Anthropogenic impacts on tidal creek sedimentation since 1900

Land cover and use around the margins of estuaries has shifted since 1950 at many sites in North America due to development pressures from higher population densities. Small coastal watersheds are ubiquitous along estuarine margins and most of this coastal land-cover change occurred in these tidal creek watersheds. A change in land cover could modify the contribution of sediments from tidal creek watersheds to downstream areas and affect estuarine habitats that rely on sediments to persist or are adversely impacted by sediment loading. The resilience of wetlands to accelerating relative sea-level rise depends, in part, on the supply of lithogenic sediment to support accretion and maintain elevation; however, subtidal habitats such as oyster reefs and seagrass beds are stressed under conditions of high turbidity and sedimentation. Here we compare sediment accumulation rates before and after 1950 using 210Pb in 12 tidal creeks across two distinct regions in North Carolina, one region of low relief tidal-creek watersheds where land cover change since 1959 was dominated by fluctuations in forest, silviculture, and agriculture, and another region of relatively high relief tidal-creek watersheds where land-use change was dominated by increasing suburban development. At eight of the creeks, mass accumulation rates (g cm-2 y-1) measured at the outlet of the creeks increased contemporaneously with the largest shift in land cover, within the resolution of the land-cover data set (~5-years). All but two creek sites experienced a doubling or more in sediment accumulation rates (cm yr-1) after 1950 and most sites experienced sediment accumulation rates that exceeded the rate of local relative sea-level rise, suggesting that there is an excess of sediment being delivered to these tidal creeks and that they may slowly be infilling. After 1950, land cover within one creek watershed changed little, as did mass accumulation rates at the coring location, and another creek coring site did not record an increase in mass accumulation rates at the creek outlet despite a massive increase in development in the watershed that included the construction of retention ponds. These abundant tidal-creek watersheds have little relief, area, and flow, but they are impacted by changes in land cover more, in terms of percent area, than their larger riverine counterparts, and down-stream areas are highly connected to their associated watersheds. This work expands the scientific understanding of connectivity between lower coastal plain watersheds and estuaries and provides important information for coastal zone managers seeking to balance development pressures and environmental protections.

Efficacy of digital cognitive behavioural therapy for symptoms of generalised anxiety disorder: a study protocol for a randomised controlled trial

Background

Generalised anxiety disorder (GAD) is a chronic and disabling condition with considerable personal and economic impact. Cognitive behavioural therapy (CBT) is a recommended psychological therapy for GAD; however, there are substantial barriers to accessing treatment. Digital CBT, in particular smartphone-delivered CBT, has the potential to improve accessibility and increase dissemination of CBT. Despite the emerging evidence of smartphone-based psychological interventions for reducing anxiety, effect size scores are typically smaller than in-person interventions, and there is a lack of research assessing the efficacy of smartphone-delivered digital interventions specifically for GAD.

Methods

In the DeLTA trial (DigitaL Therapy for Anxiety), we plan to conduct a parallel-group superiority randomised controlled trial examining the efficacy of a novel smartphone-based digital CBT intervention for GAD compared to a waitlist control. We aim to recruit 242 adults (aged 18 years or above) with moderate-to-severe symptoms of GAD. This trial will be conducted entirely online and will involve assessments at baseline (week 0; immediately preceding randomisation), mid-intervention (week 3), post-intervention (week 6; primary end point) and follow-up (week 10). The primary objective is to evaluate the efficacy of the intervention on GAD symptom severity compared to a waitlist control at post-intervention. Secondary objectives are to examine between-group effects on GAD at follow-up, and to examine the following secondary outcomes at both post-intervention and follow-up: 1) worry; 2) depressive symptoms; 3) wellbeing; 4) quality of life; and 5) sleep difficulty.

Discussion

This trial will report findings on the initial efficacy of a novel digital CBT intervention for GAD. Results have the potential to contribute towards the evidence base for digital CBT for GAD and increase the dissemination of CBT.

Trial registration

ISRCTN, ISRCTN12765810. Registered on 11 January 2019.

Sleep interventions for osteoarthritis and spinal pain: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

To determine if sleep interventions improve pain and sleep in people with osteoarthritis (OA) and/or spinal pain compared to control/placebo.

DESIGN

Medline, Embase, AMED, PsycINFO, CENTRAL, CINAHL and PEDro were searched from their inception date to July 2017. Keywords relating to "sleep", "OA", "spinal pain", and "randomized controlled trial (RCT)" were combined. Included RCTs investigated the use of sleep interventions for people with OA and/or spinal pain, and measured at least one sleep and health related outcome. Meta-analyses were performed to pool mean differences for pain and sleep quality.

PROSPERO

CRD42016036315.

RESULTS

Of 1445 unique records, 24 studies were included. Sixteen studies included participants with spinal pain, seven with OA, and one included a mixed population. Sleep interventions included established sleep interventions (ESI) [cognitive behavioural therapy (CBT) and pharmacological interventions], and a range of others. Intervention periods ranged from 4 to 10 weeks. Thirteen studies were of moderate to high quality (PEDro ≥ 6/10). Due to high heterogeneity between studies we also performed sub-group and sensitivity analyses. ESI decreased Insomnia Severity Index (ISI) for people with low back pain (LBP) (pooled mean difference: -6.78/28, 95% confidence interval (95% CI): [-9.47, -4.09], I² = 40%) and OA (-2.41, [-4.19, -0.63], 0%). However ESI decreased pain for people with LBP (pooled mean difference: visual analogue scale (VAS) -12.77/100, 95% CI: [-17.57, -7.97], I² = 0%), but not OA (-2.32, [-7.18, 2.54], 27%).

CONCLUSION

ESI appeared to improve sleep and pain for people with LBP, and sleep for people with OA. However more vigorous studies need to be conducted.

Lipid formulations of amphotericin B preserve and stabilize renal function in HSCT recipients

The current study assessed renal function based on medical records in adult hematopoietic stem cell transplant (HSCT) recipients with proven or probable invasive fungal infection (IFI) transplanted between 1995 and 2000. We confirm that amphotericin B deoxycholate (AmB-d) is nephrotoxic in a large percentage of HSCT recipients. Due to nephrotoxicity, defined as serum creatinine (SCr) >2.5 mg/dl or a 100% increase in SCr from baseline, 88% of patients treated with AmB-d were switched to a lipid formulation of amphotericin B (LFAB). In total, 53% of patients initiated on AmB-d were switched within the first week of therapy. Significantly more patients (70.6%) treated with AmB-d experienced a 100% increase in SCr from baseline compared to patients treated with either AmBisome (44.4%) or Abelcet (41.2%). A Cox Proportional Hazards Model revealed that, compared to patients initiated on AmBisome or Abelcet, the risk of nephrotoxicity (RR=1.5 vs AmBisome; RR=1.7 vs Abelcet), dialysis (RR=2.4 vs AmBisome; RR=1.4 vs Abelcet), and death (RR=2.0 vs AmBisome; RR=1.1 vs Abelcet) were all increased for patients initiated on AmB-d. Study results suggest that renal function improves and mortality declines when an LFAB is given to HSCT patients as initial therapy rather than as second-line therapy, the current practice.

Long-term follow-up of intensive ara-C-based chemotherapy followed by bone marrow transplantation for adult acute lymphoblastic leukemia: impact of induction Ara-C dose and post-remission therapy

We report single institution outcome of brief, intensive ara-C-based chemotherapy using bone marrow transplantation as primary intensification for untreated adult patients with acute lymphoblastic leukemia (ALL). Overall disease-free and overall survival were inferior to those reported with prolonged chemotherapy modeled on pediatric protocols. Survival and disease-free survival were superior for patients receiving allogeneic BMT compared with chemopurged autologous transplant or maintenance chemotherapy (patients ineligible for or declining BMT). In multivariate analysis, non-L2-FAB, higher ara-C dose, absence of CNS disease, non-Ph1+ karyotype, allogeneic BMT, T cell phenotype, and younger age were associated with improved disease-free survival. Autologous BMT was not superior to chemotherapy, and appears unlikely to provide adequate curative treatment for most adult ALL patients if not followed by maintenance.

