Primary plasma cell leukemia: a retrospective multicenter study of 73 patients.

BACKGROUND: Epidemiological and clinical information on primary plasma cell leukemia (pPCL) are rarely reported. The aims are to evaluate the clinical features, prognostic factors, and efficacy of treatments in pPCL. PATIENTS AND METHODS: A multicenter retrospective cohort study was carried out from January 2000 to December 2008 in 26 Italian hematology divisions. A total of 128 cases of plasma cell leukemia were collected, and 73 of them (57%) were classified as primary (male/female 43/30). RESULTS: Sixty-four patients had at least 1 sign of end-organ damage and 10 had extramedullary localization. One patient died early; of the remaining patients, 36 (50%) received anthracycline-based regimens as first-line therapy, 17 (24%) single alkylating agents, and 30 (42%) bortezomib or thalidomide as additional (n = 11) or unique treatments (n = 19). Twenty-three patients (31%) underwent autologous and/or allogeneic hematopoietic stem cell transplantation (HSCT). The median overall survival (OS) was 12.6 months; complete or partial response was achieved in 22 (30%) and 18 patients (25%), respectively; the median duration of response (DOR) was 16.4 months. HSCT patients had a longer OS and DOR (median 38.1 and 25.8 months, respectively) compared with nontransplanted patients (9.1 and 7.3 months, respectively, P < 0.001). OS was influenced by nonresponse to treatment, hypoalbuminemia, and HSCT. DOR was favorably influenced only by HSCT. CONCLUSIONS: pPCL is an aggressive disease with a poor prognosis and a low response rate to conventional therapy. HSCT is effective, increasing OS and DOR by 69% and 88%, respectively. The use of bortezomib and thalidomide may improve outcomes.

Construction of chromosomal integrants of Bacillus sphaericus 2362 by conjugation with Escherichia coli.

IncP-based plasmids conjugated between Escherichia coli and mosquitocidal strains of Bacillus sphaericus at frequencies of 10(-7) to 10(-9) per recipient. Plasmid transfer was most efficient when a restriction-deficient strain of B. sphaericus 2362 (serotype 5a5b) was used as recipient and was least efficient with recipients from serotypes 1a and 2a2b. A deleted version of the cryptic locus 'gene 80' from strain 2362 was cloned into the suicide vector pMTL30, which could not replicate in B. sphaericus to provide a site for chromosomal integration. Conjugational transfer from E. coli and integration into the B. sphaericus recipient chromosome was achieved with this construct. The coding region of the cry11A gene from Bacillus thuringiensis subsp. israelensis was PCR-amplified and fused to the promoter of the crystal protein (Bin) gene of B. sphaericus 2362. This construct was cloned into the integrative vector, conjugated with B. sphaericus 2362 and chromosomal integrants were recovered which harboured the cry11A gene. The fusion gene was efficiently transcribed in the recombinant host, but cells failed to accumulate appreciable amounts of Cry11A toxin. This system offers a simple and efficient means of transferring plasmids into B. sphaericus and obtaining chromosomal integration for strain construction and gene analysis.

Phylogenetic analysis of Bacillus sphaericus and development of an oligonucleotide probe specific for mosquito-pathogenic strains.

The 16S rRNA gene sequences for six strains of Bacillus sphaericus representing five distinct DNA homology groups and one strain of Bacillus fusiformis have been determined. An-oligonucleotide probe based on the area approximately between position 186 and 198 (Escherichia coli numbering) of the 16S rRNA gene of the mosquito pathogen, strain 2362, hybridised to DNA from strains of DNA homology group IIA which contains all known mosquito pathogens and not to any of ten other Bacillus species. It can be used to identify potential mosquito-pathogenic strains of B. sphaericus in screening programmes.

A DNA probe for the detection and identification of Bacillus sporothermodurans using the 16S-23S rDNA spacer region and phylogenetic analysis of some field isolates of Bacillus which form highly heat resistant spores.

The spacer regions between the 16S and 23S rRNA genes (spacer regions 1) of Bacillus sporothermodurans were PCR-amplified, cloned and sequenced. Six unique spacer sequences in four size classes were recovered from two strains, rrnA (about 190 bp), rrnB (about 303 bp), rrnC (355 bp) and rrnD (554 bp). rrnD contained two tRNA genes which were deciphered as tRNA(ala) and tRNA(ile) separated from each other by 13 nucleotides. The primary structures of the tRNA molecules clearly resembled those found in Bacillus subtilis; the tRNA(ala) genes were identical and the tRNA(ile) genes were 95% similar. The mixed rrnA and rrnB spacers when PCR-amplified from chromosomal DNA were effective as a hybridization probe for identification of B. sporothermodurans strains. However, high background signals with DNA from some other bacilli were encountered. A more discriminating probe was prepared from the cloned rrnB spacer region. Of eight aerobic, endospore-forming bacteria isolated from silage following heat enrichment, one was identified as B. sporothermodurans using the probe and its identity was confirmed from partial 16S rDNA analysis (phylotyping). This indicated that contamination in milk and dairies by B. sporothermodurans could originate from cattle feeds such as silage. Of the other seven silage strains, only two were identified conclusively by phylotyping and three represented probable new species. The latter three strains were subjected to phylogenetic analysis using almost complete 16S rDNA sequences. Branch lengths, bootstrap percentage values, and 16S rDNA similarity to other Bacillus species suggested that these isolates are likely to constitute new species within the genus Bacillus.

Growth and pathogenicity of isolates of the fungus Metarhizium anisopliae against the parasitic mite, Psoroptes ovis: effects of temperature and formulation.

