Human T-cell leukemia virus type-1-encoded protein HBZ represses p53 function by inhibiting the acetyltransferase activity of p300/CBP and HBO1

Adult T-cell leukemia (ATL) is an often fatal malignancy caused by infection with the complex retrovirus, human T-cell Leukemia Virus, type 1 (HTLV-1). In ATL patient samples, the tumor suppressor, p53, is infrequently mutated; however, it has been shown to be inactivated by the viral protein, Tax. Here, we show that another HTLV-1 protein, HBZ, represses p53 activity. In HCT116 p53+/+ cells treated with the DNA-damaging agent, etoposide, HBZ reduced p53-mediated activation of p21/CDKN1A and GADD45A expression, which was associated with a delay in G2 phase-arrest. These effects were attributed to direct inhibition of the histone acetyltransferase (HAT) activity of p300/CBP by HBZ, causing a reduction in p53 acetylation, which has be linked to decreased p53 activity. In addition, HBZ bound to, and inhibited the HAT activity of HBO1. Although HBO1 did not acetylate p53, it acted as a coactivator for p53 at the p21/CDKN1A promoter. Therefore, through interactions with two separate HAT proteins, HBZ impairs the ability of p53 to activate transcription. This mechanism may explain how p53 activity is restricted in ATL cells that do not express Tax due to modifications of the HTLV-1 provirus, which accounts for a majority of patient samples.

A comparative assessment of waste incinerators in the UK

The uptake in Europe of Energy from Waste (EfW) incinerator plants has increased rapidly in recent years. In the UK, 25 municipal waste incinerators with energy recovery are now in operation; however, their waste supply chains and business practices vary significantly. With over a hundred more plant developments being considered it is important to establish best business practices for ensuring efficient environmental and operational performance. By reviewing the 25 plants we identify four suitable case study plants to compare technologies (moving grate, fluidised bed and rotary kiln), plant economics and operations. Using data collected from annual reports and through interviews and site visits we provide recommendations for improving the supply chain for waste incinerators and highlight the current issues and challenges faced by the industry. We find that plants using moving grate have a high availability of 87-92%. However, compared to the fluidised bed and rotary kiln, quantities of bottom ash and emissions of hydrogen chloride and carbon monoxide are high. The uptake of integrated recycling practices, combined heat and power, and post incineration non-ferrous metal collections needs to be increased among EfW incinerators in the UK. We conclude that one of the major difficulties encountered by waste facilities is the appropriate selection of technology, capacity, site, waste suppliers and heat consumers. This study will be of particular value to EfW plant developers, government authorities and researchers working within the sector of waste management.

First Report of Phoma herbarum on Tedera (Bituminaria bituminosa var. albomarginata) in Australia

Tedera (Bituminaria bituminosa (L.) C.H. Stirton var. albomarginata) has been successfully established across the mixed-farming (wheat-sheep) region of Western Australia because this species has remarkable drought tolerance and can survive the dry-summer period with strong retention of green leaf. A leaf spot symptom involving pale brown lesions with distinct dark brown margins had been observed in genetic evaluation plots of tedera at Medina and Mount Barker, Western Australia, and a Phoma sp. was isolated. Single-spore isolations of a typical Phoma sp. isolate were made onto potato dextrose agar and maintained at 20°C, and a representative culture has been lodged in the Western Australian Culture Collection Herbarium maintained at the Department of Agriculture and Food Western Australia (Accession No. WAC13435). Amplification of the internal transcribed spacer (ITS) 1 and ITS2 regions flanking the 5.8S rRNA gene were carried out with universal primers ITS1 and ITS4 according to published protocol (3). The DNA PCR products were sequenced and BLAST analyses was used to compare sequences with those in GenBank. The sequence had 99% nucleotide identity with the corresponding sequence in GenBank for Phoma herbarum. Isolates also showed morphological (e.g., 1) and molecular (e.g., 2) similarities with P. herbarum as described in other reports. The relevant sequence information for a representative isolate has been lodged in GenBank (Accession No. JQ282910). A conidial suspension of 10⁷ conidia ml^-1 from a single-spore culture was spray inoculated onto foliage of 6-week-old tedera plants maintained under >90% relative humidity conditions for 72-h postinoculation. Symptoms evident by 10 days postinoculation consisted of pale brown lesions, mostly 1.5 to 4 mm in diameter, which developed a distinct, dark brown margin. Occasional lesions also showed a distinct chlorotic halo extending 1 to 1.5 mm outside the boundary of the lesion. Infection studies were successfully repeated twice and P. herbarum was readily reisolated from infected foliage. No disease was observed on and no P. herbarum were isolated from water-inoculated control plants. Except for a recent published report of P. herbarum on field pea (Pisum sativum L.) (2), this pathogen has only been noted in the Australian Plant Pest Database as occurring on lucerne (Medicago sativa L.) and soybean (Glycine max (L.) Merr.) in Western Australia in 1985 and on a Protea sp. in 1991. To our knowledge, this is the first published report of P. herbarum as a pathogen on tedera in Australia or elsewhere. That P. herbarum occurs on other hosts in Australia and has a wide host range elsewhere together suggest its potential to be a pathogen on a wider range of host genera and species. References: (1) G. L. Kinsey. No. 1501 in: IMI Descriptions of Fungi and Bacteria. 2002. (2) Y. P. Li et al. Plant Dis. 95:1590, 2011. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.

The HTLV-1-encoded protein HBZ directly inhibits the acetyl transferase activity of p300/CBP

The homologous cellular coactivators p300 and CBP contain intrinsic lysine acetyl transferase (termed HAT) activity. This activity is responsible for acetylation of several sites on the histones as well as modification of transcription factors. In a previous study, we found that HBZ, encoded by the Human T-cell Leukemia Virus type 1 (HTLV-1), binds to multiple domains of p300/CBP, including the HAT domain. In this study, we found that HBZ inhibits the HAT activity of p300/CBP through the bZIP domain of the viral protein. This effect correlated with a reduction of H3K18 acetylation, a specific target of p300/CBP, in cells expressing HBZ. Interestingly, lower levels of H3K18 acetylation were detected in HTLV-1 infected cells compared to non-infected cells. The inhibitory effect of HBZ was not limited to histones, as HBZ also inhibited acetylation of the NF-κB subunit, p65, and the tumor suppressor, p53. Recent studies reported that mutations in the HAT domain of p300/CBP that cause a defect in acetylation are found in certain types of leukemia. These observations suggest that inhibition of the HAT activity by HBZ is important for the development of adult T-cell leukemia associated with HTLV-1 infection.

Postoperative hydrocephalus in cranial base surgery

The incidence of postoperative hydrocephalus and factors relating to it were analyzed in 257 patients undergoing cranial base surgery for tumor resection. A total of 21 (8%) patients developed postoperative hydrocephalus, and all required shunting, Forty-two (17%) patients developed cerebrospinal fluid (CSF) leak that required placement of external drainage systems (ventriculostomy or lumbar drain, or both); 10 (23%) of these 42 patients eventually needed shunt placement to stop the leak because of hydrocephalus. Prior craniotomy, prior radiation therapy, and postoperative CSF infection were also associated with an increased risk of developing hydrocephalus (48% versus 6%, 19% versus 8%, and 14% versus 7%, respectively). Prior radiation and postoperative CSF infection increased the risk of CSF leak in patients with hydrocephalus (30% versus 18% and 30% versus 9%, respectively). CSF leak and hydrocephalus commonly occurred in patients who underwent resection of a glomus tumor. In conclusion, 8% of patients who underwent cranial base surgery for tumors developed de novo hydrocephalus; half of them also had CSF leak in addition to hydrocephalus; and all required shunt placement for CSF diversion.

