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Plasmablastic lymphoma (PBL) is a rare subtype of diffuse large B cell lymphoma (DLBCL), often associated with HIV infection. We present a case of a 53-year-old HIV-negative man with untreated hepatitis C viral infection who presented with abdominal pain and lymphadenopathy. Lymph node and bone marrow biopsies were consistent with plasmablastic lymphoma. He had partial response (PR) to 6 cycles of EPOCH but disease progressed seven weeks later. Repeat biopsy was consistent with plasmablastic lymphoma. Three cycles of bortezomib, ifosfamide, carboplatin, and etoposide (B-ICE) chemotherapy resulted in a partial response (PR). Five months later, he presented with widespread lymphadenopathy and tumor lysis syndrome with circulating blasts. Flow cytometry revealed a different population of lymphoma cells, this time positive for CD5, CD19, CD20, and CD22, with dim expression of CD45 and CD38. The patient died on the first day of ESHAP chemotherapy. There are no treatment recommendations or standard of care for plasmablastic lymphoma. A literature search yielded 10 cases in which bortezomib was administered in either HIV-positive or HIV-negative PBL. Six reported a partial response, 3 reported a complete response, and 1 was a near-complete response. Bortezomib, in combination with chemotherapy, may be an effective treatment option in PBL as reported here., Competing Interests: The authors declare that they have no conflict of interests.

Background: Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disease resulting in systemic microvascular thrombosis. The disease is caused by excessive platelet (PLT) adhesion to ultra-large (UL) von Willebrand factor (VWF) multimers inadequately cleaved by the processing enzyme ADAMTS-13. While many cases respond to plasma exchange performed with or without concurrent corticosteroids, treatment of the 10% to 20% of patients with refractory disease is difficult. Experimental studies demonstrating that N-acetylcysteine (NAC) inhibits PLT binding to endothelial cell-secreted and anchored UL VWF multimers suggest that NAC may be useful in the treatment of TTP., Case Report: A 44-year-old woman presented with malaise, confusion, chest and abdominal pain, and transient visual loss. Laboratory results and peripheral blood smear were consistent with TTP. The patient was begun on plasma exchange and corticosteroid treatment, but after 10 days the PLT count was still less than 10.0 × 10(9) /L and she developed a fever. Rituximab was initiated, but the patient's condition worsened and she became comatose. Antibiotics were initiated, but cultures remained sterile. After 3 days of coma and further clinical deterioration, treatment with NAC was begun. The patient received a loading dose of 150 mg/kg NAC intravenously (IV) over 1 hour. Within 18 hours the patient awakened abruptly and began communicating with medical personnel. Plasma exchange, corticosteroids, rituximab, and NAC infusion (150 mg/kg IV over 17 hr daily × 10 days) were continued and by Day 17 the PLT count was more than 50 × 10(9) /L. The patient fully recovered and was discharged on Day 31., Conclusion: This is the first complete report of a TTP patient treated with NAC. NAC was a safe and effective supplementary treatment for refractory TTP in this patient., (© 2013 American Association of Blood Banks.)

Understanding the process by which red cell precursors lose their nuclei developed in the late 19th and early 20th centuries led to the identification of nuclear remnants in circulating red cells in certain pathological states, particularly absence or decreased function of the spleen. William Howell, an American, and Justin Jolly, a Frenchman, were among a number of early contributors to this field. Early on, their names were applied, singly or in tandem, to these red cell inclusions, and the eponym, Howell-Jolly bodies, has stuck. It was, however, not until after the mid-20th century that Howell-Jolly bodies were clearly differentiated from basophilic stippling and that the mechanisms of their formation and removal from red cells were understood.

Purpose: To determine which internal medicine (IM) clerkship characteristics are associated with better student examination performance., Method: The authors collected data from 17 U.S. medical schools (1,817 students) regarding characteristics of their IM clerkships, including structural characteristics, pedagogical approaches, patient contact, and clinical teacher characteristics. Outcomes of interest were postclerkship National Board of Medical Examiners (NBME) subject examination score, United States Medical Licensing Examination (USMLE) 2 score, and change in score from USMLE 1 to 2. To examine how associations of various clerkship characteristics and examination performance may differ for students of different prior achievement, the authors categorized students into those who scored in the top (1/4) of the cohort on USMLE 1 and the bottom (1/4). The authors conducted analyses at both the school and the individual student levels., Results: In school-level analyses (using a reduced four-variable model), independent variables associated with higher NBME subject examination score were more small-group hours/week and use of community-based preceptors. Greater score increase from USMLE 1 to 2 was associated with students caring for more patients/day. Several variables were associated with enhanced student examination performance at the student level. The most consistent finding was that more patients cared for per day was associated with higher examination performance. More structured learning activities were associated with higher examination scores for students with lower baseline USMLE 1 achievement., Conclusion: Certain clerkship characteristics are associated with better student examination performance, the most salient being caring for more patients per day.

