bluuebunny/crossref_metadata_2025_split huggingface dataset:
Filterability of subpopulations of leukocytes: effect of pentoxifylline
Authors: Schmalzer EA , Chien S 
Published: October 2019

Abstract
Human leukocytes were separated by density into two fractions, one containing predominantly granulocytes (FI) and the other, lymphocytes and monocytes (FII). The filterability of these fractions and their mixture was determined from the pressure measured during constant flow through 5-microns Nuclepore filters. The pressure-time curve of FI indicates the behavior of a relatively homogeneous cell population. The FII pressure-time curve can be analyzed to distinguish the effect of the more numerous and more filterable lymphocytes from that of the sparser but less filterable monocytes. Pressure generated by mixed leukocytes, which had been treated with 1 and 10 mmol/L of pentoxifylline (PTX) or its metabolite I, was substantially less than untreated control; at 10 mmol/L, the pressure was reduced to about 50% of control. PTX appears to affect the filterability of monocytes and polymorphonuclear leukocytes but not lymphocytes. Scanning electron microscopy showed an inhibition of protopod formation in the treated granulocytes. The degree of cell adhesion to the filter, as measured by the number of cells remaining on the outflow side of the filter, was similar in all groups (FI and FII, treated and untreated). The results indicate that the variations in filterability between the leukocyte subpopulations and the improvement by PTX treatment reflect differences in the cells' ability to deform under the test conditions.
An objective sign in painful crisis in sickle cell anemia: the concomitant reduction of high density red cells
Authors: Fabry ME , Benjamin L , Lawrence C , Nagel RL 
Published: October 2019

Abstract
The etiopathologic basis of painful crisis in sickle cell anemia is largely unknown, and no objective criteria for its diagnosis and follow- up exist at present. We have studied 11 patients through 14 painful crises and observed a significant decrease of the densest fraction of red cells in 12 of the 14 crises as determined by isopycnic Percoll- Stractan continuous density gradients. If the first observation is normalized to 100%, the average decrease in dense cells was 77% with a range of 36% to 94%. The time needed for the percentage of dense cells to return to the steady-state level varied from seven to more than 30 days. These findings were in sharp contrast to the stability of the density pattern observed in another group of sickle cell patients, who were studied during crisis-free periods. The mechanism of the disappearance of dense cells could involve selective destruction by the reticuloendothelial (RE) system, selective sequestration in the areas of vasoocclusion, or a combination of both factors.
Abnormal VIII: von Willebrand factor patterns in the plasma of patients with the hemolytic-uremic syndrome
Authors: Moake JL , Byrnes JJ , Troll JH , Rudy CK , Weinstein MJ , Colannino NM , Hong SL 
Published: October 2019

Abstract
Plasma VIII:von Willebrand factor antigen (VIII:vWF) levels were elevated approximately two- to eightfold in seven patients (three adults and four children) during acute episodes of thrombocytopenia, renal failure, and hemolytic anemia (the hemolytic-uremic syndrome, HUS). In all seven patients, there was an alteration in plasma VIII:vWF patterns during these acute HUS episodes, so that the largest VIII:vWF forms were relatively decreased. Plasma VIII:vWF multimer patterns returned to normal, or nearly to normal, as platelet counts returned to preexisting levels, even in the patients whose recovery of renal function was incomplete and whose plasma VIII:vWF antigen level remained above normal. The sister of one of the HUS patients had a similar clinical prodrome (gastroenteritis) that was not followed by thrombocytopenia or renal failure and was not accompanied by an elevated level or abnormal forms of plasma VIII:vWF. These results suggest that an alteration in VIII:vWF metabolism, distribution, or interaction with platelets is associated with acute HUS episodes. In contrast to patients with chronic relapsing thrombotic thrombocytopenic purpura, none of the HUS patients (either during or after the acute HUS episodes) had a defect in the conversion of unusually large VIII:vWF multimers derived from endothelial cells to the VIII:vWF forms found in normal plasma.
Bone marrow histologic pattern--the best single prognostic parameter in chronic lymphocytic leukemia: a multivariate survival analysis of 329 cases
Authors: Rozman C , Montserrat E , Rodriguez-Fernandez JM , Ayats R , Vallespi T , Parody R , Rios A , Prados D , Morey M , Gomis F 
Published: October 2019

