Chronic graft versus host disease is associated with long-term risk for pneumococcal infections in recipients of bone marrow transplants

Incidences of and risk factors for Streptococcus pneumoniae sepsis (SPS) after hematopoietic stem cell transplantation were analyzed in 1329 patients treated at a single center between 1973 and 1997. SPS developed in 31 patients a median of 10 months after transplantation (range, 3 to 187 months). The infection was fatal in 7 patients. The probability of SPS developing at 5 and 10 years was 4% and 6%, respectively. Age, sex, diagnosis, and graft versus host disease (GVHD) prophylaxis did not influence the development of SPS. Allogeneic transplantation (10-year probability, 7% vs 3% for nonallogeneic transplants; P =.03) and chronic GVHD (10-year probability, 14% vs 4%; P =.002) were associated with significantly higher risk for SPS. All the episodes of SPS were seen in patients who had undergone allograft or total body irradiation (TBI) (31 of 1202 vs 0 of 127; P =.07). Eight patients were taking regular penicillin prophylaxis at the time of SPS, whereas 23 were not taking any prophylaxis. None of the 7 patients with fatal infections was taking prophylaxis for Pneumococcus. Pneumococcal bacteremia was associated with higher incidences of mortality (6 of 15 vs 1 of 16; P =.04). We conclude that there is a significant long-term risk for pneumococcal infection in patients who have undergone allograft transplantation, especially those with chronic GVHD. Patients who have undergone autograft transplantation after TBI-containing regimens also appear to be at increased risk. These patients should receive lifelong pneumococcus prophylaxis. Consistent with increasing resistance to penicillin, penicillin prophylaxis does not universally prevent SPS, though it may protect against fatal infections. Further studies are required to determine the optimum prophylactic strategy in patients at risk. (Blood. 2000;95:3683-3686)

Role of type I IFNs in the in vitro attenuation of live, temperature-sensitive vaccine strains of human respiratory syncytial virus

The contributions of type I interferons (IFNs) to the in vitro attenuation of three temperature-sensitive (Ts) subgroup A and one subgroup B deletion mutant RSV strains were evaluated. The ability of these vaccine viruses to induce IFNs at their permissive and restrictive temperatures and their sensitivity to the antiviral effects of exogenous I IFNs were tested in human lung epithelial A549 cells. Our results show that the highly attenuated and immunogenic subgroup A vaccine strain Ts1C produced higher levels of IFN-beta than its parent RSS-2 or two related strains, Ts1A and Ts1B, at their permissive temperature. Growth of RSV-infected A549 cultures at restrictive temperatures or prior UV inactivation of the virus abolished the observed induction of IFN-beta, suggesting a strict requirement of viral replication for cellular IFN induction. The enhanced induction of IFN-beta by the highly immunogenic Ts1C at permissive temperature may be an advantageous characteristic of a live intranasal vaccine candidate. The subgroup B strain RSV B1 and its mutant cp-52 (with SH and G gene deletions) both induced similar but low levels of IFN-beta. Hence the observed overattenuation of cp-52 in human infants is probably not due to enhanced IFN induction during its replication in the host. The ability of cp-52, which does not express the SH and G proteins, to induce IFN-beta levels similar to those of its parent strain suggests that these viral proteins may not have a role in the induction of IFN-beta in the host. In addition, both subgroup A and B mutants and their respective parent strains were similarly resistant to the antiviral effects of exogenous IFN-alpha or -beta. Therefore, increased sensitivity of the mutants to IFNs does not seem to contribute to their attenuation.

Interplanetary Network Localization of GRB 991208 and the Discovery of its Afterglow

The extremely energetic ( approximately 10-4 ergs cm-2) gamma-ray burst (GRB) of 1999 December 8 was triangulated to an approximately 14 arcmin2 error box approximately 1.8 days after its arrival at Earth with the third interplanetary network (IPN), which consists of the Ulysses, Near-Earth Asteroid Rendezvous, and Wind spacecraft. Radio observations with the Very Large Array approximately 2.7 days after the burst revealed a bright fading counterpart whose position is consistent with that of an optical transient source with a redshift of 0.707. We present the time history, peak flux, fluence, and refined 1.3 arcmin2 error box of this event and discuss its energetics. This is the first time that a counterpart has been found for a GRB localized only by the IPN.

Acute lymphoblastic leukaemia-type intensive chemotherapy to eliminate minimal residual disease after high-dose melphalan and autologous transplantation in multiple myeloma - a phase I/II feasibility and tolerance study of 17 patients

Aiming to target the minimal residual disease in patients with multiple myeloma, a phase I/II single centre study was undertaken for feasibility and tolerance of intensive acute lymphoblastic leukaemia consolidation chemotherapy (ALL-IC) as part of a strategy for post-transplant consolidation targeted at pre-B cells. Seventeen newly diagnosed patients with myeloma (median age 55 years; 30-65) were initially treated with courses of infused cyclophosphamide, vincristine, adriamycin and methylprednisolone (C-VAMP) followed by melphalan 200 mg/m2(HDM) and peripheral blood stem cell rescue (PBSC). Forty-seven percent were in CR and the rest in PR after HDM. ALL-IC consisted of vincristine, daunorubicin, etoposide, cytarabine, 6-thioguanine and prednisolone given over 5 days. All patients became neutropenic (<0.5 x 109/l) at a median of 10 days (4-18) and one of the 17 patients (5.8%) died 15 days post ALL-IC of sepsis. A further four have died of relapse with an overall survival (OS) of 67% at 4 years. Two of nine patients in PR at the time of ALL-IC achieved CR. Matched-pair analysis of 34 control patients shows no difference for OS and event-free survival between ALL-IC and controls. We conclude that ALL-IC given to myeloma patients after HDM/PBSC is as safe as when used in ALL and warrants further assessment in randomised trials for myeloma.

Allogeneic blood and bone-marrow stem-cell transplantation in haematological malignant diseases: a randomised trial

BACKGROUND

Autologous transplantation with peripheral blood stem cells (PBSC) results in faster haematopoietic-cell repopulation than with bone marrow. We prospectively compared bone marrow and PBSC for allogeneic transplantation.

METHODS

Adult HLA-identical sibling donors provided bone marrow and lenograstim-mobilised PBSC. 39 patients with malignant haematological disorders were infused with either bone marrow (n=19) or PBSC (n=20) after standard conditioning regimens in a double-blind, randomised fashion. The identity of the infused products for all patients remained masked until 1 year after the last patient had received transplantation.

FINDINGS

The PBSC group had significantly faster neutrophil recovery to 0.5x10(9)/L (median 17.5 vs 23 days, p=0.002), and platelet recovery to 20x10(9)/L (median 11 vs 18 days, p<0.0001) and to 50x10(9)/L (median 20.5 vs 27 days, p=0.02) than the bone-marrow group. PBSC patients were discharged from hospital earlier than were bone-marrow patients (median 26 vs 31 days, p=0.01). At 4 weeks after transplantation, absolute lymphocytes (0.48 vs 0.63, p=0.08) and CD25 cells (0.04 vs 0.08, p=0.007) were higher in the PBSC group, and the proportion of patients with absolute lymphopenia (74% vs 33%, p=0.03) and CD4 lymphopenia (59% vs 24%, p=0.05) was significantly higher in the bone-marrow group. There was no significant difference in the occurrence of acute or chronic graft-versus-host disease and overall survival. The probability of relapse was significantly higher in the bone-marrow group than in the PBSC group (p=0.01); all five relapses occurred among bone-marrow recipients.