Exploring the feasibility of selective depletion of T lymphocyte subsets by whole blood immunoadsorption cytapheresis

Normal turnover of T lymphocytes is slow relative to other blood cells. Consequently, the physical removal of circulating leucocytes by thoracic duct drainage, repeated leukapheresis or blood filtration results in T cell depletion and immunosuppression. However, clinical use of such procedures is impractical compared with immunosuppressive drugs or radiation. None the less, immunosuppression by physical depletion of T cells, avoiding the systemic toxicities of drugs and radiation, might have clinical advantages if immunophenotypically distinct T cell subsets could be depleted selectively. Recent advances in targeted plasma protein apheresis using adsorbent macrobead columns prompted us to determine whether analogous techniques might permit CD4+ T lymphocytes to be removed selectively from whole blood. To explore this possibility, we linked murine anti-human-CD4 and isotype-identical control monoclonal antibodies (mAbs) to agarose, polyacrylamide and polystyrene macrobeads (150-350 microm) and then evaluated the selectivity, specificity and efficiency of macrobead columns to remove CD4+ T cells from anti-coagulated whole blood at varying mAb densities and flow rates. We also examined saturation kinetics and Fc-oriention versus random coupling of mAbs to macrobeads. Sepharose 6MB macrobead (250-350 microm) columns proved to be most effective, selectively removing up to 98% of CD4+ T cells from whole blood. Moreover, depletion efficiency and selectivity were retained when these columns were reused after elution of adherent CD4+ cells. These studies indicate that selective depletion of T lymphocyte subsets by whole blood immunoadsorption apheresis using mAb-linked macrobead columns may be feasible on a clinical scale. It is possible that such apheresis techniques could achieve targeted forms of immunosuppression not possible with drugs or radiation.

Tandem cycles of high-dose melphalan and autologous stem cell transplantation increases the response rate in AL amyloidosis

Clinical outcomes of patients with AL amyloidosis treated with high-dose melphalan and stem cell transplantation (HDM/SCT) are tightly linked to the achievement of a hematologic complete response (HCR). We conducted a prospective trial to determine whether a second cycle of HDM/SCT could induce HCR in patients in whom the plasma cell dyscrasia persisted following initial treatment with HDM/SCT. Sixty-two patients were enrolled. Nine patients (15%) were removed from the protocol. Of the 53 patients continuing in this study, four died within 100 days of treatment (8%), and 27 (55%) achieved an HCR at 6 months after the first cycle of HDM/SCT. Of the 22 patients who did not achieve an HCR after initial treatment, 17 received a second HDM/SCT, 1 died within 100 days of treatment (6%), while 5 (31%) achieved an HCR. Thus, the HCR rate was 67% (32/48) for surviving patients on study, 60% (32/53) for all patients who received initial cycle of HDM/SCT, and 56% (35/62) by intention-to-treat. The median survival for all patients enrolled on the trial has not yet been reached. Thus, tandem cycles of HDM/SCT can increase the proportion of patients who achieve an HCR.

AL amyloidosis associated with B-cell lymphoproliferative disorders: frequency and treatment outcomes

AL amyloidosis, a systemic disorder characterized by widespread deposition of amyloid fibrils derived from monoclonal Ig light chains in organs and soft tissues, is typically caused by an underlying plasma cell dyscrasia. However, this disease can also be associated rarely with a B-cell lymphoproliferative disorder. In this report, we describe the presentation and clinical course of 16 patients with this association. Although amyloid-related organ involvement in these patients was typical of AL amyloidosis, the patients in this series were on average older and more likely to be female than patients with disease associated with a plasma cell dyscrasia. They were also more likely to have multisystem involvement. Treatment decisions were based primarily on the dominent hematopathologic features of the associated lymphoproliferative disorder. However, high-dose melphalan and stem cell transplantation was the primary therapy in 5 patients, and each of these patients had prolonged survival, ranging from 36 to 102 months.

Clinical and molecular characteristics of patients with non-amyloid light chain deposition disorders, and outcome following treatment with high-dose melphalan and autologous stem cell transplantation

Light chain deposition disease (LCDD) is caused by a clonal plasma cell disorder in which fragments of monoclonal immunoglobulin light chains form non-fibrillary deposits in various tissues resulting in organ dysfunction. Crystal storing histiocytosis (CSH) is another light chain deposition disorder in which monoclonal light chains form intracytoplasmic crystals. Both are uncommon diseases for which there is limited treatment experience. Between 2003 and 2005, five patients with LCDD and one with CSH were treated at Boston University Medical Center with high-dose melphalan and autologous peripheral blood stem cell transplantation (HDM/SCT). Five of the six patients had predominantly renal involvement, and one patient with LCDD had biopsy-proven deposits in the myocardium. Molecular characterization revealed that the pathologic light chains were kappa in four of the six patients, and sequence analysis revealed unusual germline donor genes and high rates of amino-acid substitutions. One light chain sequence encoded a new potential N-linked glycosylation site, and another showed evidence of antigen selection. All patients are alive and five of the six patients are in complete hematologic remission at a median follow-up of 12 months (range 4-29 months) after HDM/SCT. In our experience, HDM/SCT is a feasible and effective treatment approach for these disorders.

Serum free light-chain responses after high-dose intravenous melphalan and autologous stem cell transplantation for AL (primary) amyloidosis

Serum free light-chain (FLC) concentrations were measured by a sensitive nephelometric immunoassay in 66 patients with AL amyloidosis before and after treatment with high-dose melphalan and autologous stem cell transplantation (HDM/SCT). At 1 year after HDM/SCT, 27 patients (41%) achieved a complete hematologic response (CR), that is, disappearance of the monoclonal gammopathy previously evident by immunofixation electrophoresis (IFE) in serum and urine and of plasma cell clonality in the bone marrow. Abnormally elevated FLC levels became normal in 27 patients (41%), and decreased by >90% in 37 (56%). Average improvements in FLC were 94% for patients who achieved a CR and 72% for those who did not (P=0.0001). However, a reduction in FLC of >90% was associated with a similar high likelihood of clinical improvement and prolonged survival, whether or not patients achieved a CR. While CR, as defined by standard criteria, is a more stringent indicator of hematologic response than are decreases in abnormally elevated FLC levels per se, these measures of hematologic response are complementary, and decreases in FLC are more readily detected early after treatment than are the changes in IFE and marrow studies required to determine CR.

Predictive factors for hematopoietic engraftment after autologous peripheral blood stem cell transplantation for AL amyloidosis

Treatment of patients with AL amyloidosis with high-dose melphalan and autologous peripheral blood stem cells (PBSC) produces hematologic remissions in approximately 40% of evaluable patients, accompanied by improvements in organ disease and quality of life. These patients, who frequently have amyloid deposits in bone marrow blood vessels and interstitium and impaired function of kidneys, liver, spleen, and heart, represent an unusual population for stem cell transplantation, with unique problems. To identify factors influencing engraftment rates after chemotherapy and autologous granulocyte colony-stimulating factor (G-CSF)-mobilized PBSC reinfusion, we studied a group of 225 patients. The median time to neutrophil engraftment was 10 days (range, 8-17 days). In a multivariate analysis, the factors positively affecting the rate of neutrophil engraftment were CD34+ stem cell dose, female gender, and minimal prior alkylator therapy. The median time to platelet engraftment was 13 days (range, 7-52 days). Factors positively affecting platelet engraftment, in addition to CD34+ cell dose, included preserved renal function and the absence of neutropenic fever. The conditioning dose of intravenous melphalan was not found to be an independent predictive factor for hematopoietic recovery. Thus, in this patient population, organ function and host and hematopoietic factors influence engraftment after PBSC rescue.