Long-term results of blood and marrow transplantation for Hodgkin's lymphoma

PURPOSE

To evaluate the long-term outcome after allogeneic (allo) and autologous (auto) blood or marrow transplantation (BMT) in patients with relapsed or refractory Hodgkin's lymphoma (HL).

PATIENTS AND METHODS

We analyzed the outcome of 157 consecutive patients with relapsed or refractory HL, who underwent BMT between March 1985 and April 1998. Patients <or= age 55 with HLA-matched siblings were prioritized toward allo BMT. The median age was 28 years (range, 13 to 52 years) for the 53 allo patients and 30.5 years (range, 11 to 62 years) for the 104 auto patients.

RESULTS

The median follow-up after BMT for surviving patients was 5.1 years (range, 1 to 13.8 years). For the entire group, the probabilities of event-free survival (EFS) and relapse at 10 years were 26% (95% confidence interval [CI], 18% to 33%) and 58% (95% CI, 48% to 69%), respectively. According to multivariate analysis, disease status before BMT (sensitive relapse if responding to conventional-dose therapy or resistant disease if not) (hazard ratio [HR] = 0.39, P < .0001) and date of BMT (HR = 0.93, P = .004) were independent predictors of EFS, whereas only disease status (HR = 0.35, P < .0001) influenced relapse. There was a trend for probability of relapse in sensitive patients to be less after allo BMT at 34% (range, 8% to 59%) versus 51% (range, 36% to 67%) for the auto patients (HR = 0.51, P = .17). There was a continuing risk of relapse or secondary acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS) for 12 years after auto BMT, whereas there were no cases of secondary AML/MDS or relapses beyond 3 years after allo BMT.

CONCLUSION

There seems to be a clinical graft-versus-HL effect associated with allo BMT. Allo BMT for HL also seems to have a lower risk of secondary AML/MDS than auto BMT. Thus, allo BMT warrants continued study in HL.

The effect of graft purging with 4-hydroperoxycyclophosphamide in autologous bone marrow transplantation for acute myelogenous leukemia

BACKGROUND

Autologous bone marrow transplantation is an important therapy for patients with acute myelogenous leukemia (AML). However, leukemia in the graft may contribute to posttransplant relapse. Treatment of the graft with 4-hydroperoxycyclophosphamide (4HC) is sometimes used to decrease numbers of infused leukemia cells (4HC purging). No large controlled trials evaluating efficacy and toxicity of 4HC purging are reported.

METHODS

We studied 294 patients reported to the Autologous Blood and Marrow Registry receiving either a 4HC-purged (n = 211) or unpurged (n = 83) autograft for AML in first (n = 209) or second (n = 85) remission. Analyses were restricted to patients transplanted less than 6 months after achieving remission. Using Cox proportional hazards regression, we compared time to treatment failure (death or relapse, inverse of leukemia-free survival) after 4HC-purged vs unpurged transplants while controlling for important prognostic factors.

RESULTS

Median duration of posttransplant neutropenia was 40 (range, 10-200) days after 4HC-purged transplants and 29 (9-97) days after unpurged transplants (p < 0.01). Transplant-related mortality was similar in the two groups. In multivariate analysis, patients receiving 4HC-purged transplants had lower risks of treatment failure than those receiving unpurged transplants (relative risk, 0.69, p = 0.12 in the first posttransplant year; relative risk, 0.28, p < 0.0001 thereafter). Adjusted three-year probabilities of leukemia-free survival (95% confidence interval) were 56% (47-64%) and 31% (18-45%) after 4HC-purged and unpurged transplants in first remission, respectively. Corresponding probabilities in second remission were 39% (25-53%) and 10% (1-29%).

CONCLUSION

Grafts purged with 4HC are associated with higher leukemia-free survival after autologous bone marrow transplants for AML.

Impact of the putative differentiating agent sodium phenylbutyrate on myelodysplastic syndromes and acute myeloid leukemia

Sodium phenylbutyrate (PB) is an aromatic fatty acid with cytostatic and differentiating activity against malignant myeloid cells (ID(50), 1-2 mM). Higher doses induce apoptosis. Patients with myelodysplasia (n = 11) and acute myeloid leukemia (n = 16) were treated with PB as a 7-day continuous infusion repeated every 28 days in a Phase I dose escalation study. The maximum tolerated dose was 375 mg/kg/day; higher doses led to dose-limiting reversible neurocortical toxicity. At the maximum tolerated dose, PB was extremely well tolerated, with no significant toxicities; median steady-state plasma concentration at this dose was 0.29 +/- 0.16 mM. Although no patients achieved complete or partial remission, four patients achieved hematological improvement (neutrophils in three, platelet transfusion-independence in one). Other patients developed transient increases in neutrophils or platelets and decrements in circulating blasts. Monitoring of the percentage of clonal cells using centromere fluorescence in situ hybridization over the course of PB administration showed that hematopoiesis remained clonal. Hematological response was often associated with increases in both colony-forming units-granulocyte-macrophage and leukemic colony-forming units. PB administration was also associated with increases in fetal erythrocytes. These data document the safety of continuous infusion PB and provide preliminary evidence of clinical activity in patients with myeloid malignancies.

Erythropoietin in stem cell transplantation

Anemia is universal after allogeneic and autologous stem cell transplantation, with both increased red cell utilization and decreased production playing a role. This anemia sometimes is associated with a relative erythropoietin deficiency. In allogeneic stem cell transplantation, randomized trials have demonstrated improved erythropoiesis and a decrease in red cell transfusions in recombinant human erythropoietin (rHuEPO)-treated patients. Studies of rHuEPO in patients undergoing autologous stem cell transplants, however, have not shown a benefit. The role of rHuEPO in stem cell mobilization and treatment of delayed erythropoiesis has yet to be defined and further studies are needed.

Current treatments for infection in neutropenic patients with hematologic malignancy

Neutropenic patients with cancer are a heterogeneous group of patients who carry a variable risk for infection. When such patients present with fever, appropriate empiric antibiotic therapy is initiated and continued until clinical improvement or clinical or microbiologic data direct a modification in treatment. As the duration of neutropenia increases, so does the need for antimicrobial modifications. Changes in therapy may include antimicrobials directed against gram-positive bacteria, resistant gram-negative bacteria, or fungi. Because of the high risk for colonization by vancomycin-resistant enterococci, vancomycin use is restricted as first-line empiric therapy unless the patient is at a high risk for serious gram-positive infection. Usually in the setting of neutropenia, gram-positive infections are of low virulence. Prophylactic antibiotic therapy may increase the selection of resistant strains and should be avoided. Antibiotic therapy should always be combined with prudent infection-control measures, such as aseptic practices, barrier isolation, handwashing, removal of infected catheters, and infection monitoring. In the immunocompromised patient with cancer and neutropenia, all infections should be treated, with the extent, duration, and site of treatment being directed by risk stratification and specific pathogen identification. Patients with neutropenia are at risk for severe morbidity and mortality related to infection.

A dose-finding study of liposomal daunorubicin with CVP (COP-X) in advanced NHL

BACKGROUND

Standard therapy for lymphoma consists of a cyclophosphamide (C), doxorubicin, vincristine (V), and prednisone (P) (CHOP) combination regimen. Liposomal daunorubicin (DaunoXome) is an alternative to doxorubicin for patients with lymphoma because of its more favorable safety profile and potentially more selective uptake in lymphoma. The objectives of this study were to determine the maximum tolerated dose (MTD) of liposomal daunorubucin with CVP (COP-X) and the tolerability of the regimen in patients with indolent lymphoma.