INTERPRETATION

Our small study indicates that PBSCs are better than bone marrow for allogeneic transplantation from HLA-identical siblings in terms of faster haematopoietic and immune recovery, and have the potential to reduce disease recurrence.

The SH2 tyrosine phosphatase shp2 is required for mammalian limb development

The tyrosine phosphatase Shp2 is recruited into tyrosine-kinase signalling pathways through binding of its two amino-terminal SH2 domains to specific phosphotyrosine motifs, concurrent with its re-localization and stimulation of phosphatase activity. Shp2 can potentiate signalling through the MAP-kinase pathway and is required during early mouse development for gastrulation. Chimaeric analysis can identify, by study of phenotypically normal embryos, tissues that tolerate mutant cells (and therefore do not require the mutated gene) or lack mutant cells (and presumably require the mutated gene during their developmental history). We therefore generated chimaeric mouse embryos to explore the cellular requirements for Shp2. This analysis revealed an obligatory role for Shp2 during outgrowth of the limb. Shp2 is specifically required in mesenchyme cells of the progress zone (PZ), directly beneath the distal ectoderm of the limb bud. Comparison of Ptpn11 (encoding Shp2)-mutant and Fgfr1 (encoding fibroblast growth factor receptor-1)-mutant chimaeric limbs indicated that in both cases mutant cells fail to contribute to the PZ of phenotypically normal chimaeras, leading to the hypothesis that a signal transduction pathway, initiated by Fgfr1 and acting through Shp2, is essential within PZ cells. Rather than integrating proliferative signals, Shp2 probably exerts its effects on limb development by influencing cell shape, movement or adhesion. Furthermore, the branchial arches, which also use Fgfs during bud outgrowth, similarly require Shp2. Thus, Shp2 regulates phosphotyrosine-signalling events during the complex ectodermal-mesenchymal interactions that regulate mammalian budding morphogenesis.

Effects of salt and pH stress on temperature-tolerant Rhizobium sp. NBRI330 nodulating Prosopis juliflora

A study was conducted to examine the growth response of a rhizobial strain Rhizobium sp. NBRI330 isolated from root nodules of Prosopis juliflora growing in alkaline soil. The strain had the ability to nodulate P. juliflora. Nursery grown plants inoculated with Rhizobium sp. NBRI330 had 60.6% higher plant dry weight, as compared with uninoculated plants. The individual stress survival limit of a rhizobial strain Rhizobium sp. NBRI330 isolated from alkaline soil in a medium containing 32% (wt/vol) salt was 8 h, and at 55 degrees C up to 3 h. The length of Rhizobium sp. NBRI330 in salt-stressed cells increased significantly to 3.04 microm from 1.75 microm of non-stressed control cells. On the contrary, the length of pH-stressed cells declined to 1.40 microm. Compared with non-stressed control rod-shaped cells, the shape of temperature-stressed cells changed to spherical, of 0.42 microm diameter. High temperature (45 degrees C) was tolerated efficiently by Rhizobium sp. NBRI330 in the presence of salt at pH 12, as compared with pH 7.

Programmed cell death signaling via cell-surface expression of a single-chain antibody transgene

BACKGROUND

The monoclonal antibody, 5H7, is specific for a monomorphic determinant on the a3 domain of human class I MHC (A, B, C). Immobilized 5H7 delivers programmed cell death (PCD) signals to human lymphoid tumor cells as well as peripheral blood mononuclear cells.

METHODS

The potential clinical utility of 5H7 was addressed by design of a single-chain variable antibody (scFv), termed 5H7scFv, which was coupled to glycophosphotidylinostitol (GPI), thereby providing membrane expression of the 5H7 idiotype (5H7scFv-GPI). Membrane expression of 5H7scFv-GPI conferred PCD-inducing properties to cells that do not normally have the capability to process and express whole antibody molecules. The initial construction was undertaken in a bacterial expression system, and appropriate protein folding was determined by binding to class I MHC-expressing cells.

RESULTS

5H7scFv-GPI-transfected Chinese hamster ovary cells demonstrated reconstitution of the 5H7 idiotype and binding to soluble HLA-A2. Cross-linking of class I MHC, via membrane expression of the scFv, provided effective PCD signaling in B and T lymphocyte tumor cells. Peripheral blood mononuclear cells were susceptible to 5H7scFv-GPI-induced PCD, and augmentation of PCD signals was noted with anti-CD3 and anti-CD28 preactivation. Responder cells demonstrated typical histologic features of PCD and Annexin V-fluorescein isothiocyanate binding.

CONCLUSIONS

Cell surface anchorage of scFv thus provides effective delivery of immune modulatory signals, which may be manipulated for various therapeutic strategies.

A revised model of platelet aggregation

In this study we have examined the mechanism of platelet aggregation under physiological flow conditions using an in vitro flow-based platelet aggregation assay and an in vivo rat thrombosis model. Our studies demonstrate an unexpected complexity to the platelet aggregation process in which platelets in flowing blood continuously tether, translocate, and/or detach from the luminal surface of a growing platelet thrombus at both arterial and venous shear rates. Studies of platelets congenitally deficient in von Willebrand factor (vWf) or integrin alpha(IIb)beta(3) demonstrated a key role for platelet vWf in mediating platelet tethering and translocation, whereas integrin alpha(IIb)beta(3) mediated cell arrest. Platelet aggregation under flow appears to be a multistep process involving: (a) exposure of vWf on the surface of immobilized platelets; (b) a reversible phase of platelet aggregation mediated by the binding of GPIbalpha on the surface of free-flowing platelets to vWf on the surface of immobilized platelets; and (c) an irreversible phase of aggregation dependent on integrin alpha(IIb)beta(3). Studies of platelet thrombus formation in vivo demonstrate that this multistep adhesion mechanism is indispensable for platelet aggregation in arterioles and also appears to promote platelet aggregate formation in venules. Together, our studies demonstrate an important role for platelet vWf in initiating the platelet aggregation process under flow and challenge the currently accepted view that the vWf-GPIbalpha interaction is exclusively involved in initiating platelet aggregation at elevated shear rates.

The role of autologous transplantation in patients with multiple myeloma aged 65 years and over

Autologous stem cell transplantation after high-dose melphalan for the treatment with multiple myeloma has resulted in prolonged progression-free survival and overall survival in patients under 65 years. We have examined the role of autologous transplantation in 17 patients with multiple myeloma over 65 years at our centre using a matched pair analysis with younger patients. The median age of this cohort of patients over 65 years was 67 years (65-74) and their outcome and transplant-related morbidity was compared with 17 younger pair mates with a median age of 55 years (31-64). Sixteen patients received high-dose melphalan, and one received busulphan with autologous stem cell rescue. The high-dose therapy was well tolerated in both elderly patients and the matched pairs, with comparable time to recover neutrophils and platelets. Treatment-related mortality also did not differ significantly in both the groups. Median overall survival of the elderly patients was 3.59 years similar to 3.01 years of the pair mates (P = 0.92). Autologous stem cell transplantation after high-dose melphalan conditioning was equally well tolerated in groups of patients above and below 65 years. There was no difference in relapse rate, OS and myelotoxicity in both the groups. These findings suggest that advanced age should not be an exclusion criterion from autologous transplant programmes. Bone Marrow Transplantation (2000) 25, 533-539.