High-dose intravenous melphalan and autologous stem cell transplantation as initial therapy or following two cycles of oral chemotherapy for the treatment of AL amyloidosis: results of a prospective randomized trial

SUMMARY

A prospective randomized trial was conducted to study the timing of high-dose intravenous melphalan and autologous stem cell transplantation (HDM/SCT) in AL amyloidosis. In all, 100 newly diagnosed patients were randomized to receive HDM/SCT, either as initial therapy (Arm-1) or following two cycles of oral melphalan and prednisone (Arm-2). The objectives of the trial were to compare survival and hematologic and clinical responses. With a median follow-up of 45 months (range 24-70), the overall survival was not significantly different between the two treatment arms (P=0.39). The hematologic response and organ system improvements after treatment did not differ between the two groups. Fewer patients received HDM/SCT in Arm-2 because of disease progression during the oral chemotherapy phase of the study, rendering them ineligible for subsequent high-dose therapy. This affected patients with cardiac involvement particularly, and led to a trend for an early survival disadvantage in Arm-2. Hence, newly diagnosed patients with AL amyloidosis eligible for HDM/SCT did not benefit from initial treatment with oral melphalan and prednisone, and there was a survival disadvantage for patients with cardiac involvement if HDM/SCT was delayed by initial oral chemotherapy.

Spontaneous rupture of the spleen in AL amyloidosis

The frequency of splenic involvement in AL amyloidosis is not precisely known. However, splenomegaly has been reported in 4-13% of patients. We report four cases of spontaneous splenic rupture in patients with AL amyloidosis. Splenic rupture was the initial manifestation of the disease in one of these patients. The other three experienced splenic rupture during or after high-dose intravenous melphalan with autologous peripheral blood stem cell transplantation (HDM/SCT): one during stem cell mobilization with G-CSF prior to HDM/SCT and two after hematopoietic recovery following treatment. Two of the four patients had Factor X deficiency, the most common coagulation abnormality associated with AL amyloidosis. All four patients underwent splenectomy without significant postoperative complications. Splenic rupture in AL amyloidosis as a complication of aggressive treatment with HDM/SCT has not been reported previously.

Acquired disorders of phagocyte function complicating medical and surgical illnesses

There is evidence that acquired dysfunction of neutrophils, monocytes, or macrophages is an important cause of infection in patients with diabetes mellitus, renal or hepatic failure, alcoholism, autoimmune diseases, influenza or human immunodeficiency virus infection, burns, and trauma. Distinguishable mechanisms of acquired phagocyte dysfunction include inhibitory effects of metabolic disturbances (e.g., hyperglycemia, uremia), chemical toxins (e.g., ethanol), viral proteins on phagocyte activation, and pathologic activation of phagocytes in the circulation (e.g., after hemodialysis, burns, or cardiopulmonary bypass). Although the burden of morbidity and mortality resulting from acquired phagocyte dysfunction appears to be vast, research in this area has been hampered by the complexity of the underlying illnesses and by limitations of laboratory assays and clinical study methodology. Given the advent of improved assays of phagocyte functions and treatments that can enhance these functions, there is a pressing need for more prospective studies of acquired phagocyte dysfunction.

Immunologic recovery after autologous blood stem cell transplantation in patients with AL-amyloidosis

We prospectively studied absolute lymphocyte (ALC) and monocyte counts (AMC), lymphocyte subsets and proliferative in vitro responses to mitogen and antigen in 12 patients with AL-amyloidosis (AL) undergoing autologous blood stem cell transplantation (SCT) with high-dose i.v. melphalan. Myeloid and lymphoid recovery (>500 per microl) occurred in a median of 10 days post SCT. While there was a continuous decline in the number of CD4+ T cells at 3 months, ALC, AMC, B cells (CD19+), CD8+ T cells, and NK cells (CD16+/56+) returned to baseline. While T cell proliferative responses to phytohemagglutinin (PHA) remained depressed, B cell function measured by the proliferative response to staphylococcal antigen returned to baseline by 3 months. To supplement our findings, we retrospectively evaluated ALC, AMC and serum immunoglobulin levels in a separate group of patients treated with the same protocol at our institution. ALC and AMC recovery was similar to the pattern observed in the initial study group. Immunoglobulin levels remained within normal ranges at 3 and 12 months after SCT. Of 50 patients who were followed for a minimum of 1 year following SCT, seven (14%) developed shingles and one (2%) had PCP pneumonia. In conclusion, cellular immune function, reflected by absolute numbers of CD4+ T cells and PHA responsive T cell proliferation, is significantly suppressed at 3 months after SCT in patients with AL, and this post-transplant immunosuppression is associated with a low but clinically meaningful occurrence of opportunistic infections typical of T cell immunosuppression.

An overview of the use of high-dose melphalan with autologous stem cell transplantation for the treatment of AL amyloidosis

Primary or AL amyloidosis results from a plasma cell dyscrasia in which fibrillar light chain protein deposition leads to organ failure and death. Standard treatment for AL amyloidosis has been oral melphalan and prednisone. However, this form of treatment modifies the natural history of this lethal disease only marginally, extending median survival from 13 months following diagnosis to 17 months. At Boston University Medical Center, we have developed treatment protocols using high-dose intravenous melphalan with autologous peripheral blood stem cell transplantation (HDM/SCT) to treat AL amyloidosis, and we have treated over 200 patients with HDM/SCT during the past six years. This extensive experience has shown that patients with AL amyloidosis, despite multisystem involvement and compromised organ function can tolerate this aggressive form of treatment. Furthermore, HDM/SCT results in durable hematologic responses in a substantial proportion of patients, and such responses are associated with clinical improvement, decreased amyloid-related organ dysfunction, and prolonged survival. However, toxicity from treatment is high (overall peri-transplant mortality, 14%), particularly for those patients with clinically significant cardiac involvement. For this reason, we believe a multidisciplinary management approach is essential when using HDM/SCT for treatment of AL amyloidosis. Based on our experience, we believe that HDM/SCT is the treatment of choice for patients with AL amyloidosis who have a good performance status and limited cardiac involvement at the time of diagnosis. HDM/SCT offers the best chance for hematologic remission, prolongation of survival, and reversal of amyloid-related disease. At the same time, we believe that HDM/SCT should continue to be examined in the context of clinical trials, directed at developing approaches to broaden the applicability of this therapy by minimizing toxicity and to increase the likelihood of complete hematologic responses.

