Biochemical profiles, restriction fragment length polymorphism (RFLP), random amplified polymorphic DNA (RAPD) and multilocus variable number tandem repeat analysis (MLVA) for typing Staphylococcus aureus isolated from dairy products

The study concerns 130 Staphylococcus aureus strains isolated from different raw-milk dairy products (122 isolates) and human samples (eight isolates). Four different typing techniques were applied: biochemical profiles (Biolog GP), restriction fragment length polymorphism of coagulase gene (coaRFLP), random amplified polymorphic DNA (RAPD) and multilocus variable number tandem repeat analysis (MLVA). Moreover multiplex-PCR was used to study the distribution of genes encoding staphylococcal enterotoxins. The results of this study reveal marked genomic and phenotypic variability among the tested S. aureus. The considered techniques were all found useful for strain typing, but, based on discriminatory power as the key parameter of the typing system, MLVA and Biolog GP were found to be the most powerful techniques. The methods showed little concordance in terms of discerning the clusters of related strains.

Detection of classical enterotoxins and identification of enterotoxin genes in Staphylococcus aureus from milk and dairy products

Milk and dairy products are frequently contaminated with enterotoxigenic Staphylococcus aureus, which is often involved in staphylococcal food poisoning. The distribution of genes encoding staphylococcal enterotoxins (SE) in S. aureus isolated from bovine, goat, sheep and buffalo milk and dairy products was verified by the presence of the corresponding SE production. A total of 112 strains of S. aureus were tested for SE production by immuno-enzymatic (SEA-SEE) and reversed passive latex agglutination (SEA-SED) methods, while multiplex-PCR was applied for SE genes (sea, sec, sed, seg, seh, sei, sej and sel). Of the total strains studied, 67% were detected to have some SE genes (se), but only 52% produced a detectable amount of the classic antigenic SE types. The bovine isolates frequently had enterotoxin SEA, SED and sej, while SEC and sel predominated in the goat and sheep strains. The results demonstrated (i) marked enterotoxigenic S. aureus strain variations, in accordance with strain origin and (ii) the two methods resulted in different information but concurred on the risk of foodstuff infection by S. aureus.

Technical Note: Improved Method for Rapid DNA Extraction of Mastitis Pathogens Directly from Milk

Efficient control against bovine mastitis requires sensitive, rapid, and specific tests to detect and identify the main bacteria that cause heavy losses to the dairy industry. Molecular detection of pathogenic microorganisms is based on DNA amplification of the target pathogen. Therefore, efficient extraction of DNA from pathogenic bacteria is a major step. In this study, we aimed to develop a specific, sensitive, and rapid method to extract DNA directly from the main gram-positive bacteria known to cause bovine mastitis (Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis) found in milk samples. The DNA extraction method is based on the lysing and nuclease-inactivating properties of the chaotropic agent, guanidinium thiocyanate, together with the nucleic acid-binding properties of the silica particles. An efficient protocol consisting of 6 basic steps (3 of which were done twice) was developed and applied directly to milk samples. Absence of PCR inhibitors and DNA quality were evaluated by PCR amplification of the species-specific DNA sequences of the target bacteria. The level of sensitivity achieved in our experiments is applicable to milk sample analysis without sample enrichment.

Risk-oriented postremission strategies in adult acute lymphoblastic leukemia: prospective confirmation of anthracycline activity in standard-risk class and role of hematopoietic stem cell transplants in high-risk groups

INTRODUCTION

Although definite risk classes are well known, risk-adapted modulation of first-line therapy is seldom attempted in adult ALL. So, a prospective validation of the therapeutic efficacy of a protocol (or a component thereof) in specific risk groups is uncommon.

MATERIALS AND METHODS

From 1996-1999 a risk-oriented program (08/96) was evaluated in 102/121 unselected patients (median age 35 years, blast count 0-450 x 10(9)/l, 100 B(lin) (lineage), 21 T(lin)) responsive to induction therapy. The standard risk (SR) class was B(lin) CD10+ Ph- with blasts < 10 x 10(9)/l (prior studies: disease-free survival (DFS) rate 52% at five years with dose-intensive anthracycline-containing programs). The SR protocol was therefore anthracycline-rich (early consolidation cycles with total idarubicin 96 mg/m2), and comprised long-term maintenance. High-risk (HR) patients were eligible to the following three options: allogeneic hematopoietic stem cell transplantation (HSCT) from related family donor; short sequence with high-dose cyclophosphamide-cytarabine-methotrexate followed by melphalan/total body irradiation with autologous HSCT; or T(lin) ALL chemotherapy regimen inclusive of high-dose cytarabine and methotrexate.

