Effects of a diuretic regimen on body weight and echocardiographic parameters of the tricuspid valve in patients scheduled for transcatheter tricuspid annuloplasty

Background

Echocardiographic severity of tricuspid regurgitation is known to be highly variable and strongly related to the volume status of the individual patient. Interventional therapies for tricuspid valve repair or replacement are dependent on reliable measurements in order to select the appropriate device size.

Purpose

In patients scheduled for transcatheter tricuspid valve annuloplasty, we sought to evaluate the effects of a diuretic regimen started at the screening visit on body weight and tricuspid valve dimensions at the time point of transcatheter intervention.

Methods

After successful screening for transcatheter tricuspid annuloplasty, an individualized intensified diuretic regimen was initiated in 15 patients. At baseline and at the timepoint of the intervention, body weight and 3D echocardiographic dimensions of the tricuspid valve were documented and compared.

Results

The cohort comprised 6 males and 9 females (mean age 77±7 years) with severe or higher degree functional tricuspid regurgitation. In all patients not more than mild pulmonary artery hypertension was present (PaP mean 29±5 mmHg). The interval between the screening visit and the timepoint of the procedure was 64±50 days. At baseline mean body weight was 72±12 kg. In 11 patients a reduction of the body weight could be achieved, with a median weight reduction of 2.2 kg (min/max 1.2/6.4 kg). Overall, the average relative reduction of the tricuspid annulur perimeter was 13% (p<0,001), of the tricuspid valve area 2.7% (n.s.), the anterseptal diameter 3.3% (n.s.), while the bicommissural diameter remained almost unchanged (0.4%; n.s.). The average predicted required band length changed by only 1.5% (n.s.). The strongest correlations were found between the absolute change in body weight and the change of the tricuspid valve area (r=0.48), relative change in body weight and relative change of tricuspid valve area (r=0.52), absolute change in body weight and absolute change in predicted band length (r=0.48), and relative changes of the respective variables (r=0.52). More importantly, in 13 out of 15 patients the band size which would have been selected was identical between the screening and the annuloplasty procedure. Only in two patients a smaller device was implanted than predicted at the screening visit.

Conclusion

Instituting a diuretic therapy in candidates for transcatheter tricuspid annuloplasty prior to the procedure helps to keep tricuspid valve dimensions in a stable range. Changes in body weight in patients with functional tricuspid regurgitation are correlated to changes of tricuspid valve dimensions.

Funding Acknowledgement

Type of funding sources: None.

Changes of tricuspid valve geometry after interventional implantation of an anuloplasty band

Background

Implantation of an anuloplasty band (Cardioband, Edwards Lifesciences) is a new treatment option for patients with functional tricuspid regurgitation (TR). The initial clinical results are promising. Nevertheless very few details about the mechanism of reducing TR beyond the basic principle of reducing the annular perimeter are known. Therefore we sought to study the changes of the tricuspid valve geometry after Cardioband implantation.

Methods

In all patients, that were treated by Cardioband implantation for tricuspid valve implantation at our institution, fluoroscopic images of the implant were optained at an angle, which would correspond to an echocardiographic “enface” view of the tricuspid valve. In these images the area enclosed by the implant, the perimeter of this area, the septal to lateral diameter, the anterior to posterior diameter and the length of the implant before and after contracting the band was measured. In all patients an echocardiographic evaluation of the tricuspid regurgitation before and after cardioband implantation was performed. These clinical finding were correlated to changes of the above mentioned dimension in the fluoroscopic images.

Results

Between October 2018 und January 2019 17 patients with severe tricuspid regurgitation were treated by Cardioband implantation. In one patient the procedure had to be aborted due to extensive movement of the tricuspid annulus. In the remaining 16 patients (mean age 78±8 years, 7 males) the procedure could be completed successfully and the required measurements were done. The mean severity grade (5 grade scale) of the TR was 3.5±0.6 before and 2±0.7 (p<0.0001) after the implantation, the corresponding mean vena contracta changed from 12±4 mm to 6±3 mm (p<0.000, 51% reduction). The area decreased after band contraction from 10.6±1.4 cm2 to 4.7±1.4 cm2 (p<0.0001; 56% reduction), the perimeter from 13.4±1.8 cm to 9.6±1.6 cm (p<0.0001; 28% reduction) the septal to lateral diameter from 2.8±0.5 cm to 1.6±0.2 cm (p<0.0001; 40% reduction), the anterior to posterior diameter from 4.8±0.9 cm to 3.8±1.0 cm (p<0.005; 19% reduction) and the measured device length from 8.6 cm±1.0 to 5.8±0.8 cm (p<0.0001; 32% reduction). The strongest correlation was seen between area reduction and reduction of the vena contracta (r=0.5), reduction of the septal to lateral dimension as well as the reduction of the device length had a weaker correlation (r=0.3 and r=0.2). The reduction of the anterior posterior diameter and perimeter reduction showed no relevant correlation with regard to TR reduction.