Bone marrow aspiration, biopsy, and culture in the evaluation of HIV-infected patients for invasive mycobacteria and histoplasma infections

Bone marrow (BM) aspiration and biopsy are used commonly in clinical practice to diagnose invasive tissue infections caused by Mycobacterium avium intracellulare (MAC), Mycobacterium tuberculosis (TB), and Histoplasma capsulatum (HC) in patients with human immunodeficiency virus-1 (HIV) infection. However, the value of these invasive procedures relative to other diagnostic approaches has not been clearly defined. To determine the value of BM culture and BM histology in the diagnosis of opportunistic MAC/TB and HC infections in immunosuppressed patients with HIV, we retrospectively reviewed the records of 56 adult patients with HIV who underwent a single BM aspiration, biopsy, and culture because of unexplained fever and/or other clinical features suggestive of MAC/TB or HC infection. Thirty-two patients (57%) were ultimately diagnosed with MAC/TB or HC infection by positive cultures of BM, blood, sputum, or bronchoalveolar lavage fluid or by the histologic detection of organisms in biopsies of BM or other tissues. The diagnostic sensitivity of BM cultures was equal to that of blood cultures (20/32, or 63%). Granuloma and/or histologically apparent organisms were seen in BM biopsy specimens in 11 of 32 individuals (34%) ultimately diagnosed with MAC/TB or HC infections. Among these 11 cases, both granuloma and acid-fast staining organisms were found in the BM biopsy specimens of 2 individuals for whom both BM and blood cultures were negative. Certain clinical symptoms and signs at the time of BM examination were found by logistic regression analysis to be significantly associated with a subsequent diagnosis of MAC/TB or HC infections; these included high fever, long duration of febrile days prior to BM examination, and elevated direct bilirubin. In conclusion, while the diagnostic sensitivity of BM cultures was found to be no greater than that of blood cultures in detecting MAC/TB or HC infections in immunosuppressed HIV+ patients, histopathologic examination of BM specimens resulted in the relatively rapid identification of nearly one third of infected patients who underwent BM examination, and also identified infections in some patients who were culture negative. These findings support the continued use of BM aspiration, biopsy, and culture for the diagnosis of opportunistic MAC/TB or HC infections in immunosuppressed HIV+ patients, particularly when selected clinical features are present.

Effect of dose-intensive intravenous melphalan and autologous blood stem-cell transplantation on al amyloidosis-associated renal disease

BACKGROUND

Dose-intensive intravenous melphalan with autologous blood stem-cell transplantation induces remission of the plasma cell dyscrasia in a substantial proportion of patients with AL amyloidosis. The impact of this treatment on associated renal disease is not known.

OBJECTIVE

To determine the effect of dose-intensive intravenous melphalan and autologous blood stem-cell transplantation on AL amyloidosis-associated renal disease.

DESIGN

Prospective cohort study.

SETTING

Academic medical center.

PATIENTS

65 patients with AL amyloidosis and urinary protein excretion greater than 1 g/24 h who received dose-intensive intravenous melphalan and autologous blood stem-cell transplantation between 1 July 1994 and 30 June 1998.

MEASUREMENTS

24-hour urinary protein excretion, serum cholesterol level, serum albumin level, creatinine clearance, urine and serum immunoelectrophoresis, and bone marrow biopsy. Renal response was defined as a greater than 50% reduction in urinary protein excretion in the absence of a 25% or greater reduction in creatinine clearance. Complete hematologic response was defined as absence of detectable monoclonal protein in serum and urine and a bone marrow specimen containing less than 5% plasma cells without clonal dominance of kappa or lambda isotype.

RESULTS

Among the 50 patients who survived for at least 12 months, proteinuria, hypoalbuminemia, and hypercholesterolemia improved during follow-up; 36% met criteria for a renal response. Median 24-hour urinary protein excretion decreased from a baseline value of 9.6 g/24 h to 1.6 g/24 h at 12 months among patients with complete hematologic response, and 71% met criteria for a renal response. Twenty-hour urinary protein excretion did not decrease during follow-up among patients with persistent plasma cell disease, and only 11% had a renal response at 12 months (P < 0.001 for hematologic responders vs. nonresponders).

CONCLUSION

Dose-intensive intravenous melphalan with autologous blood stem-cell transplantation improves the nephrotic syndrome in patients with AL amyloidosis-associated renal disease. The benefit is largely limited to patients achieving eradication of the underlying plasma cell dyscrasia.

Acquired factor X deficiency in patients with amyloid light-chain amyloidosis: incidence, bleeding manifestations, and response to high-dose chemotherapy

Acquired deficiency of factor X occurs in patients with systemic amyloid light-chain (AL) amyloidosis, presumably due to adsorption of factor X to amyloid fibrils. Of 368 consecutive patients with systemic AL amyloidosis evaluated at Boston Medical Center, 32 patients (8.7%) had factor X levels below 50% of normal. Eighteen of these patients (56%) had bleeding complications, which were more frequent and severe in the 12 patients below 25% of normal; 2 episodes were fatal. Ten factor X-deficient patients received high-dose melphalan chemotherapy followed by autologous stem cell transplantation. Of 7 patients alive 1 year after treatment, 4 had a complete hematologic response, and all 4 experienced improvement in their factor X levels. One of 2 additional patients with partial hematologic responses had improvement in factor X. Thus, aggressive treatment of the underlying plasma cell dyscrasia in AL amyloidosis can lead to the amelioration of amyloid-related factor X deficiency.

Providing quality medical care at a remote, isolated duty station

The U.S. armed forces deploy active duty personnel to virtually every region of the world. Family members accompany the service member at many of these remote, isolated assignments. This discussion highlights the barriers to the provision of medical care to these active duty personnel, their families, and other eligible beneficiaries, such as government service and Department of Defense civilians. To succeed in this endeavor, the isolated military medical treatment facility must first consider the critical resources available that will enable it to overcome known barriers. Next, careful deliberation will identify the necessary components of a health care network suitable for the remote duty station. The facility must then recognize and address its responsibility to conduct ongoing evaluation of the quality of care and of customer satisfaction with its network. This discussion concludes with a description of a successfully implemented health care network at a remote, isolated duty station.

Autoantibodies to leukocyte alphaMbeta2 integrin glycoproteins in HIV infection

HIV infection is often associated with polyclonal B-cell activation, autoantibodies, and clinically evident autoimmune disease. Because neutropenia and anti-neutrophil autoantibodies are common clinical features of HIV disease, we studied a series of HIV+ patients to determine whether anti-alphaMbeta2 integrin (MAC-1) specific anti-neutrophil autoantibodies occur in HIV disease, as we have shown to occur in patients with immune neutropenia not associated with HIV. Two new assays specific for anti-alphaMbeta2 IgG were developed to carry out these studies: an ELISA method using affinity-purified alphaMbeta2 integrin protein, and a flow cytometry method using subclones of the 293 human fetal kidney cell line, stably transfected with cDNAs for the alphaM and/or beta2 integrin subunits. In studies of the sera of 20 untreated HIV+ individuals, anti-alphaMbeta2 activity was detected in 9 (45%) by one or the other of these assays and in 5 (25%) by both assays. Seven of the 20 HIV+ study subjects had unexplained neutropenia, and of these, 6 (86%) were positive for anti-alphaMbeta2 autoantibodies. Our findings indicate that anti-alphaMbeta2 integrin autoantibodies are frequent in HIV+ individuals, particularly when unexplained neutropenia is also present, and raise the possibility that these autoantibodies may have a role in the acquired neutrophil dysfunction and increased risk of nonopportunistic bacterial infections observed in HIV disease.

