Genetic alterations in thyroid hyperfunctioning adenomas

Thirty-seven thyroid autonomously hyperfunctioning adenomas were screened for mutations in the TSH receptor (TSHR), G alpha s (gsp), and ras genes. Polymerase chain reaction-amplified fragments of the TSHR C-terminal part (exon 10), the G alpha s (exons 8 and 9), and the three ras genes were obtained from the genomic DNA extracted from 37 tumors and their adjacent normal tissues and were studied by direct nucleotide sequencing and hybridization with synthetic probes. A point mutation in the third intracellular loop (codon 623) of the TSHR was found in 3 of 37 adenomas studied. This mutation codes for a change (Ala to Ser) in the TSHR structure and is somatic and heterozygotic. Constitutive activation of the TSHR was demonstrated by an increase in basal cAMP levels after transfection of Chinese hamster ovary cells with a mutated Ser623-TSHR complementary DNA. Nine gsp[00ae]MDRV[00af]- and one ras-activating mutations were also detected. No simultaneous alteration of the studied genes was present. Thus, in hyperfunctioning thyroid adenomas, our data suggest that a mutational activation of the TSHR and gsp genes may play a tumorigenic role through constitutive activation of the cAMP pathway.

P170 glycoprotein expression and impaired anthracycline retention in chronic myeloid leukaemia

Chronic myeloid leukaemia (CML) is a well known model of a disease refractory to chemotherapy, including anthracyclines and other drugs that are believed to be pumped out of the cells by a 170 Kd transmembrane glycoprotein (P170). In 35 cases of Ph+ CML we investigated the reactivity of leukaemic cells to a P170-directed monoclonal antibody (MRK-16), by means of flow cytometry. P170 overexpression was found in 4/14 (29%) chronic phase CML cases and in 16/23 (70%) accelerated and blastic phase CML cases (P = 0.01). The same cells were assayed for their ability to retain Daunorubicin and Idarubicin after 2-hours in vitro incubation with 1000 ng/ml of either drug. It was found that anthracycline cell concentration was negatively related with the degree of the reactivity to MRK-16. In accelerated and blastic phase, CML cells simultaneously expressed P170 and the stem cell related marker, CD34. These data confirm that Ph+ leukaemic cells overexpress P170, show that P170 overexpression is functionally relevant, and suggest that P170-related multidrug resistance may be an important factor for chemotherapy failure in Ph+ CML.

MDR-related P170-glycoprotein modulates cytotoxic activity of homoharringtonine

Homoharringtonine (HHT) is a new drug with antileukemic activity which is currently tested for treatment of acute and chronic leukemias, either alone or in combination with other agents. Since HHT showed a low efficacy in refractory and relapsed acute leukemia and in the blastic phase of chronic myeloid leukemia (CML) which are frequently characterized by an overexpresion of the multidrug resistance (MDR)-related P170-glycoprotein, we postulated a relationship between the poor antileukemic effect of HHT in these leukemias and the expression of P170-glycoprotein. For this reason, sensitive (LOVO109 and CEM) and MDR (LOVO DX and CEM VLB) cell lines were exposed to HHT with or without some MDR modifiers, namely, Cyclosporine A (CyA), the Cyclosporine derivative SDZ PSC 833 (PSC), and the D-isomer of Verapamil (DVRP). It was found that MDR cells were about 15 times more resistant to HHT than non-MDR cells, and that resistance to HHT was significantly decreased by all the MDR modifiers that were tested. This in vitro study showed that HHT belongs to the category of MDR-related drugs, like anthracyclines, vinca alkaloids, epipodophylline derivatives, and taxol.

Laparoscopic splenectomy in the management of hematological diseases

The indications for splenectomy in hematological diseases are well known. In particular, they include idiopathic thrombocytopenic purpura (ITP), hereditary spherocytosis (HS) and Hodgkin's disease (HD) (as a part of subdiaphragmatic staging). We present here our initial experience of 10 cases (6 ITP, 2 HS and 2 HD) managed with a laparoscopic approach as opposed to the traditional laparotomy. Advantages over the open operation include decrease of post-operative pain, pulmonary sequelae and infections, cosmetic advantages, faster recovery and reduced hospitalization.

Does the type of BCR/ABL junction predict the survival of patients with Ph1-positive chronic myeloid leukemia?