Renal cell carcinoma as significant manifestation of tuberous sclerosis complex

We present a case of renal cell carcinoma diagnosed in 1982; aged 20 years. Regular follow up of the abdomen by USG noted first the presence of 2 nodules in the remaining kidney in 1994, age 30 and more lesions in 1997, aged 35. These were suspected to be angiomyolipomas on USG. The radiologist on this basis raised the question of tuberous sclerosis. Subsequent evaluation by internist/neurologist showed few adenoma sebaceum lesions a single ash leaf macule, a shagreen patch on the back, and characteristic multiple subependymal calcifications diagnostic of tuberous sclerosis on CT scan brain. The mentation was normal, there was history of only a single fit in childhood. The renal cell carcinoma was thus the first significant manifestation of tuberous sclerosis complex (TSC).

Comparison of marrow and blood cell yields from the same donors in a double-blind, randomized study of allogeneic marrow vs blood stem cell transplantation

Forty healthy adult donors underwent marrow (BM) as well as peripheral blood (PBSC) stem cell collections for their HLA-identical adult siblings with hematologic malignancies. BM was harvested on day 1 (target 3 x 108 nucleated cells/kg, 10 microg/kg lenograstim (glycosylated G-CSF) administered on days 2-6, and a single leukapheresis performed on day 6. The blood volume processed was the higher of 200% donor blood volume or 10 liters. The total nucleated cell (TNC) yields from PBSC were 1.1- to 4.3-fold higher than BM (median 7.0 vs 3.1 x 10(8)/kg, P < 0.0001). Although BM contained a higher proportion of CD34+cells (1.3% vs 0.7%, P < 0. 0001) and a comparable proportion of CD3+ cells (median 29% vs 26%, P = 0.4), the absolute numbers of CD34+ and CD3+ cells and their subsets were several times higher in PBSC. There was a poor correlation between BM and PBSC CD34 and TNC numbers, but a significant correlation between BM and PBSC CD3 numbers. Only five of 40 BM harvests contained >/=2 x 10(6) CD34+ cells/kg compared with 35 of 40 PBSC harvests (P < 0.0001). We conclude that the numbers of progenitor and immunocompetent cells in PBSC are several times higher than in BM. It is possible to collect adequate numbers of progenitor cells from blood after lenograstim stimulation more frequently than from marrow, and donors yielding low quantities of progenitor cells from BM usually deliver better quantities from PBSC. Bone Marrow Transplantation (2000) 25, 501-505.

Melphalan/TBI is not more carcinogeneic than cyclophosphamide/TBI for transplant conditioning: follow-up of 725 patients from a single centre over a period of 26 years

As there is concern regarding the high carcinogenic potential of melphalan (Mel), 725 patients with haematological malignancies who received allogeneic (n = 714) or syngeneic (n = 11) transplants over the last 26 years were followed-up to evaluate if melphalan was more likely to result in secondary malignant neoplasms (SMNs) than cyclophosphamide (Cy). Three hundred and ninety-five were treated with Cy/TBI and 330 with Mel/TBI. Twelve patients developed non-haematological SMN. Median time to develop a SMN was 7 years (range 2-17 years). Age-adjusted rate was significantly higher than in the general population (observed 12 expected 1.2, risk 10; P < 0.0001). The cumulative overall risk of developing a SMN at 2, 5, 10 and 15 years post transplant was 0.4% (95% CI 0.1-2.6%), 1.7% (95% CI 0.6-4.4%), 6.4% (95% CI 2.8-10.8%) and 6.6% (95% CI 3.4-12.4%), respectively. Even though age-adjusted rates were higher than the general population melphalan/TBI was not associated with higher age-adjusted risk than Cy/TBI (increased risk 7.9 vs 11.4; P = NS). The cumulative overall risk of SMNs was not different with CY/TBI or Mel/TBI (8/393 vs 4/363; 10 year risk 4.4%, 95% CI 1.8-10.6 vs 8.4%, 95% CI 2.9-22.9; P = NS). The risk was significantly higher with use of additional cranial or cranio-spinal irradiation (17.5% vs 2.7% at 10 years; P = 0.0241). Transplants for acute lymphatic leukaemia resulted in a higher incidence of SMNs than did transplants for other diseases (ALL: 17.4%, 95% CI 6.3-42.6%; other diseases: 3.4% (95% 1.3-8.5%, P = 0.0469). The risk of SMN for patients with chronic GVHD was 8.4% (95% CI 3.7-18.7%) as compared to 3.5% (95% CI 1-11.1%) for patients without chronic GVHD (P = NS). No factor was associated with independently increased risk in multivariate analysis. Use of melphalan and TBI for transplant conditioning does not appear to be associated with higher risk of second malignant neoplasms than cyclophosphamide and TBI.

The von Willebrand factor-glycoprotein Ib/V/IX interaction induces actin polymerization and cytoskeletal reorganization in rolling platelets and glycoprotein Ib/V/IX-transfected cells

Platelet adhesion to sites of vascular injury is initiated by the binding of the platelet glycoprotein (GP) Ib-V-IX complex to matrix-bound von Willebrand factor (vWf). This receptor-ligand interaction is characterized by a rapid on-off rate that enables efficient platelet tethering and rolling under conditions of rapid blood flow. We demonstrate here that platelets adhering to immobilized vWf under flow conditions undergo rapid morphological conversion from flat discs to spiny spheres during surface translocation. Studies of Glanzmann thrombasthenic platelets (lacking integrin alpha(IIb)beta(3)) and Chinese hamster ovary (CHO) cells transfected with GPIb/IX (CHO-Ib/IX) confirmed that vWf binding to GPIb/IX was sufficient to induce actin polymerization and cytoskeletal reorganization independent of integrin alpha(IIb)beta(3). vWf-induced cytoskeletal reorganization occurred independently of several well characterized signaling processes linked to platelet activation, including calcium influx, prostaglandin metabolism, protein tyrosine phosphorylation, activation of protein kinase C or phosphatidylinositol 3-kinase but was critically dependent on the mobilization of intracellular calcium. Studies of Oregon Green 488 1, 2-bis(o-amino-5-fluorophenoxy)ethane-N,N,N',N-tetraacetic acid tetraacetoxymethyl ester-loaded platelets and CHO-Ib/IX cells demonstrated that these cells mobilize intracellular calcium in a shear-dependent manner during surface translocation on vWf. Taken together, these studies suggest that the vWf-GPIb interaction stimulates actin polymerization and cytoskeletal reorganization in rolling platelets via a shear-sensitive signaling pathway linked to intracellular calcium mobilization.