Anti-CD34+ Fabs generated against hematopoietic stem cells in HIV-derived combinatorial immunoglobulin library suggest antigen-selected autoantibodies

Bone marrow suppression associated with HIV infection does not appear to be solely due to direct viral cytopathic effects. Autoantibodies may play a role in myelosuppression, however it is unclear whether autoantibodies produced in HIV infection represent a primary pathogenic process or merely reflect polyclonal B cell activation. To address these questions, we generated combinatorial immunoglobulin libraries using the pComb3 phagemid from an HIV+ individual with evidence of circulating autoantibodies. From one library, three anti-CD34 Fabs were identified using fresh CD34+ cells as antigenic targets by a method of phage subtraction. The anti-CD34 Fabs are specific by immunoblotting and Elisa and are of high affinity, with calculated Kds in the range of 10(-7) -10(-8) M. Nucleic acid sequencing revealed all three to be of the VH3 family and to have lambda light chains with some gene segments expressing little somatic mutation, while other segments were somatically mutated in patterns suggestive of antigen selection. These findings indicate that (1) A subset of HIV-associated anti-CD34 autoantibodies are monospecific and antigen-selected and are not merely a consequence of polyclonal B cell activation and elevated Ig levels in HIV. Autoreactivity in HIV therefore includes both polyspecific, low affinity antibodies as well as monospecific antigen-selected high affinity antibodies. (2) Although bone marrow suppression in HIV is likely to be multifactorial, autoantibodies to hematopoietic stem cells may contribute to its pathogenesis. (3) Library sampling of VH gene family rearrangements shows no evidence for under-representation of the VH3 family in the immune dysregulation of HIV infection. Phage subtraction is corroborated to be an effective means of identifying, cloning, and characterizing antibodies to hematopoietic differentiation antigens.

Dose-intensive melphalan with blood stem-cell support for the treatment of AL (amyloid light-chain) amyloidosis: survival and responses in 25 patients

AL (amyloid light-chain) amyloidosis is an uncommon plasma cell disorder in which depositions of amyloid light-chain protein cause progressive organ failure and death in a median of 13 months. Autologous stem-cell transplantation is effective therapy for multiple myeloma and therefore, we evaluated its efficacy for AL amyloidosis. Patients with adequate cardiac, pulmonary, and renal function had stem cells mobilized with granulocyte-colony stimulating factor and were treated with dose-intensive intravenous melphalan (200 mg/m2). Response to therapy was determined by survival and improvement of performance status, complete response or persistence of the clonal plasma cell disorder, and change in the function of organs involved with amyloid at baseline. We enrolled 25 patients with a median age of 48 years (range, 29-60), all of whom had biopsy-proven amyloidosis with clonal plasma cell disorders. Twenty-two (88%) were Southwest Oncology Group performance status 1 or 2 within a year of diagnosis, and 16 (64%) had received no prior therapy. Predominant amyloid-related organ involvement was cardiac (n = 8), renal (n = 7), hepatic (n = 6), neuropathic (n = 3), and lymphatic (n = 1). Fifteen patients had one or two organ systems involved, whereas 10 had three or more involved. With a median follow-up of 24 months (12-38), 17 of 25 patients (68%) are alive, and the median survival has not been reached. Thirteen of 21 patients (62%) evaluated 3 months posttransplant had complete responses of their clonal plasma cell disorders. Currently, two thirds of the surviving patients (11 of 17) have experienced improvements of amyloid-related organ involvement in all systems, whereas 4 of 17 have stable disease. The improvement in the median performance status of the 17 survivors at follow-up (0 [range, 0-3]) is statistically significant versus baseline (2 [range, 1-3]; P < . 01). Significant negative prognostic factors with respect to overall survival include amyloid involvement of more than two major organ systems and predominant cardiac involvement. Three patients have experienced relapses of the clonal plasma cell disorder at 12 and 24 months. Dose-intensive therapy should currently be considered as the preferred therapy for patients with AL amyloidosis who meet functional criteria for autologous transplantation.

Mobilized CD34+ cells selected as autografts in patients with primary light-chain amyloidosis: rationale and application

BACKGROUND

Concern about tumor cell contamination in stem cell preparations has led to the use of CD34+ cell selection as a means of purging. Increasing the number of CD34+ cells per leukapheresis may help to provide an adequate dose of CD34+ cells.

STUDY DESIGN AND METHODS

The reverse transcriptase polymerase chain reaction (RT-PCR) was employed to clone overexpressed clonotypic immunoglobulin light-chain variable region genes (Ig VL) from bone marrows of patients with primary light-chain amyloidosis (AL). Patient-specific primers were designed to evaluate stem cell collections for contamination. CD34+ cell selection was performed on components from AL patients who underwent mobilization with granulocyte-colony-stimulating factor (G-CSF) (filgrastim; 16 microg/kg/d for 4 days) and collection by large-volume leukapheresis (LVL;25L) on Days 4 and 5. The selected cells alone were transfused after patients received mephalan (200 mg/m2).

RESULTS

Contamination was found in collections from 4 to 7 patients, which provided the rationale for a subsequent trial of CD34+ cell selection. The median number of CD34+ cells per kg collected on Days 4 and 5, and in toto, was 4.0 x 10(6)(1.1-12.7), 7.9 x 10(6)(1.8-12.7), and 10.7 x 10(6)(2.9-25.4), respectively (n = 9 patients). The median yield per selection was 38 percent, with a purity of 85 percent (45-97%), and the viability of CD34+ cells averaged 96.4 +/- 3.6 percent (n = 18 selections). The median number of CD34+ cells infused was 5.9 x 10(6) per kg (2.1-10.1). In comparison with AL patients given unselected autografts, patients receiving selected CD34+ cells experienced similar reconstitution of neutrophils and platelets but slower lymphocyte recovery.

CONCLUSION

Patients with AL often have contamination with clonotypic cells in their blood autografts. G-CSF mobilization and LVL provide components that allow the selection of adequate doses of CD34+ cells. The use of CD34+ cells in patients with AL achieves rapid neutrophil and platelet recovery but delayed lymphocyte recovery. CD34+ cell selection is feasible in the treatment of AL, but its effectiveness in purging clonotypic cells remains to be ascertained.

Calcaneal osteomyelitis caused by nail puncture wounds

Plantar puncture wounds to the foot are a common injury. A small number (1.8%) of these puncture wounds become infected and progress to osteomyelitis. The purpose of this article is to report the cases of six patients who developed osteomyelitis of the calcaneus after a puncture wound to the heel caused by a nail. The characteristics of the patients, the pathogenic organism, and the outcome were studied. Patients who were healthy and had no systemic illness (N = 4) had only one pathogenic organism cultured, whereas patients who had systemic illness (diabetes mellitus, N = 2) had more than one pathogenic organism cultured. The only amputation in this group occurred in a patient with diabetes mellitus. It was concluded that diabetic patients who develop calcaneal osteomyelitis from a nail puncture wound are more likely to have multiple pathogens cultured. Furthermore, if a diabetic neuropathy is also present, the nail puncture wound may be the initial injury leading to a chronic ulceration, increasing the risk of amputation.

Endoscopic plantar fascia release: a cross-sectional anatomic study

Endoscopic plantar fascia release is a new procedure proposed to treat heel pain and plantar fasciitis. The purpose of this study was to assess the structures at risk during plantar fascia release using this method. Ten fresh-frozen cadaver feet were divided into two groups. All specimens underwent cannula placement inferior to the plantar fascia. Five-of the specimens had plantar fascia release using the endoscopic technique. Six of the specimens were then frozen and cut in transverse, sagittal, and coronal sections to visualize the relationship between the cannula and plantar fascia and surrounding structures. Gross dissection was performed on the remaining four specimens. The amount of plantar fascia released, the relationship to the nerve to abductor digiti minimi, and the fascia of the abductor hallucis muscle were assessed. The average distance from the cannula margin to the nerve to the abductor digiti minimi was 6 mm at the medial border of the plantar fascia. The average amount of plantar fascia released was 90%. Although a complete release was attempted, the fascia to the abductor hallucis was not released in any of the specimens. The nerve to the abductor digiti minimi was not damaged in any of the specimens. On coronal sections, the nerve was closer to the cannula and plantar fascia release than previously reported.

