A risk profile of emergency room adult trauma victims: intentional versus unintentional trauma injuries

This article presents a prospective study of 285 adult trauma victims admitted to a Los Angeles inner-city level 1 trauma center, from November 1991 to February 1992. The purpose of this study was to determine the magnitude of intentional and unintentional trauma injuries in this adult patient population, and to identify sociodemographic, lifestyle and medical risk factors predisposing patients to intentional vs. unintentional trauma injury. Chi-square analysis revealed that intentional trauma victims and unintentional trauma victims significantly differ in 8 of 13 risk factors. The resulting risk profile indicated that intentional trauma victims were more likely to be between the ages of 16-29 years old; African American males and more likely to present to the emergency room with injury severity scores higher than 15 (indicating severe injuries) than unintentional trauma victims. Strategies for prevention and medical social work intervention are discussed.

Blood polymorphonuclear leukocytes from the majority of sickle cell patients in the crisis phase of the disease show enhanced adhesion to vascular endothelium and increased expression of CD64

There is increasing interest in the role of blood polymorphonuclear leukocytes (PMNs) in the pathogenesis of sickle cell crisis. We studied the adherence of PMNs from 18 sickle cell patients in crisis, 25 out of crisis, and 43 healthy subjects (controls) to monolayers of human umbilical cord endothelium that were either untreated or pretreated with tumor necrosis factor alpha (TNFalpha). Overall, the PMNs from patients in crisis were more adherent than control PMNs to untreated endothelial monolayers (mean 53% increase; P < .001) and TNFalpha-treated monolayers (mean 41% increase; P < .002). Increased adhesiveness was not associated with an abnormal expression of CD11a, CD11b, CD11c, CD18, CD62L, or CD15. There was an increase in the number of PMNs expressing CD64 in patients in crisis (median value, 44%) compared with patients out of crisis (median, 21%; P = .025) and controls (median, 6.5%; P < .001). Sera from patients in crisis had normal levels of granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, interferon-gamma, TNFalpha, interleukin-1 (IL-1), IL-6, or IL-8 and did not modify the adherence of PMNs or their expression of CD64. Only IFN-gamma induced CD64 expression on PMNs, but this effect was not associated with enhanced binding to endothelium. Because PMNs bound to endothelial monolayers were CD64(+) and CD64-enriched PMNs were 7 times more adherent to endothelial monolayers than CD64-depleted PMNs, it is likely that CD64 is a marker of adherent PMNs. Two of the three anti-CD64 antibodies used in our antibody blocking studies (clones 32.2 and 197) partially inhibited the binding of sickle cell PMNs to untreated endothelium (mean inhibitions of 33% [P = .01] and 21% [P = .03], respectively), whereas only one (clone 197) inhibited binding to TNFalpha-treated endothelium (mean inhibition, 29%; P = . 004). In some patients with sickle cell disease, an enhanced PMN adhesion to vascular endothelium could contribute to the vascular occlusion that characterizes the acute crisis of the disease.

Molecular scanning of the human peroxisome proliferator activated receptor gamma (hPPAR gamma) gene in diabetic Caucasians: identification of a Pro12Ala PPAR gamma 2 missense mutation

Peroxisome proliferator activated receptor-gamma (PPAR gamma) is a nuclear receptor that regulates adipocyte differentiation, and possibly lipid metabolism and insulin sensitivity. As such, PPAR gamma is a promising candidate gene for several human disorders including obesity and type 2 diabetes mellitus. Screening for mutations in the entire coding region of the PPAR gamma gene (both gamma 1 and gamma 2 isoforms) was performed with DNA of 26 diabetic Caucasians with or without obesity. Two base substitutions were identified: a silent mutation at nucleotide 1431 (CACHis-->CATHis) and a missense mutation (CCGPro-->GCGAla) at codon 12 of PPAR gamma 2. The allele frequency of the Pro12Ala PPAR gamma 2 variant was 0.12 in Caucasian Americans, 0.10 in Mexican Americans, 0.08 in Samoans, 0.03 in African Americans, 0.02 in Nauruans, and 0.01 in Chinese. We conclude that the Pro12Ala PPAR gamma 2 gene variant is present in diverse populations. Further studies of the Pro12Ala variant will determine its relevance to obesity, insulin resistance, and type 2 diabetes.