Plasmablastic lymphoma is an aggressive neoplasm that shares many cytomorphologic and immunophenotypic features with plasmablastic plasma cell myeloma. However, plasmablastic lymphoma is listed in the World Health Organization (WHO) classification as a variant of diffuse large B-cell lymphoma. To characterize the relationship between plasmablastic lymphoma and plasmablastic plasma cell myeloma, we performed immunohistochemistry using a large panel of B-cell and plasma cell markers on nine cases of plasmablastic lymphoma and seven cases of plasmablastic plasma cell myeloma with and without HIV/AIDS. The expression profiles of the tumor suppressor genes p53, p16, and p27, and the presence of Epstein-Barr virus (EBV) and human herpes virus type 8 (HHV-8) were also analyzed. All cases of plasmablastic lymphoma and plasmablastic plasma cell myeloma were positive for MUM1/IRF4, CD138, and CD38, and negative for CD20, corresponding to a plasma cell immunophenotype. PAX-5 and BCL-6 were weakly positive in 2/9 and 1/5 plasmablastic lymphomas, and negative in all plasmablastic plasma cell myelomas. Three markers that are often aberrantly expressed in cases of plasma cell myelomas, CD56, CD4 and CD10, were positive in 5/9, 2/5, and 6/9 plasmablastic lymphomas, and in 3/7, 1/5, and 2/7 plasmablastic plasma cell myelomas. A high Ki-67 proliferation index, overexpression of p53, and loss of expression of p16 and p27 were present in both tumors. No evidence of HHV-8 infection was detected in either neoplasm. The only significant difference between plasmablastic lymphoma and plasma cell myeloma was the presence of EBV-encoded RNA, which was positive in all plasmablastic lymphoma cases tested and negative in all plasma cell myelomas. In conclusion, most cases of AIDS-related plasmablastic lymphoma have an immunophenotype and tumor suppressor gene expression profile virtually identical to plasmablastic plasma cell myeloma, and unlike diffuse large B-cell lymphoma. These results do not support the suggestion in the WHO classification that plasmablastic lymphoma is a variant of diffuse large B-cell lymphoma.

Hemolysis is the principal toxicity of acute exposure to ethylene glycol monobutyl ether (EGBE) in rats. EGBE itself is not an active hemolytic agent, but its metabolite, butoxyacetic acid (BAA) formed as a result of dehydrogenase activity is a potent hemolysin. Here we address the role of osmolarity and cation composition of the suspending buffers in the mechanism of BAA-induced hemolysis of rat red blood cells in vitro. Rat erythrocytes were protected from BAA-induced cell swelling and hemolysis by the addition of sucrose to the suspending media. Hemolysis and cell swelling were also reduced by replacing external sodium with potassium. When calcium was not present in the suspending medium or when chelated by EGTA, hemolysis was increased after 2 h incubation with 1 mM or 2 mM BAA. Addition of as little as 0.05 mM CaCl(2) reduced hemolysis significantly while the addition of MgCl(2) had no effect. The dose-response relationship between BAA concentration and hemolysis determined in the presence or absence of calcium showed an increased effect of BAA in the absence of calcium. BAA-induced spherocytosis and cell fragmentation were more pronounced in the absence of calcium. The time course of BAA-induced hemolysis in the presence and absence of calcium demonstrated that the effect of calcium is to delay the onset of hemolysis. Increased intracellular calcium as a result of exposure to BAA was verified by atomic absorption spectroscopy. Charybdotoxin, an inhibitor of the calcium activated potassium channel, blocked the protective effect of calcium suggesting that the delay of onset of hemolysis in the presence of calcium is due to potassium loss caused by this channel. We conclude that the mode of action of BAA is to cause a colloid osmotic lysis of the rat red blood cell. Hemolysis requires external sodium and is associated with calcium uptake. Calcium appears to delay the onset of hemolysis. We speculate that: (1) BAA causes sodium and calcium to enter the cell; (2) calcium initially has a protective effect via the calcium activated potassium channel which facilitates the loss of potassium thereby, compensating for the osmotic effect of increased cell sodium; (3) calcium subsequently may have other deleterious effects through activation of proteases and externalization of phosphatidylserine in the exterior leaflet of the membrane.

The toxicity of diethylene glycol butyl ether (DGBE), and its principal metabolite, butoxyethoxyacetic acid (BEAA), were assessed in vitro for rat and human red blood cells. Rat erythrocytes showed evidence of mild hemolysis when exposed to BEAA at concentrations of 5 or 10 mM for 4 h. BEAA treated rat red blood cells also showed evidence of sub-hemolytic damage: increased spherocytosis, a shift in distribution of cell size to larger cells, a significant increase in mean cellular volume, and a decrease in cellular deformability. However, DGBE had no effect on rat red blood cell morphology, cell size, hemolysis or deformability. There was no hemolysis when human red blood cells were exposed to DGBE or BEAA at the same concentrations. No changes in mean cellular volume, distribution of cell size, or morphologic appearance of human red blood cells were observed. No evidence for decreased deformability of human red blood cells exposed to DGBE or BEAA was found. In conclusion, BEAA has weak hemolytic activity and sub-hemolytic effects in vitro on rat erythrocytes, which is consistent with the finding of mild hemolysis when the parent compound DGBE is administered to rats by gavage. The absence of hemolysis or sub-hemolytic damage when human red blood cells were exposed to BEAA or DGBE in vitro indicates that it is unlikely that hemolysis will occur as a result of human exposure to DGBE.

Pappenheimer is credited with describing the intraerythrocytic collections of iron, or siderotic granules, as they appear on Wright-stained blood smears of certain patients after splenectomy. The history of their description and elucidation of their origin and disposition shows the interaction of morphology with the increasing understanding of red cell physiology in the mid-twentieth century., (Copyright 2004 Wiley-Liss, Inc.)

