Comparison of lymphomononuclear cell energy metabolism between healthy, impaired glucose intolerance and type 2 diabetes mellitus patients

Diabetes mellitus (DM) is a complex disease that affects many systems. The most important cells of the immune system are lymphomononuclear (LMN) cells. Here, we aimed to evaluate the energy metabolism of LMN cells in patients with diabetes and impaired glucose tolerance. We measured LMN cell energy metabolism in patients with type 2 diabetes mellitus, impaired glucose tolerance (IGT) and healthy subjects. Cells were freshly isolated from peripheral blood and the subgroups were determined by flow cytometric method. Lactate production and glycogen utilization were significantly increased in the LMN cells of patients with type 2 DM and IGT when compared with healthy volunteers. No statistical difference was observed between the patients with type 2 DM and IGT. There was a significant correlation between fasting plasma glucose and lactate production in LMN cells. LMN cells changed their energy pathway in a diabetic state and preferred anaerobic glycolysis. Prediabetic range also affected energy metabolism in LMN cells. This abnormal energy production might cause dysfunction in LMN cells and the immune system in diabetic and prediabetic patients. In conclusion, we concluded that impaired glucose metabolism could change energy metabolism.

Effects of bortezomib on platelet aggregation and ATP release in human platelets, in vitro

INTRODUCTION

Proteasome inhibitor bortezomib (PS-341) has been the first proteasome inhibitor that has entered clinical trials with its antiproliferative and proapoptotic effects in patients with multiple myeloma. Recent studies indicate that proteasome inhibitors can be useful in prevention of experimental arterial thrombosis in renovascular hypertensive rat models. The aim of the present study is to investigate the effect of bortezomib on in vitro platelet aggregation and adenosine triphosphate (ATP) release of human platelets.

MATERIALS AND METHODS

For this purpose, platelet aggregation was induced in the platelet-rich plasma (PRP) using 3 microg ml(-1) collagen, 5 microM adenosine diphosphate (ADP), 10 microM epinephrine and 1 U ml(-1) thrombin and ATP release was induced by collagen.

RESULTS AND CONCLUSIONS

Bortezomib showed an inhibitory effect on platelet aggregation induced by ADP in human PRP in a dose- and time-dependent manner, whereas it had no effect on collagen-, epinephrin and thrombin-induced aggregation. ATP-release reaction induced by collagen was inhibited dose- and time-dependently by bortezomib, even though collagen-induced platelet aggregation was apparently not affected in human PRP. These findings indicate that bortezomib may be an antiaggregating agent and its' effects may be related to adenine nucleotide receptor dependent regulatory proteins which are important for physiological and pathophysiological cellular processes. However, our in vitro studies suggest that this hypothesis is inadequate to explain the observations completely. This phenomenon and its clinical implication justify further clinical investigations.

Radiological evidence of double inferior vena cava in a young adult male

The development of the inferior vena cava IVC is a complex process comprising the formation and regression of some anastomoses, so various anomalies may occur during embryogenesis. These variations can increase the difficulty of aneurysm resection as well as the risk of venous injury and subsequent excessive bleeding during retroperitoneal and thoracic surgical interventions. Here, we report a patient with double inferior vena cava by radiographically during his investigation for the etiology of pancytopenia.

In vitro synergistic cytoreductive effects of zoledronic acid and radiation on breast cancer cells

Introduction

Bisphosphonates are mostly used in the treatment of bone metastases. They have been shown to act synergistically with other chemotherapeutic agents. It is not known, however, whether similar synergistic effects exist with radiation on breast cancer cells.

Methods

Human MCF-7 breast cancer cells were treated with up to 100 μM zoledronic acid, were irradiated with up to 800 cGy or were exposed to combinations of both treatments to determine the antiproliferative effects of zoledronic acid and radiation.

Results

Zoledronic acid and radiation caused a dose-dependent and time-dependent decrease in cell viability (approximate 50% growth inhibition values were 48 μM and 20 μM for 24 hours and 72 hours, respectively, for zoledronic acid and 500 cGy for radiation). A synergistic cytotoxic effect of the combination of zoledronic acid and radiation was confirmed by isobologram analysis.

