Toxicity and efficacy of busulfan and fludarabine myeloablative conditioning for HLA-identical sibling allogeneic hematopoietic cell transplantation in AML and MDS

The safety and efficacy of a 4-day myeloablative conditioning (MAC) regimen consisting of Bu 3.2 mg/kg and fludarabine 40 mg/m(2)/day for HLA-identical sibling allogeneic hematopoietic cell transplantation (HCT) in myeloid malignancies was investigated in 133 patients (median age, 47 years; range 19-74 years) with de novo AML (60%), secondary AML (20%) or myelodysplastic syndrome (20%). All patients engrafted. Hepatic veno-occlusive disease occurred in five patients (4%), and severe toxicities, mostly mucositis, occurred in twenty-three (17%) patients. The non-relapse mortality (NRM) at 100 days was 1.5%. The incidences of acute GVHD grade 2-4 and grade 3-4 were 32 and 13%, respectively. At a median follow-up of 38 months, the cumulative incidence of chronic GVHD was 67%. The relapse incidence was 30% (27 and 31%, respectively, in patients with early- and late-stage disease), and the overall NRM was 15%. The actuarial 4-year disease-free survival (DFS) and overall survival (OS) were 54 and 62%, respectively. Patients aged <50 years had better outcomes compared with older patients (DFS 64 vs 42%, P=0.006; OS 73 vs 47%, P<0.001, respectively).

Experience with anidulafungin in patients with allogeneic hematopoietic stem cell transplantation and graft-versus-host disease

BACKGROUND

It is well known that both acute and chronic graft-versus-host disease (GVHD) are associated with invasive fungal disease (IFD). Because the galactomannan antigen diagnostic test has low specificity and sensitivity outside of the neutropenic period, many institutions use posaconazole or voriconazole for IFD prophylaxis during GVHD treatment. Moreover, several factors, mainly hepatic impairment, can limit the use of extended spectrum azoles, both in prophylaxis or treatment.

METHODS

We retrospectively analyzed 25 patients with allogeneic hematopoietic stem cell transplantation (HSCT) and GVHD - grade III-IV acute GHVD (n = 15), progressive chronic GVHD (n = 7), and "overlap" GVHD (n = 3) - who received intravenous anidulafungin (200 mg on day 1, followed by 100 mg once daily). If necessary, anidulafungin treatment was followed by oral administration of 200 mg voriconazole twice a day or 200 mg posaconazole 3 times daily until patients were considered not at risk for IFD.

RESULTS

Twenty-one patients (85%) received anidulafungin as prophylaxis and 5 patients (15%) received it as treatment. Median duration of intravenous anidulafungin administration was 8 days (range 6-17). Seven patients (28%) presented mild adverse effects, with no significant interactions with calcineurin inhibitors. Sequentially, 4 patients received voriconazole and 6 posaconazole. Two patients (8%) developed IFD after anidulafungin withdrawal: 1 with Candida albicans and the other with Mucor, 8 and 5 days after withdrawal, respectively.

CONCLUSIONS

Our results are of interest owing to the absence of data in the literature on anidulafungin use in HSCT patients with GVHD, and suggest that anidulafungin, because of its spectrum, pharmacological profile, low toxicity, and absence of interactions with immunosuppressants, could be a drug of choice in this setting.

Strategies for developing multi-epitope, subunit-based, chemically synthesized anti-malarial vaccines

An anti-malarial vaccine against the extremely lethal Plasmodium falciparum is desperately needed. Peptides from this parasite's proteins involved in invasion and having high red blood cell-binding ability were identified; these conserved peptides were not immun genic or protection-inducing when used for immunizing Aotus monkeys. Modifying some critical binding residues in these high-activi binding peptides' (HABPs') attachment to red blood cells (RBC) allowed them to induce immunogenicity and protection against expermental challenge and acquire the ability to bind to specific HLA-DRp1* alleles. These modified HABPs adopted certain characterist structural configurations as determined by circular dichroism (CD) and ¹H nuclear magnetic resonance (NMR) associated with certain HLA-DRβ1* haplotype binding activities and characteristics, such as a 2-Å-distance difference between amino acids fitting into HLA-DRp1 Pockets 1 to 9, residues participating in binding to HLA-DR pockets and residues making contact with the TCR, suggesting haplotyp and allele-conscious TCR. This has been demonstrated in HLA-DR-like genotyped monkeys and provides the basis for designing high effective, subunit-based, multi-antigen, multi-stage, synthetic vaccines, for immediate human use, malaria being one of them.

