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As nanoscale science, engineering, and technology (NSET) becomes more integrated into precollege science curricula, it is crucial for teachers to develop coherent understandings of science principles (e.g., the structure of matter, size and scale, forces and interactions, and size-dependent properties) that allow them to coordinate these understandings from the macro- to the nanoscale. Furthermore, as teachers acquire new NSET content knowledge through professional learning opportunities, it is incumbent upon NSET educators to understand their developing content knowledge. To this end, we report results from a study in which we used a pre-/post-/delayed-posttest design to examine the change in 24 secondary (grades 7–12) science teachers’ NSET content knowledge as a result of their participation in a year-long professional development program that consisted of a 2-week intensive course and academic year follow-up activities. Participants showed significant gains from pretest to posttest and significant gains on the delayed test compared to the pretest. We also present trends that emerged in teachers’ open-ended responses that provided deeper insight into teachers’ NSET content knowledge. Finally, we discuss issues related to the assessment of teachers’ NSET content knowledge as well as the design of NSET professional development for teachers.

Purpose: This study aims to characterize the June 2020 COVID-19 outbreak at San Quentin California State Prison and to describe what made San Quentin so vulnerable to uncontrolled transmission., Design/methodology/approach: Since its onset, the COVID-19 pandemic has exposed and exacerbated the profound health harms of carceral settings, such that nearly half of state prisons reported COVID-19 infection rates that were four or more times (and up to 15 times) the rate found in the state's general population. Thus, addressing the public health crises and inequities of carceral settings during a respiratory pandemic requires analyzing the myriad factors shaping them. In this study, we reported observations and findings from environmental risk assessments during visits to San Quentin California State Prison. We complemented our assessments with analyses of administrative data., Findings: For future respiratory pathogens that cannot be prevented with effective vaccines, this study argues that outbreaks will no doubt occur again without robust implementation of additional levels of preparedness - improved ventilation, air filtration, decarceration with emergency evacuation planning - alongside addressing the vulnerabilities of carceral settings themselves., Originality/value: This study addresses two critical aspects that are insufficiently covered in the literature: how to prepare processes to safely implement emergency epidemic measures when needed, such as potential evacuation, and how to address unique challenges throughout an evolving pandemic for each carceral setting., (© Ada Kwan, Rachel Sklar, Drew B. Cameron, Robert C. Schell, Stefano M. Bertozzi, Sandra I. McCoy, Brie Williams and David A. Sears.)

Background: The Ending the HIV Epidemic initiative, which aims to decrease the annual incidence of HIV infections in the United States (US) by 90% over the next decade, will require growth of a limited HIV provider workforce. Existing HIV training pathways within Family Medicine (FM) and Internal Medicine (IM) residency programs may address the shortage of HIV medical providers, but their curricula and outcomes have not previously been assessed., Methods: We identified HIV residency pathways via literature review, Internet search, and snowball sampling and designed a cross-sectional study of existing HIV pathways in the US. This survey of pathway directors included 33 quantitative items regarding pathway organization, curricular content, graduate outcomes, and challenges. We used descriptive statistics to summarize responses., Results: Twenty-five residency programs with dedicated HIV pathways in the US were identified (14 FM and 11 IM), with most located in the West and Northeast. All 25 (100%) pathway directors completed the survey. Since 2006, a total of 228 residents (77 FM and 151 IM) have graduated from these HIV pathways. Ninety (39%) of 228 pathway graduates provide primary care to persons with HIV (PWH)., Conclusions: HIV pathways are effective in graduating providers who can care for PWH, but generally are not located in nor do graduates practice in the geographic areas of highest need. Our findings can inform quality improvement for existing programs, development of new pathways, and workforce development strategies. Specifically, expanding pathways in regions of greatest need and incentivizing pathway graduates to work in these regions could augment the HIV workforce., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

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.

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.)

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.)

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.

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.)

Serum soluble transferrin receptor (sTfR) concentration has been evaluated in the diagnosis of iron deficiency in otherwise healthy individuals and in patients with rheumatoid arthritis, but has not been studied in a general population of patients with complicated clinical presentations. In this study, 145 anaemic patients with a variety of medical conditions undergoing diagnostic bone marrow aspiration for any reason were tested by a complete blood count, a panel of biochemical tests to evaluate iron status, bone-marrow aspirate iron stain, and serum sTfR concentration. Sixteen per cent lacked stainable iron in the marrow aspirate. All biochemical parameters differed significantly between patients with or without stainable marrow iron. The sTfR assay was significantly more sensitive but less specific than other iron status assays in identifying the absence of stainable iron. Logistic regression analysis demonstrated that only sTfR and ferritin contributed independently to the prediction of marrow iron status. Serum ferritin alone was highly specific but insensitive. A decision algorithm combining serum ferritin and sTfR was as sensitive as TfR and as specific as serum ferritin. The measurement of serum sTfR, especially in conjunction with serum ferritin, is a valuable addition to the existing methods for predicting the results of marrow aspirate iron stains.