Conclusion

These data constitute the first in vitro evidence for synergistic effects between zoledronic acid and radiation. This combination therapy might thus be expected to be more effective than either treatment alone in patients with metastatic breast carcinoma.

Oral fludarabine treatment of cutaneous infiltration in a patient with B-cell chronic lymphocytic leukaemia

In B-cell chronic lymphocytic leukaemia (B-CLL), cutaneous infiltration is far less common than in T-cell CLL. However, the effect of fludarabine on cutaneous infiltration in patients with B-CLL is uncertain. We describe a 63-year-old man with B-CLL presenting with cutaneous lesions, who was treated successfully with oral fludarabine. Skin biopsy of one of these lesions revealed diffuse infiltration of uniform lymphocytes. Using PCR analysis, the same immunoglobulin heavy-chain gene rearrangement was found in lymphocytes in all samples (peripheral blood, bone marrow and skin lesion). The patient received four courses of oral fludarabine. Simultaneously with the normalization of the peripheral blood lymphocytosis, the patient became free of the cutaneous infiltration of CLL after four courses of oral fludarabine. Skin lesions had not recurred by the 12-month follow-up examination. To our knowledge, this is the first case of B-CLL leukaemia cutis treated with oral fludarabine. The introduction of fludarabine may contribute to a better outlook for these patients in the future.

The effect of two fibre impregnation methods on the cytotoxicity of a glass and carbon fibre-reinforced acrylic resin denture base material on oral epithelial cells and fibroblasts

Acrylic resin dentures may have cytotoxic effects on oral soft tissues. However, there is sparse data about the cytotoxic effect of fibre-reinforced acrylic resin denture base materials. The purpose of this in vitro study was to determine the effect of two fibre impregnation methods on the cytotoxicity of a glass and carbon fibre-reinforced heat-polymerized acrylic resin denture base material on oral epithelial cells and fibroblasts. One hundred acrylic resin discs were assigned to five experimental groups (n = 20). One of the groups did not include any fibre. Two groups consisted of silane and monomer treated glass fibres (Vetrolex) impregnated into acrylic resin (QC-20) discs. The other two groups consisted of silane and monomer treated carbon fibres (Type Tenox J, HTA). Untreated cell culture was used as positive control. The human oral epithelial cell line and buccal fibroblast cultures were exposed to test specimens. The cytotoxicity of the test materials was determined by succinic dehydrogenase activity (MTT method) after 24 and 72 h exposures. Data were analysed with a statistical software program (SPSSFW, 9.0). A one-way analysis of variance (anova) test and Bonferroni test were used for the comparisons between the groups. All statistical tests were performed at the 0.95 confidence level (P < 0.05). After 24 and 72 h incubation, cell viability percentages of all experimental groups showed significant decrease according to the positive control cell culture. Fibroblastic cell viability percentages of silane and monomer treated fibre-reinforced groups were lower than the unreinforced group. Cell viability of monomer-treated groups displayed the lowest percentages. Elapsed incubation time decreased epithelial cell viability in silane-treated groups. Fibroblastic cell viability was not influenced by elapsed time except the unreinforced group.

The plasma levels of soluble P-selectin in subjects with prediabetes

Prediabetes has been associated with an increased risk of cardiovascular disease and mortality. Soluble P-selectin (sP-selectin) is an index of platelet activation and also a risk factor for future vascular events. sP-selectin levels were investigated in prediabetic subjects who had no confounding factors such as hypertension, obesity or dyslipidaemia. sP-selectin, hsCRP levels and HOMA-IR indexes were measured in 40 prediabetic subjects (n = 24 for IFG and n = 16 for IGT) and age-, sex- and BMI-matched 40 healthy controls. sP-selectin levels in prediabetic subjects were not significantly different compared with those in controls (p = 0.12). Prediabetic group had similar hsCRP (p = 0.29), higher HOMA-IR indexes (p < 0.001) and lower HDL cholesterol levels (p = 0.001) when compared with healthy controls. The power of the study was 0.93 for sP-selectin, 0.7 for hsCRP and 1.0 for HOMA. Our data suggest that sP-selectin may not contribute to the prothrombotic state as well as the accelerated atherogenesis associated with prediabetes.