Based on HLA-DR beta1* allele binding specificities, striking differences in distance and TCR Contacting Residue Orientation can be observed in modified protection-inducing malarial synthetic peptides

An anti-malarial vaccine is urgently needed, especially against P. falciparum which causes 2 to 3 million deaths each year, mostly in Sub-Saharan African children. This vaccine should contain molecules from the parasite's different developmental stages due to the parasite's remarkable complexity and genetic variability. The first approach using synthetic peptides from different parasite stage molecules (the SPf66 malaria vaccine) conferred limited protective efficacy in Aotus monkeys and in large field-trials carried out in different parts of the world SPf66 contains red blood cell (RBC) binding merozoite peptides for which immune responses against them are genetically controlled by HLA-DR region. Therefore, a systematic search of conserved high activity binding peptides (HABP) was undertaken aimed at using them as immunogens. However, these peptides were poorly immunogenic and had poor protection-inducing capacity against experimental challenge with a P. falciparum strain highly infective for Aotus monkeys an experimental model with an immune system quite similar to humans. Modifications were thus made to key residues to render them immunogenic and protection-inducing. These native and modified HABPs' three-dimensional structure was determined by (1)H-NMR studies and their ability in forming stable Major Histocompatibility Class II - peptide (MHCII-peptide) complexes was correlated with their ability to bind in vitro to purified HLA-DR beta1* molecules. Our experimental data suggests a correlation between modified HABPs' three-dimensional structure, HLA-DR beta1* binding preferences and their protection-inducing capacity in monkeys. Furthermore, the data presented here indicates that a synthetic peptide vaccine's three-dimensional structural features dictate both HLA-DR beta1* allele binding preference (imposing genetic restriction on the immune response) and on these vaccines' protection-inducing value. Basic knowledge of a parasite's functionally active peptides, their 3D structure and their interaction for forming the MHC II- peptide-TCR complex will thus contribute towards designing fully effective multi-component, multi-stage subunit-based malarial vaccines.

[Pregnancy rate in cryopreserved embryos based on the classical morphologic scoring and the integrity of blastomeres at thawing]

Two different thaw embryo classifications were evaluated, the morphologic classic evaluation (Veeck, 1990) and all blastomeres intact at the time of embryo transfer. We also discuss the clinic parameters and the physiopathological causes implicated in the successful of this treatment. 176 ovarian stimulation cycles and 513 cryopreserved embryos were reviewed. We found better pregnancy rate and delivery rate in embryo transfers were at least one embryo had all blastomeres intact compare with the transfers with good quality embryos (1+, 2+) of the morphologic classic evaluation without statistic significance (p > 0.05). Pregnancy and delivery rate were higher in cases with embryo in pronuclear stage compare with cleavage stage (p < 0.05). The blastomeric harm disturbs the embryo implantation phase and the future is oriented to the microsurgical remove of the damaged blastomeres and the use of assisted hatching.

Treatment of acute leukemia in children: recent advances and future challenges

Recently advances have been made in the treatment of acute leukemia in children, it is now possible to cure more than 70% of children with acute lymphoblastic leukemia. With the introduction of more intensive chemotherapy regimens in patients at higher risk of relapse and the identification of cases that could be less intensely treated to diminish long-term toxicity, it could be possible to improve these excellent results. In contrast, pediatric acute myeloid leukaemia seems to be a more heterogeneous disease and its response to conventional chemotherapy is not as uniform. Introduction of new and more efficacious therapies is necessary to improve the poor outcome, especially among patients with high-risk features.

Neuroendocrine cervical carcinoma: a diagnostic and therapeutic challenge

OBJECTIVE

The aim of this study was to analyze diagnostic criteria, response to chemotherapy, rate and site of relapse, and overall survival (OS) in neuroendocrine cervical carcinoma.

