Prospective assessment of white matter integrity in adult stem cell transplant recipients

Hematopoietic stem cell transplantation (HSCT) is often used in the treatment of hematologic disorders. Although it can be curative, the pre-transplant conditioning regimen can be associated with neurotoxicity. In this prospective study, we examined white matter (WM) integrity with diffusion tensor imaging (DTI) and neuropsychological functioning before and one year after HSCT in twenty-two patients with hematologic disorders and ten healthy controls evaluated at similar intervals. Eighteen patients received conditioning treatment with high-dose (HD) chemotherapy, and four had full dose total body irradiation (fTBI) and HD chemotherapy prior to undergoing an allogeneic or autologous HSCT. The results showed a significant decrease in mean diffusivity (MD) and axial diffusivity (AD) in diffuse WM regions one year after HSCT (p-corrected <0.05) in the patient group compared to healthy controls. At baseline, patients treated with allogeneic HSCT had higher MD and AD in the left hemisphere WM than autologous HSCT patients (p-corrected <0.05). One year post-transplant, patients treated with allogeneic HSCT had lower fractional anisotropy (FA) and higher radial diffusivity (RD) in the right hemisphere and left frontal WM compared to patients treated with autologous HSCT (p-corrected <0.05).There were modest but significant correlations between MD values and cognitive test scores, and these were greatest for timed tests and in projection tracts. Patients showed a trend toward a decline in working memory, and had lower cognitive test scores than healthy controls at the one-year assessment. The findings suggest a relatively diffuse pattern of alterations in WM integrity in adult survivors of HSCT.

A prospective evaluation of changes in brain structure and cognitive functions in adult stem cell transplant recipients

Hematopoietic stem cell transplantation (HSCT) is an efficacious treatment for many hematologic malignancies. However, the conditioning regimen of high-dose (HD) chemotherapy with or without total body irradiation (TBI) can be associated with neurotoxicity. In this prospective study, we used quantitative neuroimaging techniques to examine regional gray matter and ventricular volumes, and standardized neuropsychological tests to assess cognitive function before and 1 year after HSCT in 28 patients with hematologic malignancies and in ten healthy controls evaluated at similar intervals. Nineteen patients received conditioning treatment with HD chemotherapy alone and nine had both TBI and HD chemotherapy. There was a significant reduction in gray matter volume in the middle frontal gyrus bilaterally and in the left caudate nucleus in the patient group (all patients combined) but not among healthy controls over the 1-year follow-up period. There was a significant increase in left lateral ventricle volume and in total ventricle volume in the patient group, relative to healthy controls. Similar brain structural changes were seen for patients treated with HD chemotherapy alone. The neuropsychological results showed that 21% of patients could be classified as impaired at baseline. The Reliable Change Index suggested no significantly different rates of cognitive decline between patients and healthy controls. The findings suggest that HSCT patients may be at an increased risk for developing regional brain volume loss, and that subgroups may experience cognitive dysfunction prior to and 1 year following the transplant.

Graft-versus-host disease after double-unit cord blood transplantation has unique features and an association with engrafting unit-to-recipient HLA match

Manifestations of and risk factors for graft-versus-host disease (GVHD) after double-unit cord blood transplantation (DCBT) are not firmly established. We evaluated 115 DCBT recipients (median age, 37 years) who underwent transplantation for hematologic malignancies with myeloablative or nonmyeloablative conditioning and calcineurin inhibitor/mycophenolate mofetil immunosuppression. Incidence of day 180 grades II to IV and III to IV acute GVHD (aGVHD) were 53% (95% confidence interval, 44 to 62) and 23% (95% confidence interval, 15 to 31), respectively, with a median onset of 40 days (range, 14 to 169). Eighty percent of patients with grades II to IV aGVHD had gut involvement, and 79% and 85% had day 28 treatment responses to systemic corticosteroids or budesonide, respectively. Of 89 engrafted patients cancer-free at day 100, 54% subsequently had active GVHD, with 79% of those affected having persistent or recurrent aGVHD or overlap syndrome. Late GVHD in the form of classic chronic GVHD was uncommon. Notably, grades III to IV aGVHD incidence was lower if the engrafting unit human leukocyte antigen (HLA)-A, -B, -DRB1 allele match was >4/6 to the recipient (hazard ratio, 0.385; P = .031), whereas engrafting unit infused nucleated cell dose and unit-to-unit HLA match were not significant. GVHD after DCBT was common in our study, predominantly affected the gut, and had a high therapy response, and late GVHD frequently had acute features. Our findings support the consideration of HLA- A,-B,-DRB1 allele donor-recipient (but not unit-unit) HLA match in unit selection, a practice change in the field. Moreover, new prophylaxis strategies that target the gastrointestinal tract are needed.

Prospects for advanced electron cyclotron resonance and electron beam ion source charge breeding methods for EURISOL

As the most ambitious concept of isotope separation on line (ISOL) facility, EURISOL aims at producing unprecedented intensities of post-accelerated radioactive isotopes. Charge breeding, which transforms the charge state of radioactive beams from 1+ to an n+ charge state prior to post-acceleration, is a key technology which has to overcome the following challenges: high charge states for high energies, efficiency, rapidity and purity. On the roadmap to EURISOL, a dedicated R&D is being undertaken to push forward the frontiers of the present state-of-the-art techniques which use either electron cyclotron resonance or electron beam ion sources. We describe here the guidelines of this R&D.

