Acquired von Willebrand's Syndrome in a Patient with Concomitant Chronic Lymphocytic Lymphoma and Smoldering Multiple Myeloma

An African-American female in her sixties presented to the hospital with intermittent gum bleeding for the past two years along with severe anemia. This case details the differential and workup that lead to the diagnosis of acquired von Willebrand's syndrome (AvWS). A thorough investigation in the possible etiologies of AvWS revealed that the patient had concomitant chronic lymphocytic lymphoma (CLL) and smoldering multiple myeloma (SMM). Due to the concomitant diagnosis of CLL and SMM, there was a dilemma regarding whether CLL, SMM, or both was driving this patient's AvWS. Decision was made to treat the underlying CLL initially with rituximab and later on at recurrence with obinutuzumab/venetoclax with complete resolution of patient's bleeding and normalization of her factor VIII activity, von Willebrand factor antigen levels, and vWF:ristocetin cofactor levels. We believe this is first case in the literature of a patient with AvWS with concurrent CLL and SMM.

The Direct Support Workforce: An Examination of Direct Support Professionals and Frontline Supervisors During COVID-19

Direct support professionals (DSPs) and frontline supervisors (FLSs) have critical roles in home and community-based services for people with intellectual and developmental disabilities. Low wages and high levels of responsibility created a long-term crisis in recruitment and retention and are exacerbated by the COVID-19 pandemic. A national sample of DSPs and FLSs were compared on demographics and work-related circumstances using data from the third Direct Support Workforce COVID-19 Survey. Significant differences were found in demographics, hours worked, wages, wage augmentations, and quality of work-life. Policy recommendations to address the worsening workforce crisis are provided.

Expert consensus on microtransplant for acute myeloid leukemia in elderly patients -report from the international microtransplant interest group

Recent studies have shown that microtransplant (MST) could improve outcome of patients with elderly acute myeloid leukemia (EAML). To further standardize the MST therapy and improve outcomes in EAML patients, based on analysis of the literature on MST, especially MST with EAML from January 1st, 2011 to November 30th, 2022, the International Microtransplant Interest Group provides recommendations and considerations for MST in the treatment of EAML. Four major issues related to MST for treating EAML were addressed: therapeutic principle of MST (1), candidates for MST (2), induction chemotherapy regimens (3), and post-remission therapy based on MST (4). Others included donor screening, infusion of donor cells, laboratory examinations, and complications of treatment.

Transcriptomics of acute myeloid leukaemia core bone marrow biopsies reveals distinct therapy response-specific osteo-mesenchymal profiles

While the bone marrow (BM) microenvironment is significantly remodelled in acute myeloid leukaemia (AML), molecular insight into AML-specific alterations in the microenvironment has been historically limited by the analysis of liquid marrow aspirates rather than core biopsies that contain solid-phase BM stroma. We assessed the effect of anthracycline- and cytarabine-based induction chemotherapy on both haematopoietic and non-haematopoietic cells directly in core BM biopsies using RNA-seq and histological analysis. We compared matched human core BM biopsies at diagnosis and 2 weeks after cytarabine- and anthracycline-based induction therapy in responders (<5% blasts present after treatment) and non-responders (≥5% blasts present after treatment). Our data indicated enrichment in vimentin (VIM), platelet-derived growth factor receptor beta (PDGFRB) and Snail family transcriptional repressor 2 (SNAI2) transcripts in responders, consistent with the reactivation of the mesenchymal population in the BM stroma. Enrichment of osteoblast maturation-related transcripts of biglycan (BGN), osteopontin (SPP1) and osteonectin (SPARC) was observed in non-responders. To the best of our knowledge, this is the first report demonstrating distinct osteogenic and mesenchymal transcriptome profiles specific to AML response to induction chemotherapy assessed directly in core BM biopsies. Detailing treatment response-specific alterations in the BM stroma may inform optimised therapeutic strategies for AML.

Direct Oral Anticoagulants Versus Vitamin K Antagonists in Cerebral Venous Thrombosis: A Systematic Review and Meta-Analysis

BACKGROUND

High level evidence for direct oral anticoagulants (DOACs) in patients with cerebral venous thrombosis is lacking. We performed a systematic review and meta-analysis to assess the efficacy and safety of DOACs versus vitamin K antagonists in patients with cerebral venous thrombosis.