Purification and characterization of recombinant catalase-peroxidase, which confers isoniazid sensitivity in Mycobacterium tuberculosis

The Mycobacterium tuberculosis katG gene encodes a dual-function enzyme called catalase-peroxidase, which confers sensitivity in M. tuberculosis to isonicotinic acid hydrazide. We have constructed a system for the high level expression of a recombinant form of this enzyme by amplifying the katG gene from the pYZ56 construct (1) and subcloning into a vector suitable for expression in Escherichia coli. The resulting plasmid, pTBCP, produced the catalase-peroxidase in large quantities, corresponding to 30% of total cell protein. The enzyme has been purified to homogeneity and appears to be a dimer in the native form. Using either hydrogen peroxide or t-butyl hydroperoxide and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) as substrates, kcat and Km values have been obtained for both catalatic and peroxidatic activities, respectively. The availability of significant quantities of an active, folded, recombinant form of M. tuberculosis catalase-peroxidase should thus facilitate future studies of its role in drug activation and antibiotic resistance.

Aqueous-based microcapsules are detected primarily in gut-associated dendritic cells after oral inoculation of mice

We previously found that aqueous-based microencapsulation enhanced virus-specific humoral immune responses after oral inoculation of mice. However, the mechanism by which microencapsulation enhances immunogenicity remains unclear. We found that spermine-alginate microcapsules were detected primarily in gut-associated dendritic cells (i.e. CD11c/CD18+, Ia+, CD11b-, CD45R-) after oral inoculation of adult mice. Microencapsulation may enhance immunogenicity by involving antigen presenting cells which are more efficient than those recruited during natural infection.

A new locus for non-syndromal, autosomal recessive, sensorineural hearing loss (DFNB16) maps to human chromosome 15q21-q22

Non-syndromal, recessive deafness (NSRD) is the most common form of inherited deafness or hearing impairment in humans. NSRD is genetically heterogeneous and it has been estimated that as many as 35 different loci may be involved. We report the mapping of a novel locus for autosomal recessive, non-syndromal deafness (DFNB16) in three consanguineous families originating from Pakistan and the Middle East. Using multipoint analysis (HOMOZ/MAPMAKER) a maximum combined lod score of 6.5 was obtained for the interval D15S1039-D15S123. Recombination events and haplotype analysis define a 12-14 cM critical region between the markers D15S1039 and D15S155 on chromosome 15q15-q21.

Salmonella typhimurium aroB mutants are attentuated in BALB/c mice

The aroB gene of Salmonella typhimurium, encoding dehydroquinate synthase, has been cloned into pUC19 and the DNA sequence determined. The aroB gene was isolated from a cosmid gene bank by complementation of an Escherichia coli aroB mutant and screening by Southern blot analysis. The nucleotide sequence of the S. typhimurium aroB gene revealed the presence of an open reading frame, encoding a protein of 362 amino acids with a calculated molecular mass of 38696 Daltons. The amino acid sequence of S. typhimurium dehydroquinate synthase is nearly identical to the E. coli homologue and shows high homology with other aroB gene products from other organisms. Subsequently, a stable insertional mutation in aroB was introduced into the wild-type S. typhimurium C5 strain. This mutant was auxotrophic for aromatic compounds. Infection of BALB/c mice with this mutant demonstrated attenuation comparable to other S. typhimurium mutants unable to biosynthesize aromatic amino acids.

A new method for studying the selective adherence of blood lymphocytes to the microvasculature of human retina

PURPOSE

To develop a sensitive and reproducible technique for measuring the adherence of blood lymphocytes to vessel walls exposed in sections of human retina and for examining the role of lymphocyte and vascular adhesion molecules in these events.