RESULTS

Treatment realization and three-year DFS rates according to risk class, HR subset and postremission treatment intensity were the following. SR group (n = 28): realization rate 93%, DFS 68.5%. HR group (n = 74): realization rate 80%, DFS 39% (P = 0.052 vs SR category). In HR group, three-year DFS rates by disease subtype were the following. B(lin) Ph- (n = 35) 43%; Ph+ (n = 19) 13% at 2.7 years (P = 0.006 vs other HR subtypes); T(lin) (n = 18) 59.5%. And DFS rates by treatment intensity were: allograft (n = 21) 40%; autograft (n = 28) 27%; shift to SR protocol (n = 13) 52% (P = ns vs allograft/autograft); T(lin) program (n = 10) 57%. Matched analyses of treatment protocols and disease subtypes suggested a possible therapeutic role of the autograft regimen in B(lin) Ph- ALL with a blast count < 25 x 10(9)/l, and of T(lin) protocol for T(lin) ALL. Comparisons with retrospective control cohorts were confirmatory of anthracycline activity in SR subclass.

CONCLUSION

The intended strategy was applicable to the majority of study patients, confirming the value of anthracyclines in SR class and, preliminarily, the usefulness a T(lin)-specific treatment. Apart from the case of Ph+ ALL, the indications for high-dose procedures with HSCT remains largely undetermined in this study.

Role of early anthracycline dose-intensity according to expression of Philadelphia chromosome/BCR-ABL rearrangements in B-precursor adult acute lymphoblastic leukemia

INTRODUCTION

The use of anthracycline antibiotics in adult acute lymphoblastic leukemia (ALL) has resulted in an improved outcome to remission induction therapy. However,the exact role of these drugs in consolidation therapy is less clear, especially in specific ALL subsets.

MATERIALS AND METHODS

A retrospective analysis was conducted on the outcome of 308 patients (median age 35 years, range 13-75) with the most frequent subtype, early-B ALL, treated between 1974 and 1998 on eight consecutive protocols. Anthracycline-related effects were assessed by evaluating the impact of planned anthracycline dose-intensity (A-DI) on long-term outcome. A-DI (in mg/m(2)/week) during the first twelve weeks of consolidation therapy was classified as either "high" (doxorubicin>20, idarubicin>7) or "low".

RESULTS

Complete remission was achieved in 78% of cases. With a median follow-up of 6.5 years, on multivariate analysis, disease-free survival (DFS) correlated only with expression of the Philadelphia (Ph) chromosome and/or associated BCR-ABL rearrangements (Ph/BCR(+)) (P=0.0001) and planned A-DI (P<0.0001). On this basis, four major prognostic groups with significantly different DFS could be identified: (1) Ph/BCR(-), "high" A-DI (n=102), median 3.5 years and 41% at five years, respectively; (2) Ph/BCR(-), "low" A-DI (n=64), 1.3 years and 16%; (3) Ph/BCR(+), "high" A-DI (n=35), 1.7 years and 20%; (4) Ph/BCR(+), "low" A-DI (n=39), 0.75 years and 0%. When analyzed separately for Ph/BCR(-) (n=166) and Ph/BCR(+) (n=74) patients, the A-DI effect on DFS was preserved in the former (P=0.018) whereas, in Ph/BCR(+) patients, only age <50 years (P=0.004) and blast count <25 x 10(9)/l (P=0.02) correlated with better DFS. However, Ph/BCR(+) patients with the best prognostic profile (age <50 years and blast count <25 x 10(9)/l; n=21) who were treated on "high" A-DI regimens experienced a median DFS of 2.2 years with DFS 21% at five years, compared to 0.67-1 years and 0-10% in other cases (n=53, P<0.01).

CONCLUSION

A "high" A-DI may act as a positive treatment-related prognostic factor in early B-lineage ALL. Although mainly restricted to patients with Ph/BCR(-) ALL, A-DI could also influence the outcome in Ph/BCR(+) patients with other favorable prognostic factors.