Differentiating effect of thalidomide and FGM-CS combination on HL-60 acute promyelocytic leukemia cells

AIM

To investigate whether granulocyte-macrophage colony-stimulating factor (GM-CSF) with or without thalidomide can induce apoptosis and differentiation of HL-60 acute promyelocytic leukemia cell line in vitro.

METHODS

Effect of GM-CSF and thalidomide on proliferation of HL-60 cells was evaluated by MTT assay, cell cycle analysis was performed by propidium iodide staining approach and flow cytometry, and apoptosis rate was analyzed using FITC-conjugated annexin-V and FACScan flow cytometry.

RESULTS

The study revealed that thalidomide alone at high concentrations inhibited HL-60 cell growth and induced apoptosis. Three days treatment of low-dose thalidomide in combination with GM-CSF induced marked terminal differentiation of HL-60 cells, as it was assessed by increased expression of differentiation antigens on cell surface.

CONCLUSION

Treatment of HL-60 cells by low concentration of thalidomide combined with GM-CSF induced terminal differentiation of HL60 cells in vitro, which may be advantageous for the elaboration of novel therapeutic regimens in patients with differentiation-inducible leukemias.

Association of plasma adiponectin concentrations with chronic lymphocytic leukemia and myeloproliferative diseases

Adiponectin, an adipocyte-secreted hormone, is an important negative regulator in the immune system and hematopoiesis. In this study, we investigated the association of adiponectin levels with chronic lymphocytic leukemia (CLL) and myeloproliferative diseases (MPDs). We measured adiponectin levels in 19 patients with CLL and 30 patients with MPD (chronic myelogenous leukemia, 15; polycythemia vera, 9; myelofibrosis, 4; essential thrombocythemia, 2). The data were (chronic myelogenous leukemia, 15; polycythemia vera, 9; myelofibrosis, 4; essential thrombocythemia, 2). The data were compared with results from a control group of healthy volunteers who were matched according to age, sex, and body mass index. The adiponectin levels in patients with CLL were lower than in the controls (4.71 +/- 1.33 microg/mL versus 16.61 +/- 3.91 microg/mL; P <.001). They were also significantly lower in patients with MPD than in the controls (8.95 +/- 1.33 microg/mL versus 16.16 +/- 4.77 microg/mL; P <.001). In addition, we compared the adiponectin levels of MPD patients who were treated with interferon (IFN) to the levels of patients who were not treated with IFN. Adipnectin levels were significantly higher in IFN-treated patients (11.03 +/- 1.39 microg/mL versus 6.87 +/- 1.79 microg/mL; P <.001). These results suggest that lymphopoiesis and myelopoiesis negatively influence adiponectin levels. Adiponectin may be related to inflammatory cytokine release. IFN therapy appears to have a positive influence on adiponectin secretion by suppressing inflammatory cytokines. Future studies are needed to prove causality and to provide insight about this hormone's mechanism of action and its potential role regarding the etiology and progression of CLL and MPD.

Cross-resistance to cytosine arabinoside in human acute myeloid leukemia cells selected for resistance to vincristine

AIM

The goals of the study were to reveal the involvement of P-glycoprotein (P-gp), the product of multidrug resistance 1 gene (MDR1) in cellular resistance to vincristine (VCR) and investigate cross-resistance against cytosine arabinoside (Ara-C) in HL60 and HL60/VCR cell lines.

METHODS

HL60 cells (human acute myeloid leukemia cell line) were cultured on medium with 1-50 nM of VCR for 4-6 weeks, and VCR resistant cells (HL60/VCR) were selected. The viability of cells was assessed by MTT assay and the expression of MDR1 gene was detected by RT-PCR.