Complete remission rate and outcome after intensive treatment of 177 patients under 75 years of age with IgG myeloma defining a circumscribed disease entity with a new staging system

Because the presence of IgG paraprotein in the blood is clear cut, it makes IgG myeloma a more circumscribed disease than myeloma as a whole in which to study treatment efficacy, particularly relating to complete remission (CR). Between May 1989 and December 1997, 177 consecutive patients with IgG myeloma who were <75 years old were seen, of whom 153 entered a sequential therapy (ST) programme of initial courses of C-VAMP infusional chemotherapy (IC), high-dose treatment (with or without stem cell rescue) (119 patients) and maintenance interferon (87 patients). 74/153 (48.4%) patients entered CR. Median overall survival (OS) and event-free survival (EFS) were 4.9 and 2.1 years, respectively. Multivariate analysis at presentation showed OS was significantly prolonged for beta2M <2.7 mg/l and age <median 52, whilst beta2M <2.7 mg/l and Hb >8.5 g/dl predicted for longer EFS. For CR patients, age <median 51 years, absence of Bence-Jones proteinuria (BJP), male sex and white blood cells (WBC) <7 x 109/l predicted for a longer OS. Longer length of first CR was predicted by absence of BJP at presentation (P = 0.03) and fewer than five courses of IC (P = 0.02) to attain CR. We have therefore been able to refine the use of ST in IgG myeloma, redefine CR as a 'macro' endpoint, and propose a new staging system for IgG myelomas. Analysis of 41 comparable IgA patients showed IgG to be a distinct entity.

Oral idarubicin as a single agent therapy in patients with relapsed or resistant multiple myeloma

The established treatment for multiple myeloma (MM) comprises induction with infusional chemotherapy, high dose chemotherapy (HDC) and autologous transplantation followed by maintenance interferon. On relapse, patients (pts) are reconsidered for this however some are unsuitable and in this situation the therapeutic options are limited. Between June 1995 and May 1997, 14 pts with previously treated relapsed or refractory MM were recruited. Using a prospective database, the tolerability and efficacy of chronic low dose oral idarubicin was evaluated. The median age of pts was 63 years. All had received previous anthracycline in the form of infusional cVAMP chemotherapy. 11/14 had received previous HDC. Median time from diagnosis to commencing idarubicin was 77 months. 10 mg idarubicin was administered 3 times/week for 3 weeks of a 5 week cycle. The maximum number of courses was 6. Three pts completed 6 courses, 5 pts 3 courses, 2 pts 2 courses and 4 pts 1 course. The reasons for stopping treatment were death due to progressive disease (PD) in 7 pts, persistent thrombocytopenia in 2 pts, PD in 1 pt and 1 pt suffered a cerebral infarction not considered to be related to the idarubicin therapy. Two pts showed evidence of response, neither amounting to a partial response. One had stabilisation of paraprotein with a reduction in bone marrow infiltration (47% to 7% plasma cells), the other had a reduction in bone marrow infiltration after 3 course but an increase after 6 courses. In total forty-one courses of treatment were administered. Grade 3/4 haematological toxicities were noted in a minor fraction of cases and were as follows: anaemia 6/41, neutropenia 10/41 and thrombocytopenia 11/41. Our data therefore shows a minor response in 2/14 (14%) of heavily pretreated patients with MM, without evidence of severe toxicity. It provides the rationale for using oral idarubicin as either single agent or in combination therapy for patients earlier on in their disease course especially if they are unsuitable for standard therapy.

8-anilino-1-naphthalene sulfonic acid (ANS) induces folding of acid unfolded cytochrome c to molten globule state as a result of electrostatic interactions

Hydrophobic interaction of 8-anilino-1-naphthalene sulfonic acid (ANS) with proteins is one of the widely used methods for characterizing/detecting partially folded states of proteins. We have carried out a systematic investigation on the effect of ANS, a charged hydrophobic fluorescent dye, on structural properties of acid-unfolded horse heart cytochrome c at pH 2.0 by a combination of optical methods and electrospray ionization mass spectroscopy (ESI MS). ANS was found to induce, a secondary structure similar to native protein and quenching of fluorescence of tryptophan residue, in the acid-unfolded protein. However, the tertiary structure was found to be disrupted thus indicating that ANS stabilizes a molten globule state in acid-unfolded protein. To understand the mechanism of ANS-induced folding of acid-unfolded cytochrome c, comparative ESI MS, soret absorption, and tryptophan fluorescence studies using nile red, a neutral hydrophobic dye, and ANS were carried out. These studies suggested that, at low pH, electrostatic interactions between negatively charged ANS molecules and positively charged amino acid residues present in acid-unfolded cytochrome c are probably responsible for ANS-induced folding of acid-unfolded protein to partially folded compact state or molten globule state. This is the first experimental demonstration of ANS induced folding of unfolded protein and puts to question the usefulness of ANS for characterization/determination of partially folded intermediates of proteins observed under low pH conditions.

Immunochemotherapy for Leishmania donovani infection in golden hamsters: combinatorial action of poly ICLC plus L-arginine and sodium stibogluconate (Stibanate)

We demonstrate that golden hamsters infected with Leishmania donovani amastigotes develop the capacity to eliminate intracellular pathogens on treatment with low-dose standard antileishmanial sodium stibogluconate (Stibanate) in combination with polyinosinic-polycytidilic acid stabilized with polylysine and carboxymethycellulose (poly ICLC), a potent inducer of interferon (IFN) and immune enhancer, plus L-arginine. Data suggest that low doses of both Stibanate and poly ICLC plus L-arginine provide marginal inhibition against L. donovani infection in golden hamsters. When given in combination, however, a significant inhibition was achieved without toxicity, as all the animals survived up to 45 or 60 days. These results suggest that combination therapy using Stibanate and poly ICLC plus L-arginine may be very effective in reducing the dose of Stibanate and, hence, its dose-dependent toxicity in clinical situations.

Allograft reconstruction of the extensor mechanism for progressive extensor lag after total knee arthroplasty and previous patellectomy: a 3-year follow-up

Major extensor lag after total knee arthroplasty may follow operative damage to the patellar tendon or its insertion. It may also occur in a late progressive form postoperatively. A successful allograft reconstruction of the extensor mechanism for progressive extensor lag after total knee arthroplasty is described. Patellectomy had been carried out earlier on the same knee for patellofemoral osteoarthritis.

Respiratory syncytial virus strain A2 is resistant to the antiviral effects of type I interferons and human MxA

Respiratory syncytial virus (RSV) belongs to Paramyxoviridae family of enveloped negative-strand RNA viruses and causes severe bronchiolitis and pneumonia in children younger than 2 years of age. As members of Paramyxoviridae family, RSV and parainfluenza type 3 (PIV3) have similar modes of infection and replication. A variety of negative-strand RNA virus infections, including that of PIV3, are inhibited by human MxA protein, a type I interferon (IFN)-inducible GTPase. We tested whether the MxA protein, induced either by type I human IFNs or by stable transfection of human MxA gene in human (U-87) or simian (Vero) cells, confers resistance to these cells against infection by RSV strain A2. RSV infection was resistant to antiviral effects induced by 0-10,000 U/ml type I IFNs (IFN-alpha or -beta) in both human lung epithelial, A549, and fibroblast, MRC-5 cells. RSV virus yield was reduced only by 10- to 20-fold, and viral protein synthesis was not significantly affected under conditions of IFN treatment where PIV3 yield was reduced by 1000- to 10,000-fold. Human or simian cell lines constitutively expressing MxA were protected against infection by PIV3 but not by RSV. Our results indicate that RSV A2 is resistant to the antiviral effects of MxA, even though RSV and PIV3 have similar replication strategies. In IFN-treated coinfected cultures, IFN-resistant RSV A2 did not prevent the IFN-mediated inhibition of PIV3 multiplication. Hence the resistance of RSV A2 to type I IFNs does not appear to be due to soluble factors released into the medium or a disruption in the cellular antiviral machinery brought about by RSV A2 infection.

