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M Prokocimer

Publications and source records attributed to M Prokocimer.

At least 19 recordsLinked to original sources
PubMed2001

Thiamine deficiency in patients with B-chronic lymphocytic leukaemia: a pilot study.

Malignancy associated primary thiamine deficiency has been documented in several experimental tumours, sporadic clinical case reports, and in a number of patients with fast growing haematological malignancies. Thiamine status was assessed prospectively in 14 untreated B-chronic lymphocytic leukaemia (CLL) patients, and in 14 age matched control patients with non-malignant disease. Patients with any known cause of absolute, relative, or functional thiamine deficiency were excluded. High (>15%) thiamine pyrophosphate effect (TPPE), indicating thiamine deficiency, was found in five out of 14 CLL patients (35.7%) and in none of the controls (p=0.057). Mean (SD) TPPE in the thiamine deficient patients group was 21.6 (3.4)%. In all the patients, thiamine deficiency was subclinical. No correlates for the thiamine deficiency have been found save for an increment of more than 20% in the total leucocyte count over the preceding three months, which was found in all five thiamine deficient patients compared with only one of the nine non-thiamine deficient CLL patients. Thus, CLL patients may be prone to develop primary thiamine deficiency possibly promoted by the increased leucocytes span, which may increase thiamine consumption. Since even subclinical thiamine deficiency may be detrimental to the patient's clinical course, and in view of the theoretical danger of thiamine promoted tumour cell proliferation, further large scale studies are warranted to confirm this observation, and to elucidate the issue of thiamine supplementation to CLL patients.

Aged↗
PubMed2001

Erythropoietin can obviate the need for repeated heart valve replacement in high-risk patients with severe mechanical hemolytic anemia: case reports and literature review.

BACKGROUND AND AIM OF THE STUDY: Brisk hemolysis due to perivalvular leak is usually an indication for valve re-replacement. Repeated surgery after multiple previous valve operations is associated with high mortality, morbidity and failure rates. The present study evaluated the role of erythropoietin (EPO) administration in deferring or obviating the need for repeated surgery. METHODS: Three patients (two men, one woman; age range 62-76 years) with two mechanical valves each and two to four previous heart valve operations, who suffered from severe mechanical hemolytic anemia, were given subcutaneous EPO for 15-17 months. RESULTS: A marked reduction in red blood cell consumption was achieved with a weekly EPO dose of 18,000 U in two patients, both of whom also had mild or moderate kidney malfunction. A third patient with normal renal function and extreme hemolysis showed a transient, partial response to 30,000 U of EPO per week, and eventually needed a fifth operation. CONCLUSION: EPO may defer or even obviate the need for repeated valve surgery in patients with severe hemolysis due to perivalvular leak, especially those with inadequate EPO response, such as those with renal malfunction.

Aged↗
PubMed1999

Cutaneous necrosis as a terminal paraneoplastic thromboembolic event in a patient with non-Hodgkin's lymphoma.

Thrombotic complications in non-Hodgkin's lymphoma often originate in the large veins. We describe a patient with refractory advanced high-grade lymphoma who presented with the rare complication of extensive cutaneous necrosis due to thrombosis of dermal vessels; there was also a recent new peak of monoclonal IgM-kappa protein. Direct immunofluorescence demonstrated immune deposits with complement in the dermal vessel wall. Based on these observations and on published data, we suggest that these complexes were the trigger for the thrombotic events and that the monoclonal IgM acted as xenoreactive antibodies, initiating a cascade of events. The first step of this cascade was activation of the complement and the membrane attack complex, which caused secretion of IL-1 alpha by endothelial cells, followed by overexpression of tissue factor on the surface of the dermal vessel wall endothelium. Dermal vessel thrombosis was the final event in this cascade.

Humans↗
PubMed1999

Significance of BCR-ABL transcripts in bone marrow aspirates of Philadelphia-negative essential thrombocythemia patients.

Philadelphia-negative (Ph-neg) essential thrombocythemia (ET), polycythemia vera (PV) and idiopathic myelofibrosis (IMF) form a syndrome of related chronic myeloproliferative disorders (MPD) characterized by expansion of one or more of the hematopoietic progenitors. Based on our previous finding of BCR-ABL transcripts in bone marrow aspirates of 12/25 Ph-neg ET patients, we have expanded our study up to 40 patients. Here we describe the rational for performing this study and report 19 of 40 patients who have BCR-ABL transcripts in their BM, 11 of them carry b3a2 and 8 carry b2a2. The two groups, BCR-ABL positive and negative, were completely identical with regard to clinical characteristics and laboratory data. We also report preliminary results of our attempt to examine concordance or discordance of BCR-ABL expression in the peripheral blood and bone marrow of Ph-neg ET patients.

