The use of Ferastral in iron-deficient, non-pregnant Gambian adults

A new parenteral iron preparation, iron-poly (sorbitol-gluconic acid) complex, (Ferastral) has been evaluated in the treatment of iron-deficient, non-pregnant Gambian adults. A total of twenty patients of both sexes were included in the study. The cause of anaemia in the majority of cases was hookworm infection but also other diagnostic categories were present. Sixteen patients completed their treatment without difficulty. All patients showed a good initial haematological response. Over the first three weeks the mean daily increments followed a linear trend. There was a significant inverse correlation between initial haemoglobin concentration and the increment in concentration after three weeks treatment. Side-effects were noted in four patients; in two patients it was ascribed to treatment, in two there was concurrent infection. Parenteral iron therapy is considered to have definite advantages over oral iron in the tropics because of certainty of administration, replenishment of iron stores, and effectiveness when small bowel disease or dietary factors reduce absorption.

RNA structure prediction from evolutionary patterns of nucleotide composition

Structural elements in RNA molecules have a distinct nucleotide composition, which changes gradually over evolutionary time. We discovered certain features of these compositional patterns that are shared between all RNA families. Based on this information, we developed a structure prediction method that evaluates candidate structures for a set of homologous RNAs on their ability to reproduce the patterns exhibited by biological structures. The method is named SPuNC for ‘Structure Prediction using Nucleotide Composition’. In a performance test on a diverse set of RNA families we demonstrate that the SPuNC algorithm succeeds in selecting the most realistic structures in an ensemble. The average accuracy of top-scoring structures is significantly higher than the average accuracy of all ensemble members (improvements of more than 20% observed). In addition, a consensus structure that includes the most reliable base pairs gleaned from a set of top-scoring structures is generally more accurate than a consensus derived from the full structural ensemble. Our method achieves better accuracy than existing methods on several RNA families, including novel riboswitches and ribozymes. The results clearly show that nucleotide composition can be used to reveal the quality of RNA structures and thus the presented technique should be added to the set of prediction tools.

p63 in epithelial development

The epidermis, the outer layer of the skin composed of keratinocytes, is a stratified epithelium that functions as a barrier to protect the organism from dehydration and external insults. The epidermis develops following the action of the transcription factor p63, amember of the p53 family of transcription factors. The Trp63 gene contains two promoters driving the production of distinct proteins, one with an N-terminal transactivation domain (TAp63) and one without (DeltaNp63), although their relative contribution to epidermal development is not clearly established. Trp63 mutations are involved in the pathogenesis of several human diseases, phenotypically characterized by ectodermal dysplasia. In this review, we summarize the current advances that have been made in understanding the role of p63 in epidermal morphogenesis.

The role of glycogen synthase kinase-3beta in normal haematopoiesis, angiogenesis and leukaemia

Glycogen synthase kinase 3 beta (GSK-3beta) was one of the first kinases identified and studied, initially for its role in the regulation of glycogen synthesis. Over the past decade, interest in GSK-3beta has grown far beyond glycogen metabolism, and this is due in large measure to the critical role that GSK-3beta plays in the regulation of many other cellular processes, particularly cell proliferation and apoptosis. GSK-3beta has been shown to regulate the proteolysis and sub-cellular compartmentalization of a number of proteins directly involved in the regulation of cell cycling, proliferation, differentiation and apoptosis. GSK-3beta also regulates the degradation of proteins that regulate gene expression and thus affects a variety of important cell functions. Specifically, GSK-3beta controls the degradation of beta-catenin, the main effector of Wnt that regulates haematopoiesis and stem cell function. In this case GSK-3beta is a negative regulator of Wnt. In contrast, GSK-3beta positively regulates NF-kappaB, another important biochemical pathway also involved in the regulation of multiple aspects of normal and aberrant haematopoiesis. GSK-3beta regulates degradation of IkappaB, a central inhibitor of NF-kappaB. In this way, GSK-3beta acts to control the resistance of leukaemic cells to chemotherapy through the modulation of NF-kappaB, a critical factor in maintaining leukaemic cell growth. In addition, GSK-3beta regulates the pro-inflammatory activity of NF-kappaB. As GSK-3beta is a pleiotropic regulator, inhibitors may increase the range of novel anti-leukaemic and anti-inflammatory drugs that control immune response.

