Vitamin D and iron deficiencies in children and adolescents with cerebral palsy. / Deficiencia de vitamina D y de hierro en niños y adolescentes con parálisis cerebral.

INTRODUCTION: Children and adolescents with cerebral palsy (CP) are at a greater risk of malnutrition and micronutrient deficiencies. Two deficiencies that we can study and treat are vitaminD (VD) and iron deficiencies; however, no studies have described these deficiencies in Chile. OBJECTIVE: To describe the status of VD and iron in patients with CP and evaluate the relationship with certain factors associated with deficiencies of these micronutrients. PATIENTS AND METHOD: We performed a descriptive, cross-sectional study including 69 patients aged between 2 and 21years, from two public hospitals. Data were obtained on demographic variables, motor function, use of feeding tube, and pharmacological treatment. We performed a nutritional assessment according to patterns of CP and determined 25-hydroxyvitaminD (25[OH]D) ferritin, and albumin levels. RESULTS: Patients' mean age was 11.1±4.9years; 43 (62.3%) were male; and 56 (81.2%) had moderate-to-severe CP. Thirty-five (50.7%) used a nasogastric tube and/or gastrostomy; 15.4% were underweight and 73.8% were eutrophic, all with normal height. Twenty (29%) and 4 patients (6.2%) received VD and iron supplementation, respectively. Albuminaemia was normal in all patients. Mean 25(OH)D level was 24.3±8.8ng/mL; 33 patients (47.8%) had insufficiency and 21 (30.4%) deficiency; 36 patients (52.2%) had low ferritin levels. There was no association between 25(OH)D level and the other variables studied. Low ferritin levels were found to be associated with older age (P=.03), being male (P=.006), and feeding tube use (P=.006). CONCLUSIONS: The patients studied mainly had moderate-to-severe CP, with a high frequency of suboptimal VD values and low plasma ferritin; few patients received VD and/or iron supplementation. We suggest monitoring 25(OH)D and ferritin levels due to the high rate of deficiency of these nutrients; public hospitals should be equipped with drugs to treat these deficiencies.

Urinary excretion of ciprofloxacin after administration of extended release tablets in healthy volunteers. Swellable drug-polyelectrolyte matrix versus bilayer tablets.

This paper builds on a previous paper in which new ciprofloxacin extended-release tablets were developed based on a ciprofloxacin-based swellable drug polyelectrolyte matrix (SDPM-CIP). The matrix contains a molecular dispersion of ciprofloxacin ionically bonded to the acidic groups of carbomer, forming the polyelectrolyte-drug complex CB-CIP. This formulation showed that the release profile of the ciprofloxacin bilayer tablets currently commercialised can be achieved with a simpler strategy. Thus, since ciprofloxacin urine concentrations are associated with the clinical cure of urinary tract infections, the goal of this work was to compare the urinary excretion of SDPM-CIP tablets with those of the CIPRO XR® bilayer tablets. A batch of SDPM-CIP tablets was manufactured by the wet granulation method and the CB-CIP ionic complex was obtained in situ. Fasted healthy volunteers received a single oral dose of 500 mg ciprofloxacin of either formulation in a randomised crossover study. Urinary concentrations were assessed by HPLC at intervals up to 36 h. Pharmacokinetic parameters (rate of urinary excretion, maximum urine excretion rate, tmax, area under the curve, amount and percentage of the ciprofloxacin dose excreted in urine) showed no statistical differences between both formulations at any of the time intervals of collection. The processing conditions to obtain SDPM-CIP tablets are easy to scale up since they involve technology currently employed in the pharmaceutical industry and the process is less challenging to implement. In addition, SDPM-CIP tablets met pharmacopoeial quality specifications.

The role of hyaluronan as a drug carrier to enhance the bioavailability of extended release ophthalmic formulations. Hyaluronan-timolol ionic complexes as a model case.

The aim of this work was to obtain information concerning the properties of ophthalmic formulations based on hyaluronic-drug ionic complexes, to identify the factors that determine the onset, intensity and duration of the pharmacotherapeutic effect. Dispersions of a complex of 0.5% w/v of sodium hyaluronate (HyNa) loaded with 0.5% w/v of timolol maleate (TM) were obtained and presented a counterionic condensation higher than 75%. For comparison a similar complex obtained with hyaluronic acid (HyH) was also prepared. Although the viscosity of HyNa-TM was significantly higher than that of HyH-TM, in vitro release of TM from both complexes showed a similar extended drug release profile (20-31% over 5h) controlled by diffusion and ionic exchange. Ocular pharmacokinetic study performed in normotensive rabbits showed that HyNa-TM complex exhibited attractive bioavailability properties in the aqueous humor (AUC and Cmax significantly higher and later Tmax) compared to commercial TM eye-drops. Moreover, a more prolonged period of lowered intra-ocular pressure (10h) and a more intense hypotensive activity was observed after instillation of a drop of HyNa-TM as compared to the eye-drops. Such behavior was related to the longer pre-corneal residence times (400%) observed with HyNa-TM complex. No significant changes in rabbit transcorneal permeation were detected upon complexation. These results demonstrate that the ability of HyNa to modulate TM release, together with its mucoadhesiveness related to the viscosity, affected both the pharmacokinetic and pharmacodynamic parameters. The HyNa-TM complex is a potentially useful carrier for ocular drug delivery, which could improve the TM efficacy and reduce the frequency of administration to improve patient compliance.

Minimal residual disease in acute myelogenous leukemia.

Treatment of acute myelogenous leukemia (AML) over the past four decades remains mostly unchanged and the prognosis for the majority of patients remains poor. Most of the significant advances that have been observed are in defining cytogenetic abnormalities, as well as the genetic and epigenetic profiles of AML patients. While new cytogenetic and genetic aberrations such as the FLT3-ITD and NPM1 mutations are able to guide prognosis for the majority of patients with AML, outcomes are still dismal and relapse rates remain high. It is thought that relapse in AML is in part driven by minimal residual disease (MRD) that remains in the patient following treatment. Thus, there is a need for sensitive and objective methodology for MRD detection. Methodologies such as multiparameter flow cytometry (MFC), quantitative real-time polymerase chain reaction (RQ-PCR), digital PCR (dPCR), or next-generation sequencing (NGS) are being employed to evaluate their utility in MRD assessment. In this review, we will provide an overview of AML and the clinical utility of MRD measurement. We will discuss optimal timing to MRD measurement, the different approaches that are available, and efforts in the standardization across laboratories.

Reduced food interaction and enhanced gastrointestinal tolerability of a new system based on risedronate complexed with Eudragit E100: Mechanistic approaches from in vitro and in vivo studies.

Novel complexes consisting of Eudragit E100-risedronate are presented. The oral bioavailability of risedronate in rats was determined through its percentage excreted in urine after administration of complexed or free risedronate in fed and fasted conditions. The evaluation of the risedronate gastro-duodenal irritation potential was carried out by macroscopic and histological analyses in an experimental rat model. The degree of counterionic condensation between Eudragit E100 and risedronate was assessed by dialysis with, mechanistic information about the interaction with calcium and the release of risedronate from the complexes being obtained using physiological solution and simulated gastric fluid without pepsin. Non-significant differences were observed in the urinary excretion of risedronate when the complex or free risedronate was administered to fasted rats. However, the urinary excretion of risedronate in the complex group was 4-times higher than in the free risedronate group when animals were concomitantly administered with food. This behavior was related to the high degree of counterionic condensation in the complex (86.5%), which led to a reduction in the calcium induced rate and magnitude of risedronate precipitation and resulted in a decrease in the gastroduodenal damage from the complex, as evidenced by a lower frequency of gastric mucosae hemorrhage. A sustained release of risedronate from the complex was observed toward water, simulated gastric fluid or physiological solution, through an ionic-exchange mechanism. In conclusion, complexation with Eudragit E100 could be a useful strategy to overcome the unfavorable properties of risedronate.

Pharmacological targeting of miR-155 via the NEDD8-activating enzyme inhibitor MLN4924 (Pevonedistat) in FLT3-ITD acute myeloid leukemia.

High levels of microRNA-155 (miR-155) are associated with poor outcome in acute myeloid leukemia (AML). In AML, miR-155 is regulated by NF-κB, the activity of which is, in part, controlled by the NEDD8-dependent ubiquitin ligases. We demonstrate that MLN4924, an inhibitor of NEDD8-activating enzyme presently being evaluated in clinical trials, decreases binding of NF-κB to the miR-155 promoter and downregulates miR-155 in AML cells. This results in the upregulation of the miR-155 targets SHIP1, an inhibitor of the PI3K/Akt pathway, and PU.1, a transcription factor important for myeloid differentiation, leading to monocytic differentiation and apoptosis. Consistent with these results, overexpression of miR-155 diminishes MLN4924-induced antileukemic effects. In vivo, MLN4924 reduces miR-155 expression and prolongs the survival of mice engrafted with leukemic cells. Our study demonstrates the potential of miR-155 as a novel therapeutic target in AML via pharmacologic interference with NF-κB-dependent regulatory mechanisms. We show the targeting of this oncogenic microRNA with MLN4924, a compound presently being evaluated in clinical trials in AML. As high miR-155 levels have been consistently associated with aggressive clinical phenotypes, our work opens new avenues for microRNA-targeting therapeutic approaches to leukemia and cancer patients.