METHODS

Cryostat sections of human retina were overlaid with blood lymphocytes from healthy subjects, and experimental conditions were sought by which preferential attachment of the cells occurred to blood vessel walls in the retinal sections. Adherent lymphocytes were identified by staining with methyl green-thionine, and transected blood vessels were identified by their structure and by staining of basement membranes with periodic acid-Schiff. The adherence of enriched preparations of CD4+ (T-helper) and CD8+ (T-cytotoxic) lymphocytes, of interleukin-2 (IL-2)-activated cells, and of lymphocytes from patients with ocular Behçet's disease was examined. The distribution of adhesion molecules on retinal vessel walls was determined by immunohistochemistry, and the contribution of leukocyte integrins to lymphocyte binding was studied by blocking experiments with monoclonal antibodies.

RESULTS

The optimal selectivity of blood lymphocyte attachment to retinal vessel walls occurred when purified lymphocytes were suspended in culture medium with 10% fetal calf serum and overlaid onto retinal sections for 30 minutes at 23 degrees C with gentle agitation. Under these conditions, 92% of the lymphocytes that adhered to the section were confined to the retinal microvasculature, and CD4+ T cells were more adherent than CD8+ T cells (P < 0.01). Prior exposure of normal lymphocytes to IL-2 enhanced their binding to retinal blood vessels, and lymphocytes from patients with Behçet's disease showed supranormal vascular adherence (P < 0.005). Many transected vessels stained positively for CD31; PECAM (mean 62%), CD54; ICAM-1 (mean 73%), CD62E; E-selectin (mean 35%), CD62P; P-selectin (mean 61%), and CD106; VCAM-1 (mean 42%). However, these vascular adhesion molecules occupied < 20% of the area of the blood vessel walls. Lymphocyte adhesion to the retinal vessels was more dependent on CD29 (the common chain of the beta 1 integrins) expression than either CD11a/CD18 or CD49d.

CONCLUSIONS

This technique allows measurements to be made of lymphocyte adherence to vascular and nonvascular structures of retina ex vivo. Extension of this approach to the study of leukocyte adherence to sections of pathologic retina may be of clinical and experimental applicability in understanding mechanisms of retinal inflammation.

Nonmalignant disorders of lymphocytes

OBJECTIVE

To review the etiology, pathophysiology, clinical features, and laboratory findings in nonmalignant disorders of lymphocytes.

DATA SOURCES

Current literature.

STUDY SELECTION

Determined by author.

DATA EXTRACTION

Determined by author.

DATA SYNTHESIS

Assessing qualitative and quantitative changes in lymphocytes provides important information regarding immune reactions, disease conditions, and responses to therapy. Quantitative nonmalignant disorders encompass those conditions in which the total number of lymphocytes may be either increased (lymphocytosis) or decreased (lymphocytopenia). Frequently encountered disorders with a lymphocytosis include infectious mononucleosis and cytomegalovirus infection. Lymphocytopenia is not detected as often or as easily in the clinical laboratory, but may be induced by several causes such as stress, certain types of therapy, nutrient deficiencies, or premature destruction of lymphocytes as occurs in acquired immunodeficiency syndrome. Clinical and laboratory findings provide significant clues in defining the etiology of a nonmalignant disorder of lymphocytes.

CONCLUSION

Disorders of lymphocytes include both benign and malignant quantitative and qualitative variations. A reactive lymphocytosis is commonly associated with many viral and certain bacterial infections. The clinical laboratory plays an important role in differentiating reactive and malignant lymphoproliferative processes. Benign lymphocytopenia, although not a frequent finding, must also be characterized by the laboratory.

Minimal criteria for placement of adults on the liver transplant waiting list: a report of a national conference organized by the American Society of Transplant Physicians and the American Association for the Study of Liver Diseases