PATIENTS AND METHODS

Patients with low-grade and intermediate-grade lymphoma having adequate cardiac, hepatic, and renal function were enrolled. Patients received C 750 mg/m2, V 1.4 mg/m2 (maximum 2.0 mg), and liposomal daunorubicin 50-100 mg/m2 i.v. on day 1 and P 100 mg p.o. on days 1-5. MTD was the liposomal daunorubicin dose associated with 20% dose-limiting toxicity (ANC < 500/mm3 for > 5 days or febrile neutropenia).

RESULTS

Twenty patients, median age 59 years, were treated. The liposomal daunorubicin MTD combined with CVP was 70-80 mg/m2, depending on patient population. No significant non-hematologic toxicity occurred. Response rate was 44% (2 complete and 5 partial responses).

CONCLUSIONS

A liposomal daunorubicin dose of 80 mg/m2 in the COP-X regimen was well tolerated with little nonhematologic toxicity.

Refinements of environmental assessment during an outbreak investigation of invasive aspergillosis in a leukemia and bone marrow transplant unit

OBJECTIVES

To investigate an outbreak of aspergillosis in a leukemia and bone marrow transplant (BMT) unit and to improve environmental assessment strategies to detect Aspergillus.

DESIGN

Epidemiological investigation and detailed environmental assessment.

SETTING

A tertiary-care university hospital with a 37-bed leukemia and BMT unit

PARTICIPANTS

Leukemic or BMT patients with invasive aspergillosis identified through prospective surveillance and confirmed by chart review.

INTERVENTIONS

We verified the diagnosis of invasive fungal infection by reviewing medical charts of at-risk patients, performing a case-control study to determine risk factors for infection, instituting wet mopping to clean all floors, providing N95 masks to protect patients outside high-efficiency particulate air (HEPA)-filtered areas, altering traffic patterns into the unit, and performing molecular typing of selected Aspergillus flavus isolates. To assess the environment, we verified pressure relationships between the rooms and hallway and between buildings, and we compared the ability of large-volume (1,200 L) and small-volume (160 L) air samplers to detect Aspergillus spores.

RESULTS

Of 29 potential invasive aspergillosis cases, 21 were confirmed by medical chart review. Risk factors for developing invasive aspergillosis included the length of time since malignancy was diagnosed (odds ratio [OR], 1.0; P=.05) and hospitalization in a patient room located near a stairwell door (OR, 3.7; P=.05). Two of five A. flavus patient isolates were identical to one of the environmental isolates. The pressure in most of the rooms was higher than in the corridors, but the pressure in the oncology unit was negative with respect to the physically adjacent hospital; consequently, the unit acted essentially as a vacuum that siphoned non-HEPA-filtered air from the main hospital. Of the 78 samples obtained with a small-volume air sampler, none grew an Aspergillus species, whereas 10 of 40 cultures obtained with a large-volume air sampler did.

CONCLUSIONS

During active construction, Aspergillus spores may have entered the oncology unit from the physically adjacent hospital because the air pressure differed. Guidelines that establish the minimum acceptable pressures and specify which pressure relationships to test in healthcare settings are needed. Our data show that large-volume air samples are superior to small-volume samples to assess for Aspergillus in the healthcare environment.

Growth characteristics of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies

OBJECTIVE

To determine if there is a difference in in vitro growth of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies. To determine the effects of a corticosteroid and monokine on in vitro growth of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies.

STUDY DESIGN

Growth of fibroblasts from tissues harvested from the trunk and limb were compared from horse and pony samples grown in control media and control media with triamcinolone or monokine added.

ANIMALS OR SAMPLE POPULATION

Dermal and subcutaneous tissue from 22 horses and 17 ponies of various ages and breeds.

METHODS

Fibroblast growth was assessed by tritiated thymidine uptake using standard cell culture techniques. The effect of a monokine or triamcinolone plus control media were compared with control media for fibroblast growth.

RESULTS

Fibroblast growth from tissues isolated from the horse limb was significantly less than growth from the horse trunk and the limb and trunk of ponies. Monokine was more effective than triamcinolone in suppressing fibroblast growth from tissues isolated from the trunk and limb in both horses and ponies.

CONCLUSIONS

There are growth differences in fibroblasts isolated from the limb of horses compared with those isolated from the trunk and from the limb and trunk of ponies.

CLINICAL RELEVANCE

The difference in fibroblast growth from tissues isolated from the trunk and limb of horses and ponies may provide evidence for the difference reported in the healing characteristics of limb wounds in horses and ponies. Influencing fibroblast growth may provide a key to controlling the development of exuberant granulation tissue in horses and ponies.

Philadelphia chromosome-negative engraftment after autologous transplantation with granulocyte-macrophage colony-stimulating factor for chronic myeloid leukemia

Autologous bone marrow transplantation (BMT) has not been curative in chronic myeloid leukemia (CML), because of the inability to purge CML from the autograft and the absence of the allogeneic T cell-mediated antileukemic activity. However, recent advances demonstrate that normal progenitors can be selected from CML marrows by a variety of techniques, including isolation by their small size. Furthermore, we found that myeloid growth factors have a potent antileukemic effect against CML progenitors in vitro by inducing their terminal differentiation. Based on these data, we initiated a trial of autologous BMT in patients with high-risk CML. Autografts were processed in an attempt to enrich for normal progenitors, first by isolating small cells by counterflow centrifugal elutriation and then incubating them in granulocyte-macrophage colony-stimulating factor (GM-CSF) for 72 hours. After a conditioning regimen of busulfan and cyclophosphamide, all patients received GM-CSF daily for 2 months. The median age of the 13 patients in the trial was 45 years (range 17-56 years). The median duration of disease before BMT was 24 months (range 13-72 months). Eight patients were in chronic phase (CP), and five were in accelerated phase (AP). All patients failed to achieve a cytogenetic response to interferon-alpha and were 100% Philadelphia chromosome (Ph)+ before BMT. There were three transplant-related deaths, all AP patients. All of the remaining 10 patients engrafted with some degree of Ph- hematopoiesis; despite high-risk features, nine patients engrafted 100% Ph-. All patients relapsed cytogenetically at a median of 6 months (range 4-22 months). These results demonstrate that autologous BMT can consistently induce complete Ph- engraftment in CP patients. GM-CSF appears to produce a clinical antileukemic effect against CML after autologous BMT.

Vancomycin-resistant enterococci: the clinical effect of a common nosocomial pathogen

Enterococcus spp. is now the third most common pathogen among hospitalized patients, accounting for nearly 12% of nosocomial infections. Enterococcus faecalis is the most prevalent enterococcal species (85%-89%), whereas Enterococcus faecium accounts for 10%-15% of enterococcal isolates. Only 5% of E. faecalis isolates are resistant to glycopeptides. E. faecium has also been shown to be resistant to nonglycopeptide compounds, such as penicillins (97%), high-level gentamicin (52.1%), and high-level streptomycin (58.3%). Numerous risk factors for vancomycin-resistant enterococci (VRE) have been identified, including as length of hospital- or ICU-stay, proximity to a hospitalized, colonized VRE, patient severity of illness, renal failure, recent surgery, immunosuppression, and organ recipient status. An important risk factor is prior exposure to antibiotics such as vancomycin, ceftazidime, ciprofloxacin, and metronidazole, as well as the number and duration of recent antibiotics. Interventions to reduce nosocomial VRE cross-transmission have also been studied. Using gowns in addition to gloves diminished the incidence of VRE in one study, but had a negligible effect in a second study. Studies have shown that in many cases (> 60%) vancomycin usage is inappropriate. While controlling the use of vancomycin alone has only variably diminished VRE colonization, other efforts such as narrowing the spectrum of antibiotics, antiseptics, and reducing immunosuppression may be salutary. Attempts to eradicate VRE intestinal carriage with enteral agents (bacitracin, tetracycline + rifampin, novobiocin) have been reported but seem to have only a transient effect. Non-antimicrobial interventions such as removal of intravenous or bladder catheters and/or surgical or percutaneous drainage may be beneficial. In addition, the development of new antimicrobial agents such as streptogramins, glycopeptides, everninomicins, and oxazalididones will hopefully play an important role in reducing morbidity from these pathogens.