Abstract
In previous studies, the prognostic value of bone marrow (BM) histologic patterns in chronic lymphocytic leukemia (CLL) has been demonstrated. In order to investigate whether such a value is independent of other prognostic parameters, a multivariate survival analysis (Cox's regression model) was undertaken in a series of 329 CLL patients in whom a BM had been performed. The following binary variables were included in the analysis: age (more than 60 years), lymphadenopathy (more than two areas involved), splenomegaly, hepatomegaly, absolute lymphocyte count (more than 30,000 microL), anemia (hemoglobin less than 10 g/dL), thrombocytopenia (less than 100,000 microL), and BM pattern (diffuse v nondiffuse). Three variables entered the regression at significant level: BM pattern (P less than .001), anemia (P less than .001), and hepatomegaly (P = .03). The model was also tested by expressing the variables in a continuous way when possible. Again, BM pattern entered first in the regression (P less than .001), followed by the hepatomegaly (P = .002), hemoglobin level (P = .02), and lymphadenopathy (P = .04). When both the binary and the continuous models were tested separately in 227 patients with BM as initial staging procedure and in 102 patients in whom this was performed later during the course of the disease, in all instances, BM pattern entered first in the regression at a highly significant level. BM histologic pattern appears to be a better single prognostic parameter than any one of the variables employed in current clinical staging systems. A combined clinicopathologic system incorporating the BM pattern, together with the usual clinical variables, is presented.
Production of T lymphocyte colony-forming units from precursors in human long-term bone marrow cultures
Authors: Touw I , Lowenberg B 
Published: October 2019

Abstract
T cell differentiation in human marrow was studied in Dexter type long- term bone marrow cultures. In these cultures, T lymphocyte colony- forming units (TL-CFU), E rosette-forming cells (E+), and T3+, T4+, and T8+ cells (assayed by indirect immunofluorescence) were found to be present for at least 7 weeks. It was investigated whether the existence of T cells in long-term culture resulted from the persistence of inoculated T lymphocytes or from the production by immature progenitors. No significant numbers of E+, T3+, T4+, or T8+ cells were detected in cultures that were established from E+ lymphocyte-depleted bone marrow, indicating little or no production of T lymphocytes from E- negative precursors. On the other hand, bone marrow cells purged of E+ lymphocytes did not contain TL-CFU, but appeared to regain high numbers of TL-CFU during Dexter culture; this suggested that an earlier step in T cell differentiation may take place in this culture system. The generation of TL-CFU in the E-negative long-term marrow cultures only occurred when an adherent stroma layer had been established in the culture flask; it did not require added mitogens or detectable interleukin 2 in the culture medium. TL-CFU in fresh marrow (TL-CFU II) are mature (E+, T3+) T cells and are capable of producing helper (T4+) and suppressor/cytotoxic (T8+) phenotype cells in colonies. The TL-CFU newly formed in E-depleted Dexter cultures (TL-CFU I) are distinct from this population, as they are E-negative and give rise to colonies of the helper type only. T3 cell depletion of the marrow inoculum prior to culture did not prevent the appearance of TL-CFU I in long-term culture; this suggests that TL-CFU I are derived from an E- and T3- precursor (pre-TL-CFU).
Enrichment of pluripotent hemopoietic progenitor cells from human bone marrow
Authors: Bodger MP , Hann IM , Maclean RF , Beard ME 
Published: October 2019

Abstract
Pluripotent hemopoietic progenitor cells (CFU-GEMM, cells forming mixed hemopoietic colonies in methylcellulose) from human bone marrow were enriched 90-fold by positive selection on the fluorescence-activated cell sorter using monoclonal antibody RFB-1. Bone marrow cells were separated by cell size, using log 90 degrees light scatter, and the cell fraction containing CFU-GEMM was further separated by relative fluorescence intensity for the RFB-1 antigen. Further enrichment, up to 150-fold, was achieved by depleting bone marrow of T cells and mature myeloid cells prior to RFB-1 selection. These procedures yield a cell fraction containing 51% blast cells, 2% promyelocytes, and 47% undifferentiated (lymphocyte-like) mononuclear cells, although only 1% of the cells formed a mixed colony. CFU-GEMM are strongly positive for the RFB-1 antigen, whereas morphologically identifiable erythroblasts, myeloblasts, and promyelocytes are weakly RFB-1+. This suggests that the relative concentration of the RFB-1 antigen on bone marrow cells is inversely related to their maturity. The greatly increased recovery of CFU-GEMM after the separation of bone marrow by log 90 degrees light scatter and the removal of T cells and mature myeloid cells suggested that accessory cells that normally regulate the cloning efficiency of CFU-GEMM were removed.
Enhancement of chemotactic factor-stimulated neutrophil oxidative metabolism by leukotriene B4
Authors: Gay JC , Beckman JK , Brash AR , Oates JA , Lukens JN 
Published: October 2019