Conclusion

In our patient population Cardioband implantation lead to effective TR reduction. Area reduction and reduction of the septal to lateral diameter of the tricuspid valve seem to have the strongest impact. These findings may be considered when implantations techniques are being optimized or when new devices for TR treatment are developed.

Funding Acknowledgement

Type of funding source: None

Histone deacetylase inhibition in combination with MEK or BCL-2 inhibition in multiple myeloma

Despite recent advances in the treatment of multiple myeloma, patients with this disease still inevitably relapse and become refractory to existing therapies. Mutations in K-RAS, N-RAS and B-RAF are common in multiple myeloma, affecting 50% of patients at diagnosis and >70% at relapse. However, targeting mutated RAS/RAF via MEK inhibition is merely cytostatic in myeloma and largely ineffective in the clinic. We examined mechanisms mediating this resistance and identified histone deacetylase inhibitors as potent synergistic partners. Combining the MEK inhibitor AZD6244 (selumetinib) with the pan-histone deacetylase inhibitor LBH589 (panobinostat) induced synergistic apoptosis in RAS/RAF mutated multiple myeloma cell lines. Interestingly, this synergy was dependent on the pro-apoptotic protein BIM. We determined that while single-agent MEK inhibition increased BIM levels, the protein remained sequestered by antiapoptotic BCL-2 family members. LBH589 dissociated BIM from MCL-1 and BCL-X_L, which allowed it to bind BAX/BAK and thereby initiate apoptosis. The AZD6244/LBH589 combination was specifically active in cell lines with more BIM:MCL-1 complexes at baseline; resistant cell lines had more BIM:BCL-2 complexes. Those resistant cell lines were synergistically killed by combining the BH3 mimetic ABT-199 (venetoclax) with LBH589. Using more specific histone deacetylase inhibitors, i.e. MS275 (entinostat) and FK228 (romidepsin), and genetic methods, we determined that concomitant inhibition of histone deacetylases 1 and 2 was sufficient to synergize with either MEK or BCL-2 inhibition. Furthermore, these drug combinations effectively killed plasma cells from myeloma patients ex vivo. Given the preponderance of RAS/RAF mutations, and the fact that ABT-199 has demonstrated clinical efficacy in relapsed/refractory multiple myeloma, these drug combinations hold prom ise as biomarker-driven therapies.

Abstract 3909: HDAC inhibition in combination with MEK or BCL-2 inhibition as novel therapeutic strategies in multiple myeloma

Multiple myeloma (MM) is an incurable malignancy of plasma cells. It is the second most common hematologic cancer, affecting nearly 30,000 people in the United States annually. Substantial progress has been made in the past fifteen years in the treatment of MM due to the approval of several new classes of drugs. However, patients inevitably relapse and become refractory to existing therapies. Hence, there is an immediate unmet need to develop novel therapies for MM based on a better understanding of the disease biology. Mutations in RAS have been found to occur in about 40% of newly diagnosed MM patients, with the frequency increasing to around 70% in relapsed/refractory patients. Such mutations are absent in patients with the premalignant conditions monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM). Clearly, RAS mutations contribute to both disease progression and relapse. However, targeting the MEK/ERK pathway has been unsuccessful in MM patients to date. Given the high frequency of RAS mutations in MM, we hypothesized that targeting this pathway could still be a promising strategy when combined with existing agents that have multifaceted mechanisms to promote tumor cell death, such as the recently approved histone deacetylase (HDAC) inhibitor LBH589 (panobinostat). Our results clearly demonstrate that low doses of LBH589 in combination with the MEK inhibitor AZD6244 induce BIM-dependent synergistic cell death in several MM cell lines and patient cells. Our studies also suggest that mutations in RAS/RAF could serve as a predictive biomarker for sensitivity to AZD6244/LBH589. RAS/RAF mutations appear to confer Mcl-1 dependence in MM cells, in part by driving up the phosphorylation of Mcl-1. The AZD6244/LBH589 combination is able to decrease the phosphorylation of Mcl-1 at several sites, which dissociates BIM-Mcl-1 complexes, ultimately leading to activation of the intrinsic apoptosis pathway. Additionally, we identified that wild-type RAS/RAF cells have relatively lower levels of phospho-Mcl-1, as well as higher levels of Bcl-2 and phospho-Bcl-2 when compared to mutated RAS/RAF cells. This seems to confer functional Bcl-2 dependence. Consequently, we found that wild-type RAS/RAF cells are sensitive to the BH3-mimetic ABT199 (venetoclax) when combined with LBH589. Through ongoing experiments, we hope to further confirm the mechanism of action of both these combinations, identify the particular HDAC that is required to be inhibited for the observed synergy, and validate RAS/RAF mutational status as a biomarker for predicting sensitivity to either combination. Our findings have broad therapeutic potential given the prevalence of RAS mutations in MM. Moreover, the ABT199/LBH589 combination could emerge as a targeted therapy for wild-type RAS patients, perhaps broadening the scope and capacity of Bcl-2 inhibition in MM.