Autotransplants for Hodgkin's disease in patients never achieving remission: a report from the Autologous Blood and Marrow Transplant Registry

PURPOSE

Hodgkin's disease patients who never achieve complete remission with conventional chemotherapy (i.e., those with primary induction failure) have a poor prognosis. Some subjects who receive high-dose therapy with autologous hematopoietic progenitor-cell infusion experience prolonged progression-free survival.

PATIENTS AND METHODS

Detailed records from the Autologous Blood and Marrow Transplant Registry (ABMTR) on 122 Hodgkin's disease patients who failed to achieve complete remission after one or more conventional therapy regimens and subsequently received an autotransplant between 1989 and 1995 were reviewed.

RESULTS

Median age was 27 years (range, 7 to 57 years). Median time from diagnosis to transplantation was 14 months (range, 5 to 38 months). Most patients received high-dose chemotherapy without radiation for pretransplantation conditioning (n = 107). The regimen most frequently used was cyclophosphamide, carmustine, and etoposide (n = 47). Fifteen patients received total-body irradiation (n = 15). The graft consisted of bone marrow (n = 86), blood stem cells (n = 25), or both (n = 11). The 100-day mortality was 12% (95% confidence interval, 7% to 19%). Sixty patients (50%) were considered to have achieved complete remission after autotransplantation; 37 of these had negative imaging studies, whereas scan abnormalities of unknown significance persisted in 23 patients. Twenty-seven patients (22%) had no response or progressive disease after transplantation. Probabilities of progression-free and overall survival at 3 years were 38% (95% confidence interval, 28% to 48%) and 50% (95% confidence interval, 39% to 60%), respectively. In multivariate analysis, "B" symptoms at diagnosis and poor performance score at transplantation were adverse prognostic factors for outcome.

CONCLUSION

Autotransplants should be considered for patients with Hodgkin's disease who do not achieve complete remission with conventional therapy.

A phase II "window" study of topotecan in untreated patients with high risk adult acute lymphoblastic leukemia

To further evaluate the activity of topotecan (TPT) in acute leukemia, TPT was administered (2.1 mg/m2/day for 5 days by continuous i.v. infusion) to adult patients with previously untreated acute lymphoblastic leukemia (ALL) with high-risk features (13 patients) or relapsed ALL (1 patient). Patients achieving a partial response or significant hematological improvement received a second course. All patients subsequently received standard treatment for ALL. Because complete response was achieved in only 1 of 14 patients, the study was terminated prematurely. An additional patient achieved minimal response, and a third patient normalized her hemogram despite ongoing leukemia in the marrow. Overall, six patients had significant hematological improvement (normalization of platelet and/or absolute neutrophil count). Two patients expired due to infections during induction chemotherapy. The primary nonhematological toxicities were mucositis and diarrhea. Exposure to TPT did not appear to influence the response to subsequent standard chemotherapy. The mean steady-state TPT plasma concentration, 16.1+/-1 nM, overlapped the range of LD90 values of primary human leukemia specimens. Cellular topo I content varied over a 3-fold range, encompassing levels found previously in relapsed patients. No relationship was found between topo I expression and markers of cellular proliferation or response to therapy. In contrast, low expression of the apoptosis inhibitor Bcl-2 was associated with response to TPT therapy. TPT has significant, albeit modest, single-agent activity against high-risk adult ALL. This study demonstrates the feasibility of evaluating promising new therapeutic agents in untreated patients with acute leukemia at high risk for failure with conventional therapy.

Randomized, double-blind clinical trial of amphotericin B colloidal dispersion vs. amphotericin B in the empirical treatment of fever and neutropenia

We conducted a prospective, randomized, double-blind study comparing amphotericin B colloidal dispersion (ABCD) with amphotericin B in the empirical treatment of fever and neutropenia. Patients with neutropenia and unresolved fever after > or = 3 days of empirical antibiotic therapy were stratified by age and concomitant use of cyclosporine or tacrolimus. Patients were then randomized to receive therapy with ABCD (4 mg/[kg.d]) or amphotericin B (0.8 mg/[kg.d]) for < or = 14 days. A total of 213 patients were enrolled, of whom 196 were evaluable for efficacy. Fifty percent of ABCD-treated patients and 43.2% of amphotericin B-treated patients had a therapeutic response (P = .31). Renal dysfunction was less likely to develop and occurred later in ABCD recipients than in amphotericin B recipients (P < .001 for both parameters). Infusion-related hypoxia and chills were more common in ABCD recipients than in amphotericin B recipients (P = .013 and P = .018, respectively). ABCD appeared comparable in efficacy with amphotericin B, and renal dysfunction associated with ABCD was significantly less than that associated with amphotericin B. However, infusion-related events were more common with ABCD treatment than with amphotericin B treatment.

Topoisomerase II and the response to antileukemic therapy

A number of recent studies have investigated the expression of topoisomerase II in clinical leukemia specimens. Here we outline the rationale for these studies, identify potential pitfalls, summarize recent results, and discuss unanswered questions in this area.

Treatment of invasive fungal infections in renally impaired patients with amphotericin B colloidal dispersion

Amphotericin B colloidal dispersion (ABCD) is a new formulation of conventional amphotericin B designed to minimize drug distribution in the kidney and reduce nephrotoxicity. We studied the safety and efficacy of ABCD in 133 renally compromised patients with invasive fungal infections. Patients had either nephrotoxicity from amphotericin B or preexisting renal disease. Intravenous treatment with ABCD (4 mg/kg of body weight daily) was administered for up to 6 weeks. Evaluations included clinical response to treatment and adverse events, with emphasis on changes in serum creatinine levels. ABCD did not appear to have an adverse effect on renal function: mean serum creatinine level tended to decrease slightly with days on therapy, and increases were not dose related. Complete or partial response to treatment was reported for 50% of the 133 intent-to-treat patients and 67% of the 58 evaluable patients.

Utility of fiberoptic bronchoscopy in bone marrow transplant patients

Fiberoptic bronchoscopy (FOB) has been reported to have a high diagnostic yield and to be safe in BMT patients with pulmonary infiltrates. At our institution, BMT patients with respiratory symptoms and/or pulmonary infiltrates had a thoracic CT and bronchoalveolar lavage (BAL). Transbronchial biopsy (TBBx) was considered if the platelet count could be raised to >30 x 10(9)/l. From March 1993 to August 1995, 52 patients had 68 FOBs (42 BAL + TBBx, 26 BAL only) for 60 episodes of clinical pneumonia. Patients' characteristics were: 38 males, mean age 42 years, and 39 allogeneic BMTs. Of the 68 FOBs, 47 were performed to evaluate diffuse infiltrates, 10 were done on mechanically ventilated patients, and 50 of the FOBs were preceded by a platelet transfusion. Thirty-one percent of FOBs (21 FOBs, 19 patients) were diagnostic. Twenty-four percent of FOBs (11 diagnostic FOBs, six nondiagnostic FOBs) changed therapy. Ten complications (15%) occurred in 10 FOBs (five acute respiratory failure, three pneumothoraces, one nose bleed, one death). Hospital and 6-month survival based on episodes of clinical pneumonia were 47 and 32%, respectively. Patients who had a diagnostic FOB or a FOB that changed treatment did not have better hospital or 6-month survival compared to patients who had FOBs that were nondiagnostic or did not change treatment. FOB in our BMT patient population, had a low diagnostic yield (31%), infrequently changed treatment (24%), a significant complication rate (15%) and was not associated with improved patient survival. The role of routine diagnostic FOB in BMT patients with pulmonary infiltrates and/or respiratory symptoms should be reevaluated.