The prognostic value of the site of DNA rearrangement within the M-BCR on chromosome 22 or of the type of transcript has been debated in the last years. The majority of the studies do not support the hypothesis of a predictive value of such molecular parameters. Results coming from a multicentric, prospective trial, based on alpha-IFN therapy, seem to indicate a better karyotypic response in 3' rearranged patients. The possibility of evoking a cytotoxic immune response directed towards peptides originating from each of the different BCR/ABL junctions constitute an important challenge for the future.

Evaluation of the clinical relevance of the anionic glutathione-s-transferase (GST pi) and multidrug resistance (mdr-1) gene coexpression in leukemias and lymphomas

By using RNA slot-blot technique, the frequency and the degree of GST pi and mdr-1 gene coexpression were investigated in 23 AML patients, 9 ALL, 9 CLL and 11 cases of NHL in an attempt to study their clinical and prognostic relevance. GST pi and mdr-1 levels were expressed as arbitrary units (U) with respect to the negative controls (U = 0), MCF7 and HL60 sensitive cell lines, and the positive controls (U = 10), MCF7/DOXO and HL60/DNR resistant cell lines. The concomitant GST pi/mdr-1 gene overexpression showed a negative prognostic value in the set of newly diagnosed AML pts (10 cases), furthermore higher GST pi and mdr-1 mRNA levels were averagely detected in the relapsed/resistant ALL pts (4 cases), and in CLL (7 cases) and NHL (8 cases) heavily pretreated patients who were unresponsive to chemotherapy and with a disease progression. These preliminary data show that two different mechanisms of drug resistance can be coexpressed at the same time in those leukemias and lymphomas with a clinically unfavourable course.

Verifying the future of electronic eligibility verification

Many vendors and potential users of eligibility verification systems know the obstacles that deter the widespread acceptance and implementation of the technology. On the following pages, executives of firms representing the payor, provider and clearinghouse communities express their perceptions regarding the status and need for online eligibility verification and its cost advantages.

Recombinant human granulocyte-macrophage colony-stimulating factor reverses neutropenia and reduces secondary infections in visceral leishmaniasis

Twenty-four patients with acute visceral leishmaniasis and leukopenia (< 1500 neutrophils/mm3) due to Leishmania chagasi were studied, 4 in an open-label pilot study and 20 in a double-blind, placebo-controlled trial. Patients received granulocyte-macrophage colony-stimulating factor (GM-CSF), 5 micrograms/kg daily, or placebo for 10 days, plus 10-20 mg/kg pentavalent antimony daily for 20 days. In GM-CSF recipients, neutrophil counts increased threefold and fourfold over baseline at 5 and 10 days, respectively, and were significantly higher than those in placebo recipients (P < .02). Eosinophil and monocyte counts were significantly increase in GM-CSF recipients at 10 days (P < or = .03). Secondary infections occurred in 3 GM-CSF and in 8 placebo recipients (P = .04). All patients had complete resolution of their leishmaniasis at 3 months. Few adverse events were recorded. GM-CSF, 5 micrograms/kg daily for 10 days, was safe, rapidly reversed neutropenia, and reduced the number of secondary infections in patients with leishmaniasis.

Development of autoimmune thyroid diseases during long-term treatment of hematological malignancies with alpha-interferons

In recent years recombinant alpha-interferons (alpha-IFNs) have been widely used in the treatment of several hematological malignancies. Prolonged courses of IFN have been shown to induce autoantibodies and to support the exacerbation or even the development of autoimmune diseases. In this report we describe the development of symptomatic autoimmune thyroid diseases in 4 (7.4%) out of 54 patients in chronic treatment with recombinant alpha-IFNs in our department. Two patients developed a disease resembling Hashimoto's thyroiditis after 17 and 49 months of continuous IFN treatment, while the other two developed a typical Graves' disease after 41 and 52 months of therapy. The mechanism by which IFN induces autoimmune thyroid diseases, the choice of searching for anti-thyroid autoantibodies before starting long-term IFN treatment, the option of discontinuing IFN therapy in the presence of overt thyroid diseases, and the management of these diseases are discussed.

Coexpression of anionic glutathione-S-transferase (GST pi) and multidrug resistance (mdr1) genes in acute myeloid and lymphoid leukemias

By using RNA slot-blot technique the frequency and degree of GST pi and mdr1 gene coexpression was investigated in 23 patients with acute myeloid leukemia (AML), and nine patients with acute lymphoid leukemia (ALL). With respect to the negative controls, MCF7 and HL-60 cell lines, increased GST pi and mdr1 mRNA levels, expressed as arbitrary units (U), were respectively detected both in AML and in ALL patients. A positive and significant correlation between GST pi and mdr1 gene expression was found in the group of AML patients, while in the smaller group of ALL patients only a trend could be shown. These data show that two different mechanisms of drug resistance can be coexpressed at the same time in patients with acute myeloid and lymphoid leukemia. From this evidence many important clinical and therapeutic questions arise.