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.

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.

We describe two new forms of pica associated with iron deficiency and a new variant of a third. Previous reports on pica are tabulated. The value of a sympathetic, nonjudgmental approach to eliciting the medical history is emphasized.

ACD is probably the most common anemia among hospitalized medical patients. It is variably defined by its clinical and, particularly, its laboratory manifestations. The most consistent features are low serum iron and normal or increased serum ferritin levels, reflecting normal or increased iron stores and distinguishing ACD from iron deficiency anemia. ACD often coexists with iron deficiency and the anemia of renal insufficiency. Most patients have an underlying infectious, inflammatory, or neoplastic disease, but as many as one quarter of patients do not. Several mechanisms have been proposed, the most significant of which are a block in reutilization of hemoglobin iron for red cell production and relative deficiency of erythropoietin, but the pathogenesis and mediators involved remain uncertain. The anemia itself seldom requires treatment and is ameliorated by successful treatment of the underlying disease.

This report describes pregnant sisters with severe factor VII deficiency and peripartum management with factor VII concentrate. In this family, two affected members had previously developed severe postpartum hemorrhage when managed with fresh frozen plasma. Therapy-related complications owing to plasma infusion included viral disease transmission and pulmonary edema. Therefore, to lessen the risks of complications, specific factor therapy was initiated shortly before parturition in both patients. Factor VII concentrate was administered prior to delivery and every 6 hr for the next 72 hr to keep trough levels at approximately 10%. Based on peak and trough levels, the mean factor VII half-lives were determined to be 3.6 and 5.7 hr. Use of the concentrate was associated with uncomplicated delivery and minimal postpartum bleeding.

Therapy for acute lymphocytic leukemia (ALL) has been less successful in adults than in children. Many centers treat all adult leukemia with the same regimen. We have used vincristine and prednisone for initial therapy in 14 adults with ALL since 1971 and have followed a treatment regimen developed for childhood ALL for subsequent therapy as well. Complete remissions were attained in 13, and complications and duration of hospitalization were minimized with this nonmyelotoxic regimen. Central nervous system "prophylactic" therapy was also well tolerated in these adult patients. However, remission duration and survival in our series were similar to those reported by others. That complete remission can be attained in a high percentage of adult patients with ALL through use of relatively nontoxic treatment demonstrates the importance of selecting out this group of patients from all adults with acute leukemia.

A method utilizing sodium dodecyl sulfate--polyacrylamide gel electrophoresis for the sepration of the alpha and beta chains of hemoglobin has been adapted to quantify hemoglobin chains by simultaneous electrophoresis of globin standards with unknowns, staining with Coomassie blue, densitomeric scanning, and planimetry. This method has been used to quantify the globin chains bound to the human red cell membrane during sterile incubation and ATP depletion in vitro. In thoroughly washed (6-step) ghosts of incubated cells; (1) more beta than alpha chains were bound (beta/alpha ratio 1.28); (2) only about one third of the bound chains contained heme; and (3) globin accounted for less than 20% of the "excess" protein present in the incubated cells compared to fresh cells. Four-step ghosts contained more hemoglobin, a smaller proportion of heme-free alpha and beta chains, and approximately equal numbers of alpha and beta chains (beta/alpha ratio 1.09).

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.

Two families with Bernard-Soulier disease, including four patients and three of their parents, were studied and detailed clinical summaries are presented. One patient in each family has suffered severe bleeding problems while the other affected sibling is less severely affected. There has been no excessive bleeding in any of the parents or other family members. The patients demonstrated the abnormalities characteristic for Bernard-Soulier disease: thrombocytopenia, giant platelets, prolonged bleeding time, abnormal platelet aggregation to human FVIIIvWF and ristocetin or bovine FVIIIvWF alone, defective ristocetin-induced binding of human 125I-FVIIIvWF multimers, decreased platelet lysis by a drug-dependent antibody and complement, and a decreased concentration of membrane glycoprotein I. The parents had normal platelet counts, bleeding times, and FVIII-mediated aggregation. However, the parents had abnormally large platelets decreased sensitivity to lysis by a drug-dependent antibody and complement, and a decreased concentration of membrane glycoprotein I. Therefore the heterozygous state for Bernard-Soulier disease is recognizable by platelet membrane abnormalities although there is no defect of platelet function and no excessive bleeding. Red cell membrane proteins of one patient were normal, suggesting that phenotypic expression of the Bernard-Soulier disease defect is restricted to platelets.