Tiazofurin effects on IMP-dehydrogenase activity and expression in the leukemia cells of patients with CML blast crisis

Tricot et al have reported that the nucleoside analog tiazofurin can induce hematologic remissions in patients with chronic myelogenous leukemia in blast crisis (CML-BC). These reports prompted us to begin a derivative, phase II trial of tiazofurin in CML-BC to determine if the promising findings reported by these investigators could be reproduced. In our ongoing trial patients receive tiazofurin by IV infusion (2200-4400 mg/m2 over 1 hr) once every 24-48 hrs for up to 10 days. Each of 3 patients, treated to date on this trial, experienced substantial hematologic responses with normalization of WBC counts and complete or partial clearance of blasts from the blood within 4-11 days of treatment. These responses were relatively brief, in that leukemic blasts reaccumulated in the marrow and blood of patients within 4 weeks following treatment, but were re-induced with subsequent courses of treatment. Of interest, the rates of blast cell reaccumulation appeared to increase progressively following sequential courses of treatment. Tiazofurin, which inhibits IMP-dehydrogenase (IMPDH) and blocks guanine ribonucleotide synthesis, has been shown to increase IMPDH mRNA expression in various cell lines in vitro, as an apparently compensatory response to guanylate deprivation. Studies of IMPDH mRNA expression in the leukemic blasts of CML-BC patients receiving tiazofurin treatment showed that this same phenomenon occurs in vivo. Since IMPDH activity is linked to the proliferative activity of neoplastic cells an amplification of IMPDH message expression induced by tiazofurin may lead to an increased sensitivity of the leukemic clone to cycle active agents.

Efficiency of human HLA-mismatched CD34+ cells from unrelated donors in establishing in vitro hematopoiesis in allogeneic long-term marrow cultures

We have examined the capacity of highly purified human CD34+ marrow cell isolates from unrelated, HLA-mismatched donors to establish in vitro hematopoiesis on recipient marrow stromal cells in 2-stage hematopoietic long-term marrow cultures (H-LTMC). HLA-typing of both peripheral blood mononuclear cells and CD34+ marrow cells was performed for both HLA class I and HLA class II antigens for eight healthy individuals. Significant antigenic mismatches for these molecules ranged from three to six antigens for each recipient-donor pair. Comparison of MHC antigen expression by peripheral blood cells and CD34+ marrow cell isolates confirmed the presence of identical HLA-A, -B, and -C, and -DR specificities on the surface of these cells. Typing of -DQ specificities, however, was not consistently reactive on CD34+ cells. The > or = 20% plating efficiency of purified CD34+ cells for BFU-E, CFU-GM, and CFU-MIX allowed us to use inoculum doses of 10(3), 10(4), and 10(5) cells to determine the efficiency of allogeneic CD34+ cells in achieving in vitro engraftment and the establishment of hematopoiesis in H-LTMC. Engraftment of adherent BFU-E, CFU-GM, and CFU-MIX was equally efficient for autologous and allogeneic CD34+ cells. In vitro hematopoiesis reflected by the cumulative recoveries of progenitor cells over time was also equivalent for allogeneic and autologous CD34+ cells. These results demonstrate that highly purified, HLA-mismatched CD34+ marrow cells proliferate and establish in vitro hematopoiesis as efficiently as autologous cells in marrow derived stromal cell cultures and confirm that interactions between stromal cells and highly purified CD34+, DR-, and CD34+, DR+ marrow cell isolates are not MHC-restricted.

Dose-intensive melphalan with blood stem cell support for the treatment of AL amyloidosis: one-year follow-up in five patients

The morbidity and lethality of AL amyloidosis is caused by the deposition of lg light chains as fibrillar amyloid protein in vital organs, disrupting their function, and not by the generally low burden of clonal plasma cells that produce the paraproteins. Survival of patients with AL amyloidosis is no more than 1 to 2 years from the time of diagnosis with current management approaches. Clearly, more effective therapies are needed for this rapidly lethal disease. Five patients were treated with dose-intensive melphalan and blood stem cell support and followed for a period of 1 year. Patients were diagnosed with AL amyloidosis by tissue biopsy and categorized by performance status and organ involvement. Their plasma cell dyscrasias were evaluated with immunofixation electrophoresis of serum and urine specimens, quantitative serum lgs, and immunohistochemical staining of bone marrow biopsy specimens. After treatment with dose-intensive intravenous melphalan followed by infusion of autologous growth-factor-mobilized blood stem cells, clinical evaluations and plasma cell studies were repeated at 3 and 12 months. Three men and 2 women aged 38 to 53 years were treated. Median performance status (SWOG) was 2 (1 to 3), and clinical presentations included nephrotic syndrome (n = 1), symptomatic cardiomyopathy (n = 1), gastrointestinal involvement with polyneuropathy (n = 2), and hepatomegaly (n = 1). With a median follow-up of 13 months (12 to 17 months), all five patients are well and have shown stable or improved performance status and clinical remission of organ-related dysfunction, including a 50% reduction in daily proteinuria with no change in creatinine, reversal of symptoms of cardiomyopathy and reductions of posterior wall and septal thickening, reversal of polyneuropathy and gastric atony, and resolution of hepatomegaly by computed tomographic scan. In 3 of the 5 patients (60%) at 12 months after treatment, plasma cell dyscrasias could not be detected. Dose-intensive chemotherapy with intravenous melphalan and growth-factor-mobilized blood stem cell support is feasible therapy for patients with AL amyloidosis, even when there is clinical evidence of cardiac involvement. At least some patients with AL amyloidosis achieve complete remission of their plasma cell dyscrasia, improvement in performance status, and clinical remission of organ-specific disease after this form of treatment.

Pelvic and bladder trauma: a case report and subject review

Pelvic fracture and bladder rupture resulted in bladder wall entrapment in the fracture site of a patient involved in a severe motor vehicle accident. Although hematuria and bladder rupture are known to occur after fracture of the pelvis, our literature review showed no reports of this type of injury or management. Bladder extravasation was managed with catheter drainage and surgical extraction; viscus repair was performed for the bladder rupture. Fracture healing and bladder continuity resolved uneventfully.

Osteomyelitis

The complexities of osteomyelitis make its diagnosis and treatment challenging. Current trends emphasize early diagnosis and aggressive treatment. Imaging has improved, with nuclear scans and magnetic resonance imaging, and technique modifications have enhanced the specificity of these tests. Treatment depends on thorough debridement of necrotic bone and tissue, accurate cultures and administration of culture, and sensitivity-specific antibiotics. Antibiotic delivery has expanded to include effective oral agents and local agents mixed with polymethylmethacrylate or a biodegradable substance. Success rates in treating this disease have improved with the use of a systematic approach, making outcome more predictable.

Collection of mobilized blood progenitor cells for hematopoietic rescue by large-volume leukapheresis

BACKGROUND

Mobilized blood progenitor cells rapidly reconstitute hematopoiesis in patients after dose-intensive chemotherapy. However, optimal timing and methods of mobilized blood progenitor cell collection have yet to be fully defined.

