Pilot trial of a synthetic breakpoint peptide vaccine in patients with chronic myeloid leukemia (CML) and minimal disease

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Background: CML is characterized by a tumor-specific fusion oncoprotein, BCR-ABL. Peptides spanning the B3A2 breakpoint of BCR-ABL can elicit MHC restricted T cell responses and clinical responses. No such data have previously been reported for vaccines targeting B2A2. Methods: We initiated a clinical trial administering synthetic analog breakpoint specific peptide vaccines for either B3A2 or B2A2 breakpoints to CML patients with major or complete cytogenetic remission. Measurable minimal disease was determined by either quantitative polymerase chain reaction (RQ-PCR) or nested PCR for BCR-ABL. Vaccine was administered with GM-CSF and Montanide ISA 51 subcutaneously. Eleven vaccinations were planned over the course of 1 year with the first 5 doses administered bi-weekly. Results: Eleven of 20 planned patients have been accrued to the study. Eight had documented cytogenetic remission and 3 were BCR-ABL positive via FISH analysis. Seven of the 11 patients had measurable BCR-ABL transcript levels as determined by RQ-PCR and all 11 were positive using the nested technique. Of the 5 patients positive for BCR-ABL (by RQ-PCR) before vaccination, 3 converted from RQ-PCR positive to negative while the transcript levels in the other patients decreased by approximately 1 log after 5 doses. All 5 of these patients remained positive using the nested PCR technique. Vaccination was well tolerated with local skin reactions at the injection sites. Immunologic reactivity was assessed ex vivo by CD4 autologous proliferation assay and T cell interferon (IFN) secretion (ELISPOT) assay. Ten of 11 patients were immunologically unreactive to the peptides prior to the vaccinations. Following the 5th dose of vaccine, 8/8 patients (including 2 with B2A2) tested showed significant immunologic responses by one of the above assays. Conclusions: These preliminary results suggest vaccination with synthetic analog peptides derived from CML proteins results in immunologic responses and may be associated with molecular improvement. Clinical efficacy of these vaccines in reducing/ eliminating minimal disease has yet to be established.

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Pilot study of combination transcriptional modulation therapy with sodium phenylbutyrate and 5-azacytidine in patients with acute myeloid leukemia or myelodysplastic syndrome

Epigenetic mechanisms underlying tumorigenesis have recently received much attention as potential therapeutic targets of human cancer. We designed a pilot study to target DNA methylation and histone deacetylation through the sequential administration of 5-azacytidine followed by sodium phenylbutyrate (PB) in patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Ten evaluable patients (eight AML, two MDS) were treated with seven consecutive daily subcutaneous injections of 5-azacytidine at 75 mg/m2 followed by 5 days of sodium PB given intravenously at a dose of 200 mg/kg. Five patients (50%) were able to achieve a beneficial clinical response (partial remission or stable disease). One patient with MDS proceeded to allogeneic stem cell transplantation and is alive without evidence of disease 39 months later. The combination regimen was well tolerated with common toxicities of injection site skin reaction (90% of the patients) from 5-azacytidine, and somnolence/fatigue from the sodium PB infusion (80% of the patients). Correlative laboratory studies demonstrated the consistent reacetylation of histone H4, although no relationship with the clinical response could be demonstrated. Results from this pilot study demonstrate that a combination approach targeting different mechanisms of transcriptional modulation is clinically feasible with acceptable toxicity and measurable biologic and clinical outcomes.

Prostatic neuroendocrine tumor in multiple endocrine neoplasia Type 2B

We report the unusual occurrence of a neuroendocrine prostatic tumor in two young males with multiple endocrine neoplasia (MEN) 2B. Immunohistochemistry of the tumor markers may help differentiate a primary neuroendocrine prostate tumor from the metastasis of a medullary thyroid carcinoma of poor prognosis. MEN 2B hallmarks (i.e. plasma thyrocalcitonin and urinary metanephrines) may be systematically investigated in neuroendocrine tumors of the prostate, and conversely prostate examination may be performed in the periodic screening of MEN 2B male patients.

[Chondromas and low-grade chondrosarcomas of the larynx: a case report]

OBJECTIVE

We report a case of cricoid chondroma, underlining the difficulty in establishing a precise differential diagnosis between chondroma and low-grade chondrosarcoma of the larynx.

MATERIAL AND METHODS

A 48-year-old woman developed inspiratory dyspnea. The final diagnosis was cricoid chondroma. We reviewed our case and data in the literature on these cartilaginous tumors.

RESULTS

The patient was treated with conservative surgery. At 18 months follow-up, no recurrence has been detected.

DISCUSSION

These tumors are rarely found in an ENT location and have similar histological features. According to many authors, the clinical course alone enables a distinction between chondroma and low-grade chondrosarcoma. Surgical treatment is indicated and provides good phonatory function in the vast majority of the cases.