METHODS

This systematic review was registered in PROSPERO (CRD42021228800). We searched MEDLINE (via Ovid), EMBASE, CINAHL, and the Web of Science Core Collection between January 1, 2007 and Feb 22, 2022. Search terms included a combination of keywords and controlled vocabulary terms for cerebral venous thrombosis, vitamin K antagonists/warfarin, and DOACs. We included both randomized and nonrandomized studies that compared vitamin K antagonists and DOACs in 5 or more patients with cerebral venous thrombosis. Where studies were sufficiently similar, we performed meta-analyses for efficacy (recurrent venous thromboembolism and complete recanalization) and safety (major hemorrhage) outcomes, using relative risks (RRs).

RESULTS

Out of 10 665 records identified, we screened 254 as potentially eligible. Nineteen studies (16 observational studies [n=1735] and 3 randomized controlled trials [n=215]) met the inclusion criteria. All 3 randomized controlled trials had some concerns, and all 16 observational studies had at least moderate risk of bias. When compared with vitamin K antagonist treatment, DOAC had comparable risks of recurrent venous thromboembolism (relative risk [RR], 0.85 [95% CI, 0.52-1.37], I²=0%), major hemorrhage (RR, 0.70 [95% CI, 0.40-1.21], I²=0%), intracranial hemorrhage (RR, 0.58 [95% CI, 0.30-1.12]; I²=0%), death (RR, 1.14 [95% CI, 0.54-2.43], I²=1%), and complete venous recanalization (RR, 0.98 [95% CI, 0.87-1.11]; I²=0%).

CONCLUSIONS

This systematic review and meta-analysis suggest that in patients with cerebral venous thrombosis, DOACs, and warfarin may have comparable efficacy and safety. Given the limitations of the studies included (low number of randomized controlled trials, modest total sample size, rare outcome events), our findings should be interpreted with caution pending confirmation by ongoing randomized controlled trials and large, prospective, observational studies.

Vincristine Sulfate Liposome Injection with Bendamustine and Rituximab as First-Line Therapy for B-Cell Lymphomas: A Phase I Study

Background

We conducted an investigator-initiated, phase I trial of vincristine sulfate liposomal injection (VSLI) in combination with bendamustine and rituximab (BR) for indolent B-cell (BCL) or mantle cell lymphoma.

Methods

Participants received 6 cycles of standard BR with VSLI at patient-specific dose determined by the Escalation with Overdose Control (EWOC) model targeting 33% probability of dose-limiting toxicity (DLT). Maximum tolerated dose (MTD) was the primary endpoint; secondary endpoints included rates of adverse events (AEs), overall response rate (ORR), and complete response (CR). Vincristine sulfate liposomal injection is FDA approved for the treatment of patients with recurrent Philadelphia chromosome-negative (Ph−) acute lymphoblastic leukemia (ALL).

Results

Among 10 enrolled patients, VSLI was escalated from 1.80 to 2.24 mg/m², with one DLT (ileus) at 2.04 mg/m². Two patients discontinued VSLI early. The most common AE included lymphopenia (100%), constipation, nausea, infusion reaction (each 60%), neutropenia, and peripheral neuropathy (50%). Grade 3/4 AE included lymphopenia (90%), neutropenia (20%), and ileus (10%), with prolonged grade ≥2 lymphopenia observed in most patients. Calculated MTD for VSLI was 2.25 mg/m² (95% Bayesian credible interval: 2.00-2.40). Overall response was 100% with 50% CR. With median follow-up 26 months, 4/10 patients experienced recurrence and 1 died.

Conclusion

Vincristine sulfate liposomal injection at 2.25 mg/m² can be safely combined with BR for indolent B-cell lymphoma, but given observed toxicities and recurrences, we did not pursue an expanded cohort.

Clinical Trials Registration Number: ClinicalTrials.gov identifier NCT02257242.

