibitors of cell movement (e.g., N-ethylmaleimide and cytochalasin B), agents that promote the oxidative burst (e.g., formyl peptides and phorbol esters), and priming agents [e.g., tumor necrosis factor (TNF)]. Measurements may be taken at intervals of a few seconds, allowing comparison of rapid changes in the F-actin content to other rapidly occurring changes, such as altered membrane ion permeability and activation of cellular enzymes. The use of metabolic inhibitors has allowed dissection of some of the biochemical pathways involved in actin assembly in living cells. Although clinical studies are few thus far, the technique has also been used to study basal and stimulated F-actin levels in circulating neutrophils in neonates and in family members of patients with neutrophil-actin dysfunction.

Actins↗
PubMed1988

Protein kinase C modulates actin conformation in human T lymphocytes.

We studied the effect of activators and inhibitors of protein kinase C on actin conformation in human blood lymphocytes by flow cytometry and gel electrophoresis. PMA, 1-oleyl-2-acetyl-glycerol, and mezerein, activators of protein kinase C, caused an increase in lymphocyte F-actin within 2 to 5 min. After stimulation with PMA, lymphocytes formed pseudopods containing an increased concentration of F-actin and had an increase of actin in the Triton-insoluble cytoskeletal fraction. Sphingosine and H-7, inhibitors of protein kinase C activation, inhibited the increase in F-actin induced by PMA. The increase in F-actin in response to PMA was striking in Th and Ts lymphocytes (2- to 3-fold increase), but B lymphocytes had only a slight increase (1.15-fold). Thus, activation of protein kinase C modulates actin conformation specifically in T lymphocytes.

Actins↗
PubMed1987

Aberrant immunoglobulin and c-myc gene rearrangements in patients with nonmalignant monoclonal cryoglobulinemia.

The status of the immunoglobulin (Ig) genes was investigated in patients with idiopathic nonmalignant monoclonal IgG cryoglobulinemia (NCG). In NCG, monoclonal antibodies are synthesized at an accelerated rate by nonmalignant B lymphocytes. In order to determine whether this high production rate is related to a clonal B cell expansion, the rearrangement of the Ig genes was investigated by Southern blot analysis of genomic DNA extracted from the peripheral blood lymphocytes of four NCG patients. In three of four (VI, BR, and CH) clonal expansion of B cells was detected using probes specific for the c kappa, JH, c gamma 4 genes (in accordance with detecting IgG kappa cryoproteins in these patients). BamHI digestion of DNA from VI and BR produced three rearranged fragments which cohybridized with JH and c mu probes. This finding suggested the presence of additional nonsecretory B cell clones and/or disruption of the gene segments spanned by and detected with the probes. In VI the idiotype of the IgG cryoglobulin was also detected in association with IgM in the supernatant of Epstein-Barr virus-stimulated B lymphocytes using a murine monoclonal anti-idiotypic antibody. In addition, the possibility of aberrant gene rearrangements was supported by noting the alteration of the c-myc gene locus in genomic DNA from peripheral blood leukocytes of VI and CH. Northern blot analysis of RNA isolated from peripheral blood B cells of VI and CH demonstrated aberrant transcripts of the c-myc gene, showing an active role of the altered c-myc locus. Detection of c-myc rearrangement in NCG patients clearly shows that this event may not be a final step in malignant B cell transformation; however, it may be related to the clonal expansion and high rate of cryoglobulin synthesis of nonmalignant B lymphocytes.

Adult↗
PubMed1987

The effects of sulfhydryl inhibitors and cytochalasin on the cytoplasmic and cytoskeletal actin of human neutrophils.