Synchronous pulmonary adenocarcinoma and extranodal marginal zone/low-grade B-cell lymphoma of MALT type

A case of synchronous adenocarcinoma of lung and extranodal marginal zone/low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) is reported. Primary pulmonary non-Hodgkin's lymphoma is relatively rare, however, the majority of these lesions are low-grade B-cell lymphomas of MALT. After the stomach, the lung is the second most common location for such latter lesions. Lung adenocarcinoma in selected countries is fast becoming the leading form of non small-cell lung carcinoma. To our knowledge, this synchronous occurrence in the lung has not been previously reported. Such associations have been primarily limited to gastric lesions where an association with Helicobacter pylori infection has been identified. This case report highlights the importance of adjunctive diagnostic investigations such as molecular techniques in conclusive analysis of synchronous cases such as ours.

Leukocytosis and the retinoic acid syndrome in patients with acute promyelocytic leukemia treated with arsenic trioxide

PURPOSE

Arsenic trioxide, like all-trans-retinoic acid (RA), induces differentiation of acute promyelocytic leukemia (APL) cells in vivo. Treatment of APL patients with all-trans RA is commonly associated with leukocytosis, and approximately 50% of patients develop the RA syndrome. We reviewed our clinical experience with arsenic trioxide to determine the incidence of these two phenomena.

PATIENTS AND METHODS

Twenty-six patients with relapsed or refractory APL were treated with arsenic trioxide for remission induction at daily doses that ranged from 0.06 to 0.17 mg/kg.

RESULTS

Twenty-three patients (88%) achieved complete remission. Leukocytosis was observed in 15 patients (58%). The median baseline leukocyte count for patients with leukocytosis was 3,900 cells/microL (range, 1,200 to 72,300 cells/microL), which was higher than that for patients who did not develop leukocytosis (2,100 cells/microL; range, 500 to 5,400 cells/microL; P =.01). No other cytotoxic therapy was administered, and the leukocytosis resolved in all cases. The RA syndrome was observed in eight patients (31%). Patients who developed leukocytosis were significantly more likely to develop the RA syndrome (P <.001), and no patient without a peak leukocyte count greater than 10,000 cells/microL developed the syndrome. Among the patients with leukocytosis, there was no observed relation between the leukocyte peak and the probability of developing the syndrome (P =.37).

CONCLUSION

Induction therapy of APL with all-trans RA and arsenic trioxide is associated with leukocytosis and the RA syndrome. These clinical effects seem to be intrinsically related to the biologic responsiveness and the differentiation process induced by these new agents.

In vitro effects of desflurane, sevoflurane, isoflurane, and halothane in isolated human right atria

BACKGROUND

Direct myocardial effects of volatile anesthetics have been studied in various animal species in vitro. This study evaluated the effects of equianesthetic concentrations of desflurane, sevoflurane, isoflurane, and halothane on contractile parameters of isolated human atria in vitro.

METHODS

Human right atrial trabeculae, obtained from patients undergoing coronary bypass surgery, were studied in an oxygenated (95% O2-5% CO2) Tyrode's modified solution ([Ca2+]o = 2.0 mM, 30 degrees C, stimulation frequency 0.5 Hz). The effects of equianesthetic concentrations (0.5, 1, 1.5, 2, and 2.5 minimum alveolar concentration [MAC]) of desflurane, sevoflurane, isoflurane, and halothane on inotropic and lusitropic parameters of isometric twitches were measured.

RESULTS

Isoflurane, sevoflurane, and desflurane induced a moderate concentration-dependent decrease in active isometric force, which was significantly lower than that induced by halothane. In the presence of adrenoceptor blockade, the desflurane-induced decrease in peak of the positive force derivative and time to peak force became comparable to those induced by isoflurane. Halothane induced a concentration-dependent decrease in time to half-relaxation and a contraction-relaxation coupling parameter significantly greater than those induced by isoflurane, sevoflurane and desflurane.

CONCLUSIONS

In isolated human atrial myocardium, desflurane, sevoflurane, and isoflurane induced a moderate concentration-dependent negative inotropic effect. The effect of desflurane on time to peak force and peak of the positive force derivative could be related to intramyocardial catecholamine release. At clinically relevant concentrations, desflurane, sevoflurane, and isoflurane did not modify isometric relaxation.

An efficient three steps preparative purification of penicillin acylase from Escherichia coli cells

A new and efficient safe system for the purification of the penicillin acylase from Escherichia coli G271 is presented. It was found that after a selective precipitation with ammnonium sulphate, followed by two chromatographic steps (anion exchange followed by adsorption on hydroxyapatite support), the enzyme was enriched 98 times with a 100% activity recovery. An original way has also been used to study the chromatographic separation of the protein mixture in three major categories on DEAE resin, by an analysis of the concentrations of the different species in the breakthrough curve obtained from a complete saturation of the column.