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Publication
Journal: Italian Journal of Pediatrics
May/22/2016
Abstract
Aim of this study was to estimate the cost that is borne by the Italian National Health Service, families, and social security due to very low birth weight infants (VLBWIs) without prematurity-related morbidities up to the age of 18 months. We followed up on 150 VLBWIs and 145 comparable full-term infants (FTIs) who were born in one of 25 different neonatal intensive care units upon discharge from the hospital and at six and 18 months of age. The average length of the primary hospitalisation of the VLBWIs was 59.7 days (SD 21.6 days), with a total cost of €20,502 (SD €8409), compared with three days (SD 0.4 days) with a total cost of €907 (SD €304) for the FTIs. The total societal cost of the VLBWIs for the first 18 months of life was €58,098 (SD €21,625), while the corresponding figure for FTIs was €24,209 (SD €15,557). Among VLBWIs, both low birth weight and gestational age were correlated with the length of hospitalisation after birth (r(2) = 0.61 and r(2) = 0.57, respectively; p values < 0.0005). Our findings highlight that the existing DRGs and tariffs inadequately reflect the actual costs for Italian National Health Service.
Publication
Journal: Anaerobe
May/14/2017
Abstract
The establishment and development of the intestinal microbiota is known to be associated with profound short- and long-term effects on the health of full-term infants (FTI), but studies are just starting for preterm infants (PTI). The data also mostly come from western countries and little information is available for the Middle East. Here, we determined the composition and dynamics of the intestinal microbiota during the first month of life for PTI (n = 66) and FTI (n = 17) in Lebanon. Fecal samples were collected weekly and analyzed by quantitative PCR (q-PCR) and temporal temperature gradient gel electrophoresis (TTGE). We observed differences in the establishment and composition of the intestinal microbiota between the two groups. q-PCR showed that PTI were more highly colonized by Staphylococcus than FTI in the first three weeks of life; whereas FTI were more highly colonized by Clostridium clusters I and XI. At one month of life, PTI were mainly colonized by facultative anaerobes and a few strict anaerobes, such as Clostridium cluster I and Bifidobacterium. The type of feeding and antibiotic treatments significantly affected intestinal colonization. TTGE revealed low species diversity in both groups and high inter-individual variability in PTI. Our findings show that PTI had altered intestinal colonization with a higher occurrence of potential pathogens (Enterobacter, Clostridium sp) than FTI. This suggests the need for intervention strategies for PTI to modulate their intestinal microbiota and promote their health.
Publication
Journal: Physiological Reports
August/16/2017
Abstract
Previous studies have reported that different modes of muscle contraction (i.e., eccentric or concentric contraction) with similar contraction times can affect muscle proteolytic responses. However, the effect of different contraction modes on muscle proteolytic response under the same force-time integral (FTI: contraction force × time) has not been investigated. The purpose of this study was to investigate the effect of different contraction modes, with the same FTI, on acute proteolytic signaling responses. Eleven-week-old male Sprague-Dawley rats were randomly assigned to eccentric (EC), concentric (CC), or isometric contraction (IC) groups. Different modes of muscle contraction were performed on the right gastrocnemius muscle using electrical stimulation, with the left muscle acting as a control. In order to apply an equivalent FTI, the number of stimulation sets was modified between the groups. Muscle samples were taken immediately and three hours after exercise. Phosphorylation of FoxO3a at Ser253 was significantly increased immediately after exercise compared to controls irrespective of contraction mode. The mRNA levels of the ubiquitin ligases, MuRF1, and MAFbx mRNA were unchanged by contraction mode or time. Phosphorylation of ULK1 at Ser317 (positive regulatory site) and Ser757 (negative regulatory site) was significantly increased compared to controls, immediately or 3 h after exercise, in all contraction modes. The autophagy markers (LC3B-II/I ratio and p62 expression) were unchanged, regardless of contraction mode. These data suggest that differences in contraction mode during resistance exercise with a constant FTI, are not factors in regulating proteolytic signaling in the early phase of skeletal muscle contraction.