To better understand the changes that occur in cytoplasmic actin during cell movement, we studied the effect of inhibitors of cell movement on the molecular conformation of actin and its incorporation into the Triton-insoluble cytoskeleton of human neutrophils. The sulfhydryl reactive compound N-ethylmaleimide caused an increase in cellular F-actin as measured by uptake of the F-actin specific fluorescent probe 7-nitrobenz-2-oxadiazole-phallacidin. However, N-ethylmaleimide reduced the amount of actin associated with the Triton-insoluble cytoskeleton. Dithiobisnitrobenzoic acid, a sulfhydryl reagent that does not cross cell membranes efficiently, did not alter the F-actin content of neutrophils. The effect of N-ethylmaleimide was blocked by the presence of dithiothreitol, a donor of sulfhydryl groups. N-ethylmaleimide did not affect the polymerization of actin in a cell-free system. Cytochalasin B did not alter F-actin content of neutrophils but did decrease actin in cytoskeletons of resting neutrophils. Cytochalasin inhibited the increase in F-actin initiated by the chemoattractant N-formylmethionylleucylphenylalanine. We propose that N-ethylmaleimide blocks the stabilization of G-actin in cytoplasm, interferes with the incorporation of F-actin polymer into the cytoskeleton, and depolymerizes the cytoskeleton. In contrast cytochalasin stabilizes G-actin in the presence of chemotactic peptide. These data suggest that reversible conversion of G-actin to F-actin and incorporation of F-actin into the Triton-insoluble cytoskeleton are important for neutrophil movement.

Actins↗
PubMed1987

Maturation-associated changes in the peripheral cytoplasm of human neutrophils: a review.

The process of hemopoietic stem cell differentiation and proliferation leads to a large number of precursor cells committed to the neutrophil lineage. These precursor cells undergo a further limited degree of proliferation but, most importantly, undergo a dramatic process of maturation which alters the phenotype of the cell from a myeloblast, which is incapable of normal circulation and function into a segmented neutrophil capable of chemokinesis, chemotaxis, particle ingestion, microbicidal action, and other functions required to subserve the inflammatory process. This review describes the changes in the cell surface and cell cytoplasm that occur during precursor cell maturation and, to the extent possible, correlates molecular and macromolecular changes during maturation with the development of functional capacity.

Antigens, Surface↗
PubMed1987

Characterization of monoclonal IgG cryoglobulins: fine-structural and morphological analysis.

The morphology of the amorphous, gelatinous, and crystalline varieties of monoclonal IgG cryoglobulins was analyzed by light and transmission and scanning electron microscopy. Each cryoglobulin had a characteristic fine structure that correlated with its gross morphology. Transmission electron microscopy showed that the amorphous precipitates were random and disorganized molecular clumps. In contrast, cryogels were thin-walled, well-organized, and hydrated strawlike clusters, whereas cryocrystals formed tightly compacted, highly structured molecular clusters. Crystals that formed in blood produced rouleaux, and analysis by scanning electron microscopy indicated that the crystals could form thick-walled, branching, macromolecular nets that could physically trap cells. The morphological properties provided visual impressions by which cryoglobulins could cause clinical disease secondary to vascular occlusion produced by self-associated IgG cryoglobulin molecules.

Cryoglobulins↗
PubMed1986

The mechanisms of sulfonylurea-induced immune hemolysis: case report and review of the literature.

Chlorpropamide, a sulfonylurea antidiabetic drug, was found to be the etiologic agent in a patient with immune hemolytic anemia. Hemolysis was severe, and ceased promptly when the drug was discontinued. The direct antiglobulin test was positive for complement, and the indirect antiglobulin test was also positive when the drug, patient serum, and fresh serum complement were all present. In this patient, and in four other patients described in the literature, hemolysis was mediated by the immune complex mechanism. In reports of two other patients taking a sulfonylurea drug, a milder form of hemolysis was mediated by the hapten mechanism. Sulfonylurea drugs are widely used. Since immune complex-mediated hemolysis in these patients is dramatic, it is not likely to be missed. However, the slower, milder hemolysis mediated by the hapten mechanism may be more common than is realized. Such patients may have only mild anemia and a near-normal reticulocyte count, making the diagnosis difficult. It is thus important to consider drug-immune hemolysis in patients who become anemic while taking sulfonylurea drugs.