Background: Changes in academic medicine have left clerkship directors (CDs) anxious about their career pathway, because clerkship administrative efforts may detract from other activities., Purpose: The Clerkship Directors in Internal Medicine (CDIM) asked members about benefits of being a CD or CDIM membership toward career development., Methods: Responses were on 1-5 Likert scales with 5 (strongly agree). Background and demographic issues were analyzed for associations with the career benefits statements., Results: The response rate was 75% (n = 92). Mean agreement with CD benefit was 4.2 (SD = 0.82) and CDIM membership 3.8 (SD = 0.95). Eighty-one percent and 58% of CDs agreed with the respective statements. Significant predictors of CD benefit were CD and coordinator salary support, years as CD, and receiving a university teaching award. Structured discussions of expectations strongly predicted perceiving CDIM benefit., Conclusions: Most CDs agreed that their CD role and CDIM benefited their careers. Salary support and clearly defining expectations may increase the likelihood of perceiving benefit.

Typically certain features of red cell morphology predict the results of osmotic fragility testing. Microspherocytes generally have increased and target cells decreased fragility. Blood smears in homozygous hemoglobin C disease show an interesting admixture of microspherocytes and target cells. Yet osmotic fragility studies generally show only reduced fragility and no population of fragile cells to correspond with the spherocytes. The present study demonstrates that the red cells of patients with hemoglobin C-beta thalassemia share many characteristics with hemoglobin C red cells, including the decreased osmotic fragility of all cells despite the presence of both spherocytes and target cells. These paradoxically osmotically resistant spherocytes probably arise because of cellular dehydration due to a K-Cl transport system which may be activated by binding of hemoglobin C to the red cell membrane.

Central nervous system (CNS) involvement is a rare occurrence in the course of human immunodeficiency virus (HIV)-related Hodgkin's disease (HD). We report the clinical course of a patient with HIV infection who developed systemic HD, mixed cellularity subtype, later complicated by leptomeningeal involvement. The patient died from his illness, and autopsy was performed. Examining the brain lesion, Epstein-Barr virus (EBV) presence was demonstrated in Reed-Sternberg cells by immunohistochemistry using an EBER probe for EBV RNA. This is the second case report in the English literature of HD involving the CNS in an HIV-positive individual, and the first demonstrating EBV presence. Extranodal presence of Hodgkin's disease in patients with HIV infection is probably related to immunosuppression, and physicians treating this illness should be alert to the potential of unusual sites of involvement., (Copyright 2003 Wiley-Liss, Inc.)

When 2-butoxyethanol (2-BE) is administered to rats, hemolysis occurs as the active metabolite butoxyacetic acid (BAA) is formed. Human red blood cells appear to be relatively resistant to the hemolytic effects of BAA in vitro, whereas rat red blood cells undergo changes in deformability, cell swelling, and hemolysis. In this study, exposure of human red blood cells to high concentrations of BAA resulted in loss of deformability and a small increase in mean cellular volume, but no significant hemolysis. These changes resembled the changes that occur in rat erythrocytes exposed to much lower concentrations of BAA. Therefore, a comparison was made between the sub-hemolytic effects of BAA at high concentrations (up to 10 mM) on human red cells with the sub-hemolytic effects of lower concentrations of BAA (up to 0.1 mM) on rat erythrocytes. Under these conditions, human and rat erythrocyte deformability decreased, while mean cellular volume (MCV) and osmotic fragility increased. Although there was a substantial shift in rat erythrocytes to lower densities, human erythrocyte density was only slightly decreased. Human and rat erythrocyte sodium also increased. Rat erythrocytes demonstrated increased spherocytosis. In a survey of blood samples from adults and children, none demonstrated an increase in hemolysis (n = 97) or MCV (n = 65) after exposure to 10 mM BAA for 4 h. In these experiments, in which hemolysis was not evident, human erythrocytes required exposure to a 100-fold greater concentration of BAA to develop changes in red cell deformability, osmotic fragility, and sodium content similar to those observed in rat erythrocytes. These concentrations are not likely to occur under normal human use of 2-BE-containing products.

We investigated the effects of sickle erythrocytes on the production of vasotone mediators in endothelial cells (ECs) using an in vitro recirculating flow system. Sickle erythrocytes increased the EC production of two important vasoactivators, prostacyclin and endothelin-1, under venous wall shear stress conditions of 1dyncm2. The presence of interleukin-1 in the perfusion system, as a model for inflammatory cytokine effects, enhanced the overall amounts of released prostacyclin but did not affect the production of endothelin-1. This study demonstrates the effects of sickle erythrocytes on the function and metabolism of ECs under vascular flow environments. The altered production of vasoactivators may contribute to the vasotone instability and vasoocclusive crises in sickle cell anemia.

We describe an HIV-infected 44-year-old man who presented 1 month after discontinuation of HAART therapy with a large mass extending from the mediastinum, enclosing the heart and extending through the diaphragm to the epigastric region. Biopsies subsequently revealed a highly aggressive non-Hodgkin's lymphoma (NHL) producing sheets of cells with an organoid distribution. The cells had abundant basophilic cytoplasm and a plasmacytic appearance. Although immunohistochemistry failed to show either B- or T-cell markers, antigens consistent with plasma cells were found. An immunoglobulin heavy chain clonal rearrangement was identified by PCR analysis. These studies were supportive of a diagnosis of a plasmablastic lymphoma. While awaiting the results of these tests, the patient was reinitiated on his HAART regimen. He was found on follow-up a month later to have complete resolution of his bulky mediastinal mass. He remained free of disease for 3 months with subsequent rectal and abdominal recurrence. Treatment with CHOP chemotherapy with filgrastim support was begun which resulted in another remission. Plasmablastic lymphoma is now reported in some studies to account for 2.6% of all HIV-related NHL. Originally described in 1997 in a series of 16 patients, this entity is highly associated with HIV infection in its later stages. Often, patients present with oral or jaw lesions with a rapidly progressive course. The tumors have the morphologic appearance of a plasmacytoid tumor with high proliferative index. Markers are positive mainly for LCA, CD79a, VS38C, and CD138. Co-infection with HHV-8 and EBV has not been consistently reported. Therapy with standard regimens has variable response. One case has been reported with a 3.5 year disease free survival. The regression of disease after resumption of HAART therapy alone in this patient suggests that HAART has an important role in the treatment of lymphoma in the HIV infected patient.