RESULTS

No expression of MDR1 gene was revealed in HL60 cells, but MDR1 started to be expressed after incubation of cells with 2 nM of VCR and its expression level elevates with increase of agent concentration. MTT test has shown that HL-60/VCR cells were 75-fold more resistant to VCR and 42-fold higher resistant to cytosine arabinoside (Ara-C) compared to sensitive HL60 cells.

CONCLUSION

Aquired resistance to VCR and cross-resistance to Ara-C correlates with MDR1 gene expression in vitro.

In vitro IL-1beta release from gingival fibroblasts in response to pure metals, dental alloys and ceramic

Little information is available on the immunological basis for side-effects of dental materials. The objective of this study is to evaluate effects of pure metals, dental alloys and ceramic on cell viability and interleukin-1 beta (IL-1beta) release in three-dimensional human gingival fibroblast cultures as an indicator of their biological performance in gingival tissues. The gingival fibroblast cultures were exposed to test specimens fabricated from nickel, iron, molybdenum, copper, indium, gold, Ni-Cr-Mo alloy (Remanium CS), Au-Pt-In alloy (Pontostar) and a dental ceramic (In-ceram). Cell viability was determined by the MTT method 24 and 48 h after exposure. Assays for IL-1beta were carried out by ELISA. Statistical analysis was performed applying the non-parametric Mann-Whitney pairwise test. Dental ceramic and gold did not influence cell viability after 24 and 48 h. Cell viability was determined after 24 and 48 h to nickel (79-77%), iron (92-90%), molybdenum (86-83%), copper (48-36%), indium (90-90%), Remanium CS (83-80%), Pontostar (94-91%) compared with control cultures. Dental ceramic, Pontostar and gold had no significant influence on IL-1beta secretion. The highest amounts of IL-1beta (10-fold) levels were determined in cell cultures exposed to copper. Indium, molybdenum and iron induced twofold IL-1beta levels compared with untreated control cultures. These results support that some metals may alter immune responses and thereby contribute to a variety of dental pathological conditions and three-dimensional cell culture models for gingival fibroblasts appear to be suitable for in vitro studies.

The bisphosphonate zoledronic acid induces cytotoxicity in human myeloma cell lines with enhancing effects of dexamethasone and thalidomide

Bisphosphonates have recently been introduced in the therapeutic armamentarium for long-term treatment of patients with multiple myeloma. These pyrophosphate analogs not only reduce the occurrence of skeletal events but also provide clinical benefit to patients and improve the survival of some of them. The existence of these capabilities raises the possibility that these compounds may have a direct antiproliferative effect on tumor cells. To investigate whether these drugs exert a direct antitumor effect, we exposed human myeloma cell lines ARH-77 and RPMI-8226 to increasing concentrations of zoledronic acid (ZOL) in vitro. A concentration- but not time-dependent cytotoxic effect was detected with drug treatment of ARH-77 and RPMI-8226 cell lines (30% and 60% at 48 hours and 38% and 62% at 72 hours, respectively, for 50 microM of ZOL). Cytotoxicity was not due to ZOL-induced chelation of extracellular calcium as shown by control experiments with the calcium chelator ethylene glycol-bis(beta-aminoethylether)-N,N,N',N'-tetraacetic acid. Addition of the competitive inhibitor of the nitric oxide synthase N omega-nitro-L-arginine methyl ester did not modulate ZOL-induced cytotoxicity. However, a decrease in the number of apoptotic cells was detected when protein kinase C was inhibited by addition of staurosporine to ZOL-containing cultures. Cytotoxicity also was increased by addition of dexamethasone (Dex) and thalidomide (Thal) to ARH-77 and RPMI-8226 cultures. We demonstrated that exposing myeloma cell lines ARH-77 and RPMI-8226 to ZOL inhibits cell growth in a dose-dependent but not a time-dependent manner and that combination of Dex and Thal with ZOL induces apoptotic cell death, providing a rationale for potential applications in vivo.

Does amphotericin B lipid complex (Abelcet) affect haematological parameters erroneously?