Abstract TMP74: Direct Oral Anticoagulants Vs. Vitamin K Antagonists In Patients With Cerebral Venous Thrombosis: A Systematic Review And Meta-analysis

Introduction: Direct oral anticoagulants (DOACs) have emerged as a potential anticoagulant therapy for patients with cerebral venous thrombosis (CVT). We conducted a systematic review and meta-analysis comparing DOACs versus vitamin K antagonists (VKAs) for treatment of CVT.

Methods: We registered the review in PROSPERO (registration number CRD42021228800). We searched Medline, Embase, CINAHL, and the Web of Science Core Collection from January 1, 2007, to May 26, 2021. We included randomized controlled trials (RCTs) and non-randomized comparative studies (NRCSs) evaluating key outcomes for efficacy (recurrent venous thromboembolism [VTE] and complete recanalization) and safety (major hemorrhage). We assessed risk of bias using the Cochrane Risk of Bias Tool 2.0 (for RCTs) and the ROBINS-I tool (for NRCSs). Where studies were sufficiently similar, we performed meta-analyses using random-effects models. This review was funded by Brown Neurology.

Results: Of 8213 identified records,10 studies (1 RCT and 9 NRCSs) with a total of 662 patients (33% DOAC and 67% VKAs) met the inclusion criteria. We will present our risk of bias assessment at the conference. DOACs and VKAs had comparable efficacy: recurrent VTE (risk ratio [RR] 1.00, 95% confidence interval [CI] 0.44-2.23; I 2 =0%; 10 studies) and complete recanalization (RR 1.00, 95% CI 0.77-1.28; I 2 =0%; 6 studies). DOAC and VKA also had comparable safety: major hemorrhage (RR 0.89, 95% CI 0.37-2.14; I 2 =0%; 9 studies).

Conclusions: Studies comparing DOACs with VKAs in patients with CVT consist mostly of small, non-randomized, poorly controlled studies. While the two treatments appear comparable for major efficacy and safety outcomes, large, rigorously conducted studies, preferably randomized, are needed to overcome these limitations and permit development of clinical practice guidelines for the use of DOACs in patients with CVT.

Murine Leukemia-Derived Extracellular Vesicles Elicit Antitumor Immune Response

Background

Extracellular vesicles (EVs) are heterogeneous lipid bilayer particles secreted by cells. EVs contain proteins, RNA, DNA and other cargo that can have immunomodulatory effects. Cancer-derived EVs have been described as having immunomodulating effects in vivo with immunosuppressive and pro-tumor growth capabilities. However, cancer-derived EVs have also been harnessed and utilized for anti-cancer potential.

Methods

To assess the immunomodulatory effect of EVs produced by acute myeloid leukemia (AML) cells, we isolated vesicles secreted by the murine AML cell line, C1498, and investigated their effect on in vitro and in vivo immune responses.

Results

These leukemia-derived EVs were found to induce increased proliferation of CD3+ cells and enhanced cytolytic activity of CD3+ cells directed toward leukemic cells in vitro. Injection of leukemia-derived EVs into syngeneic naïve mice induced T cell responses in vivo and resulted in enhanced immune responses upon T cell re-stimulation in vitro.

Conclusion

These findings indicate that C1498-derived EVs have immunomodulatory effects on cell-mediated immune responses that could potentially be utilized to facilitate anti-leukemia immune responses.

Dissecting the use of recipient alloreactive responses to achieve anti-leukemic effect

Harnessing alloreactive responses to incur anti-leukemic effects has focused on the donor lymphocyte response directed toward recipient antigens. Limited studies have examined the anti-leukemic potential of recipient alloreactive responses to donor cell antigens. An example is the infusion of large numbers of haploidentical, G-CSF mobilized, donor T cells (1 – 2 × 108 CD3+ cells/kg) into patients with refractory hematological malignancies who had received100 cGy total body irradiation prior to infusion. Strong recipient immune responses were generated capable of eliminating the donor cells within two weeks (thereby preventing GVHD) with side effects of high fever (104°F), malaise, rash, and diarrhea. More than half of these patients also generated responses to the hematological malignancies(14/26, 9 major), including some complete remissions. The protocol was modified in the reopened clinical trial by elimination of both the G-CSF mobilization of donor cells and the recipient 100 cGy total body irradiation. These patients exhibited milder, self-resolving fevers and limited anti-leukemic responses (1/5 with transient response). Analysis of blood samples obtained at several different timepoints after infusion revealed diminished IL-6 levels. Increased levels of plasma IL-2 and granzyme B and increased expression of granzyme B and PD-1 by activated recipient T cells correlated with elimination of donor cells. Increased expression of PD-1 ligands on leukemic cells provides one explanation for the lack of anti-leukemic response. These results indicate that appropriate manipulation of both donor cells and patients in this protocol should improve the anti-leukemic responses of recipient lymphocytes.