Background: When carbon monoxide binds to hemoglobin, it increases the affinity of hemoglobin for oxygen and shifts the oxygen dissociation curve to the left. The resulting decrease in sickling tendency could have clinical benefit, and carbon monoxide has been suggested as a treatment for sickle-cell disease. Furthermore, in sickle-cell disease, as in other hemolytic diseases, endogenous carbon monoxide production is increased because of increased heme catabolism., Methods: In the present study, we measured carboxyhemoglobin levels in sickle-cell patients and compared them with estimates of the hemolytic and the vasoocclusive severity of the disease., Results: Significant correlation was found between carboxyhemoglobin (HbCO) levels and hematocrit, reticulocyte count, unconjugated bilirubin level, and percentage of irreversibly sickled cells. However, there was no significant correlation between carboxyhemoglobin levels and measures of the vaso-occlusive severity of the disease., Conclusions: The correlations between HbCO levels and measures of hemolytic severity are best explained by the known relationship between hemoglobin catabolism and CO production. The lack of correlation with vaso-occlusive severity may be due to the complex changes involved and the difficulty of quantifying vasoocclusive severity.

Purpose: To characterize the responsibilities, activities, and scholarly productivity of internal medicine clerkship directors (CDs)., Methods: In 1999, internal medicine CDs from 122 U.S. medical schools and one Canadian medical school were surveyed. The instrument asked about the CDs' demo-graphics, workloads, clerkship characteristics, and scholarly productivity., Results: The response rate was 89%; 72% of the respondents were men. Mean age was 45 years, mean time as CD was 6.5 years, and 58% of the CDs had completed fellowship training. The CDs spent 28% of their professional time on the clerkship, three half days weekly in clinic, and three months on inpatient services. The CDs had published a mean of 2.2 (range 0-20) articles and received a mean of 0.7 (range 0-4) grants. Similar factors were associated with publishing articles and receiving grants; gender (men), < or = three clinic half days weekly, fellowship training, having a faculty development program, teaching other courses, and discussing expectations with their department chairs. In a multivariate analysis, fellowship training, clinic half days, teaching other courses, and discussing expectations explained 22% of the variance for papers published. For grants received, a model with gender, clinic half days, a faculty development program, discussing expectations, and teaching other courses explained 35% of the variance., Conclusions: An internal medicine CD invests significant effort administering the clerkship and contributing to clinical and educational activities. The factors associated with successful scholarship may be useful for fostering CDs' academic careers.

We identified three splice variants of hSK1 whose C-terminal structures are determined by the independent deletion of two contiguous nucleotide sequences. The upstream sequence extends 25 bases in length, is initiated by a donor splice site within exon 8, and terminates at the end of the exon. The downstream sequence consists of nine bases that compose exon 9. When the upstream sequence (hSK1(-)(25b)) or both sequences (hSK1(-)(34b)) are deleted, truncated proteins are encoded in which the terminal 118 amino acids are absent. The binding of calmodulin to these variants is diminished, particularly in the absence of Ca2+ ions. The first 20 amino acids of the segment deleted from hSK1(-)(25b) and hSK1(-)(34b) contain a 1-8-14 Ca2+ calmodulin binding motif, and synthetic oligopeptides based on this region bind calmodulin better in the presence than absence of Ca2+ ions. When the downstream sequence (hSK1(-)(9b)) alone is deleted, only the three amino acids A452, Q453, and K454 are removed, and calmodulin binding is not reduced. On the basis of the relative abundance of mRNA encoding each of the four isoforms, the full-length variant appears to account for most hSK1 in the human hippocampus, while hSK1(-)(34b) predominates in reticulocytes, and hSK1(-)(9b) is especially abundant in human erythroleukemia cells in culture. We conclude that the binding of calmodulin by hSK1 can be modulated through alternative splicing.

Rats exposed to 2-butoxyethanol (2-BE) develop hemolysis preceded by red blood cell swelling and shape changes. In this study effects on red blood cell morphology of dosing rats with 2-BE by gavage were compared with the effects of incubation of rat erythrocytes in vitro with the principal metabolite of 2-BE, butoxyacetic acid (BAA). Morphology was assessed by bright-field and phase microscopy of Wright's stained blood smears and glutaraldehyde-fixed cells suspended in plasma or buffer. In vivo exposure to 2-BE resulted in stomatocytosis and spherocytosis in blood smears and cup-shaped cells and spherocytosis in the fixed samples. In vitro incubation with BAA produced erythrocytes with cup shapes, spherocytosis and red blood cell ghosts in fixed samples. The stomatocytes observed in the blood smears appear to be the morphological equivalents of the cup-shaped cells observed in fixed samples. A variable degree of echinocytosis was observed in blood smears from animals exposed to 2-BE and in the in vitro experiments with BAA. Stomatocytes, cup-shaped cells, and spherocytes are the principal morphological features of erythrocytes from rats exposed to 2-BE or in vitro exposure to BAA. In comparison, human red blood cells incubated with up to 2.0 mM BAA exhibited none of the morphological changes observed in rat erythrocytes. 2-Butoxyethanol in vivo and BAA in vitro cause similar changes in rat red blood cell morphology, adding further evidence to support the primary role of BAA in the hemolytic effect of 2-BE exposure in the rat.