Itch: a HECT-type E3 ligase regulating immunity, skin and cancer

The HECT-type E3 ubiquitin ligase (E3) Itch is absent in the non-agouti-lethal 18H or Itchy mice, which develop a severe immunological disease, including lung and stomach inflammation and hyperplasia of lymphoid and hematopoietic cells. The involvement of Itch in multiple signaling pathways and pathological conditions is presently an area of extensive scientific interest. This review aims to bring together a growing body of work exploring Itch-regulated biological processes, and to highlight recent discoveries on the regulatory mechanisms modulating its catalytic activity and substrate recognition capability. Our contribution is also an endeavor to correlate Itch substrate specificity with the pathological defects manifested by the mutant Itchy mice.

Disease-associated prion protein is not detectable in human systemic amyloid deposits

Cerebral and cardiac amyloid deposits have been reported after scrapie infection in transgenic mice expressing variant prion protein (PrP(C)) lacking the glycophosphatidylinositol anchor. The amyloid fibril protein in the systemic amyloid deposits was not characterized, and there is no clinical or pathological association between prion diseases and systemic amyloidosis in humans. Nevertheless, in view of the potential clinical significance of these murine observations, we tested both human amyloidotic tissues and isolated amyloid fibrils for the presence of PrP(Sc), the prion protein conformation associated with transmissible spongiform encephalopathy (TSE). We also sequenced the complete prion protein gene, PRNP, in amyloidosis patients. No specific immunohistochemical staining for PrP(Sc) was obtained in the amyloidotic cardiac and other visceral tissues of patients with different types of systemic amyloidosis. No protease-resistant prion protein, PrP(res), was detectable by Western blotting of amyloid fibrils isolated from cardiac and other systemic amyloid deposits. Only the complete normal wild-type PRNP gene sequence was identified, including the usual distribution of codon 129 polymorphisms. These reassuringly negative results do not support the idea that there is any relationship of prions or TSE with human systemic amyloidosis, including cardiac amyloid deposition.

Pharmacokinetics of lenalidomide in subjects with various degrees of renal function

2520

Background: Lenalidomide is a novel oral immunomodulatory drug approved for treating myelodysplastic syndrome (MDS) and multiple myeloma (MM). As unchanged lenalidomide is eliminated predominantly by urinary excretion, the present study investigated the effect of renal impairment (RI) on pharmacokinetics (PK) of lenalidomide. Results were used to refine initial dosing recommendations based on a subject’s estimated creatinine clearance. Methods: The study was conducted at 3 clinical centers. Thirty male and female subjects aged 39–76 years were stratified into 5 groups based on their creatinine clearance (CLCr) values: normal renal function (NRF) (CLCr > 80 mL/min; N = 7), mild RI (50 = CLCr = 80 mL/min; N = 5), moderate RI (30 = CLCr < 50 mL/min; N = 6), severe RI (CLCr < 30 mL/min, but not on dialysis; N = 6), and end stage renal disease (ESRD, requiring dialysis; N = 6). Subjects with NRF, mild, moderate or severe RI received a single 25-mg oral dose of lenalidomide. Subjects with ESRD received 2 single 25 mg doses which were separated by 7–10 days: one dose on a non-dialysis day and the other dose 3 hours before a 4-hour haemodialysis. Assessments included PK and safety parameters. Results: All subjects completed the study. Total and renal clearance of lenalidomide were strongly correlated with CLCr (R > 0.9, p < 0.01). As a result, AUC8 increased with decreasing CLCr. The mean difference in AUC8 between NRF and mild RI was < 20%. Compared with the pooled data from NRF and mild RI groups, mean AUC8 increased approximately 140% in moderate RI, 240% in severe RI, and 360% in ESRD (off dialysis). There was no correlation between Cmax or Tmax and CLCr. Approximately 10% of the dose was recovered in the dialysate of subjects with ESRD. Protein binding of lenalidomide was not markedly affected by RI (∼35 - 44%). The drug was well tolerated. On the basis of these data, recommendations for initial starting doses were made ( Table below). Conclusions: Lenalidomide dosage adjustment should be considered for patients with CLCr < 50 mL/min.

[Table: see text]

No significant financial relationships to disclose.