Abstract B08: New Abelson interactor-1(Abi-1)-driven mechanism of acquired drug resistance

In hematological malignancies, quiescent leukemic stem cells are responsible for persistence of minimal residual disease and relapse. We have recently identified a new signaling pathway that is significantly dysregulated in imatinib mesylate (IM) resistant leukemic cells (Chorzalska et all, Leukemia in press). A key player in this pathway is Abelson interactor-1 (Abi-1). Abi-1 was originally identified as Abl kinase associating protein that was later confirmed to be one of the Bcr-Abl interactors. Abi-1 was recently shown to interact directly with α4 integrin, which controls lodging of hematopoietic and leukemic stem cells (HSCs/LSCs) in the bone marrow microenvironment. We have recently obtained evidence that Abi-1 plays a role in signaling cross-talk between Bcr-Abl and α4 integrin. We have found that loss of Abi-1 leads to increased adhesion and quiescence, resulting in increased chemoresistance of leukemic CD34+ progenitor cells. Comparison of Abi-1 (ABI-1) and α4 integrin (ITGA4) gene expression in relapsing Bcr-Abl positive CD34+ progenitor cells demonstrated a reduction in Abi-1 and an increase in α4 integrin mRNA in the absence of Bcr-Abl mutations. This inverse correlation between Abi-1 and α4 integrin expression, as well as linkage to elevated phospho-Akt and phospho-Erk signaling, was confirmed in imatinib mesylate (IM) resistant leukemic cells. These results indicate that the α4-Abi-1 signaling pathway may mediate acquisition of the drug resistant phenotype of leukemic cells. Based on our findings, we hypothesize that chemoresistance arises as a consequence of dysregulation of a pathway involving α4 integrin and Abi-1, and is mediated through a previously unknown mechanism that is independent of oncogene activity.

Citation Format: Anna Chorzalska, Ibrahem Salloum, Philip Marjon, Diana Treaba, Christoph Schorl, Morgan John, Christine R. Bryke, John Reagan, Eric Winer, Adam J. Olszewski, Patrycja M. Dubielecka. New Abelson interactor-1(Abi-1)-driven mechanism of acquired drug resistance. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Drug Sensitivity and Resistance: Improving Cancer Therapy; Jun 18-21, 2014; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(4 Suppl): Abstract nr B08.

Induction of anti-leukemic responses using cellular immunotherapy (TUM2P.921)

Previous work has shown that blood cancers can be treated through stimulation of the cancer patient’s immune system. In initial studies, it was observed that 14/26 patients with refractory hematological malignancies responded (9 major) to the infusion of large numbers (1 -2 x 108 CD3+ cells/kg) of haploidentical white blood cells following low levels of total body irradiation (100cGy). A cytokine storm quickly developed with a median time of 14 hours and resulted in high fevers that were allowed to persist for 48 hours, if possible, and then controlled with corticosteroids if needed. However the potential role of anti-leukemic effector cells in these responses was not determined. Three patients have been enrolled into a re-opened cellular immunotherapy clinical trial in which haploidentical white blood cells are infused with no prior chemotherapy or radiation. Blood samples were obtained from the recipient approximately 1, 24, 48, 72 and 168 hours after infusion and analyzed for the persistence and activity of donor/recipient cells as well as levels of cytokines and other factors in the plasma. Thus far, the results demonstrate elimination of donor cells by day 7, rapid upregulation of PD-1 ligands on leukemic cells and prolonged plasma levels of IL-10. Evaluation of the trends obtained with increased number of patients enrolled in the clinical trials will provide insights into new approaches to enhance the anti-leukemic responses in these patients.