Abstract
Leukotriene B4 (LTB4) is a potent primary stimulator of neutrophil chemotaxis, aggregation, and degranulation and induces superoxide production at higher concentrations. In order to determine whether LTB4 modulates neutrophil responses to oxidative stimuli, human neutrophils (PMNs) were incubated with LTB4 prior to stimulation with f-Met-Leu-Phe (fMLP, 10(-7) mol/L), opsonized zymosan (OZ, 250 micrograms/mL), or phorbol myristate acetate (PMA, 32 nmol/L). Superoxide (O2-) production by stimulated PMNs was assessed by the superoxide dismutase-inhibitable reduction of cytochrome c. LTB4 alone did not stimulate O2- production in concentrations below 10(-7) mol/L and had no effect on the O2- assay. In the concentration range of 10(-12) to 10(-8) mol/L, LTB4 did not alter O2- release induced by OZ or PMA. In contrast, LTB4-treated cells demonstrated enhanced O2- production following exposure to fMLP, and in the presence of 10 nmol/LLTB4, generated 180% +/- 41% of O-2 quantities produced by control cells (n = 23). Enhancement was LTB4 dose-dependent, was maximal in the range of 1 to 10 nmol/L LTB4, was not reversed by removal of the lipid from the medium prior to fMLP stimulation, and was not dependent on the presence of Ca++ or Mg++ in the suspending medium. Chemiluminescence of fMLP-stimulated neutrophils was increased to 323% of controls in neutrophils preincubated with 10 nmol/L LTB4. Unlike augmentation of oxidative responses to fMLP seen with other degranulating stimuli, enhancement by LTB4 was not correlated with an increase in 3H-fMLP receptor binding. These results indicate that, in addition to its primary effects on neutrophil function, LTB4 modulates PMN oxidative responses to the chemotactic peptide and, thus, may amplify the release of oxygen metabolites at inflammatory foci.
Abnormal prothrombin crossed-immunoelectrophoresis in patients with lupus inhibitors
Authors: Edson JR , Vogt JM , Hasegawa DK 
Published: October 2019

Abstract
Prothrombin deficiency has been known to occur in association with lupus inhibitors for over 25 years. We studied 21 patients with lupus inhibitors and found that four of five with prothrombin deficiency and ten of 16 with quantitatively normal prothrombin had abnormal prothrombin crossed-immunoelectrophoresis (CIEP) characterized by material moving slower in the first dimension of electrophoresis than normal prothrombin. In two patients with prothrombin deficiency, all prothrombin measured by quantitative assay and all slow-moving material on CIEP were removed by treatment with Staphylococcal protein A (SPA). These patients had free antibody, which bound to normal plasma prothrombin, forming larger amounts of slow-moving material on CIEP. A third patient with prothrombin deficiency had only partial removal of prothrombin after SPA treatment. Two patients with quantitatively normal prothrombin had all slow-moving material on CIEP and about one fourth of the prothrombin by quantitative assay removed by SPA treatment. There was no correlation among the strength of the inhibitor, the presence of a “cofactor effect,” and the prothrombin abnormality. These data suggest that heterogeneous antiprothrombin antibodies, with or without prothrombin deficiency, are present in the majority of patients with lupus inhibitors.
Cleavage and activation of human factor IX by serine proteases
Authors: Enfield DL , Thompson AR 
Published: October 2019