Hepatic safety of voriconazole after allogeneic hematopoietic stem cell transplantation

Voriconazole is increasingly used in allogeneic hematopoietic stem cell transplantation (HSCT) for prophylaxis and treatment of fungal infections. Hepatic dysfunction is common in patients undergoing HSCT and may have an impact on the clinical decision to institute voriconazole. We conducted a retrospective review of all adult and pediatric HSCT recipients who received >2 consecutive doses of voriconazole between January 2005 and February 2008. Clinical hepatotoxicity was defined as the subjective attribution of liver enzyme elevation (even a mild one) to hepatotoxicity because of voriconazole by the treating physician and leading to discontinuation of voriconazole. Biochemical hepatotoxicity was defined as an elevation in one or more liver enzymes to >3 times the upper limit of normal or >3 times the baseline value if abnormal at baseline. Liver enzymes assessed included aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and total bilirubin. Simple and multiple logistic regressions were used to define the risks for hepatic dysfunction. The Wilcoxon signed-rank test was used to assess the differences in liver function test values before, during, and after the use of voriconazole. Sixty-eight of 200 patients (34%) developed hepatotoxicity while on voriconazole. The median duration of voriconazole therapy was 72 days (range, 1-804 days). Biochemical hepatotoxicity occurred in 51 patients (75%); clinical hepatotoxicity, in 17 patients (25%). Thirty-five (51%) of the patients with hepatotoxicity required discontinuation of therapy. In simple logistic regression, acute graft-versus-host disease (GVHD) was a risk factor for hepatotoxicity, and receipt of a T-cell depleted allograft was protective. In multiple logistic regression, acute GVHD (P = .002) remained significant. There were no cases of liver failure or death attributed to voriconazole. In this cohort of patients undergoing allogeneic HSCT, the rate of hepatotoxicity while on voriconazole was 34%. In general, the hepatic dysfunction was mild and reversible. Voriconazole therapy with monitoring appears to be reasonably safe for use in HSCT recipients at high risk for invasive fungal infections.

Risk factors and attributable mortality of late aspergillosis after T-cell depleted hematopoietic stem cell transplantation

AIM

Invasive aspergillosis occurs in 5-15% of allogeneic hematopoietic stem cell transplant (HSCT) recipients. Through the 1990s there has been an increase in the incidence of late aspergillosis (LA). We report on the incidence, risk factors, and attributable mortality of LA in a cohort of 398 adult and pediatric patients at Memorial Sloan-Kettering Cancer Center from January 1999 through December 2003.

METHODS

LA was defined as occurring > 40 days post HSCT. LA cases were identified by prospective surveillance and examination of a computerized database. Probable or definite aspergillosis was defined by standard EORTC/MSG criteria. Mortality was attributed to LA if it caused or significantly contributed to death.

RESULTS

The overall incidence of LA in our cohort was 4.1%. Median time from stem cell infusion to diagnosis of LA was 164 days (range 68-677) after HSCT. The incidence of LA among unmodified, T-cell depleted, or reduced intensity HSCT was 2.2%, 4%, and 6.8%, respectively (P not significant). Risk factors for LA were grade II-IV acute graft-versus-host disease (GVHD) (P=0.002), chronic GVHD (P=0.01), secondary neutropenia (P=0.02), and reduced intensity conditioning containing alemtuzumab (P=0.01). LA was the immediate cause of death in 1 of 10 (10%) T-cell depleted, 2 of 2 (100%) unmodified, and 1 of 4 (25%) of reduced-intensity HSCT.

CONCLUSIONS

LA developed a median 164 days post HSCT. All-cause 30-day mortality of LA was 56.3%. The majority of LA cases died of concurrent infections and not from invasive aspergillosis.

Invasive adenoviral infections in T-cell-depleted allogeneic hematopoietic stem cell transplantation: high mortality in the era of cidofovir

BACKGROUND

Adenovirus (ADV) infection occurs in 5-21% of allogeneic hematopoietic stem cell transplants (HSCT). Symptomatic enteritis and hemorrhagic cystitis may be encountered but are seldom fatal. In contrast, mortality rates of up to 75% are reported for adenoviral pneumonia or hepatitis. Cidofovir is currently being increasingly used for treatment of adenoviral infections after HSCT. The efficacy of cidofovir in patients with invasive adenoviral infection is not established.

FINDINGS

We reviewed 687 adult and pediatric patients who received allogeneic HSCT at our institution from 1998 through June 2005. ADV was isolated from 64 (9.3%) patients. Eleven patients received cidofovir for invasive disease occurring at median 39 days (range 3-145) post HSCT. The median age was 40 (range 6-61) years. Seventy-three percent received a T-cell-depleted graft and 18% had grade 3-4 graft-versus-host disease (GVHD) of the gut. Three out of 3 (100%) patients with adenoviral pneumonia died. One patient with hepatitis, cholecysitis, and viremia cleared the infection after 3 months. Two out of 7 (28.6%) patients with hemorrhagic colitis or cystitis died of ADV (1 with extensive GVHD).