Citation Format: Kevin C. Miller, Jessica Haug, Teresa Kimlinger, Sanjay Kumar, Wilson Gonsalves, S. Vincent Rajkumar, Shaji K. Kumar, Vijay Ramakrishnan. HDAC inhibition in combination with MEK or BCL-2 inhibition as novel therapeutic strategies in multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3909.

Smac mimetic LCL161 overcomes protective ER stress induced by obatoclax, synergistically causing cell death in multiple myeloma

Bcl2 and IAP families are anti-apoptotic proteins deregulated in multiple myeloma (MM) cells. Pharmacological inhibition of each of these families has shown significant activity only in subgroups of MM patients. Here, we have examined a broad-spectrum Bcl2 family inhibitor Obatoclax (OBX) in combination with a Smac mimetic LCL161 in MM cell lines and patient cells. LCL161/OBX combination induced synergistic cytotoxicity and anti-proliferative effects on a broad range of human MM cell lines. The cytotoxicity was mediated through inhibition of the IAPs, activation of caspases and up regulation of the pro-apoptotic proteins Bid, Bim, Puma and Noxa by the drug combination. In addition, we observed that OBX caused ER stress and activated the Unfolded Protein Response (UPR) leading to drug resistance. LCL161, however inhibited spliced Xbp-1, a pro-survival factor. In addition, we observed that OBX increased GRP78 localization to the cell surface, which then induced PI3K dependent Akt activation and resistance to cell death. LCL161 was able to block OBX induced Akt activation contributing to synergistic cell death. Our results support clinical evaluation of this combination strategy in relapsed refractory MM patients.

Abstract 2653: Preclinical activity of dual PI3K/mTOR inhibitor SPR965 in multiple myeloma

Introduction: Relapsed and refractory multiple myeloma (MM) remains a significant clinical challenge and drugs with new mechanisms of action to overcome resistance are needed. Constitutive activation of the PI3K/Akt/mTOR pathway in MM promotes tumorigenesis through propagation of the cell cycle, protein synthesis, and inhibition of apoptosis. Anti-MM effects of rapalogs are limited due to feedback activation of the PI3K/Akt signaling pathway. Agents capable of targeting PI3K and mTORC1 or both mTORC1/C2 are able to partially overcome such resistance mechanisms. However, the mTORC2 mediated increase in pAkt (Ser473) after PI3K/mTORC1 inhibition and the activation of PI3K after mTORC1/C2 inhibition could still contribute to resistance to such agents. We sought to investigate the effects of SPR965 (synthesized and provided by Sphaera Pharma, Singapore under an MTA), an orally bioavailable novel small molecule with inhibition of class 1 PI3 kinase and mTORC1/C2 kinases on MM cell lines and patient cells.

Results: SPR965 induced cytotoxicity and inhibited proliferation in all MM cell lines examined with IC50 values between 25-500nM. To understand if SPR965 induced apoptotic cell death, annexin/PI staining followed by flow cytometric assays were performed, which showed a clear increase in cells undergoing apoptosis. Western blots showed increase in caspase-3, -9, and PARP cleavage confirming apoptotic induction by SPR965. Importantly, SPR965 caused potent increase in apoptosis in cytogenetically distinct MM patient cells. Next, we examined the mechanism of action of SPR965. SPR965 caused potent mTORC1 inhibition evidenced by decreased p4E-BP1, p-p70S6K, and pS6 at doses as low as 25nM. SPR965 was able to inhibit PI3K activity as shown by decreased pPDK1 and pBTK at slightly higher concentrations of 75nM. Phosphorylation of Akt S473, a TORC2 substrate, increased at initial low concentrations of SPR965, but was attenuated at concentrations of 100 nM and above, demonstrating dose-dependent inhibition of mTORC2. Such effects were also observed when we performed western blots on MM patient derived primary plasma cells. Increased levels of p27 (KIP1) were observed suggestive of G1 growth arrest, which was confirmed on cell cycle analysis. Since SPR965 caused an increase in pAkt (both T308 and S473) at doses up to 75nM, we examined if SPR965 was able to synergize with an Akt inhibitor MK2206 at doses lower than 75nM. Our results showed potent synergy suggesting that the pAkt up regulation contributes to partial resistance, which is inhibited by SPR965 at doses of 100nM and higher, doses that are still clinically achievable.