Publication
Journal: Endocrine Connections
June/27/2014
Abstract
Oxidative stress seems to be present in patients with polycystic ovary syndrome (PCOS). The aim of this study was to evaluate the correlation between characteristics of PCOS and serum concentrations of afamin, a novel binding protein for the antioxidant vitamin E. A total of 85 patients with PCOS and 76 control subjects were investigated in a pilot cross-sectional study design between 2009 and 2013 in the University Hospital of Essen, Germany. Patients with PCOS were diagnosed according to the Rotterdam ESHRE/ASRM-sponsored PCOS Consensus Workshop Group. Afamin and diagnostic parameters of PCOS were determined at early follicular phase. Afamin concentrations were significantly higher in patients with PCOS than in controls (odds ratio (OR) for a 10 mg/ml increase in afamin=1.3, 95% CI=1.08-1.58). This difference vanished in a model adjusting for age, BMI, free testosterone index (FTI), and sex hormone-binding globulin (SHBG) (OR=1.05, 95% CI=0.80-1.38). In patients with PCOS, afamin correlated significantly with homeostatic model assessment-insulin resistance (HOMA-IR), fasting glucose, BMI, FTI, and SHBG (P<0.001), but in a multivariate linear model, only HOMA-IR remained significantly associated with afamin (P=0.001). No correlation was observed between afamin and androgens, LH, FSH, LH/FSH ratio, antral follicle count, ovarian volume, or anti-Müllerian hormone. In conclusion, elevated afamin values may indicate a state of oxidative stress and inflammation, strongly associated with IR and offering an indicator of impaired glucose tolerance in patients with PCOS irrespective of obesity.
Publication
Journal: Environmental Science & Technology
December/27/2010
Abstract
The indistinct origins of some ubiquitous perfluorinated alkyl acids have attracted great attention in recent decades. In this present work, even-chained polyfluorinated iodides (PFIs), a group of volatile perfluorinated compounds (PFCs), including four perfluorinated iodine alkanes (FIAs) and three polyfluorinated telomer iodides (FTIs) were confirmed to be present in the environment. A wide concentration range was found for FIAs at 1.41 to 3.08x10(4) pg/L, and for FTIs at 1.39 to 1.32x10(3) pg/L in the ambient air collected around a fluorochemical manufacturing plant in Shandong province, northern China. Whereas for surface soils, most of these PFIs were below detection limits and only small amounts of analytes with higher carbon chain (such as perfluorododecyl iodide and 1H,1H,2H,2H-perfluorodecyl iodide, 16.6-499 pg/g) could be sporadically detected. The presence of the PFIs in different environmental matrices in the investigated area and calculated vapor pressures (0.095-20.4 Torr) verify that they can be considered as volatile organic chemicals and easily be released into the atmosphere. Together with reported degradation ability and long-range transport potential, the identification of these PFIs indicates that unintentional release during the telomer reaction process might also be another route for the formation and distribution of certain polyfluorinated alcohols, aldehydes, and carboxylic acid derivatives under oxidative conditions in the environment.
Publication
Journal: The Lancet
July/28/1983
Abstract
The frequency of the euthyroid sick syndrome (ESS) was assessed in 3444 hospital patients. For the first 6 months the free thyroxine index (FTI) was used: 3.6% of 1674 patients had ESS compared with 17.3% of 1770 in the second 6 months diagnosed by a direct free thyroxine (FT4) assay ("Amerlex'). The relative frequencies of each type of ESS (low triiodothyronine [T3] only, low T3 plus low FT4 or FTI, and high FT4 or FTI with normal or low T3) and the frequencies of hypothyroidism (high TSH) and hyperthyroidism (high FTI/FT4 and T3) were similar in both periods. In the FT4 period requests for T3 assays increased by 300%. Measurements of both FT4 and FTI in 46 patients with ESS confirmed that ESS is diagnosed more frequently with the FT4 assay: the distribution of normal and abnormal T3 and reverse T3 levels were similar in FT4 ESS and FTIESS. FT4 is labile in illness and thus direct FT4 measurements also fluctuate, not necessarily reflecting thyroid status.