CONCLUSION

Mortality rates of ADV pneumonitis after allogeneic HSCT remain high in the era of cidofovir. Clinical trials are needed to evaluate management strategies for this life-threatening infection.

Predictors for persistent cytomegalovirus reactivation after T-cell-depleted allogeneic hematopoietic stem cell transplantation

Cytomegalovirus (CMV) reactivation occurs in up to 60% of CMV-seropositive recipients after allogeneic hematopoietic stem cell transplantation (HSCT). The incidence of CMV disease among T-cell-depleted HSCT patients has been reported from 5-15%. The incidence of reactivation refractory to antivirals in this population is not well studied.

METHODS

In this retrospective study we characterized the outcome of CMV reactivation in a cohort of 255 adult and pediatric patients who underwent T-cell-depleted HSCT at Memorial Sloan-Kettering Cancer Center from September 1999 through August 2004. CMV infection was monitored by the pp65 antigenemia assay (CMV Ag). Persistent reactivation was defined as antigenemia positivity >21 days on antiviral therapy.

RESULTS

Of 118 CMV-seropositive recipients, 69 (58.4%) had reactivated CMV. Twenty of 69 (29%) developed persistent reactivation at first episode of reactivation, and 7 (10%) in subsequent episode. All patients with persistent reactivation received >/=2 antivirals and CMV hyperimmune globulin; 45% received combination antiviral therapy. The median duration of persistent reactivation was 98 days, range 31-256 days. In multivariate analysis, maximum CMV Ag >25 cells/slide was associated with persistent reactivation (odds ratio 16.2%, 95% confidence interval 4-64, P<0.0001). CMV disease occurred in 6/27 (22%) patients with persistent reactivation. Patients with persistent reactivation had lower CD4(+) and CD8(+) lymphocyte counts compared with those with non-persistent reactivation at day +90 post HSCT (P=0.01 and 0.02, respectively).

CONCLUSIONS

Persistent reactivation occurred in 39% of T-cell-depleted HSCT despite treatment with currently available antivirals. Maximum CMV Ag >25 cells/slide was associated with persistent CMV reactivation. More effective treatment modalities are needed for this high-risk population to reduce CMV-associated morbidity and mortality.

Preemptive diagnosis and treatment of Epstein-Barr virus-associated post transplant lymphoproliferative disorder after hematopoietic stem cell transplant: an approach in development

Hematopoietic stem cell transplant (HSCT) recipients are at risk for Epstein-Barr virus (EBV)-associated, post transplant lymphoproliferative disorder (PTLD). Studies have suggested that early treatment may improve the outcome of patients with PTLD. Thus, significant attention has been focused on PCR-based approaches for preemptive (i.e., prior to clinical presentation) diagnosis. Reports from several transplant centers have demonstrated that HSCT recipients with PTLD generally have higher concentrations of EBV DNA in the peripheral blood than patients without PTLD. However, the PCR values of patients with PTLD typically span multiple orders of magnitude and overlap significantly with values from patients without PTLD. Thus, questions remain about the sensitivity and predictive value of these assays. Preemptive strategies using rituximab and/or EBV-specific cytotoxic T lymphocytes have been evaluated in patients with elevated EBV viral loads. We review the current literature, discuss our institutional experience and identify several areas of future research that could improve the diagnosis and treatment of this life-threatening disorder in HSCT recipients.

Inhibition of NOS-2 induction in LPS-stimulated J774.2 cells by 1, 5-isoquinolinediol, an inhibitor of PARP

Activation of both poly (ADP-ribose) polymerase (PARP) and inducible nitric oxide synthase (NOS-2) have been implicated in the pathogenesis of various forms of inflammation, therefore compounds which may simultaneously inhibit both pathways are of potential therapeutic interest. We tested the influence of potent inhibitor of PARP, 1, 5-isoquinolinediol (ISO), on NOS-2 induction in model of mouse macrophages (cell line J774.2) stimulated with lipopolysaccharide (1 microg/ml). Pretreatment with ISO (1-300 microM) resulted in dose-dependent inhibition of accumulation of NOS-2-derived nitrite in culture medium (IC(50) = 9,3 microM) as well as inhibition of NOS-2 protein induction in cultured J774.2 cells; ISO given 10 hours after LPS did not influence activity of NOS-2. Interestingly, another PARP inhibitor, 3-aminobenzamide (3-AB, 10-3000 microM), did not influence 24-hr nitrite accumulation in J774.2 cell culture, either administered 15 minutes prior to LPS or 10 hrs after LPS. Scavenging of reactive oxygen species by use of mixture of SOD and catalase (SOD/Cat, 100/300 - 1000/3000 U/ml) as well as cell permeable SOD-mimetic [Mn(III)TBAP, 1- 100 microM], did not influence NOS-2 induction in J774.2 cells. In summary, we identified 1, 5-isoquinoline as potent inhibitor of induction of NOS-2 in LPS-treated mouse macrophages. The exact mechanism of inhibitory action of this compound on NOS-2 induction requires further investigation.

