Increased number of chromosomal imbalances and high-level DNA amplifications in mantle cell lymphoma are associated with blastoid variants

Mantle cell lymphomas (MCLs) are characterized by 11q13 chromosomal translocations and cyclin D1 overexpression. The secondary genetic and molecular events involved in the progression of these tumors are not well known. In this study, we have analyzed 45 MCLs (32 typical and 13 blastoid variants) by comparative genomic hybridization (CGH). To identify the possible genes included in the abnormal chromosome regions, selected cases were analyzed for P53, P16(INK4a), RB, C-MYC, N-MYC, BCL2, BCL6, CDK4, and BMI-1 gene alterations. The most frequent imbalances detected by CGH were gains of chromosomes 3q (49%), 7p (27%), 8q (22%), 12q (20%), 18q (18%), and 9q34 (16%) and losses of chromosomes 13 (44%), 6q (27%), 1p (24%), 11q14-q23 (22%), 10p14-p15 (18%), 17p (16%), and 9p (16%). High-level DNA amplifications were identified in 11 different regions of the genome, predominantly in 3q27-q29 (13%), 18q23 (9%), and Xq28 (7%). The CGH analysis allowed the identification of regional consensus areas in most of the frequently involved chromosomes. Chromosome gains (P =. 02) and losses (P =.01) and DNA amplifications (P =.015) were significantly higher in blastoid variants. The significant differences between blastoid and typical tumors were gains of 3q, 7p, and 12q, and losses of 17p. CGH losses of 17p correlated with P53 gene deletions and mutations. Similarly, gains of 12q and high-level DNA amplifications of 10p12-p13 were associated with CDK4 and BMI-1 gene amplifications, respectively. One of 2 cases with 8q24 amplification showed C-MYC amplification by Southern blot. Alterations in 2p, 3q, 13, and 18q were not associated with N-MYC, BCL6, RB, or BCL2 alterations, respectively, suggesting that other genes may be the targets of these genetic abnormalities in MCLs. Increased number of gains (0 v 1-4 v >4 gains per case) (P =.002), gains of 3q (P =.02), gains of 12q (P =.03), and losses of 9p (P =. 003) were significantly associated with a shorter survival of the patients. These results indicate that an increased number of chromosome imbalances are associated with blastoid variants of MCLs and may have prognostic significance.

Surface redistribution of interferon gamma-receptor and its colocalization with the actin cytoskeleton

BACKGROUND

Specific antibodies for human IFN gamma-R1 were used to examine its mobilization in Colo 205 cells.

METHODS

We report here that antibody-IFN gamma-R1 complex induced capping and actin colocalization. Pretreatment with cytochalasin D abolished this capping. To define the role of the IFN gamma-R1 in the possible interaction with actin, transfected murine fibroblasts cell line with human cDNA IFN gamma-R1 were used.

RESULTS

Only those cells expressing the full receptor and cultured in suspension polarized the receptor and this colocalized with actin filaments. Nevertheless, cells truncated in their intracellular domain displayed no capping and actin remained unaltered either in suspension or in monolayer culture conditions. A mutant bearing an IFN gamma-R1 with substitutions in positions 270-271 of the intracellular domain redistributed both IFN gamma-R1 and actin as micropatches instead of capping. Mutation in 256-303 residues resulted in IFN gamma-R1 microaggregates but actin remained unchanged.

CONCLUSIONS

These experimental models allowed us to highlight an apparent receptor-microfilament association through the intracellular domain of IFN gamma-R1, and to specifically locate it within the intracellular region 256-303 that has been identified as relevant for ligand-receptor internalization and biological function.

IL-4 improves the detection of cytogenetic abnormalities in multiple myeloma and increases the proportion of clonally abnormal metaphases

In the present study the incidence of abnormal karyotypes and the number and proportion of abnormal metaphases obtained in multiple myeloma (MM) using three culture conditions were compared: unstimulated culture (72 h), IL-6/GM-CSF-stimulated culture (120 h) and IL-4-stimulated culture (120 h). The three types of culture conditions were assessed simultaneously on bone marrow samples from 30 consecutive myeloma patients. In addition DNA content (DNA ploidy and cell cycle) was analysed by flow cytometry. The number of MM samples with clonal karyotypic abnormalities was higher after IL-4-stimulated cultures (53%) than it was after IL-6 + GM-CSF (37%) and unstimulated (30%) cultures. The benefit of IL-4 was also observed in cases with low numbers of plasma cells in the bone marrow, in early clinical stages and in untreated patients. In those cases in whom clonal chromosomal abnormalities were detected by the three culture methods. the cytogenetic findings were always identical. According to our results the addition of IL-4 to the cultures of bone marrow cells in MM increases the number of abnormal metaphases.