Low expression of Abelson interactor-1 is linked to acquired drug resistance in Bcr-Abl-induced leukemia

The basis for persistence of leukemic stem cells in the bone marrow microenvironment (BMME) remains poorly understood. We present evidence that signaling crosstalk between α4 integrin and Abelson interactor-1 (Abi-1) is involved in acquisition of an anchorage-dependent phenotype and drug resistance in Bcr-Abl positive leukemia cells. Comparison of Abi-1 (ABI-1) and α4 integrin (ITGA4) gene expression in relapsing Bcr-Abl positive CD34+ progenitor cells demonstrated a reduction in Abi-1 and an increase in α4 integrin mRNA in the absence of Bcr-Abl mutations. This inverse correlation between Abi-1 and α4 integrin expression, as well as linkage to elevated phospho-Akt and phospho-Erk signaling, was confirmed in imatinib mesylate (IM) resistant leukemic cells. These results indicate that the α4-Abi-1 signaling pathway may mediate acquisition of the drug resistant phenotype of leukemic cells.

Anti-tumor responses driven by alloreactivity (P2058)

Previous work by our group found that infusion of G-CSF mobilized haploidentical donor white blood cells at a dose of 1 - 2 x 108 CD3+ cells/kg into refractory cancer patients who had received 100 cGy total body irradiation resulted in responses in a majority (14/27, 9 major) of patients with hematological malignancies despite elimination of the donor cells. The effector mechanism(s) responsible for these anti-cancer responses were not determined although it was noted that there was a cytokine storm that appeared within a day following the infusion of cells. One possible mechanism is that the alloreactive response overrides inhibitory mechanisms already in place in the cancer bearing patient allowing cancer reactive effector cells that are already present to become activated and lyse cancer cells. To test if this is the case, T cells were isolated from peripheral blood mononuclear cells obtained from newly diagnosed leukemic patients, mixed with fully allogeneic stimulator cells (from 1 or 2 different donors) and then tested for their ability to proliferate in response to the allogeneic stimulator cells on day five and for their ability to lyse autologous leukemia cells after stimulation for seven days. Anti-leukemic effector cells could be generated in eight out of the sixteen patients enrolled to date. The characteristics of the effector cells and the explanations for the lack of responses in some patients are the subject of current ongoing studies.

Abstract LB-350: Abelson interactor-1 (Abi1) expression levels as a prognostic and drug resistance marker in Bcr-Abl positive leukemias

In hematological malignancies, quiescent leukemic stem cells are responsible for persistence of minimal residual disease and relapse. Emerging evidence points to the involvement of the bone marrow microenvironment in survival and systemic retention of leukemic stem/progenitor cells. Integrins, particularly α4β1, which controls hematopoietic stem cell trafficking, were shown to be required for leukemic stem cells lodging to the bone marrow niche, and were shown to be crucial for the persistence of minimal residual disease. The molecular mechanism governing these processes is not known. We have just recently obtained evidence that newly identified α4 integrin-Abelson interactor 1 (Abi1) signaling cross-talk is involved in acquired drug resistance in Bcr-Abl positive leukemic cells. Our data also indicated that Abi1 and α4 integrin may be useful as prognostic markers of treatment outcome in patients with relapsing Bcr-Abl positive leukemia. Comparison of mRNA levels of Abi1 and α4 integrin in Bcr-Abl positive CD34+ progenitor cells isolated from blood or bone marrow of CML (chronic myelogenous leukemia) patients at diagnosis and at relapse revealed significant decrease in mRNA levels of Abi1 and increase in mRNA levels of α4 integrin in relapsing CD34+ progenitor cells. Subsequent analyses performed on various imatinib mesylate (IM) resistant cell lines including K562, LAMA-84 or Bcr-Abl supplemented Ba/F3 cells, confirmed abnormal expression of Abi1 and α4 integrin, both mRNA and protein levels. IM resistant cells also exhibited acquired anchorage-dependent phenotype and enhanced adhesive properties. Further detailed analyses of α4 integrin-dependent pathways revealed significant de-regulation of integrin α4 downstream signaling being due to the abnormal expression of Abi1, what resulted in elevated levels of phospho-Akt (Ser472), phospho-Erk (Thr202/Tyr204) and abnormal JNK/SAPK and p38MAPK phosphorylation signals. In summary, our results not only indicate that Abi1 and α4 integrin may serve as potentially useful prognostic markers of treatment outcome in patients with relapsing Bcr-Abl positive leukemia, but also suggest that newly identified α4 integrin-Abi1-Bcr-Abl cross-talk may play a significant role in the interactions between leukemic progenitor cells and the bone marrow microenvironment, and alterations in this signaling mediate acquisition of the drug resistant phenotype of leukemic cells and contribute to the mechanisms of acquired drug resistance.