METHODS

Twenty patients were included. Stage was Ia(2) in 1 case, Ib(1) in 4, Ib(2) in 4, II in 5, IIIb in 2, IVa in 2, and IVb in 2. Patients with stage Ib(2) or greater received neoadjuvant chemotherapy (NCH). Eighteen patients were operated on. Immunohistochemistry was performed on the surgical specimens. Statistical analysis included the Kaplan-Meier method and the chi(2) and log-rank tests.

RESULTS

The response to NCH was <50% in 2/13 cases (15.3%), >50% in 9/13 (69.4%), and complete in 2/13 (15.3%). Cytokeratin was positive in 17/18 cases, neuron-specific enolase in 15/18, chromogranin in 9/18, and synaptophysin in 8/18. Tumor was pure in 12 cases. Two cases had simultaneous ovarian carcinoma. Positive nodes were observed in 9/20 pts (45%). Tumors <4 cm had no recurrences. Pure tumors >4 cm had distant relapses (6/11). Mixed tumors >4 cm had 2/6 pelvic and 3/6 lung metastases. OS was 39%. When the initial tumor volume was <4 cm OS was 76%, and it was 18% for tumors >4 cm (P < 0.05). OS was 58% when the residual tumor after NCH was <2 cm and 21% when it was >2 cm (P < 0.05). When the tumor was pure OS was 54% and 19% when it was mixed (P < 0.05). OS was 72% among pts with negative nodes and 11% for those with positive nodes (P < 0.01).

CONCLUSIONS

(1) Stage IV was frequent (20%); (2) Response to NCH was high; (3) The pattern of relapse differs for mixed tumors; (4) For tumors <4 cm outcome is similar to that of squamous carcinoma.

Green-light transilluminator for the detection without photodamage of proteins and DNA labeled with different fluorescent dyes

The excitation spectra of Nile red and SYPRO red, two currently used dyes for the fluorescent staining of protein bands in sodium dodecyl sulfate (SDS)-polyacrylamide gels, show an excitation peak in the UV region and another in the visible region (maximum at about 550 nm). Ethidium bromide and other intercalating dyes, e.g. propidium iodide, ethidium dimers, and benzoxazolium-4-quinolinium dimer-3 (YOYO), used for the fluorescent staining of DNA bands in agarose gels also show an excitation peak in the same region of the visible spectrum. We have designed and constructed a green-light transilluminator with an emission maximum at 542 nm. This visible transilluminator allows the detection of protein bands stained with Nile red and SYPRO red with the same sensitivity obtained with a 300 nm UV transilluminator. The green-light transilluminator also allows the detection of about 2 ng of DNA per band in gels stained with ethidium bromide and the other intercalating dyes indicated above. In contrast to the UV transilluminators, the green-light transilluminator does not produce photodamage of DNA even after long exposures (10 min). This makes this transilluminator very useful for preparative work. Furthermore, the green-light transilluminator does not require UV safety equipment and, consequently, it can be very convenient for teaching laboratories.

Novel procedure for the identification of proteins by mass fingerprinting combining two-dimensional electrophoresis with fluorescent SYPRO red staining

The fluorescent sensitive SYPRO Red dye was successfully employed to stain proteins in two-dimensional gels for protein identification by peptide mass fingerprinting. Proteins which are not chemically modified during the SYPRO Red staining process are well digested enzymatically in the gel and hence the resulting peptides can be efficiently eluted and analysed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). A SYPRO Red two-dimensional gel of a complex protein extract from Candida albicans was analysed by MALDI-TOF MS. The validity of SYPRO Red staining was demonstrated by identifying, via peptide mass fingerprinting, 10 different C. albicans proteins from a total of 31 selected protein spots. The peptide mass signal intensity, the number of matched peptides and the percentage of coverage of protein sequences from SYPRO Red-stained proteins were similar to or greater than those obtained in parallel with the modified silver protein gel staining. This work demonstrates that fluorescent SYPRO Red staining is compatible with the identification of proteins separated on polyacrylamide gel and that it can be used as an alternative to silver staining. As far as we know, this is the first report in which C. albicans proteins separated using 2-D gels have been identified by peptide mass fingerprinting. The improved technique described here should be very useful for carrying out proteomic studies.