Different molecular mechanisms are involved in the multihormonal control of glucose transport in FRTL5 rat thyroid cells

We investigated the molecular mechanisms by which TSH, insulin and IGF-1 modulate the glucose transport system in FRTL5 cells. We found that TSH, insulin and IGF-1 increased the glucose transporter Glut-1 specific mRNA levels 6, 8 and 5 fold over control, respectively. The effect on Glut-1 mRNA was evident after 2 hours, followed by an increased Glut-1 protein expression in whole cells, as judged by western blot analysis, after 5 hours of stimulation with all the hormones studied. In contrast, plasma membrane Glut-1 increased (300-400% over control) after 2 hours of stimulation with TSH (10 mU/ml), dibutyryl-cAMP (1mM), IGF-1 (10 ng/ml) and insulin (10 nM). These data indicate that the glucose transport system is under multihormonal control in FRTL5 cells. Two different mechanisms are involved in TSH, IGF-1 and insulin stimulation of the glucose transport: a) neosynthesis of Glut-1 by activation of gene expression; b) recruitment of carriers from the intracellular pool to the plasma membrane.

Overexpression of MDR-related p170 glycoprotein in chronic myeloid leukemia

BACKGROUND AND METHODS

Philadelphia (Ph) positive chronic myeloid leukemia (CML) cannot be induced into a true remission with conventional chemotherapy. Blast cells and precursors obtained from 51 Ph+ CML cases were assayed for expression of the multidrug resistance (MDR)-associated glycoprotein (p170) by immunocytochemistry (APAAP) with the MRK-16 monoclonal antibody.

RESULTS AND CONCLUSIONS

Positive cells were found in 11/17 cases in chronic phase (65%), in 4/8 cases in accelerated phase, and in 23/26 cases in blastic phase (89%). The proportion of positive cells, which ranged between less than 1% and 95%, was higher in blastic phase (mean 32 +/- 29.9) than in chronic phase (mean 3 +/- 5.3) (p = 0.006). These findings show that p170 overexpression is common in Ph+ CML, especially after progression to blastic phase, and suggest that p170-related MDR may contribute significantly to treatment failure.

p170-dependent multidrug resistance. Restoring full sensitivity to idarubicin with verapamil and cyclosporin A derivatives

BACKGROUND

Cell sensitivity to anthracyclines and other drugs depends on several factors, including overexpression of a 170Kd transmembrane glycoprotein (P170) that enhances drug efflux from the cells. Since the result of treatment is negatively related to the expression of P170 in leukemia, malignant lymphoma and other tumors, it is important to investigate drugs and methods that can modify multidrug resistance (MDR).

MATERIALS AND METHODS

Using an MTT-microcultured tetrazolium colorimetric method, we assayed sensitivity to daunorubicin (DNR) and to its 4-demethoxy derivative idarubicin (IDA) in two MDR cell lines (CEM VLB and LOVO DX) and in their respective non-MDR parental lines (CEM and LOVO 109), with and without three MDR modifiers, namely the D-isomer of verapamil (DVRP), cyclosporin A (CyA) and the new CyA derivative SDZ PSC 833.

RESULTS

We showed that down-modulation of resistance with MDR modifiers was greater for DNR than for IDA in MDR cells. However, we also demonstrated that restoration of full sensitivity could only be achieved for IDA, not for DNR. DVRP and CyA in combination were more effective than either compound alone and could abolish P170-related resistance to IDA at concentrations of 1-2 microM and 1.6 microM, respectively. SDZ PSC 833 alone was even more effective and set MDR to zero at a concentration ranging between 0.8 and 1.6 microM.

CONCLUSIONS

These data suggest that combinations of IDA and MDR modifiers may improve the results of cancer and leukemia treatment and that they are worth investigating in vivo, with attention to possible effects on drug pharmacokinetics and on normal tissue damage.