A phase I and pharmacological study of topotecan infused over 30 minutes for five days in patients with refractory acute leukemia

The principal objectives of this study were to determine the feasibility of escalating doses of the hydrophilic topoisomerase I (topo I) inhibitor topotecan (TPT) as a 30-min infusion daily for 5 days in adults with refractory or relapsed acute leukemia and to study the pharmacokinetic behavior of high doses of TPT and pharmacodynamic determinants of TPT activity. Fourteen patients received 27 courses of TPT at doses ranging from 3.5 to 5.75 mg/m2/day every 3 weeks. A constellation of unusual adverse effects, consisting of high fever, rigors, precipitous anemia, and hyperbilirubinemia, was the principal dose-limiting toxicity of high doses of TPT on this schedule. These toxicities were consistently intolerable at the 5.75 mg/m2/day dose level; however, they were neither severe nor common at lower doses. Although the precise etiology of these effects is not known, high doses of TPT may induce acute hemolytic reactions in this patient population. Severe, albeit transient, mucositis was experienced by two of eight patients in 2 of 17 courses at the next lower dose level, 4.5 mg/m2/day, which was determined to be the maximum tolerated dose and the dose recommended for further trials. The pharmacokinetic behavior of TPT at high doses was not dose dependent and resembled that at lower doses. In view of preclinical data suggesting that TPT sensitivity might correlate with topo I levels, topo I content in leukemia blasts was assessed by Western blotting. Variations in topo I content were observed. Moreover, strong correlations were evident between topo I content and two markers of proliferation, proliferating cell nuclear antigen and nuclear protein B23, raising the possibility that differences in topo I content observed among various leukemia specimens might reflect differences in the proliferating fractions of cells in various leukemia samples. Although complete clearance of circulating leukemia blasts occurred in most courses, neither sustained responses nor hematopoietic recovery were observed in the heavily pretreated, poor-risk patients enrolled in this study, and it was not possible to correlate these differences in topo I content with clinical response. These results indicate that substantial dose escalation of TPT as a 30-minute infusion for a 5-day schedule above myelosuppressive doses is feasible in adults with refractory or relapsed leukemias; however, further development of alternate high-dose schedules in leukemia may be warranted in view of the nature of the dose-limiting toxicity and the lack of sustained clinical responses in this preliminary investigation.

Impact of age on outcome of patients with cancer undergoing autologous bone marrow transplant

PURPOSE

We examined the impact of age on outcomes in patients with cancer undergoing autologous bone marrow transplantation (ABMT).

PATIENTS AND METHODS

All 506 adult patients who underwent ABMT at the Johns Hopkins Oncology Center between January 1987 and January 1994 were studied. A total of 405 patients were aged 18 to 49 years and 101 were aged > or = 50. The effect of age and other prognostic variables on transplant-related mortality (TRM), relapse, and event-free survival rates were analyzed.

RESULTS

Patients aged > or = 50 years has a 2.24-fold increased risk of TRM. Although relapse rates were not different based on age, the increased TRM rate resulted in a slight decrease in overall event-free survival in the older patients. Causes of death were not different by age and were mainly related to preparative regimen toxicity. Length of hospital stay and hospitalization costs were not increased in the older patients.

CONCLUSION

While the TRM rate was higher in older patients, relapse rates were not increased. Nearly 25% of older patients were expected to be cured of the disease. These data support the use of ABMT in eligible older patients, at least up to the age of 65.

Association of BK virus with failure of prophylaxis against hemorrhagic cystitis following bone marrow transplantation

PURPOSE

Hemorrhagic cystitis (HC) after bone marrow transplantation (BMT) has been ascribed to cyclophosphamide metabolites. HC has also been associated with excretion of the BK type of polyomavirus. The relative contributions of cyclophosphamide metabolites and BK virus in the development of HC following BMT are unknown.

PATIENTS AND METHODS

We conducted a randomized trial to compare mesna with forced diuresis for prophylaxis against HC in 147 BMT recipients. We studied the association of BK virus with HC in 95 consecutive BMT recipients by prospectively monitoring urinary excretion of BK virus using polymerase chain reaction amplification of viral gene sequences.

RESULTS

HC occurred in 37 of 147 (25.2%) transplant recipients. The incidence of HC was similar in patients given mesna (26.8%, 19 of 71) or forced diuresis (23.7%, 18 of 76), and in recipients of allogeneic (27.2%, 18 of 64) or autologous marrow (22.9%, 19 of 83). The incidence of HC was unrelated to primary disease, preparative regimen, or occurrence of graft-versus-host disease (GVHD). Excretion of BK virus was demonstrated in 50 of 95 patients (52.6%); 38 patients (40%) had persistent BK viruria (> or = two consecutive positive samples). HC occurred in 19 of 38 patients (50%) with persistent BK viruria, in one of 12 (8.3%) with only a single urine sample positive for BK virus, and in none of 45 who did not excrete BK virus (P < .0001). Shedding of BK virus also had a strong temporal correlation with onset of HC (r = .95).

CONCLUSION

Mesna and forced diuresis are equally effective in abrogating the urothelial toxicity of preparative regimens for BMT. Since HC after BMT is virtually always associated with persistent BK viruria, strategies aimed at the prevention or elimination of viruria in BK seropositive recipients are warranted.

Erythropoietin after bone marrow transplantation

The anemia associated with bone marrow transplantation is in part related to a relative erythropoietin deficiency. Recombinant human erythropoietin has been studied in different clinical situations. After allogenic bone marrow transplant, recombinant human erythropoietin has enhanced erythroid engraftment and in several studies, decreased transfusion requirement.

Topoisomerase II levels and drug sensitivity in adult acute myelogenous leukemia

The topoisomerase (topo) II-directed agents etoposide, daunorubicin (DNR), and amsacrine (m-AMSA) are widely used in the treatment of acute myelogenous leukemia (AML). In the present study, multiple aspects of topo II-mediated drug action were examined in marrows from adult AML patients. Colony-forming assays revealed that the dose of etoposide, DNR, or m-AMSA required to diminish leukemic colony formation by 90% (LD90) varied over a greater than 20-fold range between different pretreatment marrows. Measurement of nuclear DNR accumulation in the absence and presence of quinidine revealed evidence of P-glycoprotein (Pgp) function in 8 of 82 samples at diagnosis and 5 of 36 samples at first relapse, but the largest quinidine-induced increment in DNR accumulation (< 2-fold) was too small to explain the variations in drug sensitivity. Restriction enzyme-based assays and sequencing of partial topo II alpha and topo II beta cDNAs from the most highly resistant specimens failed to demonstrate topo II gene mutations that could account for resistance. Western blotting of marrow samples containing greater than 80% blasts revealed that the content of the two topo II isoenzymes varied over a greater than 20-fold range, but did not correlate with drug sensitivity in vitro or in vivo. In addition, levels of topo II alpha and topo II beta in 46 of 47 clinical samples were lower than in human AML cell lines. Immunoperoxidase staining showed that these low topo II levels were accompanied by marked cell-to-cell heterogeneity, with topo II alpha being abundant in some blasts and diminished or absent from others. There was a trend toward increasing percentages of topo II alpha-positive cells in pretreatment marrows that contained more S-phase cells. Consistent with this observation, treatment of patients with granulocyte-macrophage colony-stimulating factor for 3 days before chemotherapy resulted in increases in topo II alpha-positive cells concomitant with increases in the number of cells traversing the cell cycle. These observations have implications for the regulation of topo II in AML, for the use of topo II-directed chemotherapy, and for future attempts to relate drug sensitivity to topo II levels in clinical material.

Association of Torulopsis glabrata infections with fluconazole prophylaxis in neutropenic bone marrow transplant patients

Because the use of fluconazole prophylaxis had been associated with an increased rate of Candida krusei infections at The John Hopkins Oncology Center, early empiric amphotericin B plus flucytosine were given to febrile neutropenic patients colonized by C. krusei. By this practice, the proportion of fungemias attributable to C. krusei was low (12.5%) in patients receiving fluconazole over a 6-month interval. However, Torulopsis (Candida) glabrata assumed a much higher proportion of fungemias (75%) among patients receiving fluconazole. In vitro susceptibility testing combined with this clinical experience suggests that some T. glabrata isolates are not susceptible to fluconazole and can cause breakthrough infections in patients receiving fluconazole.