Conclusion: Our findings demonstrate SPR965 induces apoptosis of MM cells through the inhibition of PI3K and mTORC1/C2 activity. Further studies are underway to better characterize the mechanism of action of SPR965, all of which will be informative for the drug to be used as a single agent or in combination with other agents in relapsed MM.

Citation Format: Jeremy T. Larsen, Vijay Ramakrishnan, Jessica Haug, Teresa Kimlinger, Somdutta Sen, Dinesh Mahajan, Sundeep Dugar, S. Vincent Rajkumar, Shaji K. Kumar. Preclinical activity of dual PI3K/mTOR inhibitor SPR965 in multiple myeloma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2653. doi:10.1158/1538-7445.AM2015-2653

Abstract 5669: Mechanisms of activity and drug resistance with proteasome inhibitors in multiple myeloma: Comparison of bortezomib and the investigational drug MLN9708

Background: Therapy with proteasome inhibitors (PIs) is an effective strategy against multiple myeloma (MM), but a significant proportion of patients is primarily resistant or eventually becomes refractory. Paradoxical activation of phospho-Akt, induction of HSP27 and excessive proteasome activity in relation to polyubiquitinated protein burden are all mechanisms for bortezomib resistance in MM cells in vitro. Preclinical data showed investigational drug MLN9708, a specific, reversible, orally bioavailable, small molecule PI, to be active in MM cell lines, patient cells and mouse models and is currently under clinical investigation. We compared the signaling pathways induced by MLN2238, the biologically active form of MLN9708, and bortezomib to outline differences that could be employed to design rational combinations to overcome resistance. Results: We performed time course experiments in MM.1S cells with EC50 doses of MLN2238 and bortezomib and analyzed signaling pathways via western blotting. Compared to bortezomib, MLN2238 induced earlier cleavage of caspase 8, 9, 3 and PARP and a significant downregulation of XIAP starting at 12 hours. Early and persistent phosphorylation of Bad, known to protect from mitochondrial apoptosis, was observed in bortezomib-, but not MLN2238-treated cells, in which phospho-Bad was reduced at 24 hours. Similarly, MLN2238 decreased phosphorylated Akt and mTOR at 24 hours, while bortezomib-treated cells only showed subtle changes. Interestingly, both drugs caused downregulation of the mTOR downstream targets phospho-p70 S6 kinase and phospho-4E-BP1, albeit of different intensity. Induction of heat shock proteins was comparable with both PI, opening the possibilities for combination therapy of MLN2238 with HSP90 inhibitors. Importantly, the inhibitory effect on phosphorylation of Akt, mTOR and Bad persisted when MM.1S cells were treated with MLN2238 in the presence of bone marrow stromal cells (BMSC). Conclusion: We observed differences in several crucial signaling pathways upon treatment of MM.1S cells with bortezomib or MLN2238. In particular, treatment with the latter inhibited phosphorylation of Bad, Akt and mTOR, suggesting a broader pro-apoptotic and anti-proliferative profile, compared to bortezomib. MLN2238 retained the capability of targeting these substrates also in the presence of BMSC. Confirmatory data on patient-derived cells are under current investigation in our lab. We believe that these data help understanding the differences in PI pharmacodynamics and bortezomib escape. This will allow us to design new drug combinations in the future that overcome clinical resistance to PIs and improve MM patient survival.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5669. doi:1538-7445.AM2012-5669

TG101209, a novel JAK2 inhibitor, has significant in vitro activity in multiple myeloma and displays preferential cytotoxicity for CD45+ myeloma cells

Interaction of myeloma cells with the bone marrow microenvironment is mediated in large part through different cytokines, especially VEGF and IL6. These cytokines, especially IL6, leads to upregulation of the JAK/STAT pathway in myeloma cell, contributing to increased proliferation, decreased apoptosis, and acquired drug resistance. Here, we examined the preclinical activity of a novel JAK2 inhibitor TG101209. TG101209 induced dose- and time-dependent cytotoxicity in a variety of multiple myeloma (MM) cell lines. The induction of cytotoxicity was associated with inhibition of cell cycle progression and induction of apoptosis in myeloma cell lines and patient-derived plasma cells. Evaluation of U266 cell lines and patient cells, which have a mix of CD45 positive and negative cells, demonstrated more profound cytotoxicity and antiproliferative activity of the drug on the CD45+ population relative to the CD45- cells. Exploring the mechanism of action of TG101209 indicated downregulation of pJak2, pStat3, and Bcl-xl levels with upregulation of pErk and pAkt levels indicating cross talk between signaling pathways. TG101209, when used in combination with the PI3K inhibitor LY294002, demonstrated synergistic cytotoxicity against myeloma cells. Our results provide the rationale for clinical evaluation of TG101209 alone or in combination with PI3K/Akt inhibitors in MM.