Frequent deletion of hSNF5/INI1, a component of the SWI/SNF complex, in chronic myeloid leukemia

During routine two-fusion fluorescence in situ hybridization analysis of patients with blast crisis of chronic myeloid leukemia (CML), we observed that yeast artificial chromosome 29GD7, which is distal to BCR at 22q11, failed to hybridize to the 9q+ derivative chromosome in 3 of 11 (27%) cases. This deleted region is close to hSNF5/INI1 (SMARCB1), a gene that encodes a widely expressed component of the SWI/SNF chromatin remodeling complex and that suffers biallelic mutations in malignant rhabdoid tumors. To determine whether hSNF5/INI1 was also deleted in patients with CML, we performed fluorescence in situ hybridization analysis with a specific cosmid probe. Deletion of hSNF5/INI1 on the 9q+ chromosome was found in 9 of 25 (36%) cases in blast crisis (lymphoid, n = 3; myeloid, n = 6). For the three of these nine patients for whom material was available prior to transformation, deletions were also seen in chronic phase, indicating that they are early events. Analysis of an additional 21 patients in chronic phase revealed heterozygous loss of hSNF5/INI1 in 5 (24%) cases. Of the 14 patients who had hSNF5/INI1 deletions, 7 showed a mosaic pattern of hybridization in which only a proportion of CML cells that harbored both the t(9;22) derivative chromosomes had a deletion, indicating that loss of hSNF5/INI1 was acquired during the course of the disease. Single-strand conformation polymorphism analysis of all nine hSNF5/INI1 exons and splice junctions failed to reveal any mutations for 31 patients in transformation, including 8 who had deletions, although two polymorphisms were identified. We conclude that deletions of hSNF5/INI1 are frequent in patients with CML. Such deletions may be associated with reduced levels of hSNF5/INI1 expression, which could contribute to leukemogenesis by altering chromatin-mediated transcriptional control. Alternatively, the deletions could target another unidentified gene at 22q11 that plays a role in the pathogenesis of CML.

The impact of karyotype on remission rates in adult patients with de novo acute myeloid leukemia receiving high-dose cytarabine-based induction chemotherapy

One hundred and twenty-eight patients aged 15 years or over (median 34) with de novo acute myeloid leukemia (AML) received 2- or 3-drug induction chemotherapy comprising 5 days of daily high-dose cytarabine (2 g/m2 q12h) and etoposide (100 mg/m2), without (n=62, 1985-90, protocol BF11) or with (n=66, 1990-97, protocol BF12) daily 5 mg/m2 anthracycline (61 idarubicin, 5 mitoxantrone). Twelve patients with t(15;17) were not included. Evaluable karyotypes were obtained in 110 (86%): 30 (27%) favorable, 60 (55%) intermediate, and 20 (18%) adverse. Three patients dying during chemotherapy were inevaluable. Eighty-four (67%) patients remitted with one cycle, and the overall complete remission (CR) rate was 72%. CR rates were comparable for patients with and without evaluable karyotypes. CR rates with BF11 (64% after one cycle; 72% overall) and BF12 (70% after one cycle; 72% overall) were comparable (P=.4 and 1.0 respectively). CR rates after one cycle (86%, 61% and 55%; P=.03) as well as overall CR rates (90%, 69% and 55%; P=.02) were significantly different for patients with favorable, intermediate and adverse karyotypes respectively. In Cox analysis, the karyotype was the only factor found to influence CR independently. We conclude that the karyotype of the leukemic clone is the most important determinant of response to high-dose cytarabine-based induction chemotherapy in AML. The addition of idarubicin to high-dose cytarabine and etoposide does not appear to improve CR rates. A different treatment strategy may be needed to improve CR rates for patients with non-favorable karyotypes.

Use of autologous growth factors in lumbar spinal fusion

The results of spinal fusion, especially posteriorly above the lumbosacral junction, have been mixed. Autologous growth factor concentrate (AGF) prepared by ultraconcentration of platelets contains multiple growth factors having a chemotactic and mitogenic effect on mesenchymal stem cells and osteoblasts and may play a role in initiating bone healing. The purpose of this retrospective study is to review our results with AGF in lumbar spinal fusions. To date, AGF has been used in 39 patients having lumbar spinal fusion. The study group consisted of the first 19 consecutive cases to allow at least 6 months follow-up. The average follow-up was 13 months (range 6 to 18 months). Follow-up compliance was 91%. There were 7 men and 12 women. Average age was 52 years (range 30-72 years). Nine patients had prior back surgery. There were 8 smokers. AGF was used in posterior (n = 15) or anterior intradiscal (n = 4) fusions. AGF was used with autograft and coraline hydroxyapatite in all posterior fusions, and autograft, coral, and intradiscal spacer (carbon fiber spinal fusion cages or Synthes femoral ring) in intradiscal fusions. Posterior stabilization was used in all cases. Eight cases were single-level fusions, 6 were two-level, and 1 was a three-level fusion. Autologous iliac crest bone graft was taken in 14 cases and local autograft used in 5 cases. Posteriorly, a total of 23 levels were fused; of these, nine were at L5-S1, eight at L4-L5, five at L3-L4, and one at L2-L3. No impending pseudoarthroses were noted on plain radiographic examination at last follow-up visit. Solid fusion was confirmed in 3 patients having routine hardware removal, and in 2 patients who had surgery at an adjacent level. There was one posterior wound infection, which was managed without sequelae. When used as an adjunct to autograft, AGF offers theoretical advantages that need to be examined in controlled studies. Further study is necessary to determine whether coralline hydroxyapatite used as a bone graft extender in lumbar spinal fusion may help to obviate the need for secondary site graft harvesting.

Calpain mediates integrin-induced signaling at a point upstream of Rho family members

Integrin-induced adhesion leads to cytoskeletal reorganizations, cell migration, spreading, proliferation, and differentiation. The details of the signaling events that induce these changes in cell behavior are not well understood but they appear to involve activation of Rho family members which activate signaling molecules such as tyrosine kinases, serine/threonine kinases, and lipid kinases. The result is the formation of focal complexes, focal adhesions, and bundles and networks of actin filaments that allow the cell to spread. The present study shows that mu-calpain is active in adherent cells, that it cleaves proteins known to be present in focal complexes and focal adhesions, and that overexpression of mu-calpain increased the cleavage of these proteins, induced an overspread morphology and induced an increased number of stress fibers and focal adhesions. Inhibition of calpain with membrane permeable inhibitors or by expression of a dominant negative form of mu-calpain resulted in an inability of cells to spread or to form focal adhesions, actin filament networks, or stress fibers. Cells expressing constitutively active Rac1 could still form focal complexes and actin filament networks (but not focal adhesions or stress fibers) in the presence of calpain inhibitors; cells expressing constitutively active RhoA could form focal adhesions and stress fibers. Taken together, these data indicate that calpain plays an important role in regulating the formation of focal adhesions and Rac- and Rho-induced cytoskeletal reorganizations and that it does so by acting at sites upstream of both Rac1 and RhoA.