Abelcet is composed of large particles which could be misinterpreted as blood cells on measurements with blood cell counters. The direct measurement of drug suspensions on blood cell counters has been performed in an in vitro study. In an ex vivo study, the haematological parameters were compared before and during Abelcet infusions. A significant interference effect was observed in platelet counts, together with minimal differences in the WBC, RBC, and Hb parameters in the in vitro study. In the ex vivo study, there were statistically significant deviations only in RBC counts and in haemoglobin (Hb) level, while there was no difference in the other parameters. It is been reported that the drug accumulates very rapidly in the reticuloendothelial system and circulates minimally in the plasma. That is why there is a significant deviation in the direct counting of platelets, while the platelet counts taken from the patients do not differ statistically.

Treatment with cerivastatin in primary mixed hyperlipidemia induces changes in platelet aggregation and coagulation system components

Platelet activation, impairment of fibrinolysis, activation of the coagulation pathway, and dyslipidemia are important factors in the pathogenesis and progression of ischemic heart disease, and patients generally need to use an antiplatelet agent. Lipid-lowering cerivastatin, a novel 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, was administered to 20 patients with primary mixed hyperlipidemia for the assessment of the effect of cerivastatin on lipid levels, plasma fibrinogen concentration, factor VII, VIII, and X levels, plasminogen and antiplasmin concentrations, platelet count, and aggregation (adenosine diphosphate [ADP], collagen, and epinephrine induced). Assessments were made immediately after 2 months of a standard lipid-lowering diet, 4 weeks of placebo administration, and 4 weeks of cerivastatin treatment. Cerivastatin achieved significant reductions in triglyceride, total cholesterol, and low-density lipoprotein cholesterol levels. The significant improvement of the lipid profile was associated with platelet aggregation reduction in vitro stimulated by ADP, collagen, and epinephrine (P < .05, P = .05, P < .005, respectively). Significantly lower levels of factor VII and fibrinogen were observed (P = .001, P < .0001) immediately after cerivastatin treatment. No significant differences were detected in factor VIII level, plasminogen and antiplasmin concentrations, and platelet count after cerivastatin treatment. It was concluded that cerivastatin in mixed hyperlipidemia can exert beneficial changes on specific hemostatic variables and platelet aggregation in addition to its positive effects on plasma lipid values.

Spironolactone: is it a novel drug for the prevention of amphotericin B-related hypokalemia in cancer patients?

OBJECTIVE

Nephrotoxicity is the major adverse effect of amphotericin B (AmB), often limiting administration of full dosage. Selective distal tubular epithelial toxicity seems to be responsible for the profound potassium wasting that is a major clinical side effect of treatment with AmB. Potassium depletion also potentiates the tubular toxicity of AmB. This study was designed to assess the ability of spironolactone to reduce potassium requirements and to prevent hypokalemia in neutropenic patients on AmB treatment.

METHODS

In this study 26 patients with various hematological disorders were randomized to receive either intravenous AmB alone or AmB and oral spironolactone 100 mg twice daily when developing a proven or suspected fungal infection.

RESULTS

Patients receiving concomitant AmB and spironolactone had significantly higher plasma potassium levels than those receiving AmB alone (P = 0.0027). Those patients receiving AmB and spironolactone required significantly less potassium supplementation to maintain their plasma potassium within the normal range (P = 0.022). Moreover, urinary potassium losses were significantly less in patients receiving AmB and spironolactone than those receiving AmB alone (P = 0.040).

CONCLUSION

This study showed that spironolactone can reduce potassium requirements and prevent hypokalemia by reducing urinary potassium loss in neutropenic patients on AmB treatment.