This report summarizes a recent meeting cosponsored by the American Society of Transplant Physicians and the American Association for the Study of Liver Diseases to formulate minimal criteria by which patients with severe liver disease will be placed on the waiting list for liver transplantation. The participants agreed that only patients in immediate need of liver transplantation should be placed on the waiting list. Patients should not be placed in anticipation of some future need for such therapy. It was agreed that minimal criteria could assist but not replace the clinical judgment of the transplant professionals at individual centers. The criteria will be summarized below for adult patients with acute or chronic liver disease. The most important non-disease-specific criterion for placement on the transplant waiting list was an estimated 90% chance of surviving 1 year. This translated into a Child-Pugh score of > or = 7 for patients with cirrhosis which places the patient in Child-Pugh class B or C. Cirrhotic patients who have experienced gastrointestinal bleeding caused by portal hypertension or a single episode of spontaneous bacterial peritonitis would meet the minimal criteria irrespective of their Child-Pugh score. There were disease-specific criteria also. These include a sole minimal criterion for patients with fulminant hepatic failure regardless of etiology of the onset of stage 2 hepatic encephalopathy. A requirement for 6 months abstinence from alcohol before placement on the transplant waiting list was considered appropriate for most patients with alcoholic liver disease. Exceptional cases could get access to the waiting list through a regional review process. Chronic cholestatic diseases present difficulties because of a different natural history than that of chronic hepatocellular diseases. The use of specific risk scores for primary biliary cirrhosis and primary sclerosing cholangitis will likely replace Childs-Pugh classification as the scoring systems become refined. Minimal criteria for any patient with a primary hepatocellular cancer would admit any patient with a tumor confined to the liver irrespective of size or number of tumors, after careful investigation had failed to show spread to lymph nodes, the portal vein, or distant organs. Unusual or rare indications for liver transplantation, including Budd-Chiari syndrome, Wilson's disease, and other hereditary disorders, were also discussed. Finally, it was agreed that there should be no absolute contraindications to placement of patients on the liver transplant waiting list. These criteria should be open to regular review to accommodate advances in the field.

Adhesion molecules are upregulated on dendritic cells isolated from human blood

This study investigated whether the high expression of adhesion molecules on enriched preparations of circulating dendritic cells (DCs) was an intrinsic property of the cells or whether it was a consequence of the procedure used to isolate them from blood. Expression of the beta 1, beta 2 integrins (CD11/CD18 family) and other adhesion molecules on DCs in whole blood was compared with that on isolated DCs. Dendritic cells were identified by flow cytometry as leucocytes that were positive for human leucocyte antigen (HLA)-DR, but negative for CD3, CD14, CD16, CD19 and CD56. In contrast to a minority of DCs in whole blood, the majority of isolated DCs expressed the beta 2 integrins and there were a greater number of cells bearing CD44, CD54 and some of the beta 1 integrins (notably CD49b, CD49d, CD49e and CD29). An increase in the proportion of DCs bearing adhesion molecules was generally apparent at the isolation stage when mononuclear cells, which had been incubated overnight, were centrifuged on a metrizamide gradient to enrich for cells of low density. Inclusion of an inhibitor of protein glycosylation and exocytosis (brefeldin A) at all stages of separation partially prevented an increase in the percentage of DCs bearing CD18, C29 and C54 whereas the inclusion of cycloheximide (an inhibitor of polypeptide synthesis) interfered with increases in the percentage of cells bearing CD29 and CD54. Neither of these antagonists had an effect on the intensity of adhesion molecule expression. We suggest that some of the adhesion-dependent functions of isolated DCs are caused, in part, by an upregulation of surface adhesion molecules induced by the enrichment procedure.

Extreme social isolation, use of community-based senior support services, and mortality among African American elderly women

The effect of extreme social isolation and use of community-based senior services on longevity was examined in a national sample of African American elderly women (ages 55-96). Consistent with previous research on the social integration/mortality link, African American elderly women who were extremely socially isolated were hypothesized to have a higher 5-year mortality rate. It was also hypothesized that use of community senior services would be negatively associated with 5-year mortality. Results of logistic regression analysis controlling for age, education, income, and health status found that extremely socially isolated African American elderly women were three times more likely than the nonisolated women to die within the 5-year period from the initial survey. Use of community senior services did not have a relationship on mortality. Results are discussed in terms of directions for future research and intervention.