DCEP (dexamethasone, cyclophosphamide, etoposide, and cisplatin) is an effective regimen for peripheral blood stem cell collection in multiple myeloma

DCEP (dexamethasone, cyclophosphamide, etoposide, and cisplatin) has proved to be an effective salvage therapy for refractory-relapsed MM patients. Little is known, however, about its potential as mobilizing therapy. The aim of this study was to evaluate the efficacy of DCEP in mobilizing PBSC and to define its toxicity. Fifty-five MM patients received DCEP followed by G-CSF as part of high-dose programs including autologous transplantation. At the time of mobilization, 40 patients had previously received VAD only, and 15 alkylating agents. Mobilization was successful (minimum number of CD34(+) cells 2 x 10(6)/kg) in 48/55 patients (87%), and 41/55 patients (75%) collected >4 x 10(6)/kg CD34(+) cells. Of the seven patients who did not mobilize stem cells, five (71%) had been previously exposed to alkylating agents. The median number of CD34(+) cells harvested was 5.8 x 10(6)/kg (range 2.1-22.4). There was no treatment-related mortality. The side-effects of DCEP were always tolerable. No neutropenia <1000/microl nor thrombocytopenia <50,000/microl were observed. No patient required transfusion as a consequence of therapy, or hospitalization for septic complications. In conclusion, DCEP, in addition to its demonstrated anti-tumor activity, is an effective regimen for mobilizing peripheral blood progenitor cells in myeloma patients, with little or no side-effects. These properties render DCEP a useful regimen for the debulking and mobilization phase of high-dose programs for multiple myeloma.

Fractionated cyclophosphamide added to the IVAP regimen (idarubicin-vincristine-L-asparaginase-prednisone) could lower the risk of primary refractory disease in T-lineage but not B-lineage acute lymphoblastic leukemia: first results from a phase II clinical study

BACKGROUND AND OBJECTIVE

In a prior study, primary resistant acute lymphoblastic leukemia (RES-ALL) was observed in 11 of 176 (6%) adult patients treated with a four drug regimen (IVAP), its incidence being higher in T-cell or Philadelphia (Ph) chromosome/BCR-ABL rearrangement positive ALL cases with a blast cell count >25x10(9)/L (RES-ALL rate 19%, p=0.04). Aiming to minimize this percentage of resistant disease, fractionated cyclophosphamide (f-CY) was then added to the IVAP regimen.

DESIGN AND METHODS

Study 08-96 was a prospective, collaborative phase II trial carried out at eight general hospital centers specialized in the care of hematologic malignancies. Historical IVAP-treated patients served as a retrospective control group. All consecutive, untreated patients (>15 years) with a diagnosis of ALL or advanced-stage lymphoblastic lymphoma (LBL) were eligible. RES-ALL was defined as the persistence of >5% ALL cells in the bone marrow 28-40 days after the start of the IVAP regimen (idarubicin 10 mg/m(2)/d on days 1 and 2; vincristine 2 mg on days 1, 8 and 15; L-asparaginase 6,000 U/m(2) on alternate days 3 6 from day 8; prednisone 60 mg/m(2)/d on days 1-21). In the new study, two f-CY schedules were sequentially adopted: CY 150 or 75 mg/m(2)/bd, given for 4 consecutive days before IVAP (f-CY 1200 or 600, expressing total CY dose in mg/m(2)).

RESULTS

Eighty-eight patients were evaluable (age range 15-74 years, blast count 0-240x10(9)/L, 14 T-lineage, 74 B-lineage, 13 Ph/BCR-ABL+). The first 39 patients received the f-CY 1200 schedule, 22 patients received f-CY 600, and the last 27 patients were not given any f-CY. These changes were dictated by the results of interim analyses of the f-CY groups (RES-ALL rate not reduced, myelotoxicity increased). Altogether, compared with the historical IVAP and no f-CY groups, the incidence of RES-ALL was not decreased by the addition of f-CY 1200/600 in B-lineage ALL, regardless of Ph/BCR-ABL expression and blast count. However, none of 14 T-ALL cases in the new study had RES-ALL (8 in f-CY groups, 5 of whom with >25x10(9)/L blast cells), compared to 5/39 (13%, overall) or 4/21 (19%, with >25x10(9)/L blast cells) among the control cases. Owing to small sample size, this difference was not statistically significant.

INTERPRETATION AND CONCLUSIONS

This preliminary experience suggests that T-ALL may be more sensitive than B-lineage ALL to an early therapy including f-CY. The hypothesis could be tested in a larger clinical trial.

Rhabdomyosarcoma presenting as acute leukemia

PURPOSE

We describe a case of a very unusual presentation of rhabdomyosarcoma.

PATIENT AND METHODS

An 18-year-old woman presented with symptoms and signs compatible with acute leukemia. The bone marrow picture showed diffuse involvement sustained by undifferentiated blasts that turned out to be of striated muscle origin by immunochemistry. While it is well known that rhabdomyosarcoma may metastasize to the bone marrow, extensive marrow involvement with leukemic spread as a unique clinical manifestation is extremely rare.