Eudragit E100 as a drug carrier: the remarkable affinity of phosphate ester for dimethylamine.

Therapeutic agents containing phosphate groups in their molecules have increasing therapeutic impact. The object of this study was to characterize the cationic polyelectrolyte Eudragit E100 (EuE100) as a carrier for drugs containing phosphate groups, using dexamethasone phosphate (DP) as a model. A series of EuE100-DP complexes was obtained by acid-base reaction in which DP neutralized 12.5-75% of the basic groups of EuE100. The solids obtained after solvent evaporation revealed by spectroscopic characterization the complete reaction between the components through the ionic interaction between the amine groups of EuE100 and the phosphate groups of DP. The reversibility of the counterion condensation, evaluated through the proton-withdrawing effect produced by the ionic exchange generated by titration with NaCl, showed a remarkable high affinity between EuE100 and DP. In line, drug delivery in bicompartimental Franz cells toward water as receptor medium was very slow (2% in 6 h). However, it was increased as water was replaced by NaCl solution, which upon diffusion generates ionic exchange. A sustained release of DP with noticeable zero order kinetics accounted for a remarkable high affinity, mainly due to the electrostatic attraction. The release rate remains constant regardless of the saline concentration of the media. Besides, the delivery control is maintained even in gastric simulated fluid, a property not informed previously for EuE100 complexes.

Clinical features of chromosome 22q11.2 microdeletion syndrome in 208 Chilean patients.

Patients with chromosome 22q11 deletion syndrome exhibit significant phenotypic variability. Epidemiologic data suggest a higher incidence in Hispanics, but limited clinical information is available from Latin-American patients. We describe the clinical features of Chilean patients with 22q11 deletion syndrome and compare their findings with those reported in large European, Japanese and US series. Data were obtained from 208 patients from five medical centers. Mean age at diagnosis was 5.2 years, with a median of 2.3 years. Congenital heart defects were present in 59.6%, lower than other large series that averaged 75.8%. Palate abnormalities were present in 79%, higher than previous reports averaging 56%. Patients with congenital heart disease were diagnosed earlier (median 0.3 years of age) than those without heart defects (median 5.6 years) and had greater mortality attributable to the syndrome (9.8% vs 2.4%, respectively). The differences in frequencies of major anomalies may be due to growing awareness of more subtle manifestations of the syndrome, differences in clinical ascertainment or the presence of modifier factors. These observations provide additional data useful for patient counseling and for the proposal of health care guidelines.

Monoclonal antibodies against IREM-1: potential for targeted therapy of AML.

IREM-1 is an inhibitory cell surface receptor with an unknown function and is expressed on myeloid cell lineages, including cell lines derived from acute myeloid leukemia (AML) patients. We have generated a series of monoclonal antibodies (mAbs) against the extracellular domain of IREM-1 and further assessed its expression in normal and AML cells. IREM-1 was restricted to cells from myeloid origin and extensive expression analysis in primary cells obtained from AML patients showed IREM-1 expression in leukemic blasts of 72% (39/54) of samples. We therefore searched for specific IREM-1 mAbs with activity in functional complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC). Lead mAbs against IREM-1 showed specific cytotoxic activity against a variety of AML-derived cell lines and freshly isolated blasts from AML patients. Internalization of mAbs upon IREM-1 binding was also shown. In vivo anticancer activity of lead mAbs was observed in an established HL-60 xenograft model with a tumor growth delay of up to 40% and in a model using primary human AML cells, where treatment with anti-IREM-1 mAb resulted in a significant reduction of engrafted human cells. These results demonstrate IREM-1 as a potential novel target for immunotherapy of AML.

Nuclear factor-kappaB is constitutively activated in primitive human acute myelogenous leukemia cells.