Effects of polyamine levels on the degradation of short-lived and long-lived proteins in cultured L-132 human lung cells

Biogenic polyamines have important regulatory functions in various biological processes and it has also been suggested that they could modulate intracellular protein degradation. For an overall assessment of the role of polyamines in this process, we have investigated the effect that the decrease in intracellular polyamine levels caused by inhibitors of polyamine biosynthesis brings about on the degradation of the pools of short- and long-lived proteins in cultured L-132 human lung cells. Treatment of cells with 100 microM (2R,5R)-delta-methyl acetylenic putrescine (MAP), a potent enzyme-activated irreversible inhibitor of ornithine decarboxylase, or with 100 microM MAP plus 50 microM N-butyl 1,3-diaminopropane, a specific inhibitor of spermine synthase, caused a similar decrease (65-70% of control) in the total intracellular levels of polyamines, although they affected the concentrations of spermidine and spermine differently. The effect of the two treatments on protein degradation was essentially the same. In polyamine-depleted cells we observed an inhibition of degradation in long-lived proteins of 16% (P<0.05), with a significant increase in the half-life (t12) of this pool from 100.5 to 120.1 h. This was concomitant with an increase of 26% (P<0. 05) in degradation in short-lived proteins, with a significant decrease in the t12 of this pool from 0.85 to 0.67 h. Recovery of polyamine levels by the addition of 50 microM spermidine to polyamine-depleted cells resulted in a restoration of the degradation rates in both pools of proteins. The way(s) by which polyamines could modulate proteolysis are discussed.

Identification of bacteria in water for pharmaceutical use

Different systems for the obtention of water used in Biopharmaceutical Industry were characterized from the bacteriological point of view. Determination of aerobic mesophilic microorganisms was performed; as well as the isolation of contaminant microorganisms for what the techniques of membrane filtration was used. For the identification of the more representative species there were made conventional biochemical tests and quick systems: API. The results show that water serving as tap water for purification systems fulfill with the microbiological requirements to this kind of water. All the isolated microorganisms were gram-negative bacteria characteristics of this environment: Pseudomonas putida, Xanthomonas maltophilia, Aeromonas salmonicida ssp. salmonicida, Flavimonas coryzihabitans and Acinetobacter iwoffi. The ultrafiltration and distillation tested systems fulfill with the established microbiological limits, except for deionization and distilled water storing systems. The isolation showed that approximately the 76.9% were of Gram-negative bacteria, the 14.6% of Gram-positive cocci and the 8.5% Gram-positive sporulated bacilli. The most representative genus of purified water were: Pseudomonas, with the higher percent of incidence, Staphylococcus, Bacillus, Flavobacterium, Sphingomonas, Aeromonas and Agrobacterium.

Prognostic value of numerical chromosome aberrations in multiple myeloma: A FISH analysis of 15 different chromosomes