STUDY DESIGN AND METHODS

The utility of large-volume leukapheresis (LVL; > 15 L blood processed) in collecting target doses of mononuclear cells (7 x 10(8)/kg) for use in autologous hematopoietic rescue was investigated. LVL was begun at a standardized interval (14 days) after a course of limited chemotherapy and subsequent daily recombinant human granulocyte-macrophage-colony-stimulating factor administration to mobilize blood progenitor cells into the circulation. With each LVL procedure, mononuclear cells, colony-forming units-granulocyte-macrophage (CFU-GM), burst-forming units-erythroid, mixed colonies, total clonogenic progenitor cells, and CD34+ cells collected per kg of patient weight were counted. After high-dose chemotherapy and infusion of cryopreserved mobilized blood progenitor cells, the days needed for neutrophils to reach levels of > 0.5 x 10(9) per L and for platelets to reach levels of > 20 x 10(9) per L were recorded.

RESULTS

In 14 previously treated cancer patients, an average of 28.9 +/- 4.9 L of blood was processed per LVL (n = 35) to collect medians of 2.5 x 10(8) mononuclear cells per kg (range, 1.0-7.4), 14 x 10(4) CFU-GM per kg (0-208), 27 x 10(4) clonogenic progenitor cells per kg (0-370), and 2.8 x 10(6) CD34+ cells per kg (0-112.5). Fifty-seven percent of patients (8/14) required one or two LVL procedures to collect adequate blood progenitor cells (range, 1-4). After dose-intensive chemotherapy, 13 patients received medians of 6.8 x 10(8) mononuclear cells per kg (range, 5.1-9.9), 53 x 10(4) CFU-GM per kg (9-208), and 12 x 10(6) CD34+ cells per kg (3.6-112.5). Rapid hematopoietic reconstitution occurred with 10 days (range, 8-12) and 9 days (6-15), respectively, for neutrophil and platelet recoveries.

CONCLUSION

Scheduled LVL, beginning on Day 14 after the administration of granulocyte-macrophage-colony-stimulating factor following chemotherapy, is a convenient and efficient method of collecting blood progenitor cells. The mononuclear cells so obtained effected consistent and rapid hematopoietic reconstitution in a highly reproducible manner in a group of heavily treated patients.

Open dislocation of the knee

Traumatic open dislocation of the knee is an infrequent, severe injury associated with extensive ligamentous damage and a high incidence of vascular and neurologic involvement. Eighteen patients with 19 open knee dislocations were treated at the affiliated hospitals of the University of Pennsylvania and Louisiana State University Medical Center during an 18-year period. Final results included three above-knee amputations, one knee fusion, and one total knee arthroplasty. The 14 knees salvaged had only fair to poor function according to the Hospital for Special Surgery Knee Injury Score at an average follow-up of 36 months after the injury (average score = 29, range - 17 to 37). Nine patients (47%) had concomitant neurologic or vascular injury, and eight patients (42%) had wound healing difficulties. Five complete disruptions of the popliteal artery or posterior tibial artery underwent emergent revascularization, successful in three of the extremities, with the remaining two extremities requiring above-knee amputations. These massive injuries are often limb-threatening despite prompt surgical intervention and early antibiotic therapy. There is a very high incidence of infection and neurologic injury with a guarded prognosis for limb survival and satisfactory function.

Inhibitory effects of HIV-1-infected stromal cell layers on the production of myeloid progenitor cells in human long-term bone marrow cultures

This report presents the results of studies using long-term bone marrow cultures (LTBMC) of human bone marrow cells to investigate the effect of HIV-1 on in vitro hematopoiesis. Confluent stromal cell layers established from human bone marrow cells were irradiated to eliminate residual hematopoietic progenitor cells and exposed to HIV-1ADA or to HIV-1IIIB, monocytotropic and lymphocytotropic strains of HIV-1, respectively. A productive infection did not develop in cultures exposed to HIV-1IIIB but did for cultures exposed to HIV-1ADA as there was a progressive increase in HIV-1 p24 antigen. Stromal cell layers infected with HIV-1ADA were also cocultured with autologous CD34+ bone marrow cells. Four days, 1, 2, and 3 weeks later, the number of colony-forming units granulocyte/macrophage (CFU-GM) in non- and HIV-infected LTBMC was determined. The number of CFU-GM increased during the first week in both non- and HIV-infected LTBMC. One week after the coculture of CD34+ cells with stromal cell layers infected with HIV-1ADA, the number of CFU-GM in six out of eight experiments was reduced compared to noninfected control LTBMC. In those six experiments, the number of CFU-GM was 53 +/- 6% standard error of the mean (SEM) of the number in noninfected LTBMC. A reduced number of CFU-GM was observed in the nonadherent fraction of HIV-infected LTBMC for at least 2 weeks. These results demonstrate that some cells in the stromal cell layers of LTBMC were targets for HIV-1 and that HIV-infected stromal cell layers suppressed or delayed the production of CFU-GM.

Contrasting effects of recombinant human granulocyte-macrophage colony-stimulating factor (CSF) and granulocyte CSF treatment on the cycling of blood elements in childhood-onset cyclic neutropenia

Recombinant human granulocyte colony-stimulating factor (G-CSF) treatment has been shown to increase average neutrophil counts substantially in patients with childhood-onset cyclic neutropenia (or "cyclic hematopoiesis"), but not to eliminate the cyclic oscillations of neutrophil counts or those of other blood elements (monocytes, platelets, eosinophils, and reticulocytes) that are characteristic of this hematopoietic disorder. Indeed, oscillations of neutrophil counts are amplified during G-CSF treatment. We have compared the effects of recombinant granulocyte-macrophage-CSF (GM-CSF) with those of G-CSF in three patients with this disease (2 men and 1 woman, 17, 30, and 32 years of age). These patients were treated with GM-CSF (2.1 micrograms/kg/day, subcutaneously) for 6 weeks, preceded and followed by 6 to 13 weeks of detailed observation to document changes in the cyclic oscillations of blood neutrophils and other blood elements; two of the patients were subsequently treated with G-CSF (5.0 micrograms/kg/d, subcutaneously) and observed for comparable periods of time. Unlike G-CSF treatment, which increased average neutrophil counts more than 20-fold, GM-CSF increased neutrophil counts only modestly, from 1.6- to 3.9-fold, although eosinophilia of varying prominence was induced in each patient. However, at the same time, GM-CSF treatment dampened or eliminated the multilineage oscillations of circulating blood elements (neutrophils, monocytes, platelets, and/or reticulocytes) in each of the patients. In contrast, G-CSF treatment of the same patients markedly amplified the oscillations of neutrophil counts and caused the cycling of other blood elements (monocytes in particular) to become more distinct. These findings support the conclusion that the distinctive cycling of blood cell production in childhood-onset cyclic neutropenia results from abnormalities in the coordinate regulation of both GM-CSF-responsive, multipotential progenitor cells and G-CSF-responsive, lineage-restricted, neutrophil progenitors.