Abstract
Human factor IX circulates as a single-chain glycoprotein. Upon activation in vitro, it is cleaved into disulfide-linked light and heavy chains and an activation peptide. After reduction of activated 125I-factor IX, the heavy and light chains are readily identified by gel electrophoresis. A direct, immunoradiometric assay for factor IXa was developed to assess activation of factor IX for proteases that cleaved it. The assay utilized radiolabeled antithrombin III with heparin to identify the active site and antibodies to distinguish factor IX. After cleavage of factor IX by factor XIa, factor VIIa- tissue thromboplastin complex, or the factor X-activating enzyme from Russell's viper venom, antithrombin III bound readily to factor IXa. Cleavage of 125I-factor IX by trypsin, chymotrypsin, and granulocyte elastase in the presence of calcium yielded major polypeptide fragments of the sizes of the factor XIa-generated light and heavy chains. Kallikrein did not cleave the zymogen. Nonactivation cleavage was noted by thrombin, but only in the absence of calcium. When the immunoradiometric assay was used to assess trypsin-cleaved factor IX, the product bound antithrombin III, but not maximally. After digesting with insolubilized trypsin, clotting activity confirmed activation. In contrast, incubation of factor IX with elastase (Takaki A et al, J Clin Invest 71:1706, 1983) or chymotrypsin did not lead to generation of an antithrombin III-binding site, despite their digestion of 125I-factor IX into heavy and light chain-sized fragments. In evaluating activation of factor IX, physical evidence of activation cleavages does not necessarily correlate with generation of an active site.
Acute monoblastic leukemia in infancy and early childhood: successful treatment with an epipodophyllotoxin
Authors: Odom LF , Gordon EM 
Published: October 2019

Abstract
Four of five infants and young children with acute monoblastic leukemia, a disease that heretofore has been highly refractory to therapy, were successfully treated with sequential infusions of a podophyllin derivative employed as a single agent over a protracted period of time. In three of the five children, monocytic leukemia cutis was present at birth. Treatment was begun in two of them when the disease had progressed to systemic involvement at a few months of age, and in the third when disease was still localized. The other two children were 11 and 18 months of age at initial presentation with widespread disease. Four children are off therapy 11 months, 26 months, 5 years, and 6 years, respectively.
Neutrophil cytoplasts: relationships of superoxide release and calcium pools
Authors: Torres M , Coates TD 
Published: October 2019

Abstract
Activation of human polymorphonuclear neutrophils (PMNs) by the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) leads to a transient increase in intracellular level of ionized calcium and an alteration of the plasma membrane permeability. Calcium has been proposed as a second messenger for activation of the PMN. Modulation of intracellular pools of calcium is of importance in the regulation of PMN activation. We have studied the changes in membrane-bound and cytoplasmic calcium in PMN and PMN devoid of granules and nucleus by quantifying changes in chlorotetracycline (CTC) and Quin 2 fluorescence and comparing their relation to O(2) release. Similar to PMN, PMN cytoplasts (PMN-CPs) produce equivalent amounts of O(2) in response to 10(-7) mol/L fMLP. The decrease in CTC fluorescence following fMLP stimulation is not significantly different in PMN-CP (-9.9% +/- 3.7%) from that observed in PMN (-12.7% +/- 2.33%), suggesting that the trigger pool of Ca++ is present in PMN-CPs. Although PMNs show a net increase in free Ca++ as measured by Quin 2, PMN-CPs display a lower sustained rise, which is totally abolished in the absence of external Ca++. PMN-CPs release O(2) efficiently in the absence of external Ca++ when stimulated with 10(-7) mol/L fMLP, whereas PMNs release significantly less O(2) under the same conditions. Our results suggest that a rapid rise in free Ca++, as monitored by Quin 2 fluorescence, is not required for expression of full activation of the oxidase system and release of O(2) from PMN-CPs.
A study of the kinetics of ADP-triggered platelet shape change
Authors: Hantgan RR 
Published: October 2019

Abstract
The rapid transformation of human blood platelets from inert discoid cells to spheroechinocytes that is induced by adenosine diphosphate (ADP) has been followed by right-angle light scattering intensity measurements using a laser light source and a sensitive photomultiplier. Two steps have been observed, and their rate constants have been determined as a function of pH and [ADP] and in the presence and absence of calcium for both platelet-rich plasma and gel-filtered platelets. Both steps are significantly faster in the presence of physiologic levels of calcium. Platelets were fixed prior to and during activation, then examined by phase-contrast and scanning electron microscopy. The light scattering and morphological changes support a model in which, under physiologic conditions of pH, temperature, ionic strength, and calcium concentration, the initial rapid event in platelet shape change is the loss of discoid shape, with a decay time of two to three seconds, leading to an intermediate with short pseudopods. The slower extension of long pseudopods occurs next, with a time constant of approximately seven to eight seconds. These results may help to resolve the contradictory descriptions of the mechanism of platelet shape change that have recently appeared in the literature.
Demonstration of a fast-acting inhibitor of plasminogen activators in human plasma
Authors: Kruithof EK , Tran-Thang C , Ransijn A , Bachmann F 
Published: October 2019