Granulocyte-macrophage colony-stimulating factor in combination with pentavalent antimony for the treatment of visceral Leishmaniasis

The efficacy of GM-CSF was investigated in 20 neutropenic patients (< 1500 neutrophils/microliters) with acute visceral leishmaniasis due to Leishmania chagasi. Patients were randomized to receive either GM-CSF, 5 micrograms/kg daily (intravenously or subcutaneously), or placebo for ten days, in combination with pentavalent antimony, 10-20 mg/kg daily for 20 days. Neutrophil counts were significantly greater on days 5 and 10 of treatment in the GM-CSF group compared with the placebo group (p < 0.02). Eosinophil and monocyte counts were also significantly increased in the GM-CSF group at day 10 (p < or = 0.03). Interestingly, at day 30, platelet counts were significantly increased in the GM-CSF group on days 5 and 10 (p = 0.04 and 0.02, respectively). Patients in the GM-CSF group experienced fewer secondary bacterial or viral infections than placebo patients. Infections occurred in only three patients given GM-CSF compared with eight patients given placebo (p < 0.04). All patients had complete resolution of disease symptoms at three months. Few adverse events were recorded. GM-CSF given subcutaneously at a dose of 5 micrograms/kg daily for ten days was well tolerated, reversed neutropenia rapidly and reduced the number of secondary infections in patients with leishmaniasis.

Role of loop diuretics in chronic renal failure

The natriuretic effects of furosemide and the long-acting loop diuretic torasemide have been compared in patients with chronic renal failure with and without nephrotic syndrome. In patients with chronic renal failure without nephrotic syndrome, furosemide and torasemide exerted similar natriuretic activity. In patients with chronic renal failure complicated by nephrotic syndrome, torasemide showed a greater natriuretic potency and a longer duration of action than furosemide.

Alpha-interferon as maintenance drug after initial fludarabine therapy for patients with chronic lymphocytic leukemia and low-grade non-Hodgkin's lymphoma

BACKGROUND

Fludarabine monophosphate (FLU) is an adenine nucleoside analogue with promising therapeutic activity in lymphoproliferative disorders. In addition, the effectiveness of alpha-interferon (alpha-IFN) in low-grade non-Hodgkin's lymphoma (LG-NHL) and B-cell chronic lymphocytic leukemia (B-CLL) has been demonstrated in several clinical trials.

METHODS

In a phase II study of 45 patients with B-CLL and 28 with LG-NHL, we used FLU as second and third-line chemotherapy. Dosages of 25 mg/m2 were given in 30-minute infusions for 5 consecutive days. Treatment was repeated every 28 days depending on patients' clinical status for a maximum of 6 cycles. Entrance in the human lymphoblastoid alpha-IFN maintenance portion of the study depended on response to initial FLU. Following randomization we administered alpha-IFN, or no therapy at all, to patients who obtained a complete or a partial response after FLU therapy. The alpha-IFN dose was 3 x 10(6) U three times per week until disease progression.

RESULTS

Twenty-one B-CLL patients achieved major responses, as did 17 of those with LG-NHL. Twenty-four of the former group and 11 of the latter failed to respond or obtained only a minor response. The 38 patients who responded well and entered the second part of the trial showed significant prolongation of remission duration with maintenance alpha-IFN.

CONCLUSIONS

In consideration of its significant activity, the role of FLU in the management of lymphoproliferative disorders needs to be evaluated further; at the same time, this preliminary analysis seems to indicate that maintenance alpha-IFN may extend remission duration in B-CLL and LG-NHL.

Expression of resistance genes in acute leukemia

To evaluate the frequency and the prognostic value of different mechanisms of drug resistance in acute leukemias, we investigated the expression of mdr1 by immunocytochemistry, mRNA slot blot or RT-PCR in 182 cases of adult acute myeloid and 37 cases of adult lymphoblastic leukemia. Before treatment, 39% of de novo AML, 38% of secondary AML, and 7% of de novo ALL exhibited a high level of mdr1 mRNA. After chemotherapy, the frequency of mdr1 gene expression in ALL raised dramatically to 60% (P < 0.005), while no significant change was found for AML cases. In 91 patients treated with MDR-related drugs, mdr1 gene expression was related to the failure of chemotherapy (P < 0.0001). The overexpression of multidrug resistance-associated protein (mrp) and anionic glutathione S-transferase (GST pi) was also investigated in 38 and 61 AML patients respectively. An overexpression of mrp gene was noted in 39% of the cases. For GST pi gene, the frequency of overexpression was 28%. A positive and significative correlation was found among mdr1, mrp and GST pi genes expression.