Publication
Journal: Journal of Medicinal Chemistry
September/26/2001
Abstract
The synthesis, structure-activity relationships, and biological properties of a novel series of imidazole-containing inhibitors of farnesyltransferase are described. Starting from a 3-aminopyrrolidinone core, a systematic series of modifications provided 5h, a non-thiol, non-peptide farnesyltransferase inhibitor with excellent bioavailability in dogs. Compound 5h was found to have an unusually favorable ratio of cell potency to intrinsic potency, compared with other known FTIs. It exhibited excellent potency against a range of tumor cell lines in vitro and showed full efficacy in the K-rasB transgenic mouse model.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
June/22/2000
Abstract
Previous studies have shown that, in patients with primary alterations in thyroid hormone secretion, the level of the natural logarithm of serum TSH (lnTSH) is negatively related to the level of free T4. Because such patients can generally be assumed to exhibit normal tissue responsivity to thyroid hormone, we were interested in determining whether the lnTSH/free T4 index (FTI) relationship in patients with established thyroid hormone resistance (THR) exhibit a lower slope than patients with normal tissue sensitivity to thyroid hormone. We have therefore analyzed the relationship between the lnTSH and the FTI in members of three families with documented THR. In these patients, a given dose of T4 was maintained for a 1- to 2-month period, to achieve hormonal equilibration. Two of the families, though not related, exhibited the same mutation, E460K. The third was identified as A317T. As anticipated, the slope of the lnTSH/FTI ratio was significantly lower in the patients with THR than in T4-treated patients who were presumed to have normal sensitivity to thyroid hormone. The slope of the lnTSH/FTI relationship seemed to be characteristic of the specific mutation involved in the three genotypes (wild-type and two mutations) examined. Further, the in vivo slope of the lnTSH/FTI relationship seemed to be linearly related to the T3 association constant of the in vitro translated receptor. These findings support the potential usefulness of measuring the slope of lnTSH, as a function of the FTI, in quantitating pituitary THR.
Publication
Journal: International Orthopaedics
April/28/2014
Abstract
OBJECTIVE
Stage II posterior tibial tendon dysfunction (PTTD) can be treated by flexor digitorum longus (FDL) tendon transfer and medial displacement calcaneal osteotomy (MDCO). Numerous authors have studied the clinical and radiographic results of this procedure. However, little is known about the kinematic changes. Therefore, the purpose of this study was to assess plantar-pressure distribution in these patients.
METHODS
Seventy-three patients with PTTD stage II underwent FDL tendon transfer and MDCO. Plantar pressure distribution and American Orthopaedic Foot and Ankle Society (AOFAS) score were assessed 48 months after surgery. Pedobarographic parameters included lateral and medial force index of the gait line, peak pressure (PP), maximum force (MF), contact area (CA), contact time (CT) and force-time integral (FTI).
RESULTS
In the lesser-toe region, PP, MF, CT, FTI and CA were reduced and MF in the forefoot region was increased. These changes were statistically significant. We found statistically significant correlations between AOFAS score and loading parameters of the medial midfoot.
CONCLUSIONS
Study results reveal that FDL tendon transfer and MDCO leads to impaired function of the lesser toes during the stance phase. However, there seems to be a compensating increased load in the forefoot region.
Publication
Journal: Medicine
August/24/2015
Abstract
Successful clinical and radiographic outcomes have been reported in patients with unilateral developmental dysplasia of the hip (DDH) following Pemberton pericapsular osteotomy (PPO). However, residual gait deviations are seen in both the affected and unaffected limbs. To date it is not known whether these deviations result in abnormal plantar pressure in such patients. This study investigated this possibility by performing pedobarographic, clinical, and radiographic examinations after PPO in 20 patients (age: 102.5 ± 19.0 months) with unilateral DDH who underwent PPO at 34.2 ± 9.8 months of age. Plantar pressure was evaluated using the Footscan pressure plate (RsScan International, Olen, Belgium). Each foot was subdivided into 10 zones and peak pressure, force-time integral as a percentage of total FTI, and contact time as a percentage of total stance time was estimated. The minimum duration of follow-up was 24 months (mean: 68.3 ± 20.3 months). The data were compared with 20 age- and weight-matched healthy controls. Despite clinical and radiographic examinations showing satisfactory results according to modified McKay and Severin criteria, significant differences in plantar pressure parameters were identified between the affected limbs, the unaffected limbs, and normal controls. No significant differences were found between patients classified as "excellent or good" and those rated as "fair" according to the modified Severin criteria. Pedobarographic results showed the existence of the residual plantar pressure deviations during walking in patients treated with PPO for unilateral DDH. Longer follow-up will be needed to more fully evaluate the effect of these deviations on gait.