Long-term outcome of adult acute leukemia patients who are alive and well two years after allogeneic bone marrow transplantation from an HLA-identical sibling

We studied the long-term outcome of 136 adults with acute leukemia (age 15-48 years at transplant, median 28; 112 myeloid, 22 lymphoblastic, 2 undifferentiated) who were alive in continuous remission two years after allografting from HLA-identical sibling donors. Six relapsed 25-46 months (median 30) after BMT. Fourteen (10%) died of non-relapse causes (12 transplant-related and 2 unrelated) 24-140 months (median 73) after BMT; mainly due to complications of chronic GVHD (8 infections, 3 secondary malignancies). One hundred and seventeen (86%) patients are alive in remission 25-226 months (median 103) after BMT; 116 (85%) in continuous remission. Eight survivors have symptomatic chronic GVHD requiring therapy (Karnofsky scores 60-90%, median 80%). The majority of those without chronic GVHD have Karnofsky scores of 100%. The 10-year probabilities of survival, toxic death, and relapse (from the 2-year mark) are 81%, 13%, and 5%. Twenty-two (19%) survivors had creatinine levels of > 110 mumol/L (one more than double), and 11 (9%) had bilirubin levels of > 17 mmol/L (one more than double) at the last follow-up. The absence of chronic GVHD at the 2-year mark (RR 3.5, P = .004), and female sex (RR 2.9, P = .04) influenced overall survival favorably, and the absence of chronic GVHD at the 2-year mark (RR 8.1, P = .001) influenced toxic death favorably. We conclude that patients with acute leukemia who are alive and well without chronic GVHD two years following an allograft have a high probability of being cured, whereas patients with active chronic GVHD requiring immunosuppression continue to be at risk of non-relapse death. The incidence of long-term liver and kidney dysfunction measured by serum bilirubin and creatinine is low.

Two patients with novel BCR/ABL fusion transcripts (e8/a2 and e13/a2) resulting from translocation breakpoints within BCR exons

We have identified novel BCR-ABL mRNA fusions by RT-PCR in two patients with Philadelphia (Ph) chromosome positive leukaemia. Sequencing revealed in-frame fusions consisting of part of BCR exon e8 spliced to ABL exon a2 in one patient and part of BCR exon e13 spliced to ABL exon a2 in the other. The breaks within BCR exons e8 and e13 did not conform to consensus splice sites, suggesting that the aberrant fusion mRNAs may have arisen as a result of translocation breakpoints at these sites. This was confirmed by genomic DNA bubble PCR for the second patient. These data show that BCR-ABL translocation breakpoints can occasionally occur within coding exons.

Long-term outcome of adult acute leukemia patients who are alive and well 2 years after autologous blood or marrow transplantation

We studied the long-term outcome of 87 adults with acute leukemia (age 15-59 years at transplant, median 27; 44 myeloid, 42 lymphoblastic, one biphenotypic) who were alive in continuous remission 2 years after a marrow (n = 74) or blood stem cell (n = 13) autograft. Nine relapsed 25-50 months (median 38) after transplantation. Five relapses were straightforward with no karyotypic or morphologic evolution of the original disease. Four recurrences were unusual, with development of myelodysplasia (n = 3) or myeloproliferative disease (n = 1). Five patients died of relapsed disease and four are still alive. Two patients died of complications related to the transplant, and one of ischemic heart disease. Seventy-nine patients (91%) are alive in remission 24-149 months (median 67) after transplantation (75 in continuous remission and four after further therapy) with Karnofsky scores of 80-100% (median 100%). The 8-year probabilities of survival, toxic death, and relapse (from the 2-year mark) are 89%, 3% and 12%. Eleven (12%) survivors had creatinine levels of >110 micromol/l (one more than double), and 14 (16%) had bilirubin levels of >17 mmol/l (one more than double) at the last follow-up. None of the following factors was found to be predictive for survival, non-relapse death, or relapse from the 2-year mark in multivariate analysis: age, sex, type of leukemia, disease stage, diagnosis, conditioning, origin of cells, and nucleated cell dose. We conclude that adult patients with acute leukemia who are alive and well 2 years following an autograft have a high probability of being cured, and the incidence of long-term liver and kidney dysfunction measured by serum bilirubin and creatinine is low.

Impact of previous high-dose therapy on outcome after allografting for multiple myeloma

We describe a single centre experience of 33 patients allografted for multiple myeloma, of which 28 received matched sibling marrow, one haploidentical family donor marrow and four matched but unrelated donor marrow. Median follow-up after transplant is 27 months, and 13 patients are currently alive. One out of four patients with an unrelated donor survives and 12 out of 28 (42.8%) with matched sibling donors. Four patients were unevaluable because of early death (<day 21), and one patient experienced graft failure. The probability of overall survival is 35.7 % at 3 years. The probability of disease-free survival is 39% at 3 years, and the probability of treatment-related mortality is 54% at 1 year. Acute GVHD developed in 26 (78.8%) patients and was responsible for six deaths. Twenty-four patients (72.7%) developed renal dysfunction and 22 (66.7%) developed hepatic dysfunction. Seventeen patients (51.5%) died of transplant-related problems in the first 150 days, and one at 6 months. Among the 13 survivors, none has experienced disease progression at a median follow-up of 27 months (range 3-65 months). We conclude that since allogeneic bone marrow transplantation is the only potentially curative option in myeloma, it should be offered to younger patients early in the course of their disease, when procedure-related morbidity and mortality are likely to be at their lowest.

Recombinant tissue plasminogen activator (rtPA) for the treatment of hepatic veno-occlusive disease (VOD)

Seventeen patients who developed hepatic veno-occlusive disease (VOD) following hematopoietic stem cell transplantation were treated with recombinant tissue plasminogen activator (rtPA) with or without heparin. rtPA was started a median of 13 days post transplant (range 4-35). All patients received rtPA at a dose of 10 mg/day as a starting dose, and 12 patients also received heparin (1500 U bolus; then 100 U/kg/day as a continuous i.v. infusion). The median number of days of rtPA therapy was 2.5 (1-12). The median total serum bilirubin level was 116 mmol/l (range 63-194) at the beginning of treatment. Six patients showed a response to rtPA treatment (29%). It was observed that by day 2 of rtPA therapy, bilirubin levels in responders showed a downwards trend as compared to those in nonresponders. In all except one patient this response was observed after two doses of rtPA. Seven out of the 11 non-responders had a past history of liver dysfunction, compared with none of the responders. There were no differences between the two groups in terms of day of onset of liver dysfunction, manifestations of disease, maximum bilirubin and creatinine levels, and day of commencing treatment. No patient experienced severe hemorrhagic complications during therapy. Four responders survived for more than 100 days compared to none of the non-responders. Probability of survival was 33% at day 100. It is difficult to unequivocally establish the role of rtPA in the treatment of VOD. The importance of bilirubin levels on days 2 or 3 of therapy in predicting outcome should be established, as should the optimum dose of rtPA and optimum duration of therapy.