Neutrophil adhesion molecule expression during cardiopulmonary bypass: a comparative study of roller and centrifugal pumps

The purpose of this study was to determine whether adhesion molecules and markers of cell activation were preferentially increased on blood neutrophils during cardiopulmonary bypass (CPB) and whether such effects were influenced by the use of a roller pump or a centrifugal pump. Forty-six patients undergoing open heart surgery were randomly allocated into either the roller or centrifugal groups. Blood (1 ml volumes) was removed from arterial and venous lines immediately before and 1 h after the start of bypass. Whole blood samples were immunolabelled and flow cytometry used to measure the distribution and expression of the adhesion molecules CD11b, CD18, CD62L on neutrophils, monocytes and lymphocytes, in addition to CD64 on neutrophils and monocytes, and CD14 on monocytes. The expression of CD11b was significantly enhanced on neutrophils in arterial and venous samples from both the roller pump (mean 84% and 100% increase, respectively; p < 0.001) and centrifugal pump (mean 74% and 73% increase, respectively; p < 0.001) groups. Neutrophil L-selectin expression increased to a small but significant extent in arterial and venous samples from the centrifugal pump group (mean 16% increase; p < 0.001) and in venous samples from the roller pump group (mean 10% increase; p < 0.01). Neither the percentage of neutrophils bearing CD11b/CD18, CD62L and CD64, nor the expression of adhesion molecules on lymphocytes and monocytes were modified by 1 h of bypass. These results suggest that patients subjected to CPB with roller or centrifugal pumps are equally at risk to neutrophil activation that could lead to increased interaction of these cells with blood vessel walls.

Genetic heterogeneity in Schwartz-Jampel syndrome: two families with neonatal Schwartz-Jampel syndrome do not map to human chromosome 1p34-p36.1

Schwartz-Jampel syndrome (SJS) is a rare autosomal recessive disorder characterised by the presence of myotonia with a mask-like face, skeletal dysplasia, and growth retardation. Two types have been defined by the age of manifestation of the symptoms. Linkage of Schwartz-Jampel syndrome to human chromosome 1p34-p36.1 has been shown in families where probands presented during infancy or early childhood. We have investigated two well documented families segregating severe neonatal SJS with microsatellite markers spanning the critical region of 1p34-p36. No demonstrable linkage to chromosome 1 was found in either family, suggesting that a second locus is responsible for the severe form of neonatal Schwartz-Jampel syndrome.

Safety of early intravenous dipyridamole technetium 99m sestamibi SPECT myocardial perfusion imaging after uncomplicated first myocardial infarction. Early Post MI IV Dipyridamole Study (EPIDS)

We assessed the safety of early (2 to 4 days) intravenous dipyridamole infusion in conjunction with technetium 99m sestamibi tomographic myocardial perfusion imaging in patients with first myocardial infarction (MI). Early risk stratification with myocardial perfusion imaging of patients after acute MI may be useful to identify patients who either require further evaluation or may be safely discharged. Because of minimal hemodynamic effects, intravenous dipyridamole may be a safe means of producing hyperemia for myocardial perfusion imaging. Stable patients with first acute MI who met entry criteria were randomized (3:1) to either intravenous dipyridamole infusion (0.56 mg/kg over a 4-minute period) 48 to 96 hours after onset of symptoms or a control (no test) group. Adverse cardiac events (unstable angina, recurrent MI, or cardiac death) were evaluated during and 24 hours after the dipyridamole infusion and during the corresponding 24 hours for the control group. Two hundred eighty-four patients received dipyridamole infusion a mean time of 3.3 +/- 0.7 days after MI. There were no adverse clinical events either during or immediately after the infusion. During the 24 hours after infusion, three patients had symptoms of unstable angina pectoris, one patient had a recurrent MI, and no patients died. The earliest event occurred 4.2 hours after the dipyridamole infusion. Three patients had unstable angina pectoris, whereas no patients had either recurrent MI or died in the control group. There were no statistically significant differences between the two groups. In a multicenter trial, dipyridamole infusion administered early after the first acute MI resulted in no increased evidence of cardiac events either immediately or 24 hours after the procedure compared with a control group. Therefore intravenous dipyridamole can be safely used as a pharmacologic vasodilator for myocardial perfusion imaging soon after uncomplicated MI.