Characterization of influenza A virus binding sites on human neutrophils

Exposure of human neutrophils (PMN) to influenza A virus (IAV) triggers discrete responses in these cells that interfere with their normal host defense functions. Because the restricted host range and tissue specificities of many viruses are determined by cell surface molecules acting as virus receptors on target cells, it seemed plausible that IAV might interact with neutrophils via specific plasma membrane glycoproteins that bind to viral hemagglutinin. When the binding of intact IAV (ATCC strain A/PR/8/34 (H1N1)) to PMNs was examined by flow cytometry, virus binding was found to be saturable and to be diminished after extensive desialation of the cells with neuraminidase. Stimulation of PMNs with FMLP (0.1 microM) caused a transient increase in IAV binding that was maximal (> 200%) at 2 min after stimulation. When neutrophil membrane proteins were separated by gel electrophoresis and transferred to nitrocellulose, IAV bound selectively to two polypeptide bands of approximately 125 and 160 kDa. Relative binding to these two bands was modified and ultimately eliminated by treatment of PMN membrane proteins with neuraminidase before electrophoresis and blotting. Intact virus precipitated a limited number of proteins from solubilized PMN plasma membrane preparations, and Abs specific for sialophorin (CD43) recognized virus-precipitated PMN membrane proteins of the same apparent m.w. as those detected in virus-membrane protein blots. These findings indicate that IAV binds to human PMNs through interactions with a limited number of PMN membrane glycoproteins, which include sialophorin (CD43).

Characterization of influenza A virus binding sites on human neutrophils

Exposure of human neutrophils (PMN) to influenza A virus (IAV) triggers discrete responses in these cells that interfere with their normal host defense functions. Because the restricted host range and tissue specificities of many viruses are determined by cell surface molecules acting as virus receptors on target cells, it seemed plausible that IAV might interact with neutrophils via specific plasma membrane glycoproteins that bind to viral hemagglutinin. When the binding of intact IAV (ATCC strain A/PR/8/34 (H1N1)) to PMNs was examined by flow cytometry, virus binding was found to be saturable and to be diminished after extensive desialation of the cells with neuraminidase. Stimulation of PMNs with FMLP (0.1 microM) caused a transient increase in IAV binding that was maximal (&gt; 200%) at 2 min after stimulation. When neutrophil membrane proteins were separated by gel electrophoresis and transferred to nitrocellulose, IAV bound selectively to two polypeptide bands of approximately 125 and 160 kDa. Relative binding to these two bands was modified and ultimately eliminated by treatment of PMN membrane proteins with neuraminidase before electrophoresis and blotting. Intact virus precipitated a limited number of proteins from solubilized PMN plasma membrane preparations, and Abs specific for sialophorin (CD43) recognized virus-precipitated PMN membrane proteins of the same apparent m.w. as those detected in virus-membrane protein blots. These findings indicate that IAV binds to human PMNs through interactions with a limited number of PMN membrane glycoproteins, which include sialophorin (CD43).

Magnetic resonance imaging for the diagnosis of osteomyelitis in the diabetic patient with a foot ulcer

Twenty-seven diabetic patients (12 males and 15 females) with clinically suspected osteomyelitis complicating soft tissue infection of the foot underwent 29 magnetic resonance imaging studies of the suspected lesion. Of these patients, 26 had plain film radiographs, 11 had technetium bone scanning, and 12 had indium-labeled leukocyte scintigraphy performed within 2 weeks of the magnetic resonance imaging. Definitive diagnosis of the presence or absence of osteomyelitis was obtained on the basis of surgical findings, histological evidence, or resolution with nonoperative therapy. Magnetic resonance imaging was 90% accurate (sensitivity 77%, specificity 100%) in the diagnosis of osteomyelitis in this patient population. Technetium bone scan was 45% accurate (sensitivity 100%, specificity 25%); indium-labeled leukocyte scintigraphy was 50% accurate (80% sensitivity, 29% specificity); and plain film roentgenography was 73% accurate (60% sensitivity, 81% specificity). Magnetic resonance imaging is a powerful, noninvasive tool for determining the presence or absence of osteomyelitis in the patient with a diabetic foot ulcer.

Involvement of a botulinum toxin-sensitive 22-kDa G protein in stimulated exocytosis of human neutrophils

Studies of human peripheral blood neutrophils (PMNs) demonstrated that botulinum neurotoxin D (BT-D) ADP-ribosylates a 22-kDa PMN G protein (G22k) and inhibits the exocytosis of both specific and azurophilic granules stimulated by FMLP. Furthermore, this inhibition of PMN exocytosis by BT-D was found to be correlated with the degree of irreversible ADP-ribosylation of G22k by BT-D and to require modification of at least 85% of PMN G22k before significant inhibition of secretion is observed. Although both pertussis toxin and BT-D inhibited exocytosis in FMLP-stimulated PMNs, the inhibitory effects of the two toxins were found to be additive. Pertussis toxin and BT-D also inhibited Ca2+/GTP/GTP gamma S-induced secretion in digitonin-permeabilized PMNs, but there were distinct differences between the inhibitory effects of the two toxins. In contrast to BT-D, the exotoxin botulinum C3 was found to ADP-ribosylate primarily a 24- to 25-kDa PMN protein, and it was not found to inhibit Ca(2+)- and GTP-induced secretion in permeabilized PMNs. Ultrastructural studies of BT-D-treated PMNs showed an accumulation of distinct membrane-bound organelles in the periphery of the cells after FMLP stimulation, suggestive of a toxin-induced block in organelle-plasma membrane fusion. Taken together, these findings indicate that BT-D-sensitive G22k has a functional role in stimulated exocytosis of PMNs.

Involvement of a botulinum toxin-sensitive 22-kDa G protein in stimulated exocytosis of human neutrophils

Studies of human peripheral blood neutrophils (PMNs) demonstrated that botulinum neurotoxin D (BT-D) ADP-ribosylates a 22-kDa PMN G protein (G22k) and inhibits the exocytosis of both specific and azurophilic granules stimulated by FMLP. Furthermore, this inhibition of PMN exocytosis by BT-D was found to be correlated with the degree of irreversible ADP-ribosylation of G22k by BT-D and to require modification of at least 85% of PMN G22k before significant inhibition of secretion is observed. Although both pertussis toxin and BT-D inhibited exocytosis in FMLP-stimulated PMNs, the inhibitory effects of the two toxins were found to be additive. Pertussis toxin and BT-D also inhibited Ca2+/GTP/GTP gamma S-induced secretion in digitonin-permeabilized PMNs, but there were distinct differences between the inhibitory effects of the two toxins. In contrast to BT-D, the exotoxin botulinum C3 was found to ADP-ribosylate primarily a 24- to 25-kDa PMN protein, and it was not found to inhibit Ca(2+)- and GTP-induced secretion in permeabilized PMNs. Ultrastructural studies of BT-D-treated PMNs showed an accumulation of distinct membrane-bound organelles in the periphery of the cells after FMLP stimulation, suggestive of a toxin-induced block in organelle-plasma membrane fusion. Taken together, these findings indicate that BT-D-sensitive G22k has a functional role in stimulated exocytosis of PMNs.

Immediate internal fixation of low-velocity gunshot-related femoral fractures

Fractures caused by gunshots are increasingly common in urban hospitals and trauma centers. The rising incidence and complexity of these injuries present difficult management problems and health care burdens. In a 3-year period, from 1989 through 1991, 21 patients with femoral shaft fractures from low-velocity bullets were treated with intramedullary fixation within 15 hours of admission. Eighteen patients were available for follow-up. The fractures had healed in all patients. Average hospitalization for an isolated injury was 7 days. There were no complications related to immediate internal fixation. Immediate internal fixation of femoral shaft fractures caused by low-velocity gunshots can be performed in an efficient and cost effective manner.