Laparoscopic staging in locally advanced cervical carcinoma: A new possible philosophy?

OBJECTIVES

The aim of this study was to evaluate the feasibility and efficacy of designing the therapeutic management of each patient, morbidity, and mortality using laparoscopic staging in locally advanced cervical carcinoma and to establish the standard procedure for a "complete" staging.

METHODS

From July 10, 1995, to June 30, 1998, 98 pts were included. Clinical staging was performed according to FIGO's criteria (22 Ib2; 38 IIb; 25 IIIb; and 6 IV). The Quetelet index was calculated for each patient. Forty-nine pts were submitted to a previous CT scan. Surgical steps for a complete staging were: (1) peritoneal washings for cytology; (2) whole abdominal cavity exploration, with a biopsy of all suspicious lesions; (3) exploration of the vesicocervical and rectovaginal septums with a biopsy of suspicious areas; (4) bilateral pelvic lymphadenectomy and, when macroscopically positive, paraaortic lymphadenectomy.

RESULTS

Eighty-four of 91 pts were evaluable. The average duration for the procedure was 108 min, and blood loss was less than 200 cc. Hospitalization time ranged from 24 to 48 h. The average number of resected pelvic nodes was 18.5 (9-31). Positive nodes were found in 38 cases; 19 pts had unresectable positive nodes. Paraaortic dissection was performed in 26 cases and 11 cases were positive. When tumor was <5 cm, 8/32 (25%) lymphadenectomies were positive; when it was >5 cm, 30/52 (58%) were positive. Thirty-eight of 49 pelvic CT scans were reported to be normal (18/38 had positive nodes) and 11/49 suspicious (6/11 had positive nodes). Tumor invasion of the vesicocervical space or of the anterior parametrium was found in 23/84 patients. The rectovaginal septum was positive in 10 cases. Four of 84 patients (4.7%) presented with intraperitoneal spread. Only one trauma to the vena cava occurred at the time of the Verres needle insertion and two postoperative lymphoceles were observed. All patients began curative treatment within 3 to 7 days.

CONCLUSIONS

This method is feasible, complications are infrequent, and subsequent treatment is not delayed.

Laparoscopically assisted Schauta operation: learning experience at the Gynecologic Oncology Unit, Buenos Aires University Hospital

OBJECTIVES

The aim of this study was to show the learning experience of the employment of laparoscopic lymphadenectomy followed by a Schauta operation to treat patients with cervical carcinoma at a university hospital and to evaluate the feasibility, complications, hospital stay, delay in return to work, and overall survival of this procedure.

METHODS

Between June 1, 1993, and December 30, 1997, 56 patients were selected. Surgical treatment began with a pelvic laparoscopic lymphadenectomy followed by a Schauta operation. Patients were staged according to FIGO criteria (Ia2, 10 cases; Ib1, 33 patients; Ib2, 8 cases; IIa, 3 cases; and IIb, 2 patients). Patients had a follow-up of 47 months. Overall survival was calculated with Kaplan-Meier tables.

RESULTS

The procedure was not completed in 9 pts, in 5 cases among the first 20 pts that were entered on the trial due to technical problems and in 4 due to extracervical spread of disease (2 with gross laparoscopically unresectable lymph node metastases, 1 with parametrial infiltration, and 1 with rectovaginal septum involvement). In the 47 pts in which the procedure could be completed, the laparoscopic approach was done in 102 min and the vaginal part in 165 min. There were 4 complications: 1 ureteral injury, 1 abscess of the ischiorectal fossa, 1 hematoma of the Schuchardt incision, and 1 case of leg edema. The mean number of resected nodes was 17. Among the 47 cases in which the surgical procedure was completed, overall survival was 100% for Stage Ia, 88% for Ib1, and 85% for Ib2 after a mean follow-up of 4 years. Four pts have relapsed and died; 3 were stage Ib1 and the other was stage Ib2. They had pelvic recurrences.

CONCLUSIONS

This surgery is secure and has an excellent outcome, so it can be considered a valid approach for the treatment of patients with cervical carcinoma, but in our hands, 20 cases were needed to obtain the minimum skill needed to perform it.