Abstract
This report describes a plasmatic, fast-acting, specific inhibitor (antiactivator) of tissue-type plasminogen activator (t-PA) and urokinase (UK). After addition of t-PA to human plasma, biexponential decay of activity occurred. The initial rapid inhibition of t-PA activity (half-life of approximately one minute) was correlated with the formation of a complex of a molecular weight of 110,000, suggesting a molecular weight in the order of 40,000 for the antiactivator. Diisopropylfluorophosphate (DFP)-inactivated t-PA did not form complexes with antiactivator. The second-order rate constant for the interaction of t-PA with antiactivator is in the order of 10(7) mol/L-1 sec-1. In plasma, UK added at low concentrations rapidly formed complexes of a mol wt of 95,000. Preincubation of the plasma with t-PA prevented complex formation of UK, and vice versa, suggesting that the same inhibitor inactivates both t-PA and UK. After exhaustion of the antiactivator, t-PA and UK formed complexes with alpha 2-antiplasmin and C1′-inhibitor at a low rate.
Decreased 5' nucleotidase activity in lymphocytes from asymptomatic sexually active homosexual men and patients with the acquired immune deficiency syndrome
Authors: Murray JL , Reuben JM , Munn CG , Mansell PW , Newell GR , Hersh EM 
Published: October 2019

Abstract
5′ Nucleotidase (5′NT) is an ectoenzyme associated with the plasma membrane of most mammalian cells. Low 5′NT activity has been observed in peripheral blood lymphocytes from patients with immunodeficiency states. 5′NT activity was measured in null and T-enriched lymphocytes from asymptomatic homosexual men and from 20 men with various degrees of the acquired immune deficiency syndrome (AIDS). Asymptomatic homosexuals were self-referred because of their concern about AIDS and were not necessarily representative of homosexuals in the general population. Enzyme activity was significantly decreased in both null (7.0 +/- 2.4 nmol/10(6) cells/h) and T-enriched (12.0 +/- 6.0 nmol/10(6) cells/h) lymphocytes in homosexuals as compared to lymphocytes from aged-matched heterosexual male and female controls (null = 10.8 +/- 6.5 and T = 22.3 +/- 10.6, P less than .0001 and .008, respectively). Decreased activity was present regardless of whether the patients were asymptomatic, had prodromal symptoms such as fever, lymph node enlargement, weight loss and diarrhea, or had opportunistic infections or Kaposi's sarcoma. Homosexuals had a significantly higher fraction of lymphocytes expressing the activation antigens T10 (20% +/- 3.3%) and Ia (13% +/- 2.9%) than controls (11% +/- 1.8% and 5% +/- 0.8%, respectively, P less than .05). They also had a significantly lower fraction of OKT4-positive helper lymphocytes than controls (22% +/- 3.4% v 35% +/- 2.2%, P less than .05). 5′NT activity in lymphocytes enriched for null cells from homosexuals correlated inversely with the percentage of Ia-positive lymphocytes (r = -.655; P less than .02). There was no correlation between 5′NT activity and the percentage of T4- or T8-positive lymphocytes or the T4/T8 ratio. Moreover, 5′NT activity was significantly decreased in both OKT4 (P less than .025) and OKT8 (P less than .05) enriched lymphocytes in homosexuals compared to controls. The data suggest that decreases in 5′NT may be a generalized defect of the peripheral blood T lymphocytes from active homosexuals that is independent of increases or decreases in specific T subpopulations or clinical status. It may contribute to the pathogenesis of AIDS.
Pre-B cell acute lymphoblastic leukemia in the newborn
Authors: Spier CM , Kjeldsberg CR , O'Brien R , Marty J 
Published: October 2019

Abstract
Leukemia in the newborn is an infrequent disease that has not been well defined using modern laboratory techniques. We describe two infants, one at birth and one at four weeks, with acute lymphoblastic leukemia. The blasts from each patient were studied in great detail, using a battery of cytochemical and immunologic procedures in addition to ultrastructural studies. Immunologic cell marker studies, not previously reported in congenital leukemia, showed the lymphoblasts from each infant to be of the pre-B cell phenotype. Each infant relapsed, one after a 17-week clinical remission and the other after a 44-week remission. The former has died while the latter is in a second remission. The subtype of pre-B cell acute lymphoblastic leukemia (ALL) which in childhood appears to confer an unfavorable prognosis, may have the same significance in neonatal ALL.