Sickle cell anemia is characterized by periodic vasoocclusive crises. Increased adhesion of sickle erythrocytes to vascular endothelium is a possible contributing factor to vasoocclusion. This study determined the effect of sickle erythrocyte perfusion at a venous shear stress level (1 dyne/cm(2)) on endothelial cell (EC) monolayers. Sickle erythrocytes up-regulated intercellular adhesion molecule-1 (ICAM-1) gene expression in cultured human endothelial cells. This was accompanied by increased cell surface expression of ICAM-1 and also elevated release of soluble ICAM-1 molecules. Expression of vascular cell adhesion molecule-1 (VCAM-1) messenger RNA (mRNA) was also strikingly elevated in cultured ECs after exposure to sickle cell perfusion, although increases in membrane-bound and soluble VCAM-1 levels were small. The presence of cytokine interleukin-1beta in the perfusion system enhanced the production of ICAM-1 and VCAM-1 mRNA, cell surface expression, and the concentrations of circulating forms. This is the first demonstration that sickle erythrocytes have direct effects on gene regulation in cultured human ECs under well-defined flow environments. The results suggest that perfusion with sickle erythrocytes increases the expression of cell adhesion molecules on ECs and stimulates the release of soluble cell adhesion molecules, which may serve as indicators of injury and/or activation of endothelial cells. The interactions between sickle red blood flow, inflammatory cytokines, and vascular adhesion events may render sickle cell disease patients vulnerable to vasoocclusive crises.

We report the case of a man with chronic myelocytic leukemia (CML) and a 46,XY,t(5;9;22) karyotype who developed acute myelocytic leukemia (AML) with a 45,X,t(8;21) karyotype 11 years after bone marrow transplantation (BMT) from his HLA-matched sister. Fluorescent in situ hybridization (FISH) studies and molecular analysis using short tandem repeat (STR) sequences proved the new leukemia to be of donor cell origin. Donor cell leukemia (DCL) after BMT is rare. Our review of the literature found 15 cases following BMT for leukemia and 2 cases after BMT for benign hematological disorders. In fewer than half the reported cases were molecular studies available to confirm the cytogenetic evidence for DCL, and the longest previously reported interval between BMT and DCL was 6 years., (Copyright 2000 Wiley-Liss, Inc.)

We report the case of a 34-year-old woman with recurrent pure red cell aplasia and evidence of hepatitis B and C infection. Review of the English literature identified 19 prior cases in which pure red cell aplasia was associated with hepatitis. This case is the first in which serologic evidence of hepatitis C infection was documented. This patient also had porphyria cutanea tarda and marked hepatic siderosis but no active hepatitis or cirrhosis. Treatment with cyclophosphamide and prednisone produced complete remission of the pure red cell aplasia. Erythroid colony formation (colony-forming unit-erythroid and erythroid burst-forming unit) was reduced in cultures of bone marrow obtained during relapse but was normal in remission marrow. However, addition of the patient serum, whether collected during relapse or remission, inhibited erythroid colony formation by her bone marrow. These observations, and the known extrahepatic immunologic manifestations of hepatitis C infection, suggest that the pure red cell aplasia occurred because of autoimmune mechanism provoked by the infection.

Autoimmune hemolytic anemia and adrenal insufficiency are rarely associated with the antiphospholipid antibody syndrome. A 49-year-old woman with a history of deep venous thrombosis and recurrent miscarriages was found to have active autoimmune hemolytic anemia after being admitted to the hospital for cholelithiasis. The patient was treated with corticosteroids and underwent laparoscopic cholecystectomy 1 month later. Two weeks after surgery she had acute adrenal insufficiency. Activated partial thromboplastin time was prolonged, and antiphospholipid antibodies were detected in significant titer. Her illness responded well to corticosteroid therapy. Her direct Coombs' test remained positive. It appears that the antiphospholipid antibody syndrome contributed to the development of venous thrombosis, recurrent miscarriages, autoimmune hemolytic anemia, adrenal insufficiency, and indirectly, pigment stone cholelithiasis in this patient.

It is usually considered that red-cell mass is controlled by erythropoietin-driven bone marrow red-cell production, and no physiological mechanisms can shorten survival of circulating red cells. In adapting to acute plethora in microgravity, astronauts' red-cell mass falls too rapidly to be explained by diminished red-cell production. Ferrokinetics show no early decline in erythropolesis, but red cells radiolabelled 12 days before launch survive normally. Selective destruction of the youngest circulating red cells-a process we call neocytolysis-is the only plausible explanation. A fall in erythropoietin below a threshold is likely to initiate neocytolysis, probably by influencing surface-adhesion molecules. Recognition of neocytolysis will require re-examination of the pathophysiology and treatment of several blood disorders, including the anaemia of renal disease.

Eosinophilic fasciitis (EF) is a rare connective tissue disorder which is frequently associated with hematologic disorders, especially aplastic anemia (AA) and variants (amegakaryocytic thrombocytopenia). The prognosis for AA with EF has generally been poor, but a few reports suggest a role for immunosuppressive therapy. We have seen four cases of AA complicating EF. All received corticosteroids and anti-thymocyte globulin without any benefit. One patient died of bleeding and infection. A second achieved unmaintained partial remission after two courses of cyclosporine A, although he had difficulty with side effects. Two patients received bone marrow transplants and both initially engrafted well. One had received marrow from a phenotypically HLA-matched parent and died of late graft failure. The second transplanted patient appears to be the only reported case of long term cure of both the AA and EF. Our four patients constitute the largest reported series of AA with EF and shed light on clinical aspects of the disease, and on the pathogenesis, particularly on responsiveness to different therapies; furthermore, there are implications to the treatment of AA in general.