ASAXS study on the formation of core-shell Ag/Au nanoparticles in glass

Nanosized metal particles of various configurations embedded in surface regions of glass have great potential as nonlinear optical materials for photonic devices. We have prepared Ag/Au nanoparticles in core-shell configuration in soda-lime silicate glass by double-ion implantation and investigated their structural characteristics by anomalous small-angle x-ray scattering (ASAXS) and transmission electron microscopy. Measurements at x-ray energies slightly below the Au L(3) edge indicate the formation of bimetallic Ag/Au shells in some of the nanoparticles for high-dose ion implantation. An element-specific analysis of the ASAXS results allowed us not only to validate and quantify the core-shell structure, but simultaneously also the composition of the shells. Hollow nanoparticles were found for an Au-Ag implantation sequence, whereas an Ag-Au sequence generates a diluted core composition. The shift of the maximum position of optical absorption of the samples due to surface plasmon resonance of bimetallic nanoparticles, as monitored by optical spectroscopy, revealed the considerable influence of the respective particle configuration.

Laser-Induced, Polarization Dependent Shape Transformation of Au/Ag Nanoparticles in Glass

Bimetallic, initially spherical Ag/Au nanoparticles in glass prepared by ion implantation have been irradiated with intense femtosecond laser pulses at intensities still below the damage threshold of the material surface. This high-intensity laser processing produces dichroism in the irradiated region, which can be assigned to the observed anisotropic nanoparticle shapes with preferential orientation of the longer particle axis along the direction of laser polarization. In addition, the particle sizes have considerably been increased upon processing.

Magnetic field and pressure dependence of small angle neutron scattering in MnSi

We report small angle neutron scattering of spontaneous and magnetic field aligned components of the helical spin polarization in MnSi for temperatures T down to 0.35 K, at pressures p up to 21 kbar, and magnetic field B up to 0.7 T. The parameter range of our study spans the first order transition between helical order and partial magnetic order at p{c}=14.6 kbar, which coincides with the onset of an extended regime of non-Fermi liquid resistivity. Our study suggests that MnSi above p{c} is not dominated by the remnants of the first order transition at p{c}, but that an unidentified mechanism favors stabilization of a new ground state other than helical order.

Bone marrow angiogenic ability and expression of angiogenic cytokines in myeloma: evidence favoring loss of marrow angiogenesis inhibitory activity with disease progression

We compared the angiogenic potential of bone marrow plasma and the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and their receptors on plasma cells from patients with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and newly diagnosed multiple myeloma (NMM). Cytokine and cytokine-receptor expression was studied by bone marrow immunohistochemistry, quantitative reverse transcription-polymerase chain reaction (RT-PCR) on sorted plasma cells, and quantitative Western blot analysis. Bone marrow angiogenic potential was studied using a human in vitro angiogenesis assay. The expression levels of VEGF, bFGF, and their receptors were similar among MGUS, SMM, and NMM. Sixty-one percent of NMM samples stimulated angiogenesis in the in vitro angiogenesis assay compared with SMM (0%) and MGUS (7%) (P <.001). Importantly, 63% of MGUS samples inhibited angiogenesis compared with SMM (43%) and NMM (4%) (P <.001). The inhibitory activity was heat stable, not overcome by the addition of VEGF, and corresponded to a molecular weight below 10 kd by size-exclusion chromatography. Our results suggest that increasing angiogenesis from MGUS to NMM is, at least in part, explained by increasing tumor burden rather than increased expression of VEGF/bFGF by individual plasma cells. The active inhibition of angiogenesis in MGUS is lost with progression, and the angiogenic switch from MGUS to NMM may involve a loss of inhibitory activity.

Plasma levels of tumour necrosis factor alpha and interleukin-6 predict progression-free survival following thalidomide therapy in patients with previously untreated multiple myeloma

We studied marrow angiogenesis and plasma levels of angiogenic cytokines in 38 patients receiving thalidomide therapy for previously untreated myeloma. The effect of therapy and the relationship of cytokine levels to myeloma cell proliferation, bone marrow microvessel density and progression-free survival (PFS) were studied. High pretreatment tumour necrosis factor-alpha (TNFalpha) levels (> 11 pg/ml) and increased interleukin (IL)-6 of > 2 pg/ml predicted for poorer PFS (TNFalpha, 48% versus 74% at 2 years, P = 0.01; IL-6, 24% versus 70% at 2 years, P = 0.01). None of the other parameters predicted response or PFS, and no significant changes in cytokine levels occurred with therapy.