Human organ-specific autoimmune disease. Molecular cloning and expression of an autoantibody gene repertoire for a major autoantigen reveals an antigenic immunodominant region and restricted immunoglobulin gene usage in the target organ

The most common organ-specific autoimmune disease in humans involves the thyroid. Autoantibodies against thyroid peroxidase (TPO) are present in the sera of virtually all patients with active disease. We report the molecular cloning of the genes for 30 high-affinity, IgG-class human autoantibodies to TPO from thyroid-infiltrating B cells. Analysis of the putative germline genes used for the TPO human autoantibodies suggests the use of only five different H and L chain combinations involving four H chains and three L chains. In addition, the same combination of H and L chains was found in multiple patients. The F(ab) proteins expressed by these genes define two major, closely associated domains (A and B) in an immunodominant region on TPO. These A and B domains contain the binding sites of approximately 80% of IgG-class TPO autoantibodies in the sera of patients with autoimmune thyroid disease. The present information permits analysis, not previously possible, of the relationship between autoantibody H and L chain genes and the antigenic domains on an autoantigen. Our data, obtained using target organ-derived autoantibodies, indicate that there is restriction in H and L chain usage in relation to the interaction with specific antigenic domains in human, organ-specific autoimmune disease.

The type of BCR/ABL junction does not predict the survival of patients with Ph1-positive chronic myeloid leukaemia

The prognostic value of the location of the breakpoint on chromosome 22 in patients with Ph1+ chronic myeloid leukaemia (CML) is still controversial. We analysed both DNA rearrangement and transcript type in a new continuous series of CML patients. By Southern blotting analysis, we found that, out of 72 patients, 43 had a 5' rearrangement and 29 a 3' one, of the 43 5'-rearranged patients, 35 carried an a2b2 transcript and eight an a2b3 one, while, of the 29 patients rearranged in the 3' part of the M-BCR area, 26 had an a2b3 transcript, one had an a2b2 transcript and two carried both types of transcript. Thus, mRNA studies allow to detect an a2b3 transcript in 17.7% of 5' rearranged patients. However, no correlation was observed between type of transcript and survival, as after DNA studies.

Molecular mechanisms of the increased glucose transport in transformed FRTL-5 rat thyroid cells

We investigated the molecular mechanisms involved in the glucose carrier (Glut 1) regulation in FRTL-5 cells and two derived transformed clones (SRC and Ki-Mol cells). When compared to the wild-type strain, SRC and Ki-Mol cells showed an increase in both glucose consumption and uptake (about 60 fold), associated with 6-8 fold higher Glut 1 mRNA levels. Transcriptional studies revealed a 2- to 3 fold increased activation of the gene in the transformed cells, suggesting that transcription alone cannot fully account for the higher Glut 1 gene expression. Western blot studies showed an increase of the Glut 1 protein in SRC and Ki-Mol cells, associated with a different gel migration pattern and a disparate distribution rate between the plasma membrane and the microsomal fraction. These data indicate that the higher rate of glucose uptake observed in SRC and Ki-Mol cells is associated to an increase in Glut 1 gene expression, and that also changes in the subcellular distribution and probably in the structure of Glut 1 protein are present.

Extra-natriuretic effects of atrial peptide in humans

To evaluate extra-natriuretic effects of atrial natriuretic peptide (ANP), plasma ANP (pANP) levels were assessed in seven healthy men on low-sodium diet (80 mEq NaCl/day), in basal conditions and during stepwise infusion of human ANP (2, 4, 8 and 16 ng/min/kg). To determine the individual physiological (PHY) pANP level, we measured pANP in the same subjects after a high-salt diet (400 mEq NaCl/day), that is, in a physiological stimulation of ANP. We then compared the effects of the PHY levels of ANP to the effects of pharmacological (PHA) pANP levels. Neither PHY nor PHA pANP levels modified creatinine clearance or blood pressure. The progressive rise in pANP levels was associated with increases in urinary excretion of Na+, K+ and urea. ANP alone respectively accounted for 41%, 30% and 92% of the increase in natriuresis, kaliuresis and urea excretion that occurred after changing salt intake from 80 to 400 mEq/day. Pharmacological ANP levels raised CH2O and reduced UOsm. Interestingly, PHA levels were associated with significant decrease in serum K+ (from 4.5 +/- .1 to 4.0 +/- .1 mEq/liter) and plasma urea (from 31.9 +/- 5 to 24.2 +/- 4 mg/dl). The mean cumulative urinary potassium and urea losses corresponded to the theoretical body losses of potassium and urea; moreover, the individual cumulative urinary losses of potassium and urea significantly correlated with the corresponding decrement in their plasma levels. In conclusion, ANP has both physiological and pharmacological significance in the control of potassium and urea metabolism by decreasing plasma levels of K+ and urea through effects on the renal excretory function.