Peripheral blood stem cell transplantation for POEMS syndrome.

In common with other plasma cell dyscrasias in which a small tumour burden is associated with severe clinical symptoms (notably systemic AL amyloidosis) the possible benefits of dose intensification are yet to be fully explored in POEMS syndrome. One important issue is whether the toxicity of the procedure is significantly increased in this group. We report two cases of POEMS syndrome with solitary asymptomatic bone lesions treated with high-dose melphalan (200 mg/m(2)) and peripheral blood stem cell (PBSC) rescue. In both cases there was minimal peri-transplant morbidity and a subsequent substantial and maintained improvement in the peripheral neuropathy.

Topoisomerase III acts upstream of Rad53p in the S-phase DNA damage checkpoint.

Deletion of the Saccharomyces cerevisiae TOP3 gene, encoding Top3p, leads to a slow-growth phenotype characterized by an accumulation of cells with a late S/G2 content of DNA (S. Gangloff, J. P. McDonald, C. Bendixen, L. Arthur, and R. Rothstein, Mol. Cell. Biol. 14:8391-8398, 1994). We have investigated the function of TOP3 during cell cycle progression and the molecular basis for the cell cycle delay seen in top3Delta strains. We show that top3Delta mutants exhibit a RAD24-dependent delay in the G2 phase, suggesting a possible role for Top3p in the resolution of abnormal DNA structures or DNA damage arising during S phase. Consistent with this notion, top3Delta strains are sensitive to killing by a variety of DNA-damaging agents, including UV light and the alkylating agent methyl methanesulfonate, and are partially defective in the intra-S-phase checkpoint that slows the rate of S-phase progression following exposure to DNA-damaging agents. This S-phase checkpoint defect is associated with a defect in phosphorylation of Rad53p, indicating that, in the absence of Top3p, the efficiency of sensing the existence of DNA damage or signaling to the Rad53 kinase is impaired. Consistent with a role for Top3p specifically during S phase, top3Delta mutants are sensitive to the replication inhibitor hydroxyurea, expression of the TOP3 mRNA is activated in late G1 phase, and DNA damage checkpoints operating outside of S phase are unaffected by deletion of TOP3. All of these phenotypic consequences of loss of Top3p function are at least partially suppressed by deletion of SGS1, the yeast homologue of the human Bloom's and Werner's syndrome genes. These data implicate Top3p and, by inference, Sgs1p in an S-phase-specific role in the cellular response to DNA damage. A model proposing a role for these proteins in S phase is presented.

In vivo CAMPATH-1H prevents GvHD following nonmyeloablative stem-cell transplantation.

BACKGROUND: We have investigated a novel nonmyeloablative conditioning regimen in 44 patients with hematological malignancies. The median patient age was 41 years. Many of the patients had high-risk features, including 19 patients with a previous failed transplant. METHODS: Recipient conditioning consisted of CAMPATH-1H 20 mg/day on Days -8 to -4, fludarabine 30 mg/m(2) on Days -7 to -3 and melphalan 140 mg/m(2) on Day -2. Thirty-six recipients received unmanipulated G-CSF mobilized PBSC from HLA identical siblings and eight received unmanipulated BM from MUD. GvHD prophylaxis was with CYA alone for 38 patients and CYA plus MTX for six sibling recipients. RESULTS: Forty-two of the 43 evaluable patients had sustained engraftment. Results of chimerism analysis using microsatellite PCR indicate that 18 of 31 patients studied were full donor chimeras, while the other patients were mixed chimeras in one or more lineages. At a median follow-up of 9 months (range, 3-29 months) 33 patients remain alive in CR, or with no evidence of disease progression. Seven patients relapsed or progressed post-transplant and four of them subsequently died. Four patients died from regimen-related complications. There were no cases of Grades III-IV acute GvHD. Only two patients developed Grade II acute GvHD and only one had chronic GvHD. The estimated probability of non-relapse mortality at 1 year was 11%.Results: Although longer follow-up is needed to establish the long-term remission rates, this study demonstrates that this nonmyeloablative preparative regimen is associated with durable engraftment, minimal toxicity and low incidence of GvHD.

In vivo CAMPATH-1H prevents graft-versus-host disease following nonmyeloablative stem cell transplantation.

A novel nonmyeloablative conditioning regimen was investigated in 44 patients with hematologic malignancies. The median patient age was 41 years. Many of the patients had high-risk features, including 19 patients with a previous failed transplant. Recipient conditioning consisted of CAMPATH-1H, 20 mg/day on days -8 to -4; fludarabine, 30 mg/m(2) on days -7 to -3; and melphalan, 140 mg/m(2) on day -2. Thirty-six recipients received unmanipulated granculocyte colony-stimulating factor-mobilized peripheral blood stem cells from HLA-identical siblings, and 8 received unmanipulated marrow from matched unrelated donors. GVHD prophylaxis was with cyclosporine A alone for 38 patients and cyclosporine A plus methotrexate for 6 sibling recipients. Forty-two of the 43 evaluable patients had sustained engraftment. Results of chimerism analysis using microsatellite polymerase chain reaction indicate that 18 of 31 patients studied were full-donor chimeras while the other patients were mixed chimeras in one or more lineages. At a median follow-up of 9 months (range 3 to 29 months), 33 patients remain alive in complete remission or with no evidence of disease progression. Seven patients relapsed or progressed post-transplantation, and 4 of them subsequently died. Four patients died of regimen-related complications. There were no cases of grades III-IV acute GVHD. Only 2 patients developed grade II acute GVHD, and only 1 had chronic GVHD. The estimated probability of nonrelapse mortality was 11%. Although longer follow-up is needed to establish the long-term remission rates, this study demonstrates that this nonmyeloablative preparative regimen is associated with durable engraftment, minimal toxicity, and low incidence of GVHD.