During sterile incubation of normal human erythrocytes at 37 degrees C., intracellular nonhemoglobin protein is bound to the membrane prior to hemolysis. These studies have characterized this phenomenon further. Protein binding to the membrane began after 12 hours incubation when cellular ATP was depleted and increased to 36 hours incubation. The binding was prevented by adding adenosine or glucose at the start of incubation and was arrested by adding adenosine to regenerate ATP during the course of incubation. However, protein, once bound, was not released by regeneration of ATP. The amount of protein bound was not altered by: (1) addition of Ca++ or EDTA to the medium, (2) blockade of sulfhydryl groups with N-ethylmaleimide, or (3) stabilization of heme-globin bonds by conversion of hemoglobin to cyanmethemoglobin. Conversion of hemoglobin to carboxyhemoglobin by incubations under carbon monoxide inhibited protein binding, but this appeared to be an effect of exclusion of oxygen rather than stabilization of heme-globin bonds since incubation under nitrogen had a similar effect. The morphological counterpart of this chemically-measured membrane-bound protein was visible in red cell ghosts stained with crystal violet as small membrane-associated particles resembling Heinz bodies. Sodium dodecyl sulfate acrylamide gel electrophoresis of membranes of incubated cells revealed a new protein band that was identical to globin monomers. This membrane binding of globin during incubation provides a model for the study of Heinz body formation in clinical disorders.

A polar, nonpenetrating compound of high specific activity, diazotized (125I)-diiodosulfanilic acid (DD125ISA), has been developed as a label for exposed proteins of the human platelet plasma membrane, and platelet proteins and the pattern of labeling have been studied with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). That DD125ISA binds specifically to membrane proteins was demonstrated by: (1) the specific activity of isolated membrane protein was five to seven times that of whole platelet protein and (2) no proteins of intact platelets were labeled which were not represented in the isolated plasma membrane. That the DD125ISA-labeled membrane proteins were exposed on the cell surface was demonstrated by: (1) DD125ISA-labeled proteins were altered by trypsin treatment of intact, labeled platelets and (2) the pattern of labeling produced by reaction of isolated membranes with DD125ISA was quite different from that produced by the labeling of intact platelets. Analysis of platelet membrane proteins by SDS-PAGE demonstrated the glycoproteins previously described at 150,000 daltons (termed glycoprotein I) and 92,000 daltons (glycoprotein III) but we could discriminate two apparently distinct glycoproteins in the intermediate region (IIa: 125,000 daltons, and II: 118,000 daltons). Glycoproteins I and III were constant whereas IIa was clearly visible only in unreduced samples and II was predominant in reduced samples. Reaction of DD125ISA with intact platelets resulted in equal labeling of three of these four membrane glycoproteins (IIa, II, and III). The pattern of exposed proteins on the platelet surface labeled by DD125ISA was different from lactoperoxidase-131I, which labeled predominantly the 92,000 dalton glycoprotein, as demonstrated by simultaneous SDS-PAGE analysis. Therefore three glycoproteins of the human platelet plasma membrane are exposed to a radioisotope probe on the platelet surface and are accessible for contact interactions.

A 59-year-old patient is described who presented with acute lymphocytic leukemia. Complete remission was induced rapidly with vincristine and prednisone. Nine months later he acquired the clinical and hematological picture of a myeloproliferative disease, and bone marrow cytogenetic studies demonstrated the presence of the Philadelphia chromosome. Within 4 months he again developed overt acute lymphocytic leukemia and died. Several lines of evidence have recently indicated a relationship between myeloproliferative and lymphoproliferative disorders, particularly chronic myelocytic and acute lymphocytic leukemia. This patient's course is another example of that association.

The thoroughly washed ghosts of erythrocytes from normal subjects and patients with sickle cell anemia were assayed for their content of total protein, total globin, hemoglobin, and alpha and beta chains by chemical and electrophoretic techniques. Total protein, globin, and hemoglobin were significantly greater in sickle cell than in normal ghosts. Ghosts prepared from different density fractions of sickle red cells showed no significant differences in protein, globin, or hemoglobin, though membrane-bound globin was highest in the most dense cells. In both whole populations and density fractions of sickle red cells, the majority of the membrane-bound globin retained its heme. Alpha and beta S chains were present in equal amounts in the sickle cell membranes.