Anemia, Hemolytic, Autoimmune↗
PubMed1986

Neutrophilic eccrine hidradenitis associated with Hodgkin's disease and chemotherapy. A case report.

A 44-year-old man with Hodgkin's disease developed fever and erythematous macules and plaques associated with doxorubicin, bleomycin, vinblastine, and dacarbazine chemotherapy. Biopsy results demonstrated a neutrophilic infiltrate around sweat glands and degeneration of eccrine glands. These findings are characteristic of neutrophilic eccrine hidradenitis, which, to our knowledge, has previously been reported only in patients with acute myelogenous leukemia who were receiving cytarabine chemotherapy. Neutrophilic eccrine hidradenitis may represent a reaction pattern to chemotherapeutic agents and may not be specific for a particular disease or drug.

Adult↗
PubMed1985

High-density lipoprotein and its apolipoproteins inhibit cytolytic activity of complement. Studies on the nature of inhibitory moiety.

Human high-density lipoprotein (HDL) and its apolipoproteins A-I and A-II inhibit complement-mediated lysis of human and sheep erythrocytes. This inhibitory activity under study is exerted after C9 is bound to membrane-associated C5b-8 complexes but prior to completed assembly and insertion of the C5b-9 complex. In this paper, we define some structure-activity relationships of the inhibitory moiety. With the exception of weak lytic inhibitory activity found in LDL/VLDL pools and in some unconcentrated minor fractions of plasma obtained by hydrophobic chromatography, all inhibitor activity was found in fractions which contained either apolipoprotein A-I, apolipoprotein A-II, or both. Intact HDL has a high level of inhibitor activity but delipidation by chloroform-methanol extraction was associated with an increase in activity on a protein-weight basis. Purified apolipoprotein A-I and apolipoprotein A-II exhibited equal inhibitory activity, greater than that exhibited by intact HDL. Nevertheless, ultracentrifugal fractions in which no free apolipoproteins could be demonstrated still possessed inhibitory activity. These experiments suggest that delipidation of HDL is not necessary for expression of inhibitor activity, although we could not rule out the possibility that apolipoproteins in dynamic equilibrium with HDL are responsible for the inhibitor activity observed in whole serum and plasma and in HDL preparations. Limited proteinase digestion completely abolished the inhibitory activity of partially delipidated HDL. Phospholipase C had little or no effect on the inhibitory activity of delipidated HDL, apolipoprotein A-I or apolipoprotein A-II, but reduced the inhibitory activity of intact HDL. These data suggest that the phospholipid polar headgroups are not necessary for inhibitory activity. However, the loss of these headgroups is associated with decreased activity, possibly due to increased hydrophobicity of HDL, or increased association among HDL micelles, and subsequent decrease in effective molar concentration of the inhibitory moiety.

Apolipoprotein A-I↗
PubMed1984

Chemotactic peptide-induced changes in neutrophil actin conformation.

The effect of the chemotatic peptide, N-formylmethionylleucylphenylalanine (FMLP), on actin conformation in human neutrophils (PMN) was studied by flow cytometry using fluorescent 7-nitrobenz-2-oxa-1,3-diazole (NBD)-phallacidin to quantitate cellular F-actin content. Uptake of NBD-phallacidin by fixed PMN was saturable and inhibited by fluid phase F-actin but not G-actin. Stimulation of PMN by greater than 1 nM FMLP resulted in a dose-dependent and reversible increase in F-actin in 70-95% of PMN by 30 s. The induced increase in F-actin was blocked by 30 microM cytochalasin B or by a t-BOC peptide that competitively inhibits FMLP binding. Under fluorescence microscopy, NBD-phallacidin stained, unstimulated PMN had faint homogeneous cytoplasmic fluorescence while cells exposed to FMLP for 30 s prior to NBD-phallacidin staining had accentuated subcortical fluorescence. In the continued presence of an initial stimulatory dose of FMLP, PMN could respond with increased F-actin content to the addition of an increased concentration of FMLP. Thus, FMLP binding to PMN induces a rapid transient conversion of unpolymerized actin to subcortical F-actin and repetitive stimulation of F-actin formation can be induced by increasing chemoattractant concentration. The directed movement of PMN in response to chemoattractant gradients may require similar rapid reversible changes in actin conformation.