Retroviral transduction of human dihydropyrimidine dehydrogenase cDNA confers resistance to 5-fluorouracil in murine hematopoietic progenitor cells and human CD34+-enriched peripheral blood progenitor cells

Severe 5-fluorouracil (5-FU) toxicity has been reported among patients lacking dihydropyrimidine dehydrogenase (DPD) enzymatic activity. DPD is the principal enzyme involved in the degradation of 5-FU to 5'-6'-dihydrofluorouracil, which is further metabolized to fluoro-beta-alanine. We demonstrate here that overexpression of human DPD confers resistance to 5-FU in NIH3T3 cells, mouse bone marrow cells, and in human CD34+-enriched hematopoietic progenitor cells. An SFG-based dicistronic retroviral vector containing human DPD cDNA, an internal ribosomal entry site (IRES), and the neomycin phosphotransferase (Neo) gene was constructed (SFG-DPD-IRES-Neo). Transduced NIH3T3 cells demonstrated a 2-fold (ED50) increase in resistance to a 4-hour exposure of 5-FU in comparison to nontransduced cells. Expression of DPD was confirmed by Northern and Western blot analyses, and DPD enzyme activity was detectable only in transduced cells. Infection of mouse bone marrow cells with this retroviral construct resulted in an increased number of 5-FU-resistant CFU-GM colonies, compared to mock-transduced bone marrow in both 4-hour and 12- to 14-day exposures. Infection of human CD34+-enriched cells with this construct and incubation with 5-FU (10(-6) M) for 14 days also resulted in an increased number of 5-FU-resistant colonies. Retroviral transduction of human hematopoietic progenitor cells with a cDNA-expressing human DPD conferred resistance to 5-FU in NIH3T3 cells, mouse bone marrow cells, and human CD34+-enriched cells. These results encourage the use of this gene as a method to protect patients from 5-FU myelotoxicity.

Erythema annulare centrifugum as the presenting sign of CD 30 positive anaplastic large cell lymphoma--association with disease activity

Erythema annulare centrifugum is a figurate erythema that has been associated with many different entities. A case of erythema annulare centrifugum related to non-Hodgkin's lymphoma in a 38-year-old woman is described in this case report. Response of the lymphoma to a combination chemotherapy was accompanied by disappearance of skin lesions. When therapy was discontinued, both disorders recurred, and both responded to reinstitution of a different chemotherapy regimen. To our knowledge, this case is the first reported association of erythema annulare centrifugum and non-Hodgkin's lymphoma in the medical literature.

The relationship between gastric-oral Helicobacter pylori and oral hygiene in patients with vitamin B12-deficiency anemia

OBJECTIVE

The aim of this study was to determine whether a relationship exists between gastric and oral Helicobacter pylori and oral hygiene in patients with vitamin B12 deficiency.

STUDY DESIGN

One hundred eight patients with vitamin B12 deficiency who were H pylori -positive in their gastric mucosa were enrolled in the study. These patients were divided into 3 groups determined by Oral Hygiene Index (OHI) scores of good, fair, or poor. H pylori was detected in the dental plaque with camphylobacter-like organism test gels. All patients were treated with a combination regimen to eradicate H pylori.

RESULTS

H pylori positivity in dental plaque was correlated with OHI scores; the positivity was 28.5%, 90.2%, or 100% in patients with good, fair, or poor OHI scores, respectively. The eradication of H pylori was associated with recovery from anemia and increased serum vitamin B12 level (P <.0001 and P <.0001). The patients with poor OHI scores had the most frequent gastric recurrence of H pylori (58.3%) compared with those with fair OHI scores (41.2%) and good OHI scores (4.8%).

CONCLUSIONS

H pylori seems to be an etiologic factor in vitamin B12 deficiency, since anemia was cured and the level of vitamin B12 in the serum increased as a result of its eradication. However, eradication of H pylori from gastric mucosa alone is not enough to prevent gastric recurrence of the bacteria. Proper oral hygiene must be established to eliminate H pylori in dental plaque. Therefore, we suggest that control of H pylori in dental plaque is necessary to control recurrence of H pylori.