Space flight results in a rapid change in total blood volume, plasma volume, and red blood cell mass because the space to contain blood is decreased. The plasma volume and total blood volume decreases during the first hours in space and remain at a decreased level for the remainder of the flight. During the first several hours following return to earth, plasma volume and total blood volume increase to preflight levels. During the first few days in space recently produced red blood cells disappear from the blood resulting in a decrease in red blood cell mass of 10-15%. Red cells 12 d old or older survive normally and production of new cells continues at near preflight levels. After the first few days in space, the red cell mass is stable at the decreased level. Following return to earth the hemoglobin and red blood cell mass concentrations decrease reflecting the increase in plasma volume. The erythropoietin levels increase responding to "postflight anemia"; red cell production increases, and the red cell mass is restored to preflight levels after several weeks.

This article reports the details of delayed hemolytic transfusion reactions in four patients with sickle cell disease. These cases demonstrate the characteristics of the reactions, the significant risks involved, and the principles useful in diagnosis and treatment. Patients with sickle cell disease are at particular risk for delayed hemolytic transfusion reactions because they may be transfused at intervals over many years; they frequently form alloantibodies because of antigenic differences from the donor population; and they may receive emergency care in different hospitals where transfusion records are not available. In addition, exchange transfusions, which are often used for patients with sickle cell disease and which were given in three of these cases, raise the risks through increased exposure to foreign erythrocyte antigens and through an increased volume of erythrocytes susceptible to hemolysis. It was concluded that the hazards of these transfusion reactions justify preventive measures, such as extended erythrocyte phenotyping of patients with sickle cell disease and extended phenotypic matching of transfused cells.

The effect of spaceflight on red blood cell mass (RBCM), plasma volume (PV), erythron iron turnover, serum erythropoietin, and red blood cell (RBC) production and survival and indexes were determined for six astronauts on two shuttle missions, 9 and 14 days in duration, respectively. PV decreased within the first day. RBCM decreased because of destruction of RBCs either newly released or scheduled to be released from the bone marrow. Older RBCs survived normally. On return to Earth, plasma volume increased, hemoglobin concentration and RBC count declined, and serum erythropoietin increased. We propose that entry into microgravity results in acute plethora as a result of a decrease in vascular space. PV decreases, causing an increase in hemoglobin concentration that effects a decrease in erythropoietin or other growth factors or cytokines. The RBCM decreases by destruction of recently formed RBCs to a level appropriate for the microgravity environment. Return to Earth results sequentially in acute hypovolemia as vascular space dependent on gravity is refilled, an increase in plasma volume, a decrease in hemoglobin concentration (anemia), and an increase in serum erythropoietin.

A decreased red blood cell mass (RBCM) and plasma volume (PV) have been consistently found in humans after return from spaceflight. Rats flown on the Spacelab Life Sciences-1 mission were studied to assess changes in RBCM, PV, erythropoiesis, and iron economy. The RBCM and PV increased in both ground control and flight animals as expected for growing rats. However on landing day, both the RBCM and PV, when normalized for body mass, were significantly decreased in the spaceflight animals. During an 8-d postflight observation period, iron incorporation into circulating red blood cells was diminished in the flight animals. During the first 4 d postflight, increases in reticulocyte counts were significantly smaller in the flight than the control animals. Fewer erythropoietin-responsive progenitor cells were recovered from the bone marrow of flight animals after landing than control rats. Serum erythropoietin (EPO) levels were the same in both groups. Thus, rats subjected to a 9-d spaceflight had less increase in RBCM than controls and diminished erythropoiesis during an 8-d post-spaceflight observation period. The rat, like humans, appears to require a smaller blood volume in microgravity.

The total-body red blood cell mass (RBCM) decreases during the first few days of spaceflight; however, the pathophysiology of "spaceflight anemia" noted on return to earth is poorly understood. In studies before, during, and after a 9-day mission we determined the rates of removal and replacement of RBCs by using chromium 51. The rate and efficiency of RBC production were assessed with iron 59. Serial measurements were made of plasma volume (PV), RBCM, serum ferritin level, and erythropoietin level. PV decreased within hours, resulting in an increased total body hematocrit during the first few days of the mission. Serum erythropoietin level decreased within 24 hours and remained low. Circulating RBCs disappeared at a normal rate during flight, but few new cells replaced those destroyed, resulting in a decrease in RBCM of 11% during the mission. After 22 hours in space, intramedullary formation of cells continued at near preflight levels as measured by erythron iron turnover. The coexistence of new cell formation in the bone marrow and failure of cells to be released into the blood is consistent with ineffective erythropoiesis. Microgravity causes blood located in gravity-dependent spaces to shift to a central volume. We conclude that the initial adaptation is a reduction in PV resulting in plethora. Increase in total body hematocrit causes a decrease in erythropoietin production. RBCM decreases because RBCs destroyed at a normal rate are not replaced.(ABSTRACT TRUNCATED AT 250 WORDS)