Lymphocyte-endothelial cell interactions in multiple sclerosis: disease specificity and relationship to circulating tumour necrosis factor-alpha and soluble adhesion molecules

This study addressed two questions; first, whether the supranormal adherence of blood lymphocytes from patients with multiple sclerosis (MS) to endothelial cell monolayers treated with tumour necrosis factor-alpha (TNF alpha) was a feature common to other inflammatory disorders; and second, whether the adherence properties of blood lymphocytes from MS patients were related to changes in disease activity and to levels of circulating TNF alpha and soluble adhesion molecules. In the first part of the investigation, lymphocytes from 14 patients with MS were more adherent to TNF alpha-treated endothelial cells (P < 0.01) than those from healthy controls, whereas the adherence properties of lymphocytes from 12 patients with rheumatoid arthritis, eight patients with psoriasis and ten patients with neurological diseases other than MS were normal. In the second phase of the work, measurement of the adhesive properties of lymphocytes isolated at monthly intervals from a further six MS patients over a 5-8 month period, found that changes in binding to TNF alpha-treated endothelial cells, directly paralleled changes in circulating levels of TNF alpha (r = 0.77; P < 0.001) and soluble vascular cell adhesion molecule-I (sVCAM-1) r = 0.67; P = 0.001). An increase in disease activity, measured by T2-weighted and gadolinium-enhanced magnetic resonance imaging of the central nervous system (CNS), occurred in two patients and was associated with heightened lymphocyte adhesiveness and a rise in serum TNF alpha levels. Further analysis of the 34 serum samples from the six MS patients revealed a direct relationship between the concentration of sL-selectin and soluble intercellular adhesion molecule-I (sICAM-I) (r = 0.65; P < 0.001) and between sL-selectin and sTNF alpha (r = 0.42; P < 0.02). These findings support the view that disease activity in MS is associated with an increased adhesive interaction of blood lymphocytes with vascular endothelium at inflammatory sites within the CNS.

Alcohol use after liver transplantation in alcoholics: a clinical cohort follow-up study

The purposes of this study were to determine among a cohort of long-term alcoholic survivors after liver transplantation (1) the incidence of alcohol use, (2) its effect on allograft integrity and extrahepatic health, and (3) the validity of the pretransplant alcohol prognosis screening process. Retrospective clinical cohort study of all alcoholic patients undergoing orthotopic liver transplantation at a single center from February 1987 until January 1991 with follow-up through December 1994, giving a median duration of follow-up of 63 months (range, 6-89 months). Multidisciplinary liver transplantation program at a tertiary-care academic medical center. Fifty alcoholic, long-term liver transplant recipients. The frequency of alcohol relapse, defined as any alcohol use in the period after transplantation, was determined by two questionnaire studies and by clinical follow-up. Allograft integrity was assessed by coded review of serial percutaneous allograft biopsies. Potential systemic effects of alcohol relapse were assessed by chart review. The alcohol prognosis screening process was evaluated by retrospectively comparing pretransplant estimates of putative indicators of alcoholism prognosis in posttransplant alcohol users and abstainers. Thirty-three recipients (66%) consistently denied any alcohol use throughout the duration of posttransplant follow-up, whereas 17 (34%) were identified as having consumed alcohol at least once since the transplant. There were no significant differences at the time of evaluation between abstainers and alcohol users in age, sex distribution, severity of liver dysfunction, median duration of abstinence, or University of Michigan alcoholism prognosis score. The median interval from transplantation to alcohol relapse was 17 months, with a range of 3 to 45 months. Recurrent alcohol use was associated with significant medical complications sufficient to require admission to the hospital in 6 patients. One patient died of graft dysfunction, noncompliance with immunosuppressant medications, and presumed graft rejection while drinking. Mild or progressive hepatitis, which was the most common abnormality in posttransplant liver biopsy findings, was equally distributed between both alcohol users and abstainers and sometimes occurred in the absence of antibody to hepatitis C virus antibodies. There was a similar frequency of biopsy-proven acute cellular rejection in alcohol users and abstainers. Typical histological features of alcoholic liver injury were present in posttransplant biopsies from 1 alcohol user only. Alcohol use by alcoholics is uncommon in the first 5 years after liver transplantation, and alcohol-associated liver injury is unusual. Mild nonspecific hepatitis is common in both alcohol users and nonusers alike. Among a small subset of alcoholic transplant recipients, drinking behavior after liver transplantation is associated with considerable morbidity, requiring hospital admissions and occasionally leading to graft loss and death.