Partial denaturation of small chromatin fragments: direct evidence for the radial distribution of nucleosomes in folded chromatin fibers

To examine the internal structure of chromatin fibers, we have developed procedures for partial denaturation of small chromatin fragments (8–30 nucleosomes) from chicken erythrocytes. Electron micrographs of samples prepared under conditions that cause nucleosome dissociation show rods and loops projecting from short compact fibers fixed by glutaraldehyde in 1.7 mM Mg2+. According to previous studies in our laboratory, these images correspond to the top view of partially denatured fibers. Our results indicate that rods and loops consist of extended duplex DNA of different lengths. DNA in loops is nicked, as demonstrated by experiments performed in the presence of high concentrations of ethidium bromide. Length measurements indicate that the radial projections of DNA are produced by unfolding of nucleosomal units. Loops are formed by DNA from denatured nucleosomes in internal positions of the fiber; DNA from denatured nucleosomes in terminal positions form rods. Our micrographs show clearly a radial distribution of DNA loops and rods projecting from fibers. Rods are orthogonal to the surface of the chromatin fragments. Considering that the high ionic strength used in this study (0.8-2.0 M NaCl) neutralizes the electrostatic repulsions between rods and fiber, this observation suggests that rods are extensions of nucleosomes radially organized inside the fiber. The position of the entry points of DNA loops into the fiber could be influenced by constraint on loops, but our results showing that the arc that separates these points in dinucleosome loops is relatively short suggest that consecutive nucleosomes are relatively close to each other in the folded fiber.

Electrophoresis of chromatin on nondenaturing agarose gels containing Mg2+. Self-assembly of small chromatin fragments and folding of the 30-nm fiber

We show that nondenaturing agarose gels can be used for the study of the structure and dynamic properties of native (uncross-linked) chromatin. In gels containing 1.7 mM Mg2+, chicken erythrocyte chromatin fragments having from about 6 to 50 nucleosomes produce well defined bands. These bands have an electrophoretic mobility that decreases only slightly with molecular weight. This surprising behavior is not observed in low ionic strength gels. Fragments with less than 6 nucleosomes and low content of histones H1-H5 give rise to broad bands in gels with Mg2+. In contrast, fragments containing only 3-4 nucleosomes but with the normal H1-H5 content are able to form associated structures with a mobility similar to that observed for high molecular weight chromatin. Electron microscopy results indicate that the associated fragments and the fragments of higher molecular weight show similar electrophoretic properties because they become very compact in the presence of Mg2+ and form cylindrical structures with a diameter of approximately 33 nm. Our results suggest that the interactions involved in the self-assembly of small fragments are the same that direct the folding of larger fragments; in both cases, the resulting compact chromatin structure is formed from a basic element containing 5-7 nucleosomes.

Internal structure of the 30 nm chromatin fiber

In the presence of 1.7 mM Mg2+, the diameter of the circular structures produced by small chromatin fragments isolated from chicken erythrocytes remains essentially unchanged when the number of nucleosomes in these fragments increases from 10 to 36. In contrast, the results obtained in unidirectional shadowing experiments show that under the same conditions the height of the chromatin fragments increases with the number of nucleosomes. These observations indicate that the electron microscope images studied in this work correspond to a top view of small chromatin fragments. Rotary-shadowed chromatin fragments show three parts: (a) a contour with a heavy deposition of platinum; (b) an annular zone between the central region and the periphery; and (c) a central hole. The heterogeneous ring generated by the deposition of platinum in the periphery suggests that nucleosomes form a one-start helix (5-7 nucleosomes per turn) that apparently can be left- or right-handed. The annular region (thickness of about 11 nm) shows spokes probably due to flat faces and core DNA of radially oriented nucleosomes. The central hole (8-12 nm) is clearly seen in many images but it is not empty because some deformed fragments show coated material (probably linker DNA) that protrudes from this central depression. We have observed that these structural elements directly detected in short chromatin fragments are also present in long chromatin fibers. This allows us to conclude that these elements are basic structural components of the 30 nm chromatin fiber.