A diffusion cell was used to examine the effect of HbS polymerization on the oxygen effective diffusivity, Deff, in packed sickle erythrocytes compared to that in packed normal erythrocytes at 25 degrees. In increasing PO2 experiments, the samples were fully oxygen saturated after a very brief transient. In decreasing PO2 experiments, the average oxygen tension decreased progressively over the time course of the experiment. At full oxygen saturation, Deff in the packed sickle erythrocyte samples was not significantly different from that in normal erythrocytes and was in agreement with prior workers' measurements of unfacilitated oxygen diffusion. Deff measured in the decreasing PO2 experiments on packed sickle erythrocytes was significantly different from that in normal erythrocytes. As the average oxygen tension decreased, Deff in packed normal erythrocytes increased to a maximum of 40% over its unfacilitated value and then decreased. In contrast, in sickle erythrocytes which contained over 90% HbS, as PO2 decreased, Deff increased only slightly and then decreased dramatically. The results of decreasing PO2 experiments on sickle erythrocytes containing significant amounts of other hemoglobins (HbF, HbC) were different from those of both the normal erythrocytes and sickle erythrocytes with dominant HbS fraction, showing the effect of hemoglobin composition on effective diffusivity. These results demonstrate a dramatic effect of HbS polymerization on the resistance to oxygen transport in sickle erythrocytes.

The objective of this work was to evaluate quantitatively the effects of flow on platelet reactions using a flow cytometric technique. Whole blood was exposed to well defined, laminar shear stress in a cone-and-plate viscometer in the absence of added agonists. Blood specimens were fixed with formaldehyde and incubated with two monoclonal antibodies. Antibody 6D1, specific for platelet membrane glycoprotein Ib (GPIb), was used to identify and enumerate platelets and platelet aggregates on the basis of their characteristic forward scatter and 6D1-FITC fluorescence profiles. Anti-CD62 antibody, specific for the granule membrane protein-140 (GMP-140), was used to measure platelet activation. Results showed platelet aggregation increasing with increasing shear stress with marked increase in this response for a pathophysiological stress level of 140 dyn/cm2 and higher. This stress level also was the apparent threshold for formation of large platelet aggregates ("large" refers to particles larger than 10 microns in equivalent sphere diameter). These platelet responses to shear stress were insensitive to aspirin, but strongly inhibited by agents that elevate platelet cyclic adenosine monophosphate (cAMP) levels. Moreover, pre-incubation of whole blood with monoclonal antibodies that inhibit von Willebrand factor binding to GPIb or von Willebrand factor and fibrinogen binding to GPIIb/IIIa inhibited platelet aggregation. Aggregation induced by shear at 37 degrees C was less in extent than at 23 degrees C. At physiological shear stresses, whole blood was more susceptible to shear-induced platelet aggregation than platelet-rich plasma. This study reaffirms that flow cytometric methods have several important advantages in studies of shear effects on platelets, and extends the methodology to whole blood unaltered by cell separation methods.

2-Butoxyethanol causes hemolysis in rodents but not in humans. 2-Butoxyethanol-induced hemolysis is primarily due to the effect of its metabolite 2-butoxyacetic acid (BAA). 2-Butoxyacetic acid did not cause hemolytic effects when incubated with blood from a limited number of normal individuals. Because 2-butoxyethanol is contained in many consumer products, the possibility that there may be human subpopulations susceptible to hemolysis by BAA was examined. 2-Butoxyacetic acid was incubated with red blood cells from healthy young and older individuals and with red blood cells from patients with hereditary spherocytosis and sickle cell disease. After incubation of red blood cells with or without 2.0 mM BAA for up to 4 h, conditions that readily hemolyzed rat red blood cells, there was no increase in hemolysis or changes in mean cellular volume or morphology. The deformability of erythrocytes treated with BAA was also measured using a nuclepore filtration technique. No changes in deformability due to treatment with BAA were detected. Although BAA is a potent cause of hemolysis in rats, red blood cells in humans, including the elderly and patients with two disorders marked by chronic hemolysis, were not susceptible to BAA-induced hemolysis or loss of deformability.

The effects of butoxyacetic acid (BAA), a metabolite of the important solvent 2-butoxyethanol, on rat and human red blood cells (RBCs) were investigated. Rat RBCs demonstrated decreased deformability as assessed by a sensitive polycarbonate sieve filtration technique and an increased mean cellular volume after incubation with 0.2 and 2.0 mM BAA for 1-4 h. Evaluation of erythrocyte morphology showed that rat RBCs exposed to BAA became spherocytic and lysed to form erythrocyte membrane ghosts. Hemolysis of rat erythrocytes was rapid in 2.0 mM BAA. Changes in the deformability of rat erythrocytes appear to precede hemolysis. Treated rat erythrocytes also demonstrated a tendency to agglutinate and to release hemoglobin, which formed visible precipitates. None of the adverse effects seen in the RBCs of rats were observed in human blood similarly incubated with 2.0 mM BAA.

Sickle red blood cells (RBC) suspended with endothelial cell (EC)-derived unusually large (UL) von Willebrand factor (vWF) multimers, but not large plasma vWF forms, adhered to human venous EC under shear flow conditions. When sickle RBC were separated by density gradient centrifugation, fractions rich in less dense RBC were the most adhesive to EC in the presence of ULvWF. Incubation of sickle RBC with monoclonal antibodies against platelet surface receptors GPIb or GPIIb/IIIa, or with the integrin receptor agonist Arg-Gly-Asp-Ser (RGDS) decreased the ULvWF-mediated sickle RBC adhesion to EC 84%, > 99%, and 90%, respectively. When incubated with EC before the flow studies, anti-GPIb antibody and RGDS inhibited the ULvWF-mediated sickle RBC adhesion to EC. ULvWF also promoted the adhesion to EC of nonsickle RBC (HbAA) from patients with an increased proportion of young erythrocytes. When the EC supernatant was depleted of most vWF forms, young nonsickle RBC adhesion decreased by 90%. Preincubation of young nonsickle RBC with anti-GPIb antibody, anti-GPIIb/IIIa antibody, or RGDS inhibited the ULvWF-mediated young RBC adhesion to EC by 47%, 88%, and 92%, respectively. These data indicate that (1) low-density erythrocyte fractions enriched in young sickle or young nonsickle RBC are capable of binding ULvWF multimers via GPIb-like and GPIIb/IIIa-like receptors; (2) the RBC vWF receptors are lost or modified as erythrocytes age in the circulation; and (3) ULvWF/RBC complexes also bind to EC via a GPIb-like receptor.