Expression of VEGF and its receptors by myeloma cells

Angiogenesis or new vessel formation is an essential component in the growth and progression of neoplasms and there is growing evidence of its importance in hematological malignancies including multiple myeloma (MM). Vascular endothelial growth factor (VEGF) is believed to play a role in tumor angiogenesis. We studied the expression of VEGF and its receptors (VEGFR1 or Flt-1 and VEGFR2 or Flk-1/KDR) by myeloma cell lines and plasma cells isolated from patients, using different methods. VEGF expression by the plasma cells was demonstrated by immunohistochemistry in 18 of 20 patients with MM. Enzyme-linked immunosorbent assay demonstrated VEGF secretion in all six different myeloma cell lines studied. Five patient marrow samples and seven different myeloma cell lines were then studied for VEGF mRNA expression by reverse-transcriptase polymerase chain reaction (RT-PCR), which was positive in all. We further evaluated the expression of both VEGFR1 and VEGFR2 in different myeloma cell lines and five sorted myeloma bone marrow samples by RT-PCR. All the myeloma cell lines expressed VEGFR1 and three of the cell lines expressed VEGFR2. VEGFR1 expression was detected in all and VEGFR2 in all but one of the sorted marrow samples. Increased expression of VEGF by the myeloma cells taken in the context of the suspected prognostic value of marrow angiogenesis suggests a pathogenetic role for this cytokine and presence of its receptors on myeloma cells points toward an autocrine mechanism. Demonstration of the presence of VEGFR2 in our study provides a potential biological explanation for the preclinical activity observed with VEGFR2 inhibitors.

T cell activation induces human osteoclast formation via receptor activator of nuclear factor kappaB ligand-dependent and -independent mechanisms

In unstimulated conditions, osteoclast (OC) formation is regulated by stromal cell production of the key osteoclastogenic factors receptor activator of nuclear factor kappaB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF). However, the mechanisms of accelerated osteoclastogenesis and bone loss characteristic of inflammatory conditions are poorly understood but appear to involve T cells. In addition, the mechanism by which OCs arise spontaneously in cultures of peripheral blood mononuclear cells in the absence of stromal cells or added cytokines remains unclear. Using a stromal cell free human osteoclast generating system, we investigated the ability of activated T cells to support osteoclastogenesis. We show that when activated by phytohemagglutinin-P (PHA), T cells (both CD4+ and CD8+) stimulate human OC formation in vitro. Although both soluble M-CSF and RANKL were detected in activated T cell supernatants, the presence of M-CSF was not essential for macrophage survival or RANKL-dependent osteoclast formation, suggesting that other soluble T cell-derived factors were capable of substituting for this cytokine. We also found that saturating concentrations of osteoprotegerin (OPG) failed to neutralize 30% of the observed OC formation and that T cell conditioned medium (CM) could superinduce osteoclastogenesis in cultures of purified monocytes maximally stimulated by RANKL and M-CSF. Together, these data suggest that activated T cells support osteoclastogenesis via RANKL-dependent and -independent mechanisms. Although not relevant for T cell-induced osteoclastogenesis, secretion of soluble M-CSF is a previously undescribed property of activated T cells.

STAT-3 activation is required for normal G-CSF-dependent proliferation and granulocytic differentiation

To investigate the role of signal transducer and activator of transcription (STAT) proteins in granulocyte colony-stimulating factor (G-CSF)-regulated biological responses, we generated transgenic mice with a targeted mutation of their G-CSF receptor (termed d715F) that abolishes G-CSF-dependent STAT-3 activation and attenuates STAT-5 activation. Homozygous mutant mice are severely neutropenic with an accumulation of immature myeloid precursors in their bone marrow. G-CSF-induced proliferation and granulocytic differentiation of hematopoietic progenitors is severely impaired. Expression of a constitutively active form of STAT-3 in d715F progenitors nearly completely rescued these defects. Conversely, expression of a dominant-negative form of STAT-3 in wild-type progenitors results in impaired G-CSF-induced proliferation and differentiation. These data suggest that STAT-3 activation by the G-CSFR is critical for the transduction of normal proliferative signals and contributes to differentiative signals.

B lymphocytes inhibit human osteoclastogenesis by secretion of TGFbeta

The role of B lymphocytes in osteoclast (OC) formation is controversial, because both stimulatory and inhibitory effects of B-lineage cells on osteoclastogenesis and life span have been reported. In this study, we have investigated the effects of mature B cells on human osteoclastogenesis using cultures of peripheral blood stem cells (PBSC), a system that generates functional OCs in the absence of stromal cells. We report that B cells inhibit the formation of OCs and shorten the life span of mature OCs by secreting transforming growth factor beta (TGFbeta), a factor that induces apoptosis in these cells. The antiosteoclastogenic effects of B cells are abolished by addition of anti-TGFbeta antibody to osteoclast cultures and mimicked by treatment of B cell-deprived PBSC cultures with recombinant TGFbeta, thus confirming TGFbeta as the B cell produced antiosteoclastogenic activity. Thus, the ability of B cells to downregulate osteoclastogenesis by secretion of the apoptotic cytokine TGFbeta provides new insights into the ability of immune cells to regulate OC formation under basal and inflammatory conditions.