BMT for severe aplastic anemia using cyclosporine

Between 1984 and 1991 24 patients with severe aplastic anemia (SAA) were transplanted with HLA identical sibling donor BM. The overall long-term survival was 79 +/- 8%. The average age was 21 years (range 4-53 years) and the median pre-transplant disease duration was 35 days (range 12-2998 days). Over one-half (15 of 24) of the patients had received > 10 units of blood product transfusions prior to BMT. The pre-transplant conditioning regimen consisted of 200 mg/kg cyclophosphamide (CY). Cyclosporine (CYA) was administered from 2 days prior to BMT and continued for 6-12 months. Two of the 24 patients failed to achieve primary engraftment (FTE). One of these patients had autologous recovery of BM function and is alive and well. Five of the 22 patients who engrafted failed to sustain engraftment (FTSE). Of these, three are alive and well following a second BMT or marrow boost. Only 1 of the 22 patients who engrafted had clinically significant (i.e. Stage II-IV) acute GVHD. No patient developed chronic GVHD. Our results indicate that BMT following a regimen consisting of CY with the continuous use of CYA in the post-transplant period is well tolerated and associated with excellent long-term survival. The high incidence of secondary graft instability (i.e. FTSE), however, suggests that future studies should focus on post-transplantation immunomodulation.

Transient normalization of lymphocyte blastogenic and specific antibody responses following boosting of healthy elderly subjects with tetanus toxoid

The diminished in vitro blastogenic response of lymphocytes from the elderly to mitogenic stimuli is cited as evidence of immunosenescence, but the response to specific microbial antigens has not been well characterized. We measured the response to tetanus toxoid before and after boosting in young and elderly subjects. Elderly subjects (age > or = 70) and young controls (age < 35) were subjected to clinical, laboratory, and nutritional evaluation to ensure a cohort of healthy subjects. Responses of lymphocytes from the elderly to the mitogens phytohemagglutinin and concanavalin A were markedly diminished compared to those from the young. For all subjects, the average in vitro blastogenic response to tetanus toxoid of lymphocytes from elderly subjects (n = 23) was significantly diminished compared to young controls (n = 23; 31,985 +/- 4502 vs 14,411 +/- 3714 cpm, p < .01). Following boosting with tetanus in those subjects in whom boosting with tetanus toxoid was indicated, blastogenesis was comparable between elderly (n = 17) and young subjects (n = 7; 38,078 +/- 11,451 vs 42,103 +/- 9247 cpm). The boosted response to tetanus apparently was not sustained, since in the subset of subjects with a history of tetanus immunization in the past 10 years, the response of the elderly was much less than that of the young. Thus, a cohort of healthy elderly with diminished blastogenic responses to mitogens was capable of at least a transiently normal response to tetanus post boosting.

Impaired erythropoietin response to anemia after bone marrow transplantation

Delayed erythroid recovery is common after bone marrow transplantation (BMT), with some patients continuing to require red blood cell (RBC) transfusion support for as long as 1 year. While the etiology is multifactorial, inadequate stimulation of erythroid progenitors by the erythroid growth factor, erythropoietin, may play a role. In this study, the erythropoietin response to anemia of 70 consecutive patients undergoing BMT at the Johns Hopkins Oncology Center was compared with the erythropoietin response in uncomplicated iron deficiency anemia. Erythropoietin levels were elevated for the degree of anemia early after BMT; however, at the time of marrow recovery, erythropoietin levels were significantly suppressed in both allogeneic and autologous BMT patients compared with the iron-deficient patients. Patients with acute graft-versus-host disease (GVHD) had a more marked suppression of the erythropoietin response to anemia. In the patients who remained anemic for extended periods of time (up to 12 months after BMT), an inadequate erythropoietin response to anemia persisted. Delayed erythroid recovery after BMT is associated with inadequate erythropoietin levels. Therefore, recombinant human erythropoietin may be useful in the treatment of the anemia associated with both autologous and allogeneic BMT.

Phase I-II trial of erythropoietin in the treatment of cisplatin-associated anemia

BACKGROUND

Cancer patients undergoing chemotherapy with cisplatin-containing regimens often develop anemia. Although the cause is multifactorial, erythropoietin deficiency appears to play an important role. Recombinant human erythropoietin (epoetin) has been reported to be effective in reversing cisplatin-associated anemia in animal studies but not in clinical trials.

PURPOSE

This pahse I-II clinical trial was designed to assess the safety and efficacy of treatment with epoetin for anemia associated with cisplatin chemotherapy.

METHODS

Twenty-one cancer patients treated with cisplatin and manifesting anemia (hemoglobin level less than 110 g/L) received epoetin at escalating doses (25, 50, 100, or 200 U/kg body weight) intravenously five times a week for 4 weeks.

RESULTS

Epoetin was well tolerated, and a maximal tolerated dose was not reached. Two patients experienced hypertension, which responded to standard antihypertensive therapy. No dose-dependent severe toxic effects were seen. The increase in hemoglobin levels from baseline on day 1 of the study was statistically significant after 4 weeks of epoetin therapy in the groups receiving 100 U/kg (mean change +/- SD = 19 +/- 13 g/L; P = .03) or 200 U/kg (mean change = 24 +/- 17 g/L; P = .007). A clinical response--an increase in hemoglobin level greater than 10 g/L--was achieved in 12 patients after 4 weeks of treatment. For these responders, the mean increase in hemoglobin level was 25 +/- 3.3 g/L over the level observed at the same time in the chemotherapy cycle preceding epoetin treatment, and this increase was statistically significant (P = .0001). Neither serum erythropoietin level nor hemoglobin level predicted a patient's response to epoetin.

CONCLUSIONS

These preliminary findings suggest that epoetin is effective and well tolerated for the reversal of cisplatin-associated anemia, with the 100-U/kg and 200-U/kg dose levels offering optimal clinical response.

IMPLICATIONS

We are conducting a phase III trial to determine the effect of epoetin on transfusion requirements in patients undergoing chemotherapy.

Phase I study of combination drug purging for autologous bone marrow transplantation

In a phase I clinical trial of autologous bone marrow transplantation, we determined the feasibility of ex vivo purging with high concentrations of pharmacologics in combination. Light-density cells isolated from the grafts of 26 patients with acute leukemia or lymphoblastic lymphoma were treated with 4-hydroperoxycyclophosphamide (4-HC; 30 to 60 micrograms/mL), vincristine (Vcr; 1.5 to 3.0 micrograms/mL), and methylprednisolone sodium succinate (MP; 5 mg/mL). All patients received marrow-lethal induction therapy followed by infusion of the treated grafts. Three patients died of transplant-related complications before achieving peripheral blood recovery of greater than 0.5 x 10(9) granulocytes per liter. All other patients achieved this parameter of engraftment at a median of 35 days after marrow infusion. The median time to last platelet transfusion was 45 days. These durations of aplasia were similar to those experienced by other patients receiving density-gradient separated grafts treated with 60 micrograms/mL of 4-HC as a single agent. No patient required infusion of untreated reserve marrow because of engraftment failure. The colony-forming unit-granulocyte macrophage (CFU-GM) content of the grafts after purging predicted these parameters of engraftment. Colony-forming unit-leukemia (CFU-L) cultured from the grafts of 12 of the patients treated for acute lymphoblastic leukemia (ALL) were considerably more sensitive to the combination regimen than to 4-HC alone; the sensitivity of CFU-GM from these patients did not differ between the two regimens. The results of this trial indicate the feasibility of treating autologous bone marrow grafts with high concentrations of pharmacologics in combination. The use of combinations may increase the efficacy of ex vivo purging without increasing the toxicity to normal hematopoietic cells.