Long-term follow-up of relapsed acute leukemia treated with immunotherapy after allogeneic transplantation: the inseparability of graft-versus-host disease and graft-versus-leukemia, and the problem of extramedullary relapse

Long-term outcome of 23 acute myeloid (AML, n=16) or lymphoblastic (ALL, n=7) leukemia patients who had received immunotherapy for treatment of persistent or recurrent disease 1.5-26 (median 4) months after allogeneic transplantation was studied to determine eventual survival. Immune manipulation comprised donor leukocyte infusion (n=18), interferon-alpha2b and/or interleukin-2 (n=15), and cyclosporine withdrawal (n=11) in various combinations. Graft-versus-host disease (GVHD) developed in 12 patients. Thirteen of 20 evaluable patients responded; 6 relapsing again. Eight patients died of toxicity, and 10 of progressive disease at 3-206 weeks (median 11). Five patients (3 AML, 2 ALL) are alive in remission with GVHD 2-46 months (median 23) after immunotherapy with Karnofsky scores of 70-100% (median 80). The overall survival of the whole group is 1-206 weeks (median 12), with an actuarial survival of 22% at 2 years. The development of GVHD was associated with superior survival in multivariate analysis (P=.007). Seven patients received immunosuppression because of the severity of GVHD (grade III/IV acute or extensive chronic): 3 died of GVHD, 3 improved but relapsed concomitantly, and 1 is alive in remission with extensive chronic GVHD. Four episodes of extramedullary relapse (granulocytic sarcomas) were seen in 3 patients with AML whose marrow remained in remission. We conclude that GVHD appears to be inseparable from graft-versus-leukemia in relapsed acute leukemia patients undergoing immunotherapy with a high proportion of patients dying due to toxicity or progressive disease, and isolated extramedullary relapse seems to be unusually common.

The genomic structure of ZNF198 and location of breakpoints in the t(8;13) myeloproliferative syndrome

The t(8;13)(p11;q12) is the most common translocation associated with the 8p11 myeloproliferative syndrome and results in an identical mRNA fusion between ZNF198 at 13q12 and FGFR1 at 8p11 in all cases thus far reported. ZNF198 is a widely expressed gene that is predicted to encode a 1377-amino-acid protein with five Zn finger-related motifs known as MYM domains. To determine the genomic DNA structure of ZNF198, we employed bubble PCR from PAC clones with a panel of gene-specific primers. Sequencing of these products revealed that ZNF198 consists of 26 exons with the initiation codon located in exon 4. The t(8;13) results in a consistent mRNA fusion of ZNF198 exon 17 to FGFR1 exon 9. Notable features of the structure of ZNF198 include three noncanonical GC donor splice sites and the presence of an alternatively spliced intron within exon 4. Amplification of genomic DNA from six t(8;13) patients with primers to ZNF198 exon 17 and FGFR1 exon 9 yielded patient-specific products ranging in size from 500 bp to 2.5 kb, indicating that the positions of the breakpoints in the t(8;13) are tightly clustered. The positions of the six t(8;13) breakpoints were determined and found to be distributed across ZNF198 intron 17 and FGFR1 intron 8 with no apparent subclustering. No consistent sequence motifs, repeats, or topoisomerase II cleavage sites were found at or near the breakpoints. It remains unclear why the t(8;13) translocation breakpoints occur within such small genomic regions, and it is possible that strict ZNF198-FGFR1 coding requirements restrict the positions of the breakpoints.

Mammalian Grb2 regulates multiple steps in embryonic development and malignant transformation

Proteins with SH2 and SH3 domains link tyrosine kinases to intracellular pathways. To investigate the biological functions of a mammalian SH2/SH3 adaptor, we have introduced a null mutation into the mouse gene for Grb2. Analysis of mutant embryonic stem cells, embryos, and chimeras reveals that Grb2 is required during embyrogenesis for the differentiation of endodermal cells and formation of the epiblast. Grb2 acts physiologically as an adaptor, since replacing the C terminus of the Ras activator Sos1 with the Grb2 SH2 domain yields a fusion protein that largely rescues the defects caused by the Grb2 mutation. Furthermore, Grb2 is rate limiting for mammary carcinomas induced by polyomavirus middle T antigen. These data provide genetic evidence for a mammalian Grb2-Ras signaling pathway, mediated by SH2/SH3 domain interactions, that has multiple functions in embryogenesis and cancer.

Stress and hypertension

Stress can cause hypertension through repeated blood pressure elevations as well as by stimulation of the nervous system to produce large amounts of vasoconstricting hormones that increase blood pressure. Factors affecting blood pressure through stress include white coat hypertension, job strain, race, social environment, and emotional distress. Furthermore, when one risk factor is coupled with other stress producing factors, the effect on blood pressure is multiplied. Overall, studies show that stress does not directly cause hypertension, but can have an effect on its development. A variety of non-pharmacologic treatments to manage stress have been found effective in reducing blood pressure and development of hypertension, examples of which are meditation, acupressure, biofeedback and music therapy. Recent results from the National Health and Nutrition Examination Survey indicate that 50 million American adults have hypertension (defined to be a systolic blood pressure of greater than 139 mm Hg or a diastolic blood pressure of greater than 89 mm Hg). In 95% of these cases, the cause of hypertension is unknown and they are categorized as "essential" hypertension. Although a single cause may not be identified, the general consensus is that various factors contribute to blood pressure elevation in essential hypertension. In these days of 70 hour work weeks, pagers, fax machines, and endless committee meetings, stress has become a prevalent part of people's lives; therefore the effect of stress on blood pressure is of increasing relevance and importance. Although stress may not directly cause hypertension, it can lead to repeated blood pressure elevations, which eventually may lead to hypertension. In this article we explore how stress can cause hypertension and what can be done about it.

Programmed cell death

Programmed cell death (PCD) is currently one of the most intensively studied areas in cell biology. Substantial evidence now exists demonstrating the integral role of PCD in many fundamental immunologic processes; therefore, understanding the mechanisms of PCD may provide advances with broad implications in immunobiology. This Overview provides a definition of PCD, a description of known PCD biochemical pathways, and finally a discussion of the implications of PCD in transplantation.

Histopathology of cultured shrimp showing gross signs of yellow head syndrome and white spot syndrome during 1994 Indian epizootics

Two epizootics of cultured shrimp occurred in India in 1994. The first case of mass mortalities of tiger shrimp Penaeus monodon in July 1994 was very similar to that caused by yellowhead virus (YHV) infection with regard to gross clinical signs, host species and size of shrimp affected, but it was histologically atypical. Very interestingly, intranuclear inclusions typical of a white spot syndrome virus (WSSV) infection were present in shrimp showing gross signs of yellow head syndrome, suggesting a dual infection. The second case of mass mortalities of P. monodon and P. indicus of all age groups and sizes in November 1994 was typical of a WSSV infection, clinically and histopathologically. Densely stained, round intracytoplasmic inclusions typical for YHV infection found in the lymphoid organ and haematopoietic tissue of WSSV-infected shrimp indicated a possible dual infection.