Human blood dendritic cells: binding to vascular endothelium and expression of adhesion molecules

To investigate the binding properties of dendritic cells (DC) to vascular endothelium, a comparative analysis was undertaken of DC, monocytes and lymphocytes isolated from the blood of 25 healthy subjects using monolayers of human umbilical vein endothelial cells as the adherence substrate. More blood DC (mean 24% adherence) were adherent to endothelial monolayers than monocytes (mean 18%; P < 0.001) and lymphocytes (mean 12%; P < 0.001). When the monolayers were pretreated with tumour necrosis factor-alpha (TNF-alpha) all leucocyte populations exhibited an increased attachment, but there was still greater binding of DC (mean 37% adherence) in comparison with monocytes (mean 23%; P < 0.001) and lymphocytes (mean 18%; P < 0.001). Flow cytometric analysis revealed that in relation to monocytes and lymphocytes the DC had a higher surface expression of the adhesion molecules CD11a (P < 0.05), CD11c (P < 0.005) and CD54 (P < 0.005) but a lower prevalence of cells bearing CD49d (mean 38%; P < 0.05) and the homing receptor CD62L (mean 14%; P < 0.001). CD1a was present on 22% of DC and virtually absent from the surface of monocytes and lymphocytes. The intensity of expression of the beta1-integrins, CD49c, CD49d and CD49e was greater on DC than lymphocytes and monocytes (P < 0.05). Antibody blocking studies demonstrated that DC binding to untreated and TNF-alpha-treated endothelium was dependent upon the expression of CD11a, CD18 and CD49d, and the simultaneous application of anti-CD18 and anti-CD49d antibodies produced an approximate 70% inhibition of adhesion (P < 0.001). Thus, the expression of both beta1- and beta2-integrins contributes to the adhesive interaction between DC and endothelium.

Differential immunohistochemical staining for DNA topoisomerase II alpha and beta in human tissues and for DNA topoisomerase II beta in non-Hodgkin's lymphomas

Topoisomerase II (Topo II) is the target for several chemotherapeutic agents, including doxorubicin and etoposide, termed Topo II poisons. Previous studies from cancer cell lines and clinical specimens attempted to correlate expression of Topo II with drug sensitivity. Mammalian cells, however, contain two isoforms of Topo II, termed Topo II alpha (subunit molecular weight, 170 kDa) and Topo II beta (subunit molecular weight, 180 kDa), both of which are sensitive to Topo II poisons. Studies of Topo II alpha in normal cells and tissues are limited, and few studies have begun to characterize the beta isoform. This study employed in situ immunohistochemical staining to characterize the tissue distribution of Topo II alpha in formalin-fixed, paraffin-embedded human tissues. A new antibody, confirmed by Western blot, specific to the beta isoform, was also used to characterize its distribution in non-neoplastic, formalin-fixed, paraffin-embedded human tissues and 33 cases of non-Hodgkin's lymphomas. Topo II alpha was identified in normal tissues with proliferating cells, especially in spermatocytes, germinal centers, and proliferative endometrium. Some terminally differentiated tissues, e.g., cerebral cortex, skeletal muscle, and nerve, showed no detectable Topo II alpha, whereas others, e.g., breast, salivary gland, and kidney, showed rare positive cells. In contrast, Topo II beta was present in all tissues, including fully differentiated tissues, e.g., cerebellum, myometrium, pancreas, as well as in tissues with cell turnover, e.g., endometrium, skin, and bowel mucosa. In non-Hodgkin's lymphomas, Topo II beta was uniformly present with no change in the intensity or staining pattern among the tumor subtypes. Topo II alpha may be distinguished from the beta isoform using immunohistochemical techniques, which permit precise localization of the enzyme in individual cells. Detection of this differential expression between the alpha and beta isoform of Topo II suggests distinct physiologic roles and might allow better therapeutic targeting for tumors.