Psoroptes mites (Acari: Psoroptidae) are important ectoparasites of mammals, and are of particular economic significance as the agents of mange in sheep. To be effective against mites, putative fungal biocontrol agents must be able to operate at the relatively high temperatures and humidities found at the sheep skin surface. To consider this, the growth rates of different isolates of the entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) Sorokin (Deuteromycotina: Hyphomycetes) were compared and the pathogenicity of these isolates against Psoroptes derived from rabbits (Psoroptes ovis Hering, syn P cuniculi) were evaluated at temperatures between 28 degrees C and 40 degrees C, and when formulated in either Tween 80 or silicone oil. For this study four multi-conidia, arthropod-derived, isolates of M anisopliae were used: from the USA, France, Denmark and Brazil. One single-conidia culture derived from the US isolate was also included in the investigation. Fungal growth was higher at the lower temperatures and none of the isolates grew at 40 degrees C. The growth of the US and single-conidia isolate declined markedly with temperature. In contrast, the Danish, French and Brazilian isolates grew almost as well at 32 degrees C and 35 degrees C as at 28 degrees C and 30 degrees C. The French and Brazilian isolates showed some growth at 37.5 degrees C but the Danish and US isolates did not. The number of fatal infections which resulted from exposure of mites to the fungal isolates was also strongly influenced by temperature. At 30 degrees C all isolates gave between 70 and 90% infection. The number of infections declined with increasing temperature and no infections were seen at 40 degrees C. However, the French and Danish isolates of M anisopliae gave higher numbers of infections than the other isolates at elevated temperatures. When formulated in silicone oil, significantly higher levels of infection were obtained than when formulated in Tween 80, even at the relatively high temperature of 37.5 degrees C. It is suggested that high-temperature adapted isolates of M anisopliae formulated in silicone oil offer good candidates as control agents under the conditions found at the sheep skin surface.

Evolution of bisphosphonate-related osteonecrosis of the jaw in patients with multiple myeloma and Waldenstrom's macroglobulinemia: a retrospective multicentric study.

Bisphosphonates (BPs) are used intravenously to treat cancer-related conditions for the prevention of pathological fractures. Osteonecrosis of the jaw (BRONJ) is a rare complication reported in 4-15% of patients. We studied, retrospectively, 55 patients with multiple myeloma or Waldenstrom's macroglobulinemia followed up from different haematological departments who developed BRONJ. All patients were treated with BPs for bone lesions and/or fractures. The most common trigger for BRONJ was dental alveolar surgery. After a median observation of 26 months, no death caused by BRONJ complication was reported. In all, 51 patients were treated with antibiotic therapy, and in 6 patients, this was performed in association with surgical debridement of necrotic bone, in 16 with hyperbaric O(2) therapy/ozonotherapy and curettage and in 12 with sequestrectomy and O(2)/hyperbaric therapy. Complete response was observed in 20 cases, partial response in 21, unchanged in 9 and worsening in 3. The association of surgical treatment with antibiotic therapy seems to be more effective in eradicating the necrotic bone than antibiotic treatment alone. O(2) hyperbaric/ozonotherapy is a very effective treatment. The cumulative dosage of BPs is important for the evolution of BRONJ. Because the most common trigger for BRONJ was dental extractions, all patients, before BP treatment, must achieve an optimal periodontal health.

Studies on the in situ physiology of Thiothrix spp. present in activated sludge.

The in situ physiology of the filamentous sulphur bacterium Thiothrix spp. was investigated in an industrial wastewater treatment plant with severe bulking problems as a result of overgrowth of Thiothrix. Identification and enumeration using fluorescence in situ hybridization (FISH) with species-specific 16S and 23S rRNA probes revealed that 5-10% of the bacteria in the activated sludge were Thiothrix spp. By using a combination of FISH and microautoradiography it was possible to study the in situ physiology of probe-defined Thiothrix filaments under different environmental conditions. The Thiothrix filaments were very versatile and showed incorporation of radiolabelled acetate and/or bicarbonate under heterotrophic, mixotrophic and chemolithoautotrophic conditions. The Thiothrix filaments were active under anaerobic conditions (with or without nitrate) in which intracellular sulphur globules were formed from thiosulphate and acetate was taken up. Thiothrix-specific substrate uptake rates and growth rates in activated sludge samples were determined under different conditions. Doubling times of 6-9 h under mixotrophic conditions and 15-30 h under autotrophic conditions were estimated. The key properties that Thiothrix might be employing to outcompete other microorganisms in activated sludge were probably related to the mixotrophic growth potential with strong stimulation of acetate uptake by thiosulphate, as well as stimulation of bicarbonate incorporation by acetate in the presence of thiosulphate.

Differentiation of mosquito-pathogenic strains of Bacillus sphaericus from non-toxic varieties by ribosomal RNA gene restriction patterns.

DNA from 17 strains of Bacillus sphaericus, including representatives of all the established DNA homology groups, was cleaved with EcoRI or HindIII and fragments were separated by agarose gel electrophoresis. Southern blots of this DNA were hybridized to a radioactively labelled DNA probe prepared from the cloned 16S rrnB ribosomal RNA operon of Escherichia coli. Banding patterns of the chromosomal DNA digests and the autoradiograms were specific to DNA homology groups I (B. sphaericus sensu stricto), IIA (mosquito-pathogenic strains), IIB (B. fusiformis) and V, but groups III and IV were not clearly distinguished. This suggests that the mosquito-pathogenic strains represent a separate subspecies.