Recent observations indicate that chromosome aberrations are important prognostic factors in patients with multiple myeloma (MM) treated with high-dose chemotherapy. Nevertheless, the inherent problems of conventional cytogenetics have hampered the systematic evaluation of this parameter in series of patients treated with conventional chemotherapy. Fluorescence in situ hybridization (FISH) analysis is an attractive alternative for evaluation of numerical chromosomal changes. In the present study, we analyze the relationship between aneuploidies of 15 different chromosomes assessed by FISH and prognosis in a series of 63 patients with MM treated with conventional chemotherapy. After a median follow-up of 61 months (range, 6 to 109), 49% of patients are still alive with a median survival of 33 months. The overall incidence of numerical chromosome abnormalities was 70%. This incidence significantly increased when seven or more chromosomes were analyzed (53 patients), reaching 81%. Trisomies of chromosomes 6, 9, and 17 were associated with prolonged survival (P = .033, P = .035, and P = .026, respectively); by contrast, overall survival (OS) was lower in cases with monosomy 13 (as assessed by deletion of Rb gene, P = .0012). From the clinical point of view, loss of Rb gene was associated with a poor performance status; low hemoglobin levels; high creatinine, C-reactive protein, and lactic dehydrogenase serum levels; high percentage of bone marrow plasma cells (BMPC); extensive bone lytic lesions; and advanced clinical stage. Other chromosome abnormalities such as trisomy of chromosome 9 and 17 were associated with good prognostic features including high hemoglobin levels, early clinical stage, beta2microglobulin less than 6 micro/mL, and low percentage of BMPC. A multivariate analysis for OS showed that S-phase PC greater than 3% (P = .010) and beta2microglobulin serum levels greater than 6 micro/mL (P = .024), together with monosomy of chromosome 13 (P = .031) and nontrisomy of chromosome 6 (P = .048) was the best combination of independent parameters for predicting survival in patients with MM. According to these results, chromosomal analysis is of great use in patients with MM at diagnosis to have a correct prognostic evaluation for clinical decision making.

Identification of two processed psuedogenes of the human Tom20 gene

The open reading frame (ORF) of the human Tom20 gene (hTom20) was amplified by PCR from a HeLa cDNA library using primers based on the sequence of HUMRSC145 and cloned into a pET15b vector. Amplification of human genomic DNA using these primers yielded a DNA fragment of the same size as that of the ORF of hTom20 cDNA. Sequencing of this fragment revealed that: (1) it has the same number of base pairs as the ORF of hTom20 cDNA (438 bp); and (2) the two sequences differ by 14 single base pair substitutions (97% similarity) causing eight changes in the amino acid sequence and two premature stop codons. Further amplification of human genomic DNA adaptor-ligated libraries using primers based on HUMRSC145 revealed three different sequence-related genomic regions; one corresponding to the fragment referred above, another corresponding to the hTom20 gene, and a third fragment of which the sequence differs from the ORF of hTom20 cDNA by only 22 base pair substitutions and a deletion of 4 bp. We conclude that, in addition to the hTom20 gene, there are two genomic DNA sequences (psi1Tom20 and psi2Tom20) that are processed pseudogenes of hTom20. Aspects concerning their evolutionary origin are discussed.

Sequential intravenous-oral ciprofloxacin plus amoxycillin/clavulanic acid shortens hospital stay in infected non severe neutropenic patients

The objective of this study was to determine the efficacy and safety of the combination ciprofloxacin plus amoxicillin/clavulanic acid as an empirical treatment of infection in hematologic patients without severe neutropenia. These drugs allowed us to carry out a sequential therapy, first intravenously and later orally, so that the patient could be discharged as soon as there was a response. Serum concentrations of ciprofloxacin were monitored in this study. Forty seven of the sixty-six patients included (71%) responded to the treatment with no differences between the dosages of ciprofloxacin employed (600-900 mg daily in two or three divided doses). In the patients who responded, the signs and symptoms of infection lasted only three days, which could allow a short hospital stay (median of six days). In the first pre and post-dose serum samples, ciprofloxacin concentrations were significantly higher when the drug was administered every 8 h. Nevertheless, 72 h after the beginning of treatment, they had leveled out in either 8 and 12 h schemes. The toxicity of the treatment was very light, with only four cases with adverse effects, grades I and II. This data suggests that the employed combination is effective and safe and can considerably decrease costs incurred through the admission of hematologic patients with serious infections but without severe neutropenia.

[Double-blind clinical trial comparing 5 days of dirithromycin versus 7 days of diacetylmidecamycin in acute bronchitis and acute exacerbations of chronic bronchitis]

BACKGROUND

Dirythromycin has several pharmacokinetic characteristics (long half life and high tissue concentrations) which suggest the possibility of administering shorter treatments than those conventionally used. The aim of this study was to determine and compare the efficacy of a 5 day treatment with dirythromycin once a day, versus diacetylmidecamycin twice a day over 7 days in the treatment of patients with acute bronchitis and acute exacerbations of chronic bronchitis.