Treatment of chemotherapy-induced anemia with recombinant human erythropoietin in cancer patients

Thirty patients with chemotherapy-induced anemia were treated with recombinant human erythropoietin for 4 weeks. In this dose-escalation study, cohorts of five to eight patients were treated per dose level. The doses of erythropoietin were 25, 50, 100, 200, or 300 IU/kg/d given intravenously for 5 days each week. Of 30 patients, 15 (50%) had a greater than 10% increase of their hemoglobin (Hb) values and were considered responders. At the two highest dose levels, 11 of 13 patients (85%) responded. In the 15 responding patients, the mean Hb level increased by 1.7 g/dL from baseline compared with an average decrease of 1.5 g/dL in the previous cycles of chemotherapy without erythropoietin administration. Recombinant human erythropoietin is effective in ameliorating chemotherapy-induced anemia when administered in adequate doses.

A survey of opinions concerning recruitment for the profession among the members of the Virginia Medical Record Association

A MRA has employed Market Strategies, Inc. (MSI), to undertake a nationwide corporate communications study and campaign. This article discusses a project MSI carried out for the Virginia Medical Record Association.

Correlation of occult clonogenic leukemia drug sensitivity with relapse after autologous bone marrow transplantation

Despite initial complete remission rates exceeding 70%, the majority of patients with acute myeloid leukemia (AML) and adults with acute lymphocytic leukemia (ALL) eventually relapse. Improving the therapeutic results in acute leukemia requires detecting, and understanding the biology of, the minimal residual leukemia remaining after therapy and responsible for relapse. To investigate the biologic relevance of an in vitro assay for clonogenic leukemia (leukemia colony-forming units [CFU-L]) as a measure of minimal residual leukemia, we studied 58 consecutive patients with acute leukemia in complete remission undergoing autologous bone marrow transplantation (BMT) with cyclophosphamide-based therapy. CFU-L were cultured from the pretransplant remission marrows in 45 of 58 patients: 35 of 43 patients with AML and 10 of 15 with ALL. Clonal rearrangements, identical to the patients' overt leukemia when available, were detected in the occult CFU-L from four of the eight patients with ALL in whom adequate DNA for analysis could be obtained from the CFU-L. None of the uncultured pretransplant remission marrows from the 15 ALL patients showed clonal gene rearrangements. We also determined the in vitro sensitivity of the occult CFU-L to 4-hydroperoxycyclophosphamide (4HC), and correlated these results with the outcome of the patients. The sensitivity of the occult CFU-L to 4HC was the only factor that predicted relapse following BMT. The actuarial probability of relapse was 18% in the 23 patients whose CFU-L were sensitive to 4HC compared with 77% in the 22 patients whose CFU-L were resistant (P less than .001). The only factor that influenced the CFU-L sensitivity to 4HC was the type of leukemia. The CFU-L from the AML patients were more sensitive to 4HC than the CFU-L from the ALL patients (P = .001). Occult CFU-L genetically and functionally represent occult leukemia. Therefore, the CFU-L assay should provide a means for studying the biology of minimal residual leukemia and improving the therapeutic results in patients with acute leukemia.

Evolution of a near-triploid karyotype in a secondary erythroleukemia

We report a case of erythroleukemia (EL;FAB M6), preceded by a myelodysplastic phase, in a 50-year-old male 8 years after treatment for Hodgkin's lymphoma. Cytogenetic analysis of bone marrow at time of diagnosis of EL revealed three cell lines: 1) 28 of 53 cells (53%) were hypodiploid, 43,XY,-5,-7,-12; 2) 23 of 53 cells (43%) were near-triploid, stemline 67-69,XY,+2,del(5)(q11.2),+del(5)(q11.2),+6,-7,+8,-9,-11,-12,+15,-16,der (17)t (17;?) (p11.2;?),-18,-20,-20,+22,+r, + mar (relative to a complete triploid cell); 3) 2 of 53 cells (4%) were normal 46,XY. The relative monosomies of 5, 7, and 12 in both abnormal lines suggest that the near-triploid line evolved from the hypodiploid line. A single hypodiploid cell with both del(5) and der(17) chromosomes that appeared identical to those in the near-triploid line suggests that polyploidization occurred after these structural rearrangements. While EL is not characterized by any well-defined structural abnormality, reported cases are frequently hypodiploid, with occasional cases of polyploidization, as in our patient, EL in adults without previous neoplasia or recognized mutagenic exposure has been shown to have loss or deletion of chromosomes 5 and 7, also characteristic of myelodysplastic syndromes and secondary leukemia. Our patient had a relative lack of chromosomes 5 and 7 in both abnormal clones, as well as a del(5)(q11) in the near-triploid line. This case of EL clearly demonstrates the evolution of a complex near-triploid line from a hypodiploid line, with chromosome abnormalities typical of both EL and secondary leukemia.

Exercise in Merino sheep dash the relationships between work intensity, endurance, anaerobic threshold and glucose metabolism

The effect of exercise intensity on (i) the ability of sheep to sustain exercise and (ii) glucose metabolism was investigated in fed non-pregnant adult Merino ewes. Five animals were prepared with cannulae to study the splanchnic tissues using the arteriovenous difference technique either at rest or during 8 levels of exercise: 3, 5, 7 and 9 km h-1 at either 0� or 9� incline. The anaerobic threshold, determined by elevation of blood lactate concentration or lactate/pyruvate ratio, occurred at a work rate of about 6-10 watts/kg body wt (7 km h-1 on 0� incline, 3 km h-1 on 9� incline). Only exercise well in excess of the anaerobic threshold resulted in ewes showing fatigue. Fatigue was not associated with carbohydrate depletion or lacticacidosis. Changes in the partial pressure of CO2 and the pH of blood indicated a marked respiratory alkalosis that was related to the severity of exercise, suggesting that thermoregulation may have been an important component of fatigue. Splanchnic blood flow declined when the intensity of exercise exceeded the anaerobic threshold; however, this did not compromise splanchnic function as assessed by oxygen and metabolite uptake. During exercise below the anaerobic threshold euglycemia was maintained while a pronounced hyperglycemia, that became more severe as the work rate increased, was found for exercise above the anaerobic threshold. The release of glucose by the liver increased significantly at all work rates and markedly so after the anaerobic threshold, such that the resultant hyperglycemia was consistent with an exaggerated hepatic glucose release due to 'feed forward' control. The contribution of lactate and glycerol to gluconeogenesis, assuming complete conversion, remained constant at 18-25% except at the highest work load where the contribution significantly declined to 9%. The decline was due to (i) saturation of hepatic lactate uptake and (ii) a failure for glycerol concentration and so uptake to increase beyond a work rate of 22 W kg-1. The requirement for gluconeogenic end products of digestion for animals grazed under extensive conditions would be 9-30% greater than for animals not exercising, depending upon the speed and inclination of exercise.

Decreased erythropoietin response in patients with the anemia of cancer

Patients with solid tumors are often anemic even before they undergo cytotoxic therapy. Since the cause of the anemia of cancer is unknown, we examined the possible role of erythropoietin. Using a sensitive radioimmunoassay, we determined serum immunoreactive erythropoietin levels in 81 anemic patients with solid tumors. For any given degree of anemia, the serum concentration of immunoreactive erythropoietin was lower in this group of patients than in a group of control patients with iron-deficiency anemia (P = 0.0001). Furthermore, the expected inverse linear relation between serum levels of immunoreactive erythropoietin and of hemoglobin was absent in the group with cancer. The erythropoietin response was further decreased in patients receiving chemotherapy; it was not influenced by the presence or absence of cisplatin in the treatment regimen. The inability of the patients with cancer to produce erythropoietin was not absolute; if they had hypoxemia, adequate erythropoietin production was restored. We conclude that erythropoietin levels are inappropriately low in anemia associated with cancer, and that erythropoietin deficiency may contribute to the development of this form of anemia. Treatment of the anemia of cancer with erythropoietin may be of value.