Human acute myelogenous leukemia (AML) is thought to arise from a rare population of malignant stem cells. Cells of this nature, herein referred to as leukemic stem cells (LSCs), have been documented for nearly all AML subtypes and appear to fulfill the criteria for stem cells in that they are self-renewing and give rise to the cells found in many leukemic populations. Because these cells are likely to be critical for the genesis and perpetuation of leukemic disease, the present studies sought to characterize unique molecular properties of the LSC population, with particular emphasis on the transcription factor, nuclear factor-kappaB (NF-kappaB). Previous experiments have shown that unstimulated human CD34(+) progenitor cells do not express NF-kappaB. In contrast, primary AML CD34(+) cells display readily detectable NF-kappaB activity as assessed by electrophoretic mobility shift assay and gene expression studies. Furthermore, detailed analyses of enriched AML stem cells (CD34(+)/CD38(-)/CD123(+)) indicate that NF-kappaB is also active in the LSC population. Given the expression of NF-kappaB in leukemic, but not normal primitive cells, the hypothesis that inhibition of NF-kappaB might induce leukemia-specific apoptosis was tested by treating primary cells with the proteasome inhibitor MG-132, a well-known inhibitor of NF-kappaB. Leukemic CD34(+)/CD38(-) cells displayed a rapid induction of cell death in response to MG-132, whereas normal CD34(+)/CD38(-) cells showed little if any effect. Taken together, these data indicate that primitive AML cells aberrantly express NF-kappaB and that the presence of this factor may provide unique opportunities to preferentially ablate LSCs.

Expression of tumor-suppressor genes interferon regulatory factor 1 and death-associated protein kinase in primitive acute myelogenous leukemia cells.

Previous studies indicate that human acute myelogenous leukemia (AML) arises from a rare population of leukemic stem cells. Cells of this nature can initiate and maintain leukemic cell growth in both long-term cultures and nonobese diabetic/severe combined immune-deficient mice. To characterize the biology of primitive AML cells, gene expression screens were performed with 7 primary AML and 3 normal specimens. For each sample, stem cell populations (CD34(+)/CD38(-)) were isolated and used to synthesize radiolabeled complementary DNA (cDNA). AML vs normal probes were then hybridized to cDNA arrays containing genes related to cancer and apoptosis. Of approximately 1400 genes analyzed, 2 tumor-suppressor genes were identified that were overexpressed in all 7 of the AML CD34(+)/CD38(-) cell populations: death-associated protein kinase and interferon regulatory factor 1. Expression of each gene was confirmed by reverse-transcription polymerase chain reaction and immunoblot analysis. It is proposed that tumor-suppressor proteins play a role in the biology of primitive AML cells. (Blood. 2001;97:2177-2179)

The interleukin-3 receptor alpha chain is a unique marker for human acute myelogenous leukemia stem cells.

Recent studies suggest that the population of malignant cells found in human acute myelogenous leukemia (AML) arises from a rare population of leukemic stem cells (LSCs). LSCs have been documented for nearly all AML subtypes and have been phenotypically described as CD34+/CD38- or CD34+/HLA-DR-. Given the potentially critical role of these primitive cells in perpetuating leukemic disease, we sought to further investigate their molecular and cellular characteristics. Flow cytometric studies using primary AML tissue showed that the interleukin-3 receptor alpha chain (IL-3Ralpha or CD123) was strongly expressed in CD34+/CD38- cells (98 +/- 2% positive) from 16 of 18 primary specimens. Conversely, normal bone marrow derived CD34+/CD38- cells showed virtually no detectable expression of the CD123 antigen. To assess the functional role of IL-3Ralpha positive cells, purified CD34+/CD123+ leukemia cells were transplanted into immune deficient NOD/SCID mice. These experiments showed that CD123+ cells were competent to establish and maintain leukemic populations in vivo. To begin to elucidate a biological role for CD123 in leukemia, primary AML samples were analyzed with respect to signal transduction activity in the MAPK, Akt, and Stat5 pathways. Phosphorylation was not detected in response to IL-3 stimulation, thereby suggesting CD123 is not active in conventional IL-3-mediated signaling. Collectively, these data indicate that CD123 represents a unique marker for primitive leukemic stem cells. Given the strong expression of this receptor on LSCs, we propose that targeting of CD123 may be a promising strategy for the preferential ablation of AML cells.

Maximal response to oxytocin of the isolated myometrium from pregnant patients with intrahepatic cholestasis.

Prematurity and fetal death are common complications in patients with cholestasis of pregnancy. Both conditions appear to be associated with abnormal patterns of uterine activity. We studied the oxytocin-induced contractile activity in uterine strips taken from patients with cholestasis of pregnancy (n = 6) and from women with normal pregnancy (n = 6). Contractile activity of the myometrium in response to oxytocin was significantly higher in patients with cholestasis of pregnancy than in normally pregnant patients, at doses of 10(-6), 10(-4), and 10(-2) M. We found that there is a greater maximal response to oxytocin in strips of myometrium from patients with cholestasis of pregnancy than from normally pregnant patients.