Consistent fusion of ZNF198 to the fibroblast growth factor receptor-1 in the t(8;13)(p11;q12) myeloproliferative syndrome

The 8p11 myeloproliferative syndrome is a rare, aggressive condition associated with reciprocal translocations of chromosome band 8p11, most commonly the t(8;13)(p11;q12). To identify the genes involved in this translocation, we used fluorescence in situ hybridization (FISH) analysis to show that the chromosome 8 breakpoints fell within YAC 899e2 and that the chromosome 13 breakpoints are clustered in a region flanked by YACs 929f11 and 911h8. FISH using chromosome 13 PAC clones indicated that the t(8;13) is not simply a reciprocal translocation but also involves an inversion of 13q11-12. Exon trapping of a PAC that spanned the chromosome 13 translocation breakpoints led to the identification of a gene, ZNF198, that detected rearranged bands when used as a probe against Southern blots of patient DNA. Conceptual translation of the full-length ZNF198 cDNA sequence predicts a protein of 1377 amino acids that shows significant homology to the DXS6673E/KIAA0385 and KIAA0425 proteins. Alignment of these three proteins revealed a novel, conserved Zn-finger-related motif (MYM domain) of the general form CX2C19-22CX3CX13-19CX2CX19-25FCX3CX3F/Y that is repeated five times in each protein. To identify the translocation partner gene on chromosome 8, 5' and 3' RACE polymerase chain reactions (PCRs) were performed on patient RNA with several combinations of ZNF198 primers. Clones were identified in which the ZNF198 was fused to exon 9 of the fibroblast growth factor receptor-1 (FGFR1), a gene known to map to 8p11. An identical ZNF198-FGFR1 fusion was detected in the three patients with a t(8;13) for whom RNA was available; reciprocal FGFR1-ZNF198 transcripts were not detected. Rearrangements of both ZNF198 and FGFR1 were found in two further patients by Southern blotting. ZNF198-FGFR1 includes the five MYM domains of ZNF198 and the intracellular tyrosine kinase domain of FGFR1. We hypothesize that this fusion leads to constitutive activation of the FGFR1 tyrosine kinase in a manner analogous to the activation of ABL by BCR in chronic myeloid leukemia.

Identification of patients who may benefit from prophylactic immunotherapy after bone marrow transplantation for acute myeloid leukemia on the basis of lymphocyte recovery early after transplantation

Two hundred and one patients (median age, 29 years) with acute myeloid leukemia (AML) underwent bone marrow transplantation (BMT) from HLA-identical sibling donors after conditioning with melphalan-total-body irradiation (TBI) (57%), cyclophosphamide-TBI (35%), or chemotherapy alone (8%). Graft-versus-host disease (GVHD) prophylaxis included cyclosporine alone (68%), cyclosporine-methotrexate (26%), or T-cell depletion (6%). The probability of relapse was calculated as a function of the absolute lymphocyte count (10(9)/L) on days 27 to 30 posttransplant (<0.1 v >/=0.1, <0.2 v >/=0.2, and <0.3 v >/=0.3). In each of these 12 comparisons, the probability of relapse was higher for the group with the lower lymphocyte count. Because the difference was most significant (P = .004) for an absolute lymphocyte count of <0.2 on day 29 (3-year relapse probability, 42%) versus >/= 0.2 (16%), this variable was included in a Cox model to determine factors independently affecting relapse. Multivariate analysis showed that conditioning regimens other than melphalan-TBI, a low lymphocyte count on day 29, French-American-British (FAB) subtypes M4-7, and a nucleated cell dose of > 2.42 x 10(8)/kg was associated with a higher risk of relapse. We conclude that slow lymphocyte recovery after allogeneic BMT, to < 0.2 x 10(9)/L 29 days in this analysis, appears to be associated with a higher risk of relapse in patients with AML. This group of patients may benefit from posttransplant immune manipulations such as abbreviated GVHD prophylaxis, or donor cell or cytokine administration to enhance graft-versus-leukemia reactions to reduce relapse.

UNC-73 activates the Rac GTPase and is required for cell and growth cone migrations in C. elegans

unc-73 is required for cell migrations and axon guidance in C. elegans and encodes overlapping isoforms of 283 and 189 kDa that are closely related to the vertebrate Trio and Kalirin proteins, respectively. UNC-73A contains, in order, eight spectrin-like repeats, a Dbl/Pleckstrin homology (DH/PH) element, an SH3-like domain, a second DH/PH element, an immunoglobulin domain, and a fibronectin type III domain. UNC-73B terminates just downstream of the SH3-like domain. The first DH/PH element specifically activates the Rac GTPase in vitro and stimulates actin polymerization when expressed in Rat2 cells. Both functions are eliminated by introducing the S1216F mutation of unc-73(rh40) into this DH domain. Our results suggest that UNC-73 acts cell autonomously in a protein complex to regulate actin dynamics during cell and growth cone migrations.

Lesion-induced transneuronal plasticity of the cholinergic innervation in the adult rat entorhinal cortex

The present experiments were designed to determine the effect that lesions of the basal forebrain cholinergic system exert on cholinergic interneurons within the entorhinal cortex (EC) in the rat. Unilateral infusion of 192 IgG-saporin into the nucleus of the horizontal diagonal band of Broca (HDB) decreased the number of ipsilateral choline acetyltransferase immunoreactive (ChAT-ir) neurons by 54%. Two-four weeks after the lesion, the ipsilateral EC exhibited a moderate but significant loss of ChAT-ir fibres and interneurons. Adjacent sections revealed a parallel loss of vasoactive intestinal polypeptide (VIP) immunoreactivity. Cell counts in the cingulate cortex were unaffected, suggesting that this effect was indeed specific to the main target area for HDB neurons. Ibotenic acid lesions also induced a significant 36% decrease in the number of cholinergic neurons in the ipsilateral HDB, and disappearance of ChAT terminals in the EC, whereas the number of ChAT-ir neurons in the EC was unchanged. Since ibotenic acid affects all cells and not only cholinergic ones, our results suggest that the specific degeneration of cholinergic neurons in the HDB after 192 IgG-saporin treatment could be inducing transsynaptic effects on their targets. Injections of 192 IgG-saporin directly into the EC also lesioned the cholinergic projection from the HDB, but had no effect on the intrinsic population. Eight weeks after immunolesion, the number of interneurons immunoreactive for ChAT and VIP in the EC had returned to normal values, and persisted for as long as 6 months after the lesion. By contrast, ChAT-ir neurons in the HDB were permanently lost. Our results suggest that the transient down-regulation of the cholinergic phenotype in entorhinal cortex interneurons could be a manifestation of activity-dependent plasticity, and that the loss of cholinergic innervation from the basal forebrain could be responsible for these effects through an imbalance of inputs. We hypothesize that the recovery of the phenotypic expression of entorhinal interneurons could be due to a recovery in their innervation, perhaps from sprouting axons in the same fields, belonging to surviving cholinergic neurons in the basal forebrain.

Cloning and characterization of the human homolog of mouse Jak2

Members of the Jak family play a critical role in signal transduction mediated by cytokine and hormone receptors. In this study, we report the cloning and characterization of human Jak2. The predicted amino acid sequence shows 91% homology to the described murine Jak2, but with a significant difference in the extreme C-terminal sequence. Using the human cDNA as a probe, we localized the gene for human Jak2 to chromosome 9p23-24. Human Jak2 mRNA is highly expressed in the spleen, lymph nodes, and peripheral blood lymphocytes (PBLs). A polyclonal antibody raised against the unique C-terminus of human Jak2 was used to characterize Jak2 protein. Levels of Jak2 protein expression increased significantly in mitogen- and anti-IgM-stimulated B cells and to a lesser degree in activated T cells. In addition, high levels of Jak2 protein were detected in pre-B leukemia cells.

Successful pregnancy outcome after hysteroscopic adhesiolysis in Asherman's syndrome

Asherman's syndrome is an uncommon finding at hysterosalpingography for infertility. Modern day management entails hysteroscopic confirmation and adhesiolysis. We present one such case of a young woman who had secondary infertility after dilatation and curettage, and who was diagnosed and treated with a successful outcome.