Adult↗
PubMed1998

Mutant p53 protein expression interferes with p53-independent apoptotic pathways.

Loss of normal p53 function was found frequently to interfere with response of cancer cells to conventional anticancer therapies. Since more than half of all human cancers possess p53 mutations, we decided to explore the involvement of mutant p53 in drug induced apoptosis. To further evaluate the relationship between the p53-dependent and p53-independent apoptotic pathways, and to elucidate the function of mutant p53 in modulating these processes, we investigated the role of a p53 temperature-sensitive (ts) mutant in a number of apoptotic pathways induced by chemotherapeutic drugs that are currently used in cancer therapy. To that end, we studied the M1/2, myeloid p53 non-producer cells, and M1/2-derived temperature-sensitive mutant p53 expressing clones. Apoptosis caused by DNA damage induced with gamma-irradiation, doxorubicin or cisplatin, was enhanced in cells expressing wild type p53 as compared to that seen in parental p53 non-producer cells; mutant p53 expressing clones were found to be more resistant to apoptosis induced by these factors. Actinomycin D, a potent inhibitor of transcription, as well as a DNA damaging agent, abrogated the restraint apoptosis mediated by mutant p53. These observations suggest that while loss of wild type p53 function clearly reduces the rate of apoptosis, p53 mutations may result in a gain of function which significantly interferes with chemotherapy induced apoptosis. Therefore, to achieve a successful cancer therapy, it is critical to consider the specific relationship between a given mutation in p53 and the chemotherapy selected.

Animals↗
PubMed1998

Pooled analysis of p53 mutations in hematological malignancies.

A computerized database is described that contains information about 507 mutations in the p53 gene of hematologic tumors and corresponding cell lines. Analysis of these mutations indicated the following findings: First, mutational spectrum analysis in these tumors was found to be similar to the pattern found for other solid tumors. However, when the patterns of base substitutions were examined separately according to the types of hematologic malignancies, followed by subgroup analysis, notable differences (in some cases of statistical significance) emerged. Second, mutational pattern analysis indicates that about 48% of base substitutions in hematologic tumors are suspected to be associated with carcinogen exposure. Third, deletions and insertions are localized mainly to exons 5-8 and repeated DNA sequences. However, the unusual profile of variations in frequency within each type of tumor suggests that, in addition to endogenous damage to template DNA, there is the factor of exposure to environmental physical and chemical carcinogens/mutagens. Fourth, p53 protein alterations analysis indicate that most of the changes in the amino acids are "semiconservative," presumably in order to avoid disrupting the structure of the p53 monomer. Consistent with this notion, structural mutations are more conservative than the binding mutations. Finally, molecular mechanisms that lead to p53 mutations, etiological factors that play a role in their formation, and the pathophysiological significance of consequent p53 protein alterations are discussed.

Amino Acid Substitution↗
PubMed1998

Molecular alterations in the TP53 gene of peripheral blood cells of patients with chronic myeloid leukemia.

The TP53 gene has been extensively studied in patients with chronic myeloid leukemia (CML), both in chronic phase and in blast crisis. Mutations in the gene were found in up to 30% of the patients, especially among those in blast crisis. We report the results of an analysis of 29 blood samples from CML patients: 8 samples from chronic phase patients, 8 from patients in the accelerated phase, and 13 from patients in blast crisis. By using genomic DNA, we sequenced PCR products of the coding exons and most introns of the TP53 gene, finding genetic changes in 30% of the blast crisis samples and 12% in chronic phase. All mutations were found in introns and were previously unreported. Immunocytochemical studies revealed accumulation of TP53 in blood cells of samples both from chronic phase and blast crisis patients. Since these samples had no TP53 mutations, we believe that wild type TP53 accumulates in blood cells of CML patients. Our results, therefore, indicate that molecular changes in coding regions of the TP53 gene are rare. The significance of the abundance of intronic changes should be investigated further. Accumulation of wild type TP53 in CML cells may indicate an additional mechanism involving this gene in the pathogenesis of this disease.

Adult↗
PubMed1998

P53 gene mutation in a T-acute lymphoblastic leukemia cell line (loucy) with t(16:20) and 5q- chromosomal aberrations.

A human T-acute lymphoblastic leukemia (ALL) cell line (Loucy), derived from cells from a patient with resistant ALL with a t(16:20) and 5q- chromosomal aberrations was evaluated for p53 gene alterations and expression. Western blot analysis of p53 showed elevated levels of the protein. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis and direct sequencing identified a point mutation at codon 272 (GTG --> ATG) of the p53 gene. Possible molecular mechanisms underlying these alterations and their role in the establishment of this cell line and in leukemogenesis in general are discussed.