A case report of sarcoma regression in a patient with MDS treated with lenalidomide

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Background: Lenalidomide is an immunomodulatory drug recently approved for the treatment of MDS patients with del 5q cytogenetic abnormality. Here we describe a case of sarcoma regression in a patient with MDS who had been treated with lenalidomide. Method: An 84 year old man was diagnosed with low risk MDS in November 2002, he was transfusion dependent requiring 2–4 units of blood a month. He was enrolled on the MDS 002 trial in February 2004. He became transfusion independent by cycle 4. Results: In March 2005 he developed abdominal pain and a CT of the abdomen revealed a 2 x 2 cm mass involving the lesser curvature of the stomach. An MRI of the abdomen followed, confirming the presence of an enhancing gastric lesion, a biopsy of the mass revealed low grade malignant sarcoma. The patient was a poor surgical candidate and the decision was made to follow the progression of the mass with repeat imaging. In October 2005 a repeat MRI failed to visualize the previously noted mass, a recent CT performed in December 2006 was also negative for the presence of the mass. A potential therapeutic role for lenalidomide in this case which may have led to the regression of the sarcoma is possible although spontaneous regression can not be ruled out. It is not known if the mass was present at the time of enrollment on the clinic trial, it is also not clear as to why the patient presented with abdominal pain several months into the clinical trial. There had been several case reports in the literature describing similar results with thalidomide in patients with soft tissue sarcoma however, to our knowledge this clinical observation has never been reported with lenalidomide previously. Conclusion: This observation merits consideration for prospectively evaluating the efficacy of lenalidomide in patients with sarcoma for whom limited therapeutic options currently exist.

No significant financial relationships to disclose.

A phase I/II study of lenalidomide (Len) in combination with rituximab (R) in relapsed/refractory mantle cell lymphoma (MCL) with early evidence of efficacy

8030

Background: MCL remains a therapeutic challenge. R targets CD20 antigen on MCL cells while Len may target the microenvironment of MCL cells and enhance the ADCC activity of R. To test this hypothesis, we initiated a single-center; open label, phase I/II study. We now report the completed phase I. Methods: Eligible patients (pts) had 1–4 lines of prior therapy including prior thalidomide or R, regardless of resistance. Each cycle of treatment consisted of Len given orally daily on days 1–21 of a 28-day cycle and R 375 mg/m2 by IV infusion weekly for 4 weeks. A standard 3+3 dose escalation was used to determine MTD with Len doses at 10 mg, 15 mg, 20 mg, and 25 mg. DLT was defined as grade (G) 3 or 4 non-hematologic or G4 hematologic toxicity during the first cycle. Results: The phase I portion completed enrollment with 15 pts (4 at 10 mg, 3 at 15 mg, 6 at 20 mg and 2 at 25 mg). Thirteen pts were evaluable. Median age was 73 (62–84); median prior lines of therapy were 3 (1–4); median cycles received to date were 2 (1–7). Two DLT's occurred at 25 mg. One pt had G3 hypercalcemia. The other had G4 neutropenic fever and died of sepsis (G5) during the first cycle. Three additional pts were therefore enrolled at 20 mg. Common non-hematologic toxic events included pruritis (21 G1–2), hypercalcemia (9 G1–2, 1 G3), fatigue (9 G1–2), constipation (8 G1), diarrhea (6 G1–2), fever (6 G1–2), myalgias (4 G1–2, 1 G3) and elevated LDH (4 G1–2, 1 G3). Hematologic events included neutropenia (20 G1–2, 4 G3), thrombocytopenia (6 G1–2, 2 G3) and anemia (6 G1). There were no responses at 10 mg or 15 mg. At 20 mg after 2 cycles, 5 out of 6 pts achieved responses including 1 CR, 1 PR, 3 minor responses (MRs) and only 1 pt progressed. The 1 pt with PR went on to achieve a CR after 6 cycles. The 3 pts with MRs had tumor reductions by 43%, 40% and 38% respectively. These 3 patients with MRs continue to receive Len and might later achieve PR or CR. Conclusions: The MTD for Len with R in relapsed/refractory MCL was 20 mg, orally daily on days 1–21 of a 28-day cycle. Responses observed at 20 mg are promising with a favorable toxicity profile and are being evaluated further in an ongoing phase II study.

[Table: see text]