T1 and T2 were measured in unclotted blood samples with 0.24- and 4.7-T spectrometers. The fraction by weight of intracellular water in the red blood cells (RBCs) was varied by either osmotic manipulation or density separation in concentrated (packed RBCs) and dilute (RBCs suspended in buffer or serum) samples. Reducing the cell water content caused a moderate decrease in T1 and a profound decrease in T2 at both 0.24 and 4.7 T. Conversely, increasing the cell water content caused an increase in both T1 and T2. The authors conclude that dehydrated RBCs in an area of hemorrhage would cause a substantial decrease in signal intensity on long TR/TE (T2-weighted) images. Overhydration of RBCs would have the opposite effect.

Alpha-factor-mediated cell cycle arrest and mating inhibition of a mating-type cells of Saccharomyces cerevisiae have been examined in liquid cultures. Cell cycle arrest may be monitored unambiguously by the appearance of morphologically abnormal cells after administration of alpha factor, whereas mating inhibition is determined by comparing the mating efficiency in the absence or presence of added alpha factor. For both cell cycle arrest and mating inhibition, a dose-dependent response may be observed at limiting concentrations of the pheromone. If cell cycle arrest and mating inhibition require a small number of alpha-factor molecules, one might expect that responsive/nonresponsive cells = K(alpha factor)(N) where N is the order of dependence of cell cycle arrest (or mating inhibition) on alpha-factor concentration. The value of N has been determined to be 0.98 +/- 0.18 (standard error of the mean) for cell cycle arrest and 1.08 +/- 0.32 for mating inhibition. These results support the notion that saturation of a single site by alpha factor is sufficient to cause cell cycle arrest or mating inhibition of a mating-type cells.

Splenic atrophy or evidence of hyposplenism occurs in as many as one third of all patients with S-C hemoglobinopathy. Yet there are few reports in the literature of clinically apparent splenic infarction in this disease. We describe four instances of acute splenic infarction in three patients with hemoglobin S-C disease which illustrate a wide spectrum of clinical manifestations and severity. Of particular interest were the observations of coincident occurrences of splenic sequestration and functional hyposplenism with splenic infarction, suggesting a close pathophysiological relationship among these syndromes.

Typhoid fever was associated with pancytopenia in five patients. Bone marrow examinations revealed histiocytic hyperplasia with marked phagocytosis of platelets, leukocytes, and red blood cells in these individuals. This phagocytosis may contribute to the pancytopenia that occurs in some patients with typhoid fever. The striking degree of the histiocytic hemophagocytosis is reminiscent of the malignant disease, histiocytic medullary reticulosis. The importance of careful exclusion of infectious etiologies in illnesses involving marrow histiocytic proliferation is emphasized.

The interactions of normal erythrocytes and erythrocytes from patients having hemoglobin S hemoglobinopathies with normal human endothelial cells (EC) were investigated under flow conditions. When EC supernatant, containing 2.8-11.0 U/dl of von Willebrand factor (vWF) antigen and vWF multimeric forms larger than those present in normal plasma, was the red blood cell (RBC)-suspending medium instead of serum-free medium (SFM), the adhesion of sickle RBC, but not normal RBC, to endothelial cells was greatly increased (range of enhancement of sickle RBC adhesion, 2- to 27-fold). Adhesion of sickle RBC to endothelial cells was reduced to near serum-free levels when EC supernatant was immunologically depleted of vWF forms. Sickle RBC suspended in SFM containing 200 U/dl of purified vWF multimers of the type found in normal human plasma or 300 micrograms/ml human fibronectin were only slightly more adhesive to endothelial cells than sickle RBC suspended in SFM alone. These data indicate that unusually large vWF multimers produced by endothelial cells are potent mediators of the adhesion of sickle erythrocytes to endothelial cells. Vaso-occlusive crises in sickle cell anemia may be caused, at least in part, by adhesive interactions between the abnormal surfaces of sickle RBC and the endothelium after the release of unusually large vWF multimeric forms from stimulated or damaged endothelial cells.

We have described the first patient to be reported in whom plasma prekallikrein (Fletcher factor) deficiency and chronic lymphocytic leukemia were both present. This most likely represents a coincidental occurrence, but the markedly elevated peripheral blood lymphocyte count and the detection of the defect using ellagic acid are unique for Fletcher factor deficiency.

As calcium has increasingly been the object of study in erythrocyte physiology, we reviewed the current methodologies for determination of calcium by atomic absorption spectrometry. The published normal values for erythrocyte calcium vary from 5 to 500 mumol/liter of packed cells. A method based on Harrison and Long's determination of calcium is presented and shows normal red cell calcium concentration to be 0.0149 +/- 0.0023 mumol/ml of packed red cells. The influence of temperature and type of crucible used in ashing red cells is assessed. The method of additions is employed to corroborate our results.