Defending genome integrity during DNA replication: a proposed role for RecQ family helicases.

The RecQ family of DNA helicases have been shown to be important for the maintenance of genomic integrity in all organisms analysed to date. In human cells, representatives of this family include the proteins defective in the cancer predisposition disorder Bloom's syndrome and the premature ageing condition, Werner's syndrome. Several pieces of evidence suggest that RecQ family helicases form associations with one or more of the cellular topoisomerases, and together these heteromeric complexes manipulate DNA structure to effect efficient DNA replication, genetic recombination, or both. Here, we propose that RecQ helicases are required for ensuring that structural abnormalities arising during replication, such as at sites where replication forks encounter DNA lesions, are corrected with high fidelity. In mutants defective in these proteins, not only is replication abnormal, but cells display aberrant responses to DNA-damaging agents or inhibitors of DNA synthesis. We suggest that RecQ helicases may be important for the integration of cellular responses to these insults, such as by linking cell cycle checkpoint responses to recombinational repair.

The Bloom's syndrome gene product is a 3'-5' DNA helicase.

Bloom's syndrome (BS) is an autosomal recessive condition characterized by short stature, immunodeficiency, and a greatly elevated frequency of many types of cancer. The gene mutated in BS, BLM, encodes a protein containing seven "signature" motifs conserved in a wide range of DNA and RNA helicases. BLM is most closely related to the subfamily of DEXH box-containing DNA helicases of which the prototypical member is Escherichia coli RecQ. To analyze its biochemical properties, we have overexpressed an oligohistidine-tagged version of the BLM gene product in Saccharomyces cerevisiae and purified the protein to apparent homogeneity using nickel chelate affinity chromatography. The recombinant BLM protein possesses an ATPase activity that is strongly stimulated by either single- or double-stranded DNA. Moreover, BLM exhibits ATP- and Mg2+-dependent DNA helicase activity that displays 3'-5' directionality. Because many of the mutations in BS individuals are predicted to truncate the BLM protein and thus eliminate the "helicase" motifs or map to conserved positions within these motifs, our data strongly suggest that these mutations will disable the 3'-5' helicase function of the BLM protein.

The successful treatment of idiopathic thrombocytopenic purpura with the low dose non specific IgG component of anti D immunoglobulin.

Five patients with ITP were treated with 2 gram intravenous infusions of intramuscular human non specific immunoglobulin (IMIg). Increased platelet counts similar to those achieved with intravenous Rhesus anti D immunoglobulin were observed in four patients. 5000 iu anti D immunoglobulin contain up to 2 g of IMIg, and the clinical responses seen in ITP patients treated with anti D may therefore be attributed to this non specific fraction. This was supported by the in vitro finding that adsorption of the rhesus specific IgG from anti D immunoglobulin did not reduce its inhibitory effect on monocyte Fc receptor function. The dose of intravenous IMIg which produced a response in ITP was less than 2% of the recommended standard dose of intravenous immunoglobulin. This correlated with the higher concentration of IgG polymers in IMIg, and we suggest therefore that the mechanism of action of this material is due to the inhibitory effect of its polymeric IgG fraction on low affinity monocyte/phagocyte Fc receptors.

The effect of anti-Rho(D) and non-specific immunoglobulins on monocyte Fc receptor function: the role of high molecular weight IgG polymers and IgG subclasses.

Anti-Rho(D) immunoglobulin (anti-D) contained more high molecular weight (HMW) IgG polymers than intravenous non-specific immunoglobulin (i.v. Ig). The low-dose anti-D and high-dose i.v. Ig regimens used to treat idiopathic thrombocytopenic purpura (ITP) therefore contained similar total amounts of HMW IgG. In vitro, the HMW IgG polymers were more effective competitive inhibitors of monocyte phagocyte Fc receptors than monomeric IgG. The IgG subclass composition of anti-D and i.v. Ig were both similar to normal human plasma. We conclude that the HMW IgG content but not the IgG subclass composition of anti-D may explain its low-dose therapeutic efficacy in ITP.

Larvivorous fishes in controlling mosquito breeding from draw wells.

Culex quinquefasciatus have been found to breed in about 29 per cent of the wells in semi-urban area and 14 per cent of the wells in rural areas of Varanasi at one time or other. Majority of such wells are used-ones. Effectiveness of Poecillia reticulata, Esomus danrica and Trichogaster fasciatus in controlling well breeding is evaluated in the present study with successful results.

Long-term response in a patient with ITP following low dose anti-D immunoglobulin therapy.

A patient with chronic ITP relapsed after conventional therapy but following an infusion with low dose anti D (Rho) immunoglobulin, she entered a remission which has now lasted 10 months. This is difficult to explain on the basis of long term macrophage Fc receptor blockade and suggests an alternative mechanism of action.