Actins↗
PubMed1983

Inhibition of the lytic action of cell-bound terminal complement components by human high density lipoproteins and apoproteins.

Human serum lipoproteins are known to participate in or modify several immunologically relevant responses, including the inhibition of target cell lysis initiated by fluid-phase C5b-7 (reactive lysis). We now report that human high density lipoproteins (HDL) can inhibit the complement (C) lytic mechanism after C5b-7, C5b-8, and even C5b-9 have been bound to the target membrane. This inhibitory activity of serum or plasma copurifies in hydrophobic chromatography with antigenically detected apolipoprotein A-I (apoA-I), the major HDL apoprotein, and with HDL in CsCl density gradient ultracentrifugation. Although HDL is more active than its apoproteins in fluid-phase inhibition of C5b-7-initiated reactive lysis, the HDL apoproteins are more effective after C5b-7, C5b-8, or C5b-9 have become bound to human or sheep erythrocytes (E). Highly purified HDL apoproteins, apoA-I and apoA-II, both have greater inhibitory activity than whole HDL on a protein weight basis, and some evidence has been obtained that apoA-I dissociating spontaneously from HDL may be the principal inhibitory moiety in physiological situations. HDL lipids themselves are inactive. The HDL-related inhibitors are ineffective when incubated with EC5b-7 and removed before C8 and C9 are added, and only minimally effective on cell-bound C5b-8 sites before C9 is added. They exert their most prominent inhibitory activity after C9 has been bound to EC5b-8 at low temperature, but before the final temperature-dependent, Zn(++)-inhibitable membrane damage steps have occurred. Therefore, HDL or its apoproteins do not act to repair already established transmembrane channels, but might interfere either with insertion of C9 into the lipid bilayer or with polymerization of C9 at C5b-8 sites. This heat-stable inhibitory activity can be demonstrated to modify lysis of erythrocytes in whole serum, i.e., it does not depend upon artificial interruption of the complement membrane attack sequence at any of the above-mentioned stages. Contributions of the target membrane itself to the mechanism of inhibition are suggested by the observations that, in contrast to sheep or normal human E, lysis of guinea pig E or human E from patients with paroxysmal nocturnal hemoglobinuria is inhibited poorly. This is the first description of a naturally occurring plasma inhibitor acting on the terminal, membrane-associated events in complement lysis. Although further study is required to assess the physiologic or immunopathologic significance of this new function of HDL, the HDL apoproteins or their relevant fragments should be useful experimentally as molecular probes of the lytic mechanism.

Animals↗
PubMed1983

Amino-sugars enhance recognition and phagocytosis of particles by human neutrophils.

Neutrophils were examined for their ability to recognize and ingest beads coated with amino-derivatives of glucose, mannose, and galactose. Radioactive or fluorescent beads coated with any of the three sugars were ingested to an extent three times that observed with albumin-coated beads. Enhancement of ingestion of sugar-coated beads was much more evident when examined by electron micrographic studies. Inclusion of glucose or mannose in the medium with glucose- or mannose-coated beads caused a dose-dependent reduction of ingestion to control levels, but ingestion of galactose-coated beads was poorly inhibited. Similarly, galactose or fucose (6-deoxy-galactose) markedly inhibited ingestion of galactose-coated beads, but caused only a slight decrease in ingestion of glucose- or mannose-coated beads. Thus, neutrophils possess carbohydrate-binding membrane structures that can mediate recognition and ingestion of sugar-coated beads. Such carbohydrate recognition systems may underlie certain interactions of neutrophils and other surfaces.

Amino Sugars↗