METHODS

A parallel, multicentric, randomized, double blind clinical study was carried out in 8 Spanish hospitals.

RESULTS

One hundred seventy-four patients were included in the study, with 87 (80 evaluable) being randomly assigned to receive dirythromycin (500 mg/day over 5 days) and 87 (83 evaluable) diacetylmidecamycin (600 mg, twice daily over 7 days). A favorable symptomatic response (cure or improvement) was observed in 72/80 of the first group (90%) and in 74/83 (89.2%) of the second group. No statistically significant differences were found in the efficacy and safety between the two treatment groups in either the evaluable patients or on intention to treat analysis.

CONCLUSIONS

The results of this study suggest that the administration of dirythromycin, once a day over 5 days, is as safe and effective as diacetylmidecamycin, twice a day over 7 days, in the treatment of acute bronchitis and acute exacerbations of chronic bronchitis.

[Peracetic acid: alternative to the sterilization of bronchofibroscopes]

The Steris system for cold sterilization with peracetic acid was evaluated by effecting a series of contaminations of a fiberoptic bronchoscope (FB) with specimens of Pseudomonas aeruginosa, Acinetobacter baumanii and Mycobacterium kansasi. The FB was contaminated 24 times, 8 times by each microorganism, using specimens containing more than 10(8) cfu/ml. After fixing the secretions on the FB and washing it with enzyme soap, the BF was sterilized. Specimens were taken for culturing after contamination of the FB, after washing, immediately after sterilization and 1 hour after sterilization. No microorganism growth of any of the samples was detected either immediately after sterilization or one hour later. Microbiological data confirmed contamination of the FB after aspiration and fixation of the inoculate. Chemical and biological tests with B. stearothermophilus spores as specified by the manufacturer were correct in all cases: 24 contaminations and 52 processes of prior training. The efficacy of washing with enzyme soap before sterilization stands out. In 14 of the 24 samples, culture was negative after washing and in 7 the concentration of microorganisms was less than 500 cfu/ml, which confirms the need for appropriate washing before any disinfection or sterilization process is begun. In conclusion, the Steris system based on peracetic acid is an alternative to other systems for cold sterilization or high level disinfection.

Alternating mini-BEAM/ESHAP as salvage therapy for refractory non-Hodgkin's lymphomas

Mini-BEAM and ESHAP are two non-cross-resistant salvage regimens that have been used separately in patients with lymphoma. The aim of the present study was to investigate the efficacy of the combination of these two regimens, administered in alternating cycles, as salvage therapy for refractory non-Hodgkin's lymphoma (NHL) patients. A total of 28 patients were included in the study: 14 patients were primary refractory, seven were partial responders, and seven were in relapse. The alternating cycles of mini-BEAM and ESHAP were given until there was maximum response or progression. The overall response rate to mini-BEAM/ESHAP was 39%; 25% of patients achieved a complete response and 14% a partial response. Nevertheless, it should be noted that none of the primary refractory patients responded to this protocol. Nine of the 11 patients who responded to mini-BEAM/ESHAP were consolidated with autologous transplantation using BEAM as a conditioning regimen. The survival at 3 years in this group of 11 patients who responded to the salvage regimen is 64%, with a disease-free survival of 67% at 2 years. No major toxic effects were observed with mini-BEAM/ESHAP. Myelosuppression was the most frequent complication, especially with the mini-BEAM cycles. Other toxicities were infrequent and no treatment-related deaths were observed. These results suggest that alternating mini-BEAM/ESHAP chemotherapy is a safe regimen that is effective in partial responders or relapsing patients with NHL who have sensitive disease, but not in primary refractory patients. Moreover, although this therapy has a potential advantage, combining as it does two non-cross-resistant regimens, it does not seem superior to ESHAP alone.

Molecular delineation of the commonly deleted segment in mature B-cell lymphoid neoplasias with deletion of 7q

FISH, using 16 probes, informative for more than 30 different loci, allowed us better to delineate the common deleted region in mature B-cell lymphoid malignancies with deletions of chromosome 7. The region spans about 5 cM and is located between bands 7q31 and 7q32, between loci D7S685 and D7S514.