Inhibition of nuclear factor-kappaB attenuates artherosclerosis in apoE/LDLR - double knockout mice

Nuclear factor - kappaB (NF-kappaB) is a good therapeutic target for cardiovascular disease and numerous efforts are being made to develop safe NF-kappaB inhibitors. Nowadays many authors address NF-kappaB as a major therapeutic target in atherosclerosis, especially for preventive measures, in the light of two main hypothesis of atherosclerosis: oxidation and inflammation. We hypothesized that ammonium pyrrolidinedithioocarbamate (PDTC) - a well-known inhibitor of NF-kappaB could inhibit the development of atherosclerosis in this experimental model. We used apoE/LDLR - DKO mouse model, which is considered as a one of the best models to study the anti-atherosclerotic effect of drugs. In this model PDTC inhibited atherogenesis, measured both by "en face" method (25,15+/-2,9% vs. 15,63+/-0,6%) and "cross-section" method (565867+/-39764 microm2 vs. 291695+/-30384 microm2). Moreover, PDTC did not change the profile of cholesterol and triglycerides in blood. To our knowledge, this is the first report that shows the effect of PDTC on atherogenesis in gene-targeted apoE/LDLR - double knockout mice.

Pre- and post-engraftment bloodstream infection rates and associated mortality in allogeneic hematopoietic stem cell transplant recipients

We report on bloodstream infection (BSI) rates, risk factors, and outcome in a cohort of 298 adult and pediatric hematopoietic stem cell transplantation (HSCT) recipients at Memorial Sloan-Kettering Hospital from September 1999 through June 2003. Methods. Prospective surveillance study. BSI rates are reported per 10,000 HSCT days. Date of engraftment is defined as the first of at least 3 consecutive dates of absolute neutrophil count >500/mm(3) after stem cell infusion. BSI severity grades: severe (intravenous antibiotics), life threatening (sepsis), or fatal (caused or contributed to death). Results. The incidence of pre- and post-engraftment BSI was 22% and 19.5%, respectively. Pre-engraftment highest rates were observed for viridans streptococci (58), Enterobacteriaceae (39), and Enterococcus faecium (34). Post-engraftment rates ranged from 0.2 to 2.9 without any predominant pathogen. In multivariate analyses, pre-engraftment BSI was associated with diagnosis of chronic myelogenous leukemia, age >18 years and peripheral blood stem cell graft; post-engraftment BSI was associated with acute graft-versus-host disease, neutropenia, and liver or kidney dysfunction. Attributable mortality was 12.5% and 1.7% for pre- and post-engraftment BSI, respectively. BSI fatality rates were 24% for viridans streptococci, 8% for E. faecium, 11% for Staphylococcus aureus, and 67% for Candida. Conclusions. Pre-engraftment BSI, especially by viridans streptococci and E. faecium, was associated with substantial attributable mortality. Post-engraftment BSI was a marker of post-transplant complications and rarely the primary cause of death.

Endothelial action of thienopyridines and thienopyrimidinones in the isolated guinea pig heart

Antiplatelet thienopyridines (ticlopidine, clopidogrel) and their thienopyrimidinone congeners, induce prostacyclin-dependent thrombolysis in vivo. Here we tested whether thienopyridines (ticlopidine, clopidogrel, and its enantiomer without antiplatelet properties) and structurally related thienopyrimidinones release NO from coronary endothelium in the isolated guinea pig heart, perfused according to Langendorff technique. The involvement of endothelium-derived NO in coronary vasodilation induced by these agents was assessed by effect of L-N(G)-nitro-arginine methyl ester (L-NAME). In addition, effect of thienopyridines or thienopyrimidinones on nitrite accumulation in cultured endothelium was assayed. Tienopyridines (10-100 micromol L(-1)) and thienopyrimidinones (10-30 micromol L(-1)) produced concentration-dependent increase in coronary flow comparable to that induced by acetylcholine (0.1 micromol L(-1)) or bradykinin (3 nmol L(-1)) which was inhibited by L-NAME (by 50-70%) but not by indomethacin. Furthermore, thienopyridines and thienopyrimidinones caused NO release from cultured endothelial cells. In conclusion, both thienopyridines independently from their antiplatelet action and their thienopyrimidinone congeners that are devoid of antiplatelet action stimulate coronary endothelium to release NO. Endothelial action of these compounds merits further investigation.

Treatment of menorrhagia in women undergoing hematopoietic stem cell transplantation

The management of uterine bleeding in female transplant patients over a 3-year period at our institution was reviewed. A total of 33 females who had undergone allogeneic hematopoietic stem cell transplant were identified as having received gynecologic consultation for the diagnosis of menorrhagia. Hormone therapy achieved a resolution of symptoms in 32 (97%) of the patients, and 26 (79%) required only one hormone regimen. Following resolution of symptoms, transition to standard-dose oral contraceptive pills as maintenance therapy prevented recurrent menorrhagia due to high circulating estrogen levels. Alternatives for patients who are unable to tolerate oral administration and those with hepatotoxicity are also discussed.