Citation Format: Anna D. Chorzalska, Ibrahem Salloum, Hammad Shafqat, Saad Khan, Philip Marjon, Vincent Falanga, Ting Zhao, John Reagan, Eric Winer, Samer Al-Homsi, Nicola Kouttab, Patrycja M. Dubielecka. Abelson interactor-1 (Abi1) expression levels as a prognostic and drug resistance marker in Bcr-Abl positive leukemias. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-350. doi:10.1158/1538-7445.AM2013-LB-350

Abstract B22: Antitumor responses driven by alloreactivity

Previous work done by our group had found that infusion of G-CSF mobilized haploidentical donor white blood cells at a dose of 1 – 2 x 108 CD3+ cells/kg into refractory cancer patients after 100 cGy total body irradiation resulted in a number of complete and partial responses in those patients with hematological malignancies. These responses occurred despite elimination of the donor cells by 2 weeks after infusion. The effector mechanism(s) responsible for these anti-cancer responses were not determined although it was noted that there was a cytokine storm appearing within a day following infusion of the cells. Alloreactive responses could be driving the anti-cancer responses using a variety of mechanisms. One possible mechanism is that the alloreactive response overrides inhibitory mechanisms present in the cancer patient allowing the existing cancer reactive effector cells to become activated and lyse cancer cells. Alternatively the alloreactive cytolytic T cells could be cross-reacting with the antigens expressed on the tumor cells. To test these possibilities, peripheral blood mononuclear cells (PBMNC) or the CD3+ T cells isolated from the PBMNC of newly diagnosed leukemic patients were mixed with mitomycin C treated fully allogeneic stimulator PBMNC (from 1 or 2 different normal controls chosen at random) or the CD3- cells from the leukemic patients. Their ability to proliferate in response to the allogeneic stimulation was tested on day five and their ability to lyse autologous leukemia cells after stimulation was tested on day seven.

Ten total patients (8 AML, 1 CML, and 1 CMML) were enrolled in the study. The average white blood cell count was 57,640 cells/uL (range 7,100 – 336,500 cells/uL) with 4 -80% peripheral blasts. The results indicated that in 16/20 combinations, leukemic T cells were able to proliferate in response to allogeneic stimulators, however anti-cancer cytolytic activity was only detected in 9/19 evaluable combinations. These results demonstrated that alloreactive responses are able to induce anti-leukemic cytolytic responses by T cells from a subset of leukemic patients. One explanation for the inability of some combinations to generate anti-leukemic cytolytic activity could be the presence of inhibitory mechanisms which could not be overcome by the alloreactive responses. Immunophenotypic analysis of the leukemic T cells did reveal an increased number of T regulatory cells and increases in the expression of inhibitory receptors on the lymphocytes from some of the patients. Alternatively, it may be that the leukemic T cells had not been stimulated with the appropriate allogeneic antigens. An allogeneic stimulator pool comprised of cells from ten different normal donors was prepared and will be used to test whether increasing the number of allogeneic disparities in culture would enhance the ability of the leukemic T cells to generate anti-leukemic responses.

These studies have suggested that cancer-reactive cells can be generated from leukemic patient T cells using alloreactive responses. To further test the role of these effector cells and identify additional effector cells, blood samples will be obtained from patients enrolled in the clinical protocol which is in the process of being restarted, having received FDA approval. Clearer definition and characterization of the anti-cancer effector cells should permit alterations to the protocol that would lead to enhanced anti-cancer responses in an increased number of refractory cancer patients.