Trisomies 8 and 20 in desmoid tumors

A nonrandom occurrence of trisomy 8 and of trisomy 20 in desmoid tumors has been recently reported. The finding of trisomy 8 in nondividing desmoid tumor cells by in situ hybridization prompted us to evaluate, in a similar way, the occurrence of trisomy 20 and the possible occurrence of both trisomies together because their co-existence was cytogenetically observed in a few cases. Double fluorescence in situ hybridization (FISH) with centromeric probes for chromosomes 8 and 20 was performed on 16 single cell suspensions of desmoid tumors. FISH confirmed the occurrence of trisomy 8 or 20 in a single cell suspension of desmoid tumors. Both individual trisomies, and even more their association in the same cells, are rare to extremely rare in solid tumors in general and in mesenchymal tumors in particular, and are only known to occur in infantile fibrosarcoma.

Clinical efficacy of dirithromycin in patients with bacteremic pneumonia

Dirithromycin is a new macrolide antimicrobial drug with a long half-life (44 hours) that reaches high tissue concentrations, thus permitting once-daily oral dosing and shorter courses of therapy. Soon after absorption, dirithromycin enters the tissue so rapidly that serum concentrations are comparatively low. It could be hypothesized that these low serum levels could endanger the outcome in patients with bacteremic pneumonia. We reviewed the database on dirithromycin pneumonia (consisting of 1108 patients randomized to receive dirithromycin or erythromycin in two double-masked trials) to ascertain its efficacy in patients with community-acquired pneumonia and concomitant bacteremia. Fourteen (2.5%) of 555 dirithromycin-treated patients and 10 (1.8%) of 553 erythromycin-treated patients had bacteremia. A favorable clinical response posttherapy was observed in 92.3% and 88.9% of these patients with a response assigned, respectively. Overall, favorable response rates were comparable between the two groups in the bacteremic subsets: patients with pneumococcal bacteremia, patients with nonbacteremic pneumococcal pneumonia, and all patients enrolled with acute pneumonia who had a posttherapy clinical response. In the treatment of patients with mild or moderate community-acquired pneumonia, including those with unsuspected and incidental bacteremia, dirithromycin is an effective macrolide antimicrobial drug.

[Infections caused by enteropathogenic Escherichia coli]

Escherichia coli strains currently recognized to cause human diarrhea can be distinguished on the basis of pathogenic mechanism and separated into five categories: enterotoxigenic (ETEC), enteroinvasive (EIEC), enterohemorrhagic (EHEC), enteroaggregative (EAggEC) and enteropathogenic (EPEC). EPEC is a bacterial pathogen that causes diarrhea in infants, particularly in developing countries. The purpose of this review is to summarize recent advances in the understanding of EPEC pathogenesis and the contribution of Mexican investigators to the knowledge of this pathogen.

Cost-effectiveness analysis of serum vancomycin concentration monitoring in patients with hematologic malignancies

OBJECTIVE

This study evaluates the cost-effectiveness of vancomycin serum concentration monitoring in patients with hematologic malignancies.

METHODS

The study was designed as a prospective randomized study. Seventy immunocompromised febrile patients with hematologic malignancies were randomly assigned to either a vancomycin therapeutic drug monitoring group (TDM group; n = 37) or to a control group (n = 33). Intervention in the TDM group involved patient follow-up by a clinical pharmacist to obtain and pharmacokinetically interpret serum vancomycin concentrations for dosage individualization.

RESULTS

Evaluation of all patients included global clinical response and nephrotoxicity, as well as the economic costs and effectiveness derived from the vancomycin monitoring program. There were no significant differences between the TDM and control groups in the outcome measures, except for the incidence of nephrotoxicity: the rates of minor nephrotoxicity were 33.3% and 13.5% in the control and TDM groups, respectively. The corresponding figures for moderate nephrotoxicity were 9.1% and 0%. Logistic regression analysis confirmed that TDM independently reduced the incidence of nephrotoxicity in this patient population. On the basis of this reduced nephrotoxicity, a incremental cost of $435 per case of nephrotoxicity prevented was found for vancomycin serum concentration monitoring.

CONCLUSIONS

A decreased incidence of nephrotoxicity provides evidence of a real clinical benefit to patient management in patients with hematologic malignancies. The TDM for vancomycin therapy in this high-risk population has been shown to be a cost-effective procedure.