Involvement of platelet activating factor in immediate heart response to lipopolysaccharide

Although lipopolysaccharide (LPS) is recognized to induce a biphasic cardiovascular response its mechanism is not fully elucidated. In this study we analysed the involvement of PAF, TXA(2) and cysteinyl leukotrienes (cysLTs) in the acute cardiovascular effects of LPS in the isolated rat heart as well as in delayed phase of LPS response using a surrogate cellular model of the induction of NOS-2 by LPS in mouse macrophages. Perfusion of rat hearts with LPS resulted, in an immediate fall in heart contractility and coronary flow by 2.5 +/- 0.59 ml x min(-1) and 560 +/- 81 mmHg x sec(-1), respectively. This response was fully blocked by platelet activating factor (PAF) antagonist - WEB 2170 and partially inhibited, by inhibitor of cyclooxygenase (indomethacin) or by inhibitor of thromboxane synthase (camonagrel). The inhibition of leukotriene synthesis (BAY x1005) or cysLTs receptors (BAY x7195) was without effect. Administration of stable PAF analog (methylcarbamyl-PAF - MC-PAF) alone, mimicked heart response to LPS. In cultured mouse macrophages, MC-PAF did not induce NOS-2 expression and when given with LPS it slightly potentiated NOS-2 induction by LPS. However, in presence of WEB 2170 NOS-2 induction by LPS was inhibited in a dose-dependent manner. Inhibition of cyclooxygenase and leukotriene pathways had no effect on NOS-2 induced by LPS. These results indicate that PAF and TXA(2) but not cysLTs mediate the instant heart response induced by LPS, while PAF alone mediates a delayed NOS-2 induction by LPS. Accordingly, PAF may constitute the mediator that links acute and delayed phases of LPS-induced cardiovascular response.

High rates of infection and colonization by nontuberculous mycobacteria after allogeneic hematopoietic stem cell transplantation

Nontuberculous mycobacteria (NTM) are essentially ubiquitous and can infect both immunocompetent and immunocompromised hosts. However, NTM infection is surprisingly uncommon in reports from allogeneic hematopoietic stem cell transplant (alloSCT) centers that do not routinely perform allograft T-cell depletion. We reviewed medical records for all adult patients who underwent alloSCT at our center between January 1993 and December 2001. American Thoracic Society and Centers for Disease Control and Prevention guidelines Were used to define definite, probable, and possible NTM infection. Of 571 patients, 36 of 372 (9.7%) T-cell depleted and 14 of 199 (7.0%) conventional alloSCT recipients (P=0.26) had a positive culture for NTM after alloSCT. Of the 50 patients with NTM infection, 16 had definite infection and 34 had probable or possible infection. Rates of NTM infection were 5 to 20-fold higher than rates reported by other centers. Of the 16 definite infections, nine were caused by Mycobacterium haemophilum. Two patients had disseminated M. avium complex (MAC) infection and one had a vascular catheter infected by MAC. Three patients died from complications of NTM infection. Patients with probable or possible NTM infection had markedly different epidemiology, risk factors, site and species of NTM infection, and prognosis than patients with definite NTM infection.

Fiberoptic bronchoscopy in allogeneic bone marrow transplantation: findings in the era of serum cytomegalovirus antigen surveillance

STUDY OBJECTIVES

Pulmonary complications occur in half of allogeneic bone marrow transplantation (BMT) patients. The incidence of these complications has been reduced by prophylaxis against Pneumocystis carinii pneumonia, preemptive therapy in patients at high risk for cytomegalovirus (CMV) reactivation, and, more recently, screening for serum CMV antigen. Since fiberoptic bronchoscopy (FOB) has historically been the primary diagnostic test to evaluate BMT patients with pulmonary disease, a review was performed to determine the impact, if any, that current prophylaxis and screening policies may have had on FOB utility.

DESIGN

The records of 174 adult patients undergoing BMT between January 1997 and December 1999 were reviewed to determine the diagnostic yield of FOB and the frequency by which FOB altered management.

RESULTS

Sixty-one patients underwent 76 bronchoscopies. FOB was diagnostic in 32 patients (42.1% of cases) and directly changed management in 24 patients (31.6% of cases). Half of these changes included the withdrawal of an antimicrobial agent. The most common findings were infection (32 cases) and diffuse alveolar hemorrhage (6 cases). CMV was the most prevalent infection identified, but FOB resulted in the addition of antiviral therapy to only two patients. P carinii pneumonia was not diagnosed in any patient studied.

CONCLUSIONS

These data suggest a changing spectrum of pulmonary disease in BMT patients. FOB has limited impact on the diagnoses of CMV disease or P carinii pneumonia with current prophylaxis and screening strategies. It may be useful in identifying other infectious etiologies and in eliminating unnecessary antimicrobials.

L-N6-(1-iminoethyl)-lysine (L-NIL) but not S-methylisothiourea sulphate (SMT) displays selectivity towards NOS-2

Our aim was to verify potency and selectiveness of two most widely used drugs regarded as NOS-2 inhibitors: L-N6-(1-iminoethyl)-lysine (L-NIL) and S-methylisothiourea sulphate (SMT). Thioglycolate-elicited rat peritoneal macrophages and coronary endothelium of isolated guinea pig heart were used as assay systems for NOS-2 and NOS-3, respectively. A non-selective NOS inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME) was used as a reference compound. We found that L-NIL but not SMT was a selective NOS-2 inhibitor. Interestingly, L-NAME displayed selectivity towards NOS-3.