Blotting, Western↗
PubMed1997

BCR-ABL transcripts in bone marrow aspirates of Philadelphia-negative essential thrombocytopenia patients: clinical presentation.

One of the diagnostic criteria of essential thrombocythemia (ET) is the absence of the Philadelphia chromosome (Ph-neg). On the molecular level, Ph-neg ET patients may carry BCR-ABL transcript. The natural history of BCR-ABL positive Ph-neg ET patients is undetermined. We examined the BCR-ABL status by reverse transcriptase two-step nested polymerase chain reaction in bone marrow aspirates of 25 Ph-neg ET patients. We found 12 BCR-ABL positive and 13 BCR-ABL negative patients in the study group. The comparison showed that the two groups had similar clinical and laboratory characteristics, except for a significant increased patients' age and decreased polymorphonuclear cell count in the BCR-ABL positive group. During a median follow-up of 20 and 22.5 months for the BCR-ABL negative and positive groups, respectively, there was neither blastic transformation nor unrelated death in both groups. We conclude that it is important to look for BCR-ABL transcript in Ph-neg ET patients and to follow them closely to investigate the nature of this translocation in this group of patients.

Adult↗
PubMed1997

Levels of proteins C and S do not decline subsequent to first line chemotherapy in lymphoma patients.

Thromboembolic complications and decrease in protein C and S have been observed in patients while receiving combination chemotherapy for breast cancer. We investigated whether initial cytotoxic treatment of non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD) is also associated with changes in these anticoagulant parameters. For this purpose 25 patients with intermediate to high grade NHL and seven with HD, undergoing primary treatment with cytotoxic drugs were evaluated at three time-points: pre-therapy, mid-therapy and post-therapy. In contrast to the breast cancer patients, no significant changes in protein C, protein S and antithrombin III levels were observed in the NHL patients during the various stages of therapy. However in HD patients, the mean protein C values had a tendency to be higher at mid-therapy compared to pre-therapy and protein S levels had a tendency to be higher at mid-therapy compared to post-therapy. In lymphoma patients receiving primary cytotoxic treatment we did not find changes in anticoagulant parameters that can explain a chemotherapy-induced hypercoagulable state, as has been reported in breast cancer patients.

Adolescent↗
PubMed1996

Severe myelotoxicity of oral etoposide in heavily pretreated patients with non-Hodgkin's lymphoma or chronic lymphatic leukemia.

BACKGROUND: Promising results have been reported for patients with non-Hodgkin's lymphoma (NHL) receiving chronic oral etoposide. Due to the small number of patients reported, information regarding side effects is limited, and therefore warrants further evaluation. METHODS: Twenty eligible patients with NHL and chronic lymphatic leukemia (CLL), resistant to or relapsed after previous protocols of polychemotherapy were treated with oral etoposide at a dosage of 50 mg/m2/day for 21 days in a 28-day cycle. Response and toxicity were evaluated according to standard criteria. RESULTS: Total response was noted in 13 patients, complete response in 2 patients, and partial response in 11 patients. Two patients had stable disease and five patients had progression of disease during treatment. Seventy-five percent of patients experienced neutropenia below 1500/microL. Half acquired infection and required hospitalization. Fifty-five percent required blood transfusions. All patients needed course shortening and dosage reduction. CONCLUSIONS: Chronic daily administration of oral etoposide is effective in patients with NHL and CLL. In heavily pretreated patients, myelotoxicity is severe. Therefore, modification of the schedule plan is mandatory in this group of patients.

Adult↗
PubMed1992

Life threatening hypophosphataemia in a patient with Philadelphia chromosome-positive chronic myelogenous leukaemia in acute blastic crisis.

Life-threatening hypophosphataemia developed in a 47 year old woman with blastic crisis of chronic myelogenous leukaemia. The patient's hospitalization was characterized by reciprocal relationship between her white cell count and the serum phosphorus levels. The patient did not demonstrate any of the usual causes of profound hypophosphataemia. The postulated mechanism of this patient's hypophosphataemia is uptake by the rapidly dividing leukaemic cells. To the best of our knowledge this is the first case in the English literature of hypophosphataemia associated with blast crisis of Philadelphia chromosome-positive chronic myelogenous leukaemia.

Blast Crisis↗
PubMed1991

Hemophagocytosis by small cell lung carcinoma.

A 60-year-old woman with disseminated small cell carcinoma of the lung and hemophagocytosis by the metastatic cells in the bone marrow is presented. It is the first clinicopathologic report on phagocytosis of erythrocytes by lung tumor cells in concordance with a recently described evidence of a macrophage origin of small cell carcinoma of the lung.

Bone Marrow↗