Successful treatment of severe aplastic anemia associated with human parvovirus B19 and Epstein-Barr virus in a healthy subject with allo-BMT

Several reports have noted pancytopenia associated with Human parvovirus B19 (PVB19) or Ebstein-Barr virus (EBV) infections in patients who have no history of immunodeficiency. To our knowledge, we report the first case of severe aplastic anemia associated with both EBV and PVB19 infections in a previously healthy 22-year-old man. He was admitted to our hematology service due to anemia and thrombocytopenia. He had no symptoms or signs of infections of these viruses. His bone marrow biopsy revealed a hypocellular marrow. Specific IgM and IgG antibodies to EBV and PVB19 were elevated. EBV and PVB19 virus genomes were detected by PCR in the bone marrow nucleated cells and the peripheral blood lymphocytes. Two months after treatment with prednisone, acyclovir, and intravenous immune globulin (IVIg), the genomes of both these viruses disappeared. However, his transfusion requirement for platelet suspensions and packed red blood cells persisted. The patient underwent allogeneic bone marrow transplant (allo-BMT) and has had an enduring complete hematological response for 8 months.

Chronic myelomonocytic leukemia developed 2 years after the onset of immune thrombocytopenic purpura like syndrome

An 80-year old man was diagnosed as having immune thrombocytopenic purpura based on epistaxis, purpura and by the platelet count 8 x 10(9)/l. Prednisolone and gamma globulin were administered and the platelet count had been kept around 50 x 10(9)/l during his follow up. Two years from the onset of immune thrombocytopenic purpura he was admitted because of leukocytosis (79 x 10(9)/l with 79% monocytes), anemia and thrombocytopenia. Hypercellular bone marrow with dysplasia of three lineages was observed. In the bone marrow cytogenic analysis, a -6, clonal cytogenic abnormality was observed. 45XY, der(6), t(6;6)(q16;q23). He was diagnosed as having chronic myelomonocytic leukemia. This is a difficult case in which it was diagnosed as refractory thrombocytopenia as a subgroup of myelodysplastic syndrome, rather than immune thrombocytopenic purpura. which might have preceded the development of chronic myelomonocytic leukemia.

Comparison of methotrexate resistance conferred by a mutated dihydrofolate reductase (DHFR) cDNA in two different retroviral vectors

We previously reported the protection of hematopoietic cells from methotrexate (MTX) toxicity using an N2-based double copy vector containing serine 31 (S31)-mutated dihydrofolate reductase (DHFR) (DC/SV6S31). To examine whether the use of SFG-based dicistronic vectors will lead to improvement in gene transfer over the DC/SV6 vector, we compared the protection provided by MTX to NIH3T3 cells and hematopoietic progenitor cells infected with these retroviral constructs containing the S31 variant DHFR cDNA. In NIH3T3 cells, the 50% effective dose values of MTX conferred by the SFG vector were 8-fold higher than those obtained with the DC/SV6 vector. DHFR mRNA levels were 22-fold and 38-fold higher than that seen for the DC/SV6 vector according to Northern blot and real-time polymerase chain reaction analysis, respectively. However, DHFR protein expression and DHFR enzyme activity were only 1.5-fold and 2-fold higher in the SFG vector, respectively, indicating that the mRNA from the SFG vector is translated less efficiently than the mRNA generated from the DC/SV6 vector. Furthermore, the degree of MTX protection conferred by each vector in both mouse and human hematopoietic cells was the same. These results indicate that the in vitro transduction efficiency and transgene expression of human DHFR in hematopoietic progenitor cells is equally conferred by both vectors.

Helicobacter pylori--is it a novel causative agent in Vitamin B12 deficiency?

BACKGROUND

Evidence for vitamin B12 deficiency usually involves combinations of low serum vitamin B12 levels, clinical and metabolic abnormalities, and therapeutic response. Identification of the underlying cause is important in the diagnosis of vitamin B12 deficiency that is usually attributed to malabsorption. Helicobacter pylori is one of the most common causes of peptic ulcer disease worldwide and a major cause of chronic superficial gastritis leading to atrophy of gastric glands. It is suggested that there may be a casual relationship between H. pylori and food-cobalamin malabsorption.

OBJECTIVES

To evaluate the H. pylori incidence in patients with vitamin B12 deficiency prospectively and to assess whether treatment for H pylori infection could correct this deficiency over time.