Comparison of immune reconstitution after unrelated and related T-cell-depleted bone marrow transplantation: effect of patient age and donor leukocyte infusions

Unrelated bone marrow transplantation (BMT) is often complicated by fatal opportunistic infections. To evaluate features unique to immune reconstitution after unrelated BMT, the lymphoid phenotype, in vitro function, and life-threatening opportunistic infections after unrelated and related T-cell-depleted (TCD) BMT were analyzed longitudinally and compared. The effects of posttransplant donor leukocyte infusions to treat or prevent cytomegalovirus (CMV) or Epstein-Barr virus (EBV) infections on immune reconstitution were also analyzed. This study demonstrates that adult recipients of TCD unrelated BMTs experience prolonged and profound deficiencies of CD3(+), CD4(+), and CD8(+) T-cell populations when compared with pediatric recipients of unrelated BMT and adults after related BMT (P <.01), that these adults have a significantly increased risk of life-threatening opportunistic infections, and that the rate of recovery of CD4 T cells correlates with the risk of developing these infections. Recovery of normal numbers of CD3(+), CD8(+), and CD4(+) T-cell populations is similar in children after related or unrelated BMT. This study also demonstrates that adoptive immunotherapy with small numbers of unirradiated donor leukocytes can be associated with rapid restoration of CD3(+), CD4(+), and CD8(+) T-cell numbers, antigen-specific T-cell responses, and resolution of CMV- and EBV-associated disease after unrelated TCD BMT.

Molecular mapping with functional antibodies localizes critical sites on the human IL receptor common gamma (gamma c) chain

The IL receptor common gamma (gamma c) chain is required for the formation of high affinity cytokine receptor complexes for IL-2, IL-4, IL-7, IL-9, and IL-15, and for signals regulating cell survival, growth, and differentiation. Our current understanding of how gamma c chain associates with multiple ligands and receptor subunits is drawn largely from its structural homology to the human growth hormone (hGH) receptor and known structure of the hGH/hGH receptor complex. These receptors share distinct features in their extracellular portions and are believed to function by a mechanism of ligand-induced association of receptor subunits. Here, we report the first directed mutational analysis of the human gamma c chain by alanine scanning conducted across seven regions likely to contain residues required for intermolecular contact. Functionally distinct, neutralizing anti-gamma c mAbs were employed to define critical residues. One particular mAb, CP.B8, unique in its ability to inhibit IL-2-, IL-4-, IL-7-, and IL-15-induced proliferation and high affinity cytokine binding of normal T cells as an intact mAb and as a Fab fragment, localized critical residues to four noncontinuous stretches, namely residues in loops AB and EF of domain 1, in the interdomain segment, and in loop FG of domain 2. Notably, these residues form a contiguous patch on the gamma c chain surface in a three-dimensional structural model. These results provide functional evidence for the location of contact points on gamma c chain required for its association with multiple ligands.

Cyclophosphamide-induced changes of serum angiotensin converting enzyme activity and pulmonary microvessels ultrastructure

The effect of cyclophosphamide (CP) on the ultrastructure of the lung tissue and the activity of angiotensin converting enzyme (ACE) in serum was evaluated in rats. The animals were given cyclophosphamide (CP) in a single intraperitoneal dose of 150 mg/kg b.w. ACE activity was evaluated in the blood serum collected from the left ventricle of the heart using the spectrophometric method. In all time subgroups, the CP-receiving animals showed a decrease in ACE activity. Ultrastructural examinations of CP-treated animals revealed increased adhesion of neutrophiles and monocytes to the damage endothelium of the alveolar septa vessels and focally accumulation of the platelets.

Cyanonitrosylmetallates as potential NO-donors

The [M(CN)xNOy]n- complexes (where M = Cr(I), Mn(I), Mn(II), Fe(I), Fe(II), Fe(III)) were studied as potential NO-donors using both pharmacological and theoretical semi-empirical methods. Only iron complexes appeared to be pharmacologically active. The quantum chemical calculations indicated that these complexes have the highest predisposition to undergo a nucleophilic attack followed by the NO+ release. The results allowed us to interpret the metabolism of the [M(CN)xNOy]n- complexes in terms of the NO(+)-donation.