Citation Format: Loren D. Fast, John Reagan, Martha Nevola, Peter Quesenberry. Antitumor responses driven by alloreactivity. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr B22.

Use of alloreactivity to generate in vivo anti-leukemic responses (46.48)

A previous clinical trial demonstrated that infusion of haploidentical G-CSF mobilized WBC (1 - 2 x 10^8 cells/kg) into patients with refractory hematological malignancies (100 cGy irradiation) resulted in a high frequency of anti-leukemic responses including some complete responses despite a lack of detectable donor cell persistence beyond two weeks. Beyond a cytokine storm, no effector mechanisms were defined. It is possible that alloreactive responses were either capable of directly attacking the leukemic cells or reactivating the patient’s anti-leukemic effector cells that were already present via cross-reactivity. PBMNC were obtained from the blood of newly diagnosed leukemic patients, and separated into CD3- and CD3+ populations. The patient’s CD3+ cells were used as responder cells in a mixed lymphocyte culture and stimulated with mitomycin C treated patient’s CD3- cells or PBMNC from allogeneic normal donors chosen at random. On day 7, the effector cells were collected and tested for their ability to lyse 51Cr labeled patient CD3- cells. The results showed that the patient’s CD3+ cells stimulated with allogeneic PBMNC were able to generate anti-leukemic responses in a stimulator dependent fashion. Thus, this assay may be useful for predicting which donor would be best for patients receiving cellular immunotherapy and may also be useful for the defining the anti-leukemic effector cells that are present with this form of cellular immunotherapy.

Marrow cell genetic phenotype change induced by human lung cancer cells

Microvesicles have been shown to mediate varieties of intercellular communication. Work in murine species has shown that lung-derived microvesicles can deliver mRNA, transcription factors, and microRNA to marrow cells and alter their phenotype. The present studies evaluated the capacity of excised human lung cancer cells to change the genetic phenotype of human marrow cells. We present the first studies on microvesicle production by excised cancers from human lung and the capacity of these microvesicles to alter the genetic phenotype of normal human marrow cells. We studied 12 cancers involving the lung and assessed nine lung-specific mRNA species (aquaporin, surfactant families, and clara cell-specific protein) in marrow cells exposed to tissue in co-culture, cultured in conditioned media, or exposed to isolated lung cancer-derived microvesicles. We assessed two or seven days of co-culture and marrow which was unseparated, separated by ficoll density gradient centrifugation or ammonium chloride lysis. Under these varying conditions, each cancer derived from lung mediated marrow expression of between one and seven lung-specific genes. Microvesicles were identified in the pellet of ultracentrifuged conditioned media and shown to enter marrow cells and induce lung-specific mRNA expression in marrow. A lung melanoma and a sarcoma also induced lung-specific mRNA in marrow cells. These data indicate that lung cancer cells may alter the genetic phenotype of normal cells and suggest that such perturbations might play a role in tumor progression, tumor recurrence, or metastases. They also suggest that the tissue environment may alter cancer cell gene expression.

Males' evolutionary responses to experimental removal of sexual selection

We evaluated the influence of pre- and post-copulatory sexual selection upon male reproductive traits in a naturally promiscuous species, Drosophila melanogaster. Sexual selection was removed in two replicate populations through enforced monogamous mating with random mate assignment or retained in polyandrous controls. Monogamous mating eliminates all opportunities for mate competition, mate discrimination, sperm competition, cryptic female choice and, hence, sexual conflict. Levels of divergence between lines in sperm production and male fitness traits were quantified after 38-81 generations of selection. Three a priori predictions were tested: (i) male investment in spermatogenesis will be lower in monogamy-line males due to the absence of sperm competition selection, (ii) due to the evolution of increased male benevolence, the fitness of females paired with monogamy-line males will be higher than that of females paired with control-line males, and (iii) monogamy-line males will exhibit decreased competitive reproductive success relative to control-line males. The first two predictions were supported, whereas the third prediction was not. Monogamy males evolved a smaller body size and the size of their testes and the number of sperm within the testes were disproportionately further reduced. In contrast, the fitness of monogamous males (and their mates) was greater when reproducing in a non-competitive context: females mated once with monogamous males produced offspring at a faster rate and produced a greater total number of surviving progeny than did females mated to control males. The results indicate that sexual selection favours the production of increased numbers of sperm in D. melanogaster and that sexual selection favours some male traits conferring a direct cost to the fecundity of females.