PATIENTS AND METHODS

We performed a prospective cohort study involving 138 patients who had anemia and vitamin B12 deficiency. An upper gastrointestinal endoscopy was performed to assess the severity of atrophic gastritis and biopsy specimens for Campylobacter-like organisms tests and histological examination for H pylori were obtained at the time of diagnosis. The diagnosis of H. pylori prompted a combination treatment.

RESULTS

Helicobacter pylori was detected in 77 (56%) of 138 patients with vitamin B12 deficiency and eradication of H pylori infection successfully improved anemia and serum vitamin B12 levels in 31 (40 %) of 77 infected patients.

CONCLUSIONS

Helicobacter pylori seems to be a causative agent in the development of adult vitamin B12 deficiency. Eradication of H. pylori infection alone may correct vitamin B12 levels and improve anemia in this subgroup of patients.

Gene therapy for endometrial carcinoma with the herpes simplex thymidine kinase gene

We investigated whether retrovirus-mediated transfer of the herpes simplex thymidine kinase gene into a human endometrial carcinoma (EC4) cell line can sensitize these cells to the prodrug ganciclovir (GCV) and thereby provide a therapeutic option for this cancer. A retrovirus encoding for the herpes simplex virus tip-1 (HSV) thymidine kinase (tk) gene was generated in which expression of tk is under control of the myeloproliferative sarcoma virus (MPSV) promoter/enhancer. We used human mutated dihydrofolate reductase (DHFR) cDNA as a selectable marker. Expression of tk was confirmed by Northern blot analysis and reverse transcription polymerase chain reaction. We demonstrated that the combination of retrovirally mediated tk gene transfer and GCV treatment effectively inhibits proliferation and causes death of EC4 cells in vitro. A bystander killing effect was observed when 90% of uninfected tumor cells were mixed with only 10% of HSVtk-infected cells. We suggest that a gene therapy approach to endometrial carcinoma can be established using retroviral transfer of HSVtk to tumor cells and subsequent administration of GCV.

Schistosoma mansoni Infection Following Allogeneic Bone Marrow Transplantation

A case of Schistosoma mansoni infection in a 28 year old male after allogeneic bone marrow transplantation presenting with portal hypertension and gross hematuria is described. Schistosomiasis was confirmed by the discovery of parasites in the feces, together with the failure the patient to respond to multiple antimicrobial and antifungal treatment. After praziquantel administration, toxic or septic shock syndrome evolved and the patients died of acute renal failure on day 39 post-transplant. In this report, we would like to emphasize the importance of pre-transplant stool and urine cultures, and appropriate serologic tests in patients coming from endemic areas. Patients diagnosed with schistosomiasis must be treated at least 3 to 7 weeks before transplantation.

Effects of hydroxyethyl starch on blood coagulation profile

The effects of hydroxyethyl starch on blood coagulation were investigated in 20 patients undergoing surgery to determine whether its use places recipients at risk of haemorrhage or thrombosis. The partial thromboplastin times are significantly prolonged; factor VIII activities and fibrinogen levels are decreased. After infusion of hydroxyethyl starch, no significant differences were detected in platelet count or prothrombin time. A decreased platelet aggregation was also found after the infusion of hydroxyethyl starch. According to our results, hydroxyethyl starch can cause haemorrhagic problems in patients when administered as a colloidal volume-expanding agent.

Acute promyelocytic leukemia in the course of acromegaly: a case report

Acromegaly is an uncommon disease due to excessive amounts of growth hormone. Benign and malignant tumors have been reported in acromegalic patients. A 41-year-old female patient who had been followed up because of acromegaly by the endocrinology department for two years, was admitted to the hematology department for the evaluation of pancytopenia and the related signs and symptoms. Dopamine agonists were being used till a diagnosis of 'acute promyelocytic leukemia' was made. Occurrence of 'acute promyelocytic leukemia' in the course of acromegaly may have been caused by excessive endogenous GH or may be a coincidental situation.