Publication
Journal: Archives of internal medicine
September/27/1980
Abstract
The free thyroxine index (FTI) was used in 2,704 adults to detect unsuspected thyroid dysfunction. Among 2,581 adults found to be clinically euthyroid without thyroid medication, 2,571 had a truly normal FTI (121 to 360) and ten had a falsely abnormal FTI (seven less than 121, three greater than 360). Among 25 subjects with newly diagnosed thyroid dysfunction, there were eight hyperthyroid (prevalence, 0.31%) and 14 hypothyroid (prevalence, 0.50%) subjects. The sensitivity of the FTI was 1.0, and the specificity was 0.996. The predictive value of an abnormal FTI with a prevalence of 0.81% was 67%. The cost to find a new case averaged $127. The annual incidence of symptomatic hyperthyroidism was 0.05%; of hypothyroidism, about 0.08%. We conclude that the FTI is cost-effective for case finding in thyroid dysfunction.
Publication
Journal: Breast Cancer Research and Treatment
May/26/2014
Abstract
Tipifarnib (T) is a farnesyl transferase inhibitor (FTI) that enhances the antineoplastic effects of cytotoxic therapy in vitro, has activity in metastatic breast cancer, and enhances the pathologic complete response (pCR) rate to neoadjuvant doxorubicin-cyclophosphamide (AC) chemotherapy. We, therefore, performed a phase I-II trial of T plus neoadjuvant sequential weekly paclitaxel and 2-week AC chemotherapy in locally advanced breast cancer. Eligible patients with HER2-negative clinical stage IIB-IIIC breast cancer received 12 weekly doses of paclitaxel (80 mg/m(2)) followed by AC (60/600 mg/m(2) every 2 weeks and filgrastim), plus T (100 or 200 mg PO on days 1-3 of each P dose, and 200 mg PO on days 2-7 of each AC cycle). The trial was powered to detect an improvement in breast pCR rate from 15 to 35 % (α = 0.10, β = 0.10) in two strata, including ER and/or PR-positive, non-inflammatory (stratum A) and inflammatory carcinoma (stratum B). Of the 60 patients accrued, there were no dose-limiting toxicities among the first six patients treated at the first T dose level (100 mg BID; N = 3) or second T dose level (200 mg BID; N = 3) plus paclitaxel. Breast pCR occurred in 6/33 patients (18 %, 95 % confidence intervals (CI) 7-36 %) and 1/22 patients (4 %, 95 % CI 0-8 %) in stratum B. Combination of the FTI T with weekly paclitaxel-AC is unlikely to be associated with a breast pCR rate of 35 % or higher in patients with locally advanced HER2/neu-negative inflammatory or non-inflammatory ER- and/or PR-positive breast carcinoma.
Publication
Journal: Journal of biomedicine & biotechnology
February/6/2011
Abstract
It has been reported that overproduction of reactive oxygen species occurs after brain injury and mediates neuronal cells degeneration. In the present study, we examined the role of Ras signaling on hydrogen peroxide-induced neuronal cells degeneration in dopaminergic neuroblastoma SH-SY5Y cells. Hydrogen peroxide significantly reduced cell viability in SH-SY5Y cultured cells. An inhibitor of the enzyme that catalyzes the farnesylation of Ras proteins, FTI-277, and a competitive inhibitor of GTP-binding proteins, GDP-beta-S significantly decreased hydrogen peroxide-induced reduction in cell viability in SH-SY5Y cultured cells. The results of this study might indicate that a Ras-dependent signaling pathway plays a role in hydrogen peroxide-induced toxicity in neuronal cells.
Publication
Journal: Psychoneuroendocrinology
January/30/1996
Abstract
Fifteen women with premenstrual syndrome (PMS) and 15 control women were tested twice for thyