Reorganization of retinotopic cortical maps in adult mammals after lesions of the retina.

The organization of the visual cortex has been considered to be highly stable in adult mammals. However, 5 degrees to 10 degrees lesions of the retina in the contralateral eye markedly altered the systematic representations of the retina in primary and secondary visual cortex when matched inputs from the ipsilateral eye were also removed. Cortical neurons that normally have receptive fields in the lesioned region of the retina acquired new receptive fields in portions of the retina surrounding the lesions. The capacity for such changes may be important for normal adjustments of sensory systems to environmental contingencies and for recoveries from brain damage.

Advances in antifungal prophylaxis and empiric therapy in patients with hematologic malignancies.

Invasive fungal infection (IFI) is associated with significant morbidity and mortality in patients with hematologic malignancies. There have been significant changes in the epidemiology and outcomes of IFI in this patient population, due in part to advances in transplant procedures, supportive care, and use of newer antifungal agents. A thorough knowledge of risk factors, potential causative organisms, and the safety and efficacy of appropriate antifungal agents is required to optimize treatment. Proper diagnosis of IFI is challenging and the correlation of delays in diagnosis and treatment with poor outcome suggest that earlier intervention may result in more effective management of high-risk patients. Because all risks may not be equal, stratifying high-risk patients may further help target patients most likely to benefit from prophylaxis. This review focuses on various risk factors specific to patients with hematologic malignancies and discusses the use of preemptive, empiric, and prophylactic strategies in the management of IFI in this patient population.

Posaconazole as salvage treatment of invasive fungal infections in patients with underlying renal impairment.

OBJECTIVES: The aim of this study is to determine the efficacy and safety of posaconazole in patients with underlying renal impairment. Patients and methods We analysed the efficacy and safety of posaconazole in patients with renal impairment in a post hoc subanalysis of a Phase 3, multicentre, open-label trial in patients with invasive fungal infections (IFIs). In the Phase 3 study, 330 patients intolerant of or with IFIs refractory to standard antifungal therapy received posaconazole 800 mg daily in divided doses. In our subanalysis, 238 patients with proven/probable IFIs, including 65 patients with renal impairment (creatinine clearance < 50 mL/min or serum creatinine (sCR) level >2 mg/dL at baseline) and 173 patients with greater renal function [creatinine clearance >/= 50 mL/min (acceptable renal function)], formed the modified intent-to-treat population. Success was defined as complete or partial response, and non-success was defined as stable disease or treatment failure. RESULTS: Overall response rates were similar in the renal impairment group (49%) and in the acceptable renal function (50%) group. Seventeen of the 41 patients with renal impairment and aspergillosis responded. Adverse events occurred in 32/65 (49%) patients with renal impairment and in 72/173 (42%) patients with acceptable renal function. The most common adverse events in both groups were nausea (14% patients with renal impairment versus 8% with acceptable renal function), altered/elevated levels of other medications (8% versus 2%), increased sCR levels (6% versus 0%), vomiting (6% versus 4%), abdominal pain (5% versus 5%) and dizziness (5% versus 1%). CONCLUSIONS: These results suggest that posaconazole is effective and well tolerated in patients with refractory IFIs regardless of renal impairment.

Retinoic acid and homeobox gene regulation.

Hox genes have been shown to be important regulators of pattern formation in vertebrates. Retinoic acid has been shown to affect the expression of Hox genes in vitro and in vivo, and some of its effects on development correspond to changes in Hox gene expression. The idea that retinoic acid is not simply a powerful pharmocological agent, but rather that it plays an important role in creating the normal expression patterns of Hox genes, is provided by the recent identification of retinoic acid responsive enhancers near Hox genes.

Low incidence of severe cGvHD and late NRM in a phase II trial of thymoglobulin, tacrolimus and sirolimus for GvHD prevention.

Chronic GvHD (cGvHD) is the leading cause of late non-relapse mortality (NRM) and morbidity after allogeneic hematopoietic stem cell transplant (AHSCT). We analyzed the late effects of a phase II trial testing the efficacy of intermediate dose rabbit anti-thymocyte globulin (Thymoglobulin Thymo) in combination with tacrolimus and sirolimus (TTS) in 47 patients (pts) for the prevention of acute and chronic GvHD after unrelated AHSCT. The median follow-up was 45.2 months. The cumulative incidence of NIH severe cGvHD at 48 months was 6.4% with no new occurrences past 6 months for the entire follow-up period. The overall cumulative incidence of cGvHD was 44.7%. Out of 20 pts who are alive and disease-free at the last follow-up, only 4 pts continue to need systemic immune suppression. We observed low late NRM with only 3 transplant-related deaths after 6 months post transplant. At 4 years of follow-up, the overall cumulative incidence of NRM and disease relapse was 27.7% and 30.0%, respectively. PFS and overall survival (OS) at 4 years were 42 and 47%. At long term follow-up, TTS was associated with low incidence of severe cGvHD and late NRM.

Risk factors and impact of non-Aspergillus mold infections following allogeneic HCT: a CIBMTR infection and immune reconstitution analysis.

Risk factors for non-Aspergillus mold infection (NAMI) and the impact on transplant outcome are poorly assessed in the current era of antifungal agents. Outcomes of 124 patients receiving allogeneic hematopoietic cell transplantation (HCT) diagnosed with either mucormycosis (n=72) or fusariosis (n=52) between days 0 and 365 after HCT are described and compared with a control cohort (n=11 856). Patients with NAMI had more advanced disease (mucormycois: 25%, fusariosis: 23% and controls: 18%; P=0.004) and were more likely to have a Karnofsky performance status (KPS) <90% at HCT (mucormycosis: 42%, fusariosis: 38% and controls: 28%; P=0.048). The 1-year survival after HCT was 22% (15-29%) for cases and was significantly inferior compared with controls (65% (64-65%); P<0.001). Survival from infection was similarly dismal regardless of mucormycosis: 15% (8-25%) and fusariosis: 21% (11-33%). In multivariable analysis, NAMI was associated with a sixfold higher risk of death (P<0.0001) regardless of the site or timing of infection. Risk factors for mucormycosis include preceding acute GvHD, prior Aspergillus infection and older age. For fusariosis, increased risks including receipt of cord blood, prior CMV infection and transplant before May 2002. In conclusion, NAMI occurs infrequently, is associated with high mortality and appears with similar frequency in the current antifungal era.

Identification of a retinoic acid responsive enhancer 3' of the murine homeobox gene Hox-1.6.

The putative vertebrate morphogen retinoic acid (RA) has been shown to induce expression of many mammalian homeobox genes in cell lines, suggesting expression of this gene family in developing vertebrate embryos may be controlled in part by RA. Using the teratocarcinoma cell line F9 as a model system, we have studied the RA-response of the murine homeobox gene Hox-1.6. RA treatment of F9 cells causes the appearance of a DNAse I hypersensitive site 3' of Hox-1.6, approximately 5 kb downstream of the Hox-1.6 promoter, and this site has been shown to reflect the presence of an RA-responsive enhancer 3' of the gene. The RA-responsiveness of the enhancer is controlled by a retinoic acid responsive element (RARE) identical to the RARE of the retinoic acid receptor (RAR) beta gene; however, other sequences also influence the activity of the enhancer, suggesting the presence of binding sites for novel proteins which regulate Hox-1.6 expression. Experiments with Hox-1.6 minigenes in which lacZ expression is controlled by the Hox-1.6 promoter and enhancer demonstrate that it is the 3' enhancer which confers RA responsiveness on the endogenous promoter, as constructs which lack the enhancer, or the RARE alone, do not respond to RA. Our results support the idea that RA is an endogenous vertebrate morphogen; identification of the RA-responsive enhancer downstream of Hox-1.6 demonstrates that RA directly controls the transcription of at least one member of a gene family that determines tissue identity in the vertebrate embryo.

Biochemical identification of alpha-fodrin and protein 4.1 in human keratinocytes.

The mature erythrocyte has a cytoskeleton of less complexity than that of nucleated cells and has been elucidated in greater detail. Two of its major components are the heterodimeric protein spectrin and protein 4.1. We report here our isolation from human keratinocytes of immunoreactive forms of both protein 4.1 and of alpha-fodrin, the extra-erythrocytic form of alpha-spectrin. These keratinocyte proteins are approximately 125 kD and 240 kD in size, respectively. We also have isolated clones containing alpha-fodrin and protein 4.1 sequences from a human keratinocyte cDNA library. These sequences confirm the active transcription in keratinocytes of the alpha-fodrin and protein 4.1 genes. Both alpha-fodrin and protein 4.1 mRNA are detectable by Northern blot analysis in human keratinocytes, where their abundance appears not to be regulated by calcium concentration in the medium.

Evaluation of the APOH gene as a positional candidate for prcd in dogs.

PURPOSE: Progressive rod-cone degeneration (prcd) is an autosomal recessive retinal degeneration of dogs characterized by abnormalities in lipid metabolism. It has recently been mapped to the centromeric region of canine chromosome 9, homologous to human 17q, which contains the apolipoprotein H (apoH, protein; APOH, gene) gene involved in lipid metabolism and regulation of triglycerides. The present study was undertaken to evaluate APOH as a positional candidate for prcd. METHODS: Expression of APOH in the retina was examined by reverse transcription-polymerase chain reaction (RT-PCR) and by immunocytochemistry in normal and prcd-affected dogs. The level of apoH in the plasma was determined by western blot analysis. Intragenic polymorphic markers were identified and typed in the prcd pedigree. Canine-rodent hybrid cell lines were analyzed to detect canine APOH. RESULTS: ApoH has been localized to the photoreceptor outer segment layer by immunocytochemistry. Its expression in the retina of normal and prcd-affected dogs was confirmed by RT-PCR. The levels of antihuman apoH cross-reacting material in plasma were similar in all dogs, regardless of disease status. Finally, linkage analysis of the APOH gene with the disease locus in the prcd pedigree detected 3 recombinants among 70 informative offsprings (lod score 15.09 at 0 = 4.3 centimorgan [cM]). CONCLUSIONS: APOH is expressed in the retina and tightly linked to the prcd locus. However, despite its potential role in phenotypes of abnormal lipid metabolism associated with prcd, the gene has been excluded as a primary candidate for prcd by linkage analysis.

Acquired amegakaryocytic thrombocytopenia treated with allogeneic BMT: a case report and review of the literature.

Despite recent advances in understanding the biology of thrombopoiesis, autoimmune thrombocytopenia caused by inhibition of megakaryocytic precursors, remains a treatment dilemma. We report a case of a 43-year-old female who developed amegakaryocytic thrombocyto- penia refractory to intravenous immunoglobulin (IVIG), prednisone, cytoxan and vincristine. She was subsequently treated with myeloablative chemotherapy (busulfan and cyclophosphamide) followed by allogeneic bone marrow transplant from a 6/6 HLA-matched sibling. The patient is currently more than 1 year after transplant with complete donor chimerism and restoration of normal thrombopoiesis. A review of the literature shows that the clinical syndrome known as amegakaryocytic thrombocytopenia represents a heterogeneous group of disorders, and clinical experience with immunosuppression varies. Appropriate initial treatment for these patients requires immunosuppressive agents, including antithymocyte globulin (ATG) for steroid refractory disease. However, in the case of symptomatic patients who have an appropriate sibling donor, early hematopoietic progenitor cell transplant, even before administration of ATG, may be necessary. Further studies are needed to better define the pathogenesis and mechanism of this heterogeneous disorder before more definitive treatment algorithms can be established.

Rapid hematopoietic engraftment following fractionated TBI conditioning and transplantation with CD34(+) enriched hematopoietic progenitor cells from partially mismatched related donors.

Nineteen adult patients with poor-risk hematologic malignancy received T cell-depleted (TCD) hematopoietic progenitor cell (HPC) transplant from partially mismatched related donors (PMRD). The preparative regimen (FITFA) included fractionated TBI, thiotepa, fludarabine, and horse (n = 3) or rabbit (n = 16) anti-thymocyte anti-sera (ATG). GVHD prophylaxis consisted of TCD by positive/negative selection using the Isolex 300i system and pre-transplant ATG with no post-transplant immunosuppression. The mean number (+/-s.d.) of transplanted CD34(+) and CD3(+) cells were 8.9 x 10(6)/kg +/-4.3 (range 2.6-19.3) and 1.4 x 10(4)/kg +/-1.2 (range 0.3-4.6) respectively. Seventeen patients evaluable for neutrophil engraftment achieved an ANC >0.5 x 10(9)/l at a median of 12 days (range 9-27), with evidence of full donor chimerism. Thirteen patients died of the following causes: relapse (n = 6), infections (n = 5), interstitial pneumonia (n = 1), and unknown causes (n = 1) None of the recipients of rabbit ATG required therapy for acute or chronic GVHD. Five patients are alive and disease-free at a median time of 303 days post transplant (range 100-660). The FITFA preparative regimen using fractionated TBI is well tolerated and is sufficiently immunosuppressive to allow rapid and stable donor origin hematopoietic engraftment without 'mega' doses of CD34(+) cells. Combination of stringent ex vivo TCD and pre-transplant ATG is effective GVHD prophylaxis.

Spatial resolution of the Galago.

The spatial vision of two adult galagos (Galago crassicaudatus) was assessed using a two choice discrimination task to determine their contrast sensitivity. Both contrast sensitivity functions exhibited low and high spatial frequency attenuation with the peak sensitivity at 1%. For one animal, the peak occurred at 0.5 c/deg and the extrapolated cutoff frequency was 2.6 c/deg; for the other, the peak was 1 c/deg and the cutoff was 4.3 c/deg. For this animal, grating acuity was also tested and, depending upon definition of threshold, yielded threshold estimates from 4.8 to 6.0 c/deg. The data supports the conclusion that the spatial vision of the galago and the cat is quite similar, a congruence that presumably reflects their adaptation to a nocturnal niche, rather than their divergent phylogenetic origins.

Rapid reorganization of cortical maps in adult cats following restricted deafferentation in retina.

The retinotopic map in the visual cortex of adult mammals can reorganize in response to a small injury in a restricted region of retina. Although the mechanisms underlying this neural plasticity in adults are not well understood, it is possible that rapid, adaptive alterations in the effectiveness of existing connections play a key role in the reorganization of cortical topography following peripheral deafferentation. In order to test this hypothesis, a small retinal lesion was made in one eye of adult cats and the visual cortex was mapped before and immediately after enucleating the non-lesioned eye. We found that substantial reorganization takes place within hours of enucleation.

Consolidation and maintenance therapy with lenalidomide, bortezomib and dexamethasone (RVD) in high-risk myeloma patients.

Prior studies have shown that myeloma patients exhibiting either genetically defined high-risk disease or plasma cell leukemia have a poor outcome with a median overall survival (OS) of ≤3 years. Results of IFM 2005-01 and 02 suggest that relatively limited bortezomib-containing induction regimens did not produce a major survival benefit among these patients. However, results of recent studies suggest that combination therapy may benefit these patients when given early and again later in the treatment. We evaluated a combination maintenance/consolidation regimen (RVD) following autologous stem cell transplant (ASCT) for high-risk patients to evaluate the impact of this approach on outcome. Following initiation of RVD maintenance, 51% of patients achieved stringent complete response (sCR), with 96% achieving at least VGPR as best response. Median progression free survival (PFS) for all patients is 32 months with a 3-year OS of 93%. The regimen was well tolerated with no grade 3/4 neuropathy. Early ASCT followed by RVD maintenance is a promising strategy for high-risk myeloma patients and delivered excellent response rates, and promising PFS and OS.

Favorable impact of pre-transplant ATG on outcomes of reduced-intensity hematopoietic cell transplants from partially mismatched unrelated donors.

Reduced-intensity conditioning (RIC) permits allogeneic hematopoietic progenitor cell transplantation in patients who would not be considered candidates for transplantation using a myeloablative preparative regimen because of age, comorbidities or prior therapy. In the setting of myeloablative transplantation, use of antithymocyte globulin (ATG) can reduce the risk of GVHD without negatively affecting transplant outcomes; however, limited data exist on the impact of ATG in the setting of RIC, particularly when there is HLA-mismatch. We performed a retrospective analysis of 85 patients who received unrelated donor transplants at our institution for hematologic malignancies following conditioning with fludarabine and melphalan (FluMel), with or without rabbit ATG (6 mg/kg). ATG was targeted to patients receiving HLA-mismatched grafts. With a median follow-up of 36 months, those receiving ATG and a mismatched graft had similar rates of acute and chronic GVHD, relapse, and similar OS compared with those receiving HLA-matched grafts without ATG. In a multivariate analysis, HLA-mismatched donor was not associated with a decrement in OS. We conclude that this intermediate dose of ATG is effective in preventing severe GVHD in the setting of HLA-mismatch, without undue compromise of the graft versus tumor effects on which RIC transplants depend.