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 abnormal adherence of sickle erythrocytes to endothelial cells (EC) has been hypothesized to play a role in the initiation of vaso-occlusion in sickle cell anemia. We studied erythrocyte/endothelial cell interactions under controlled flow conditions for normal (AA), homozygous sickle cell (SS), sickle cell trait (AS), mechanically injured normal, and "high reticulocyte control" red blood cells (RBC). Human umbilical vein endothelial cells grown to confluence on glass slides formed the base of a parallel plate flow chamber into which RBC suspensions were perfused at a constant flow rate, producing a wall shear stress of 1 dyne/cm2. Adhesion was monitored using video microscopy, and the number of adherent RBC was determined at ten-minute intervals during a wash out period. Results indicate that SS RBC were more adherent than AA RBC. Mechanically injured (sheared) RBC were also more adherent than control normal cells, but less adherent than SS RBC. AS RBC did not differ significantly in their adhesive properties from normal RBC. Less dense (younger) RBC were more adherent to EC than dense (older) cells for normal, SS and "high reticulocyte control" RBC. These findings suggest that the increased adhesion of sickle RBC is at least partially related to the increased numbers of young RBC present. Increased adherence of young cells to the EC lining vessel walls could contribute to microvascular occlusion by lengthening vascular transit times of other sickle cells. Microvascular occlusion is a major clinical problem in sickle cell anemia. This obstruction to blood flow could be due to decreased deformability of the cell and its inability to pass through small vessels. If this were the case it would be reasonable to expect that the most severely deformed sickle cells, the irreversibly sickled RBC (ISC), would play an important role in the initiation of vaso-occlusion. However, the number of circulating ISC is not well correlated with the frequency of painful crises and other microvascular occlusive phenomena. Recent evidence suggests that microvascular occlusion may be associated with increased adhesion of sickle cells to vascular endothelial cells. A strong correlation between erythrocyte adherence and clinical vaso-occlusive severity has been reported by Hebbel et al. Hoover et al. and Hebbel et al. demonstrated increased adhesion in static tests.(ABSTRACT TRUNCATED AT 400 WORDS)

We have reported the rare association of severe autoimmune hemolytic anemia with active ulcerative colitis, and added to the sparse published recommendations concerning management. Although aggressive medical therapy resulted in only partial control of the inflammatory bowel disease and hemolysis, both disorders remitted rapidly after panproctocolectomy and splenectomy. Autologous red cells were safely transfused during surgery.

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.

The topography of the external surface of the human red cell membrane has been studied using an impermeant radioactive probe, [125I]diazodiiodosulfanilic acid, which binds covalently to protein groups of the membrane following reaction with intact cells. The pattern of labeling was assessed by sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis followed by sequential analysis of single gels for carbohydrates (by staining with the periodic acid-Schiff (PAS) reagent), for proteins (by staining with Coomassie blue), and for radioactivity (by counting gels sliced in 2-mm segments). The radioactive probe bound to membrane polypeptides with apparent molecular weights of 94,200, 58,100, and 46,500 (Peaks A, B, and C, respectively). Peak A co-migrated with a small periodic acid-Schiff-positive band and protein Band 3 (nomenclature of Steck) (Steck, T.L. (1974)J. Cell Biol. 62: 1-19). Peak B migrated with protein Band(s) 4.5 slightly ahead of the major membrane glycoprotein (PAS-1). Peak C migrated like glycoprotein PAS-2 and protein Band 5, the actin-like, water-soluble membrane protein. In contrast to lactoperoxidase iodination and a number of other probes, [125I]diazodiiodosulfanilic acid reacted minimally with the major membrane glycoprotein, glycophorin. When it was reacted with isolated ghosts, all molecular weight classes of polypeptides were labeled. Treatment of labeled cells with neuraminidase or trypsin altered the glycoprotein staining pattern, but not the radioactive peaks. On the other hand, Pronase eliminated the Mr=94,200 radioactive peak, diminished the other two radioactive peaks, and profoundly changed the glycoprotein and protein staining patterns. Treatment of the membranes of labeled cells in a low ionic strength alkaline medium did not alter radioactive peaks and demonstrated that Peak C differed from the actin-like membrane protein. A nonionic detergent, Triton X-100, solubilized all radioactive components. The studies have defined the binding of [125I]diazodiiodosulfanilic acid to external proteins of the human red cell membrane. Its pattern of reaction differs quantitatively and qualitatively from other commonly used reagents, and it provides a useful additional vectorial probe for the study of membrane topography. Its reactions provide further evidence of the organizational complexity of the red cell membrane and emphasize the fact that interpretation of information derived from the use of membrane probes must take into account the differences resulting from the properties of the probing reagents themselves.