Innovations in allogeneic stem-cell transplantation

Allogeneic bone marrow transplantation (BMT) is associated with prolonged periods of neutropenia and thrombocytopenia, which can lead to severe infections and bleeding complications. Transplantation-related side effects might be ameliorated by use of cytokine-mobilized peripheral blood progenitor cells (PBPC) Instead of bone marrow. We have studied PBPC mobilization and transplantation in more than 150 patients with high-risk hematologic malignancies. Normal donors can be sufficiently mobilized with granulocyte colony-stimulating factor (G-CSF), with 91% of G-CSF-stimulated normal donors producing more than 2 x 10(6) CD34+ cells/kg by a single apheresis. The combination of G-CSF plus granulocyte-macrophage colony-stimulating factor (GM-CSF) was more effective than mobilization with G-CSF alone. A clear relationship was seen between numbers of resting CD34+ cells premobilization and numbers of PBPC collected by apheresis, indicating that resting CD34+ cells might be used to predict mobilization results and identify donors who could benefit from more effective mobilization regimens. Transplantation of G-CSF-mobilized PBPC was associated with a more rapid engraftment than that observed for BMT. While engraftment was safe and acute graft-versus-host disease (aGvHD) rates were not increased over BMT, chronic GvHD rates were higher after PBPC transplantation. An additional PBPC infusion on day +3 resulted in a further shortening of neutropenia and thrombocytopenia. Incorporation of these innovative approaches with "minimal" conditioning regimens has resulted in near-complete elimination of fever, neutropenia, thrombocytopenia, and the need for antibiotics and RBC and platelet transfusions after allogeneic transplantation.

[Positive and negative symptoms in chronic schizophrenic patients under maintenance therapy with flupenthixol decanoate for a twelve month perioid]

62 chronic schizophrenics, who after a psychotic exacerbation were stabilized again, were randomized on 3 different maintenance dosages of flupentixol-decanoate and observed for 12 months. 15 (24.2%) patients had a relapse independently of the dose. 34 of the 47 patients without relapse had complete documentations of the follow-up. After 3 to 6 months there was an obvious and constant clinical improvement as assessed by various test inventories. The BPRS-scores for psychopathology, negative and positive symptoms improved significantly between 14 to 18%. There was also significant reduction of negative symptoms assessed by SANS (22%) as well in the severity of illness (CGI) and an amelioration of psychosocial functioning (GAS, Strauss-Carpenter). At the end of trial 26.4% of the patients had mild involuntary movements (AIMS), 23.5% were on antiparkinson-medication. It is concluded that there could be an indication for flupentixol-decanoate in the long term maintenance therapy especially of chronic schizophrenics with negative symptoms and problems of compliance under oral medication.

Human blood-mobilized hematopoietic precursors differentiate into osteoclasts in the absence of stromal cells

Osteoclastogenesis is a complex process that is facilitated by bone marrow stromal cells (SCs). To determine if SCs are an absolute requirement for the differentiation of human hematopoietic precursors into fully mature, osteoclasts (OCs), CD34+ cells were mobilized into the peripheral circulation with granulocyte colony-stimulating factor, harvested by leukapheresis, and purified by magnetic-activated cell sorting. This procedure yields a population of CD34+ cells that does not contain SC precursors, as assessed by the lack of expression of the SC antigen Stro-1, and that differentiates only into hematopoietic cells. We found that CD34+, Stro-1- cells cultured with a combination of granulocyte/macrophage colony-stimulating factor, interleukin 1, and interleukin 3 generated cells that fulfill current criteria for the characterization of OCs, including multinucleation, presence of tartrate-resistant acid phosphatase, and expression of the calcitonin and vitronectin receptors and of pp60c-src tyrosine kinase. These OCs also expressed mRNA for the noninserted isoform of the calcitonin receptor and excavated characteristic resorption pits in devitalized bone slices. These data demonstrate that accessory SCs are not essential for human osteoclastogenesis and that granulocyte colony-stimulating factor treatment mobilizes OC precursors into the peripheral circulation.

Outcome of lumbar fusion in Washington State workers' compensation

STUDY DESIGN

This study covered a large, population-based cohort of workers in the Washington State workers' compensation system who received lumbar fusion between August 1, 1986 and July 31, 1987 to determine work disability status, reoperation rate, and patient satisfaction.

OBJECTIVES

To use predictors of outcome of lumbar fusion to design clearer clinical guidelines for lumbar fusion in injured workers.

METHODS

Logistic regression analysis was used to determine the predictors of work disability and risk of reoperation after fusion.