CONCLUSION

Our observation further confirms the need to consider rhabdomyosarcoma among the possible differential diagnoses in patients who present with a leukemic picture and atypical blasts lacking all hematopoietic markers.

Study of prognosis in Waldenström's macroglobulinemia: a proposal for a simple binary classification with clinical and investigational utility

Prognostic evaluation of Waldenström's macroglobulinemia (WM) is unreliable, few studies considered prognostic factors in WM and only one was derived from a multivariate analysis. One hundred forty-four retrospective, previously untreated patients with clinically overt WM were studied to learn whether overall survival was related to any of the various clinical features presented at diagnosis. Patients were homogeneously treated with intermittent doses of chlorambucil for as long as this showed an effect on the monoclonal component. The population was randomly subdivided into a 90-patient exploratory sample, on whom investigation would be conducted, and in a 54-patient test sample, on whom the results would be validated. In the exploratory sample univariate analysis identified the following parameters as the most important for prognosis: age (< or > or = 70 years), platelet count (< or > or = 120 x 10(9)/L), presence or absence of an abnormal number of red blood cells in the urine, hemoglobin concentration (< or > or = 9 g/dL), erythrocyte sedimentation rate (< or > or = 110 mm at first hour), presence or absence of cryoglobulinemia and of weight loss. Cox multivariate analysis showed that only hemoglobin, age, weight loss, and cryoglobulinemia independently affected survival. These four clinical variables were also shown to be able to discriminate survival significantly in the test sample. Moreover, it was possible to demonstrate (both in the exploratory and the test sample) that clear-cut, albeit dichotomic, survival discrimination can be reached with the presence at diagnosis of either no more than one, or any two or more, of these four prognosticators. These simple clinical criteria could be the basis of an initial binary, prognostic classification of WM, which could help in differentiating therapy according to the severity of the disease, and in properly designing future clinical trials.

Mitoxantrone alone or in combination chemotherapy (VeMP) as second-line treatment in relapsed or refractory poor-prognosis non-Hodgkin's lymphoma. A report of the Non-Hodgkin's Lymphoma Co-operative Study Group (NHLCSG)

BACKGROUND AND METHODS

From October, 1986 to July 1989, 35 consecutive patients with high- and intermediate-grade non-Hodgkin's lymphoma, relapsed or refractory to first-line-anthracycline-containing regimens, were treated with mitoxantrone alone or in combination chemotherapy (VeMP: Ve = VP-16, M = Mitoxantrone, P = Prednisolone).

RESULTS

In the first 15 patients, treated with Mitoxantrone alone, complete response (CR) and partial response (PR) each occurred in 4 patients, for a total response rate of 54%. In the following 20 patients, treated with the VeMP regimen, CR occurred in 10 patients (50%), PR in 1. The overall three-year survival was 27% in the first group and 40% in the second. Acute toxicity was generally mild. No patient developed cardiac symptoms or other toxicities requiring discontinuation of therapy. Myelosuppression was the most important side effect, being more remarkable for patients treated with VeMP regimen.

CONCLUSION

Mitoxantrone, alone or in combination chemotherapy, appears to be a drug with significant activity in aggressive non-Hodgkin's lymphomas.

Studies on the degradative mechanism of phosphoenolpyruvate carboxykinase from yeast Saccharomyces cerevisiae

Previous work carried out in our laboratory (Burlini, N., Lamponi S., Radrizzani, M., Monti, E. and Tortora P. (1987) Biochim. Biophys. Acta 930, 220-229) led to the immunological identification of a yeast 65-kDa phosphoprotein as a modified form of phosphoenolpyruvate carboxykinase; moreover the appearance of this phospho form was proven to be independent of cAMP, whereas the glucose-induced inactivation of the native enzyme is cAMP-dependent. Here, we report further investigations on the mechanism of the glucose-triggered degradation of the enzyme which led to the following results: (a) the aforementioned phospho form displayed a binding pattern to 5 AMP-Sepharose 4B quite similar to that of native enzyme, although it did not retain its oligomeric structure, nor was it catalytically active; (b) its phosphate content was of about two residues per monomer; (c) its isoelectric point was slightly higher than that of native enzyme, this shows that the enzyme undergoes additional modifications besides phosphorylation; (d) it represented about 4% of the native enzyme in glucose-depressed cells; (e) other forms immunologically cross-reactive with the native enzyme were also isolated, whose molecular mass was in the range of 60-62 kDa, and they are probable candidates as degradation products of the phospho form; (f) time courses of the native and phospho forms in the presence and the absence of glucose provided data consistent with a kinetic model involving a strong stimulation of the decay of both forms effected by the sugar; (g) in the mutant ABYS1 (Achstetter, T., Emter, O., Ehmann, C. and Wolf, D.H. (1984) J. Biol. Chem. 259, 13334-13343) which is devoid of the four major vacuolar proteinases, the decay pattern was essentially the same as in wild-type; (h) effectors lowering intracellular ATP also retarded the first step of enzyme degradation; this points to an ATP-dependence of this step. Based on these results we propose a degradation mechanism consisting of an initial cAMP- and ATP-dependent modification of the enzyme, followed by a cAMP-independent phosphorylation, which leads to the appearance of the aforementioned monomeric phospho form; this in turn seems to undergo limited proteolysis. These data strongly suggest the occurrence of an intermediate form arising from the native one and whose phosphorylation gives rise to the 65-kDa phosphoprotein described here.