In vitro evaluation of combination drug purging for autologous bone marrow transplantation

Using an in vitro model, we studied whether combining 4-hydroperoxycyclophosphamide (4HC) with other drugs could improve its effectiveness as an ex vivo purging agent for autologous bone marrow transplantation. 4HC was incubated simultaneously with vincristine and etoposide, and sequentially with methylprednisolone, in various combinations. Compared to 4HC alone, all drug combinations increased the kill of the leukemia cell lines K562 and CEM without increasing the kill of granulocyte-macrophage colony-forming units (CFU-GM). The combination of 4HC, vincristine and methylprednisolone was the most active, and this drug combination was also the only combination which showed improved selective cytotoxicity (compared to 4HC alone) toward REH cells. This combination inhibited at least 8 logs of clonogenic leukemia cells from all three cell lines at doses which spared 1% of CFU-GM. This was an increase of 1.7 to 6.6 logs of clonogenic leukemia cell kill over 4HC alone. This drug combination displayed similar differential activity between fresh clonogenic leukemia cells and CFU-GM cultured from the bone marrows of seven patients about to undergo autologous bone marrow transplantation for acute lymphocytic leukemia.

Bryostatin 1, a unique biologic response modifier: anti-leukemic activity in vitro

Bryostatin 1, a macrocyclic lactone isolated from the marine bryozoan Bugula neritina, has demonstrated both antineoplastic activity against the murine P388 leukemia line in vivo and stimulatory activity against mouse and human hematopoietic progenitors. We studied the effects of bryostatin 1 on the growth of human leukemias in vitro. Bryostatin 1 inhibited 1 to 4 logs of clonogenic leukemia cell growth from three of four leukemia cell lines. Bryostatin 1 also inhibited, by at least 1 log, the proliferation of clonogenic acute nonlymphocytic leukemia (ANLL) cells from 10 to 12 patients with newly diagnosed or relapsed ANLL. Maximal inhibition of leukemic growth occurred at 10(-9) to 10(-7) mol/L bryostatin 1. Interestingly, bryostatin 1 also inhibited the growth of hematopoietic progenitors from eight patients with myelodysplastic syndromes (MDS). Leukemia cells exposed to bryostatin 1 for up to 96 hours and then washed, demonstrated no substantial inhibition of clonogenic growth, indicating that the anti-leukemic effect of bryostatin 1 is cytostatic. The phorbol ester 12-0-tetradecanoylphorbol-13-acetate (TPA) produced more potent inhibition of clonogenic leukemia growth, and this inhibition was blocked by bryostatin 1. Thus, the anti-leukemic activity of bryostatin 1 may be mediated through activation of protein kinase C. Bryostatin 1 inhibits clonogenic leukemia cells at concentrations that stimulate normal hematopoietic progenitors. The differential effects of bryostatin 1 on normal and abnormal hematopoiesis suggest that bryostatin 1 may have value in the treatment of leukemias and MDS.

Effect of canine cardiac nerves on heart rate, rhythm, and pacemaker location

In open-chest dogs, right- and left-sided cardiac nerves were stimulated to determine their effect on heart rate, rhythm, and pacemaker location. The majority of the nerves produced chronotropic changes; 72% of the induced rhythms originated from within the atrial pacemaker complex. Ten percent of the stimulations produced an atrio-ventricular (AV) nodal rhythm; most of the time this was induced by the left posterior and anterior ansae and ventrolateral nerves. The dominance of a lateral right atrial pacemaker was observed in 8% of the stimulations; the dorsal cardiac and innominate nerves induced this rhythm the majority of the time. The general trend was for a cranial shift in the location of the pacemaker within the pacemaker complex with sympathetic stimulation and a caudal shift with parasympathetic stimulation. Exceptions to the pattern may be explained by the preferential effect of the nerves on the pacemakers in the right atrium. The study demonstrates, in the canine model, that in addition to the sinus and AV nodes, there is a system of pacemakers controlled by the cardiac nerves.

Activation sequence and potential distribution maps demonstrating multicentric atrial impulse origin in dogs

We examined the onset of atrial epicardial excitation by recording unipolar potentials from 360 electrodes arranged in templates affixed to the superior vena cava and right atrium in dogs. Both activation sequence and potential distribution maps were obtained for the period of impulse origin beginning before the surface P wave and continuing through the first 15-20 msec of atrial depolarization. The activation maps demonstrated impulse origin from multiple widely separated sites, resulting in two to three individual wavefronts that merged to form a single widely disseminated wavefront spread over a 50 X 20 mm area by 10-15 msec. Atrial potential maps obtained for the same time periods revealed multiple sites of primary negativity corresponding to the points of impulse origin in the activation maps. The potential distributions and evolution of these maps also indicated the presence of multiple wavefronts originating from widely separated locations, and suggested an extensively dispersed source of impulse origin. One of these sites at the superior cavo-appendicular junction corresponded to the rostral portion of the sinus node and the site of classical unifocal origin. Additional sites of impulse origin and primary negativity distant to the sinus node were noted either concurrently in the same map or in other maps associated with different patterns of impulse initiation. Classical physiological and pharmacological interventions were used to alter adrenergic and cholinergic input to the atrium, and resulted in coincident changes of both the patterns of impulse origin and heart rate. In addition, we examined spontaneous changes in the patterns of impulse initiation which accompanied beat-to-beat changes in cycle length (sinus arrhythmia). There was close agreement between activation and potential maps over the entire steady state and dynamic range of impulse origin. The data can be explained by the concept of a widely distributed system of functionally differentiated but coordinated atrial pacemakers.

Quantitative relation between sites of atrial impulse origin and cycle length

Having previously described the multicentric origin of the atrial impulse from sites widely distributed over the right atrium as well as an intrinsic link between these sites of origin and cycle length (CL), we undertook a quantitative study of this relationship. In 132 dogs anesthetized with pentobarbital sodium or fentanyl citrate, we recorded atrial activation sequence maps from 360 closely positioned electrodes and determined locations of impulse origin at heart rates between 80 and 240 (CL between 750 and 250). We used cardiac nerve stimulation and agonist-antagonist infusion to produce changes in CL and impulse origin. Results demonstrate a significant correlation between site of impulse origin and CL. These sites, associated with both the sinus node (SN) and extranodal sites, function predictably and consistently controlling impulse initiation at heart rates above and below rates at which the SN predominates. This relationship can be used to specify an anatomic-functional model of atrial pacemaker hierarchy and to quantitate the response of different atrial regions to specific pharmacological and physiological interventions.

Immune response to a thymus-dependent form of B512 dextran requires the presence of Lyb-5+ lymphocytes

Studies of the ontogeny of the immune response to B512 dextran (Dex) show that antibody responses equal to those of adult mice are not attained until 12 wk of age. We have examined the anti-Dex response after immunization with a thymus-dependent antigen isomaltohexaosyl-keyhole limpet hemocyanin (IM6-KLH) and have shown that the development of the cross-reacting anti-Dex response parallels the development of Lyb-5+ B cells. Adult levels of anti-Dex antibody after immunization with IM6-KLH are achieved in mice between 3 and 12 wk of age, a time when Lyb-5+ cells have reached adult levels. Neonatal mice, immunized at 1 d or 1 wk after birth, failed to produce a significant amount of anti-Dex antibodies, although they did produce IM6-specific antibodies after immunization with IM6-KLH. Data, which support the conclusion from these experiments that Lyb-5+ cells are required for an anti-polysaccharide response even when the immunizing antigen is thymus-dependent, include the failure of IM6-KLH to stimulate a normal anti-Dex response in mice with the xid defect and the direct demonstration in normal adult mice that elimination of Lyb-5+ cells from spleens of mice primed with IM6-KLH abolishes the ability of these cells to transfer an anti-Dex response. The data imply that the expressed B cell repertoire in adult animals is skewed such that the vast majority of B cells capable of responding to polysaccharide determinants are in the Lyb-5+ subset.