The conformation of the outer surface of the human red cell membrane has been studied under various conditions using the impermeant probe [125I]diazodiiodosulfanilic acid. At least seven polypeptides were labeled by the reagent, including the three extractable glycoproteins separable by the electrophoretic method employed. The Mr = 43,000 protein band was shown to contain two labeled species, one a glycoprotein, in addition to its major constituent, red cell actin. The extent and pattern of labeling were very sensitive to changes in pH and temperature. Total labeling increased with increasing pH and was greater at 4 degrees C than 37 degrees C. Binding of the probe to the Mr = 90,000 polypeptide and the major glycoprotein were relatively increased with increasing pH and temperature while opposite effects were observed for the Mr = 43,000 peptide(s). The pH effects on external membrane labeling were rapidly reversible. Results were similar in cells of different densities, suggesting that the pH and temperature effects were not related to cell age. The data presented emphasize the lability of membrane conformation and reactivity and thus the necessity to consider carefully the conditions of labeling in interpretation of studies using impermeant probes.

Two months after presenting with autoimmune hemolytic anemia, a 57-year-old man developed increased serum acid phosphatase activity. Subsequently, abnormal histiocytes were found in the bone marrow and blood, and 8 months after the onset of his illness lymph node biopsy led to the diagnosis of histiocytic medullary reticulosis. At that time the level of serum acid phosphatase activity was more than 60 times the upper limit of normal and then paralleled the activity of his disease during temporary responses to chemotherapy, rising to over 90 times normal at the time of his death 1 year after presentation. No prostatic malignancy was demonstrated by biopsies or at autopsy, and electrophoretic studies of the serum enzyme suggested that it was of extraprostatic origin. It is postulated that the acid phosphate present in the serum at levels heretofore described only in metastatic carcinoma of the prostate may have arisen from the abnormal histiocytes.

Purpose: Previous studies of the anemia of chronic disease (ACD) have generally begun with patients afflicted with one of the classical underlying diseases such as rheumatoid arthritis. The clinical spectrum of ACD has not been thoroughly examined. We hypothesized that many patients have an anemia with the characteristics of ACD but do not have one of the infectious, inflammatory, or neoplastic disorders usually associated with ACD. We therefore evaluated a series of consecutive, unselected, anemic patients admitted to a county hospital., Patients and Methods: All patients admitted to the medicine ward service of a county hospital were screened for anemia (hematocrit less than 40% in men, less than 37% in women). Additional laboratory data were collected on all anemic patients, except those with active gastrointestinal bleeding, hemolytic disease, or leukemia or multiple myeloma. The patients were divided into three groups on the basis of serum values indicating iron distribution: iron deficiency (serum ferritin less than 10 ng/mL), ACD (serum iron less than 60 micrograms/dL and serum ferritin more than 50 ng/mL), and all others (non-ACD). The hospital records of the patients in the latter two groups were reviewed and their diagnoses recorded., Results: Seven patients with iron deficiency were not considered further. Ninety patients with ACD were compared with 75 patients with non-ACD. The anemia in ACD patients was more severe than most authors describe. The mean hematocrit was 31%, and 20% of patients had hematocrits below 25%. The anemia was usually normocytic (mean red cell volume [MCV] 86 fL), but 21% had an MCV less than 80 fL. The level of saturation of serum iron-binding capacity was quite low in ACD (mean 15%) and was normal in non-ACD (mean 31%). Renal insufficiency was common in both groups; serum creatinine values were more than 2 mg/dL in 31% of patients with ACD and 20% of non-ACD patients. Sixty percent of patients with ACD had a principal diagnosis that fell into the infectious, inflammatory, and neoplastic categories commonly associated with ACD. Renal insufficiency was the major diagnosis in 16%, and the principal diagnosis in 24% was a disease not commonly considered to be associated with ACD. In non-ACD patients, the principal diagnosis was an infectious, inflammatory, or neoplastic disease in 55%, renal insufficiency in 9%, and another disease in 36%., Conclusions: When ACD was defined by the abnormalities of iron distribution, which are its most consistent and widely accepted characteristics, the spectrum of associated diseases was much broader than the traditional categories of infectious, inflammatory, and neoplastic disorders, and the overlap with non-ACD was large. Until the etiologic and pathogenetic mechanisms of ACD are better understood, a flexible and inclusive view of this disorder seems appropriate.