Factors influencing the cost of chronic low back injuries: An analysis of data from independent medical examinations

Cost factors were examined in 157 patients with work- related spine injuries who were referred to a second opinion program between 1985 and 1991. The independent medical examination (IME) included a history, physical examination, and review of imaging and other studies. Data on demographic variables, litigation, work, injury history, physical examination, and imaging studies were recorded. A standard measure of psychological status (Low Back Pain Symptom Check List) was filled out. The instrument uses pain language as a clinical marker of psychological disturbance linked to a range of conflictual issues such as suppressed anger, burdensome feeling of inferiority, damaged self- esteem, role confusion, abnormal mentation, fear of responsibility or intimacy, gender issues, sexual concerns, disturbing arousal, and the like. Since it relies exclusively on pain language for diagnosis, it does not identify the specific nature of the psychological conflict. Data on treatment, final resolution, and cost were obtained from computerized files of the insurance company. The total cost incurred was $6,551,139. This averaged to $41,727 per case. More expensive cases were associated with a surgical intervention, psychological disturbance, litigation, motor weakness, and positive radiographs. These five variables accounted for 48% of the cost variance. Surgery accounted for 19.9% of the variance and contained the most expensive cases ($68,310 vs. $31,423). Psychological disturbance was detected in 27% of the sample and accounted for 10.5% of the cost variance. Litigation was present in 72% of the cases and accounted for 9.1% of the cost variance. Motor strength and radiographs taken together accounted for 8.4% of the variance. The usefulness of this information was explored from an actuarial and medical perspective.

A pheromone-degrading aldehyde oxidase in the antennae of the moth Manduca sexta

Antennae of the tobacco hornworm moths Manduca sexta contain an aldehyde oxidase (AOX) that oxidizes aldehydes to carboxylic acids. The enzyme, which is distinguishable from aldehyde-oxidizing activities in other tissues, is secreted into the receptor lymph that bathes the primary olfactory dendrites. First detectable about 3 d before eclosion, AOX levels increase through the first day after eclosion. This parallels the development of the antennal responsiveness to bombykal (a male attractant aldehydic pheromone produced by female M. sexta) and trans-2-hexenal (an aldehyde commonly found in leaves). The AOX is about 60% more abundant in antennae of males than in antennae of females. The antennal AOX is a dimer with Mr of 295 kDa and is capable of oxidizing a variety of aldehydes. Of all aldehydes examined, the pheromone bombykal was the best substrate with an apparent Km of 5 microM, whereas the next best substrate, benzaldehyde, had an apparent Km of 255 microM. Using kinetic parameters estimated in vitro and the assumption of first-order kinetics, the half-life of bombykal in sensilla was estimated to be about 0.6 msec. The affinity of the antennal AOX for bombykal, its location in the receptor lymph, and its pattern of developmental expression all suggest that it plays a role in modulating the sensitivity of adult M. sexta to aldehyde odors and, in particular, the sensitivity of males to the pheromone bombykal.

Olfaction by melanophores: what does it mean?

Hypotheses on general olfaction can be divided into two broad groups: those that predict the existence of olfactory-specific olfactory receptor proteins and those that do not. Recently, much attention has been paid to the discovery of an odorant-stimulated adenylate cyclase in purified olfactory cilia. This finding has, for the most part, been accepted as evidence that the former hypotheses are correct. Here we report that frog melanophores, which are nonolfactory in nature, disperse their melanosomes in response to the same types and concentrations of odorants used in the investigations of olfactory cilia and that pigment dispersion is accompanied by rises in intracellular cAMP levels. The effects show that the existence of a cAMP-based second messenger system in olfactory cilia is not in itself proof of the existence of olfactory-specific olfactory receptor proteins. Also they explain the basis of Ottoson's pioneering work of 30 years ago on the electrical responses of frog olfactory epithelium to stimulation with alcohols. The results suggest that there could be two mechanisms that are important for the detection of odorants: one based on specific receptors, the other nonspecific, but both working through activation of cAMP.