Comparative activity of melarsoprol and arsenic trioxide in chronic B-cell leukemia lines

Inorganic arsenic trioxide (As2O3) was recently shown to induce apoptosis in NB4 promyelocytic leukemic cells. We have investigated the effects of the organic arsenical, melarsoprol (a drug used for treatment of trypanosomiasis), upon induction of apoptosis in cell lines representative of chronic B-cell lymphoproliferative disorders. An Epstein-Barr virus (EBV)-transformed B-prolymphocytic cell line (JVM-2), an EBV-transformed B-cell chronic lymphocytic leukemia (B-CLL) cell line (I83CLL), and one non-EBV-transformed B-CLL cell line (WSU-CLL) were used as targets. Dose-response experiments with melarsoprol (10(-7) to 10(-9) mol/L) were performed over 96 hours. Unexpectedly, we found that melarsoprol caused a dose- and time-dependent inhibition of survival and growth in all three cell lines. In contrast, As2O3 at similar concentrations had no effect on either viability or growth. After 24 hours, all three cell lines treated with melarsoprol (10(-7) mol/L) exhibited morphologic characteristics of apoptosis. We also observed prominent concentration-dependent downregulation of bcl-2 mRNA after 24 hours of exposure to melarsoprol in WSU-CLL, I83CLL, and JVM-2 cells. Decrease of bcl-2 protein expression was also observed in all three cell lines, whereas As2O3 had no effect on this parameter. We conclude that melarsoprol may inhibit the growth of lymphoid leukemic cell by promoting programmed cell death. Results of these studies suggest that melarsoprol shows promising therapeutic activity in these diseases, and a study to evaluate clinical effects of this drug has been initiated.

Effects of pentoxifylline on some peripheral blood parameters and haemostasis in acute pulmonary tissue injury after cyclophosphamide

Cyclophosphamide (CP) is one of the widely used cytostatic drugs, with a strong toxic influence on pulmonary tissue. Experimental works have shown that a single high dose of CP causes injury to all elements of the interalveolar septum, especially to the alveolar endothelial and epithelial cells. The aim of this work was to evaluate the influence of pentoxifylline (PTXF) (30 mg/kg b.w.) on the ultrastructure of lungs capillaries and blood cell count as well as plasma fibrinogen levels in Wistar rats after intraperitoneal injection of 150 mg/b.w. CP. We established that in the doses applied PTXF had no statistically significant influence on the number of leukocytes and erythrocytes determined in the left ventricular blood of rats receiving CP, while the number of white cells from animals given PTXF only was higher than in controls. There was a smaller decrease in the number of platelets (p < 0.05) and smaller reduction in fibrinogen level (p < 0.01) in the serum of PTXF-CP animals than in the CP group. The results obtained suggest a protective effect of PTXF on CP induced changes, which have been evidenced in some of the parameters examined. Ultrastructural examinations found the lungs to be the organ of extramedullary thrombocytopoiesis in CP-treated animals and revealed that platelet accumulation in the system of lung capillaries was a potential cause of the decrease observed in the number of blood platelets following CP administration.

Pilot study of 5-azacytidine (5-AZA) and carboplatin (CBDCA) in patients with relapsed/refractory leukemia

5-azacytidine (5-AZA) and carboplatin (CBDCA) are two agents which have demonstrated antileukemic activity in a number of phase I-II trials. Their mechanisms of action and pharmacology related to cell resistance suggested suitability for combination therapy. The aim of this pilot was to evaluate the effects of this combination in the treatment of patients with relapsed/refractory acute leukemia. A total of 21 patients was enrolled. 5-azacytidine, at doses ranging from 50-150 mg/m2/day, was administered as a 2-hr infusion for 5 consecutive days. On day 3, patients began a 5-day course of CBDCA given as a 24-hr continuous intravenous infusion of 250 mg/m2/day. There were no complete remissions with this regimen. Although there were three partial responses, these were generally of short duration. Nonhematologic toxicities were mild. No correlation was seen between response and serum platinum levels. These results demonstrate that the 5-AZA/CBDCA combination is ineffective therapy for heavily pretreated patients with acute leukemia.

Ischaemic cardiac hyperaemia: role of nitric oxide and other mediators

In the perfused guinea-pig heart reactive hyperaemia (RH) after occlusion of coronary flow (1-60 s) was inhibited by 100-60% with NG-nitro-L-arginine (100 microM) and to a lesser extent (by 35%) after 8-phenyltheophylline (10 microM), but not by indomethacin (5 microM). Inhibition of adenosine deaminase by erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) (5 microM) not only increased the concentration of adenosine in the coronary perfusate, but also prolonged the duration of RH. RH induced cardiac generation of prostacyclin, nitric oxide and adenosine as indicated by the appearance of 6-keto-PGF1 alpha, cyclic GMP, adenosine, inosine, hypoxanthine, xanthine and urate in the perfusate. Only NO and adenosine, but not prostacyclin, were responsible for RH. RH after short-term (1-10 s) coronary occlusion was mediated by NO, whereas adenosine and NO maintained RH that followed after longer (20 s-10 min) periods of cardiac ischaemia. Prostacyclin never participated in the mediation of RH.

Treatment of chronic neutropenia associated with large granular lymphocytosis with cyclosporine A and filgrastim

A patient with neutropenia and life-threatening infections secondary to T-gamma lymphoproliferative disease, who did not respond to treatment with recombinant human G-CSF (filgrastim), was treated with filgrastin plus cyclosporine A (CyA). The patient achieved a good response in the absolute neutrophil count and subsequently required a dose reduction in the filgrastim. The patient was eventually discontinued from the CyA but continues on filgrastim alone. While on therapy, the large granular lymphocytes disappeared from the circulation and the beta-TCR rearrangement, which was present prior to beginning therapy, became undetectable. The patient had no significant toxicity to the CyA or the filgrastim and he has not experienced any serious infections or required hospitalization. Filgrastim has proven to be relatively nontoxic and of some benefit to patients with this disease and should probably be utilized first when treatment is necessary. However, if improvement is not observed, these findings suggest that a trial of the combination of CyA plus filgrastim may be beneficial.

A pilot study of the biologic and therapeutic effects of granulocyte colony-stimulating factor (filgrastim) in patients with acute myelogenous leukemia

In a carefully monitored pilot study, the in vivo biologic effects of filgrastim were investigated in eight patients with relapsed/refractory acute myelogenous leukemia. Within each patient, filgrastim was administered as a single agent prior to any chemotherapy in escalating doses of 0.12-6.0 micrograms/kg/day as a continuous intravenous infusion. The dose was increased every 14 days until an ANC of > or = 2500/mm3 had been achieved or there was evidence of proliferation of the leukemia. In patients who demonstrated growth of the leukemic clone, cytosine arabinoside was initiated at 200 mg/m2/day for 5 days. Through-out the course of therapy, the effects of filgrastim on maturation and proliferation were assessed by in vitro studies of bone marrow aspirates. Three patients demonstrated a sustained increase in ANC; one achieved a partial remission and remained on therapy for 31 weeks. Two of the three responding patients had hypocellular marrows at the time of initiating filgrastim and demonstrated a low but normal pattern of growth in CFU-GM assay early in the treatment course. This suggested that these two characteristics may define an environment in which filgrastim can induce a growth advantage for the normal residual hematopoietic elements. In this study of selected patients, filgrastim appeared safe.

Vascular cell adhesion molecule-Ig fusion protein selectively targets activated alpha 4-integrin receptors in vivo. Inhibition of autoimmune diabetes in an adoptive transfer model in nonobese diabetic mice

The alpha 4 beta 1-integrin (CD49d, CD29) constitutively expressed on leukocytes regulates cell migration to inflammatory sites, cell activation, and development through its interactions with two alternate ligands, vascular cell adhesion molecule-1 (VCAM-1; CD106) expressed on cytokine-activated endothelium, dendritic and stromal cells, and the extracellular matrix protein fibronectin. Another alpha 4-integrin receptor, alpha 4 beta 7, expressed on leukocytes also binds VCAM-1 and fibronectin (FN), and controls homing to mucosal tissues through its interactions with mucosal vascular addressin MAdCAM-1. In vitro studies have shown that alpha 4-dependent cell adhesion is regulated by the activation state of the cell and by divalent cations. However, the existence and role of cells with different alpha 4 activation states in vivo have not been defined. Herein we show that a soluble ligand with the two N-terminal domains of human VCAM-1 fused to a human IgG1 constant region, VCAM-Ig, binds selectively to activated alpha 4-receptors on murine cells, such as those induced by Mn2+ in vitro. To determine whether the cells identified by VCAM-Ig were required under physiologic conditions, we assessed its anti-inflammatory effect. We show that VCAM-Ig is not bound to the majority of murine alpha 4+ cells after in vivo administration, yet it significantly delays the onset of adoptively transferred autoimmune diabetes. Thus, soluble VCAM-Ig can modify alpha 4-dependent disease progression, apparently by its selective action on cells with activated alpha 4-integrin receptors, thereby providing evidence for distinct alpha 4 activation states in vivo.

Vascular cell adhesion molecule-Ig fusion protein selectively targets activated alpha 4-integrin receptors in vivo. Inhibition of autoimmune diabetes in an adoptive transfer model in nonobese diabetic mice

The alpha 4 beta 1-integrin (CD49d, CD29) constitutively expressed on leukocytes regulates cell migration to inflammatory sites, cell activation, and development through its interactions with two alternate ligands, vascular cell adhesion molecule-1 (VCAM-1; CD106) expressed on cytokine-activated endothelium, dendritic and stromal cells, and the extracellular matrix protein fibronectin. Another alpha 4-integrin receptor, alpha 4 beta 7, expressed on leukocytes also binds VCAM-1 and fibronectin (FN), and controls homing to mucosal tissues through its interactions with mucosal vascular addressin MAdCAM-1. In vitro studies have shown that alpha 4-dependent cell adhesion is regulated by the activation state of the cell and by divalent cations. However, the existence and role of cells with different alpha 4 activation states in vivo have not been defined. Herein we show that a soluble ligand with the two N-terminal domains of human VCAM-1 fused to a human IgG1 constant region, VCAM-Ig, binds selectively to activated alpha 4-receptors on murine cells, such as those induced by Mn2+ in vitro. To determine whether the cells identified by VCAM-Ig were required under physiologic conditions, we assessed its anti-inflammatory effect. We show that VCAM-Ig is not bound to the majority of murine alpha 4+ cells after in vivo administration, yet it significantly delays the onset of adoptively transferred autoimmune diabetes. Thus, soluble VCAM-Ig can modify alpha 4-dependent disease progression, apparently by its selective action on cells with activated alpha 4-integrin receptors, thereby providing evidence for distinct alpha 4 activation states in vivo.