RESULTS

The lumbar fusion incidence rate was 41.7/100,000 workers a year (n = 388 patients). Overall, 68% were work disabled and 23% required further lumbar spine surgery 2 years post-fusion. Five markers of severity predicted worse work disability outcome (older age at injury, longer time from injury to fusion, increased increased time on work disability before fusion, increased number of prior low back operations, and increased number of levels fused). Even after adjusting for these variables, receiving instrumentation with fusion doubled the risk of reoperation. Most patients reported that back pain (67.7%) was worse and overall quality of life (55.8%) was no better or worse than before surgery.

CONCLUSIONS

Outcome of lumbar fusion performed on injured workers was worse than reported in published case series. Prospective studies should be conducted to determine the biologic indications that might lead to improved outcomes in this disabled population.

Occupational carpal tunnel syndrome in Washington State, 1984-1988

BACKGROUND

There are no published population-based studies of occupational carpal tunnel syndrome (OCTS) using a strict case definition. Most studies are either industry specific or present patient self-report of symptoms.

METHODS

We conducted a population-based incidence study of OCTS using the Washington State Workers' Compensation database. Incident OCTS claims were identified with paid bills for physician reported ICD codes 354.0 and 354.1.

RESULTS

There were 7,926 incident OCTS claims identified for the years 1984-1988, which yields an industry-wide incidence rate of 1.74 claims/1,000 FTEs. The mean age (37.4 years) and female/male ratio (1.2:1) in this population differ from those reported in nonoccupational carpal tunnel studies (mean age, 51 years; female/male ratio, 3:1). The female-specific OCTS incidence rate increased significantly during the study period. The highest industry specific OCTS rates were found in the food processing, carpentry, egg production, wood products, and logging industries.

CONCLUSION

Demographic differences and industry-specific rates consistent with workplace exposures suggest that OCTS is distinct from CTS occurring in nonoccupational settings. Workers' compensation data proved useful in identifying high risk industries.

[Treatment of diabetes and quality of life. On possibilities of a more normalized life style using an insulin pen for multi-injection therapy]

Forty-eight insulindependent diabetics were interviewed by a psychologist about their experiences when changing from conventional diabetes regimen to multi-injection therapy using NovoPen (a pen-like insulin injection system). They had then used the new therapy for 1 1/2 years. Most of them had made only small changes in their eating habits, but they strongly appreciated the new possibility for flexibility in eating patterns. The most mentioned advantages were: The new therapy was practical and easy to use, gave more freedom, made social life easier and improved blood glucose control. Many, mainly women, experienced less feelings of guilt, and women also placed the social advantages highest on the list of advantages. The youngest persons thought the greatest benefit was increased freedom, and persons in middle age the possibilities for improved metabolic control. Multi-injection insulin therapy is an important advancement, and is probably not acceptable to most diabetics without a practical and reliable insulin pen.

Efficacy of neuromuscular stimulation of the quadriceps femoris during continuous passive motion following total knee arthroplasty

The effect of neuromuscular stimulation of the quadriceps femoris combined with continuous passive motion (CPM) on the active extension range of motion and force of patients with total knee arthroplasty was investigated. The experimental group received three one-hour periods of electric stimulation per day in the extension cycle of the continuous passive motion. The control group received continuous passive motion without quadriceps electric stimulation. Both groups engaged in physical therapy consisting of active range of motion, quadriceps femoris setting, flexion and extension stretches, and ambulation. Manual goniometry and tensiometry were used to evaluate knee active extension range of motion and quadriceps strength. Upon dismissal, the stimulated group was able to generate more force at 90 degrees, 35 degrees, 20 degrees, and terminal extension of the involved knee, but none of these values was found to be statistically significant. Active extension range of motion of the stimulated group on dismissal showed a significant decrease in active extension lag (degrees) as compared to the control group. The experimental group averaged ten days in the hospital as compared to 12.5 for the control group, and subjectively noted decreased pain during stimulation.

[The problem of domiciliary obstetric practice (author's transl)]

From a group of 8,020 well-documented and electronically recorded deliveries at the Tübingen University Gynaecological Clinic during 1976-1979 we selected 1147 (14.3%) according to strict criteria and subjected them to further analysis. These 1147 pregnant women had one feature in common, namely, that there were absolutely no signs of any risk factor prior to delivery (Table 1).

RESULT

83% only of these children were delivered spontaneously; in 0.8% of the cases it was necessary to effect Caesarean section, and in another 15% vaginal-surgical delivery proved necessary. In 10% threatening and in 0.9% acute foetal asphyxia was the guiding sign for appropriate obstetric measures. In 31.4% of the cases we found a twisted cord, whereas the frequency rate of acidosis (pHNA less than 7100) was 7%. Apgar counts below 7 were seen in 2.3% and indices below 3 in 0.1% of the cases. Perinatal mortality was approximately 1:1000. Complications requiring follow-ups were seen in the first week post partum in every 20th child. It is concluded that domiciliary obstetric practice cannot be medically recommended since it involves a risk rate for both mother and child which is considered too high.