Transposition of c-abl oncogene in a case of masked Ph chromosome duplicated in blastic phase

A female with chronic myelocytic leukemia (CML) in blastic phase (BP) showed a masked Ph chromosome that had originated by a translocation between chromosomes 8 and 22, with no obvious involvement of chromosome 9. A duplication of the masked Ph and trisomy 13 were present as additional anomalies. The karyotype on peripheral blood unstimulated cultures was 48,XX,t(8;22)(p12;q11),+13,+der(22) t(8;22)/47,XX,t(8;22)(p12;q11),+der(22)t(8;22). While the duplication of the Ph is a frequent finding in BP of CML, we did not find any other case in the literature with duplication of a masked Ph. In situ hybridization with c-abl and bcr probes showed that a 3' bcr sequence was translocated to the der(8) chromosome, while the c-abl oncogene was transposed to the masked Ph.

Selective bone marrow involvement of lymphoplasmacytic cells secreting monoclonal IgA rheumatoid factor in a patient with Sjögren's syndrome and serum hyperviscosity

The clinical features and results of serological studies of a patient with Sjögren's syndrome, IgA kappa monoclonal gammopathy, and hyperviscosity syndrome are reported. The novel aspect of this case is the selective localisation to the bone marrow of lymphoplasmacytoid cells secreting IgA kappa morphologically identical to the cells infiltrating the salivary glands. The serum of the patient contained large amounts of immunoglobulin-anti-immunoglobulin immune complexes. By gel filtration chromatography it was shown that the immune complexes formed a peak of molecular weight 680 kilodaltons. The immune complexes were dissociable under acidic conditions. The immunoglobulin with rheumatoid activity was characterised as monoclonal IgA kappa protein. Treatment with plasmapheresis combined with immunosuppressive treatment with cyclophosphamide reduced the serum viscosity with concomitant clinical improvement.

Quantitative evaluation of the mechanisms of the anaemia in heterozygous beta-thalassaemia

Ferrokinetic studies were carried out in 8 patients with heterozygous beta-thalassaemia with anaemia of varying severity. Effective and ineffective erythropoiesis, mean red cell lifespan and non-erythroid iron turnover were estimated from the experimental data through a mathematical model of iron kinetics. Erythropoietic activity was markedly increased in all patients, but was variably ineffective (from 10 to 74%). A negative correlation (r = 0.855, P less than 0.01) was found between the amount of ineffective erythropoiesis and Hb level. Red cell lifespan was variably shortened and there was a negative correlation between the degree of daily peripheral haemolysis and Hb level (r = 0.733, P less than 0.05). Non-erythroid iron turnover was increased in most patients. The results provide quantitative measurements of the mechanisms responsible for the wide variation of the Hb level in heterozygous beta-thalaeeaemia. Ineffective erythropoiesis seems to be the major reason for the anaemia. Peripheral haemolysis contributes to it, especially in the most severely affected patients. The increased non-erythroid iron turnover may be responsible for the pathology which characterizes heterozygotes in the adult life.

Abnormal splenic uptake of red cells in long-lasting iron deficiency anemia due to self-induced bleeding (factitious anemia)

The authors report on six cases of chronic iron deficiency anemia in which a diagnosis of factitious anemia was made. Erythrokinetic studies demonstrated iron deficiency and blood loss. Besides these features, two kinetic abnormalities are described: precocious splenic sequestration of red cells and excess hemolysis. This hemolytic syndrome seems to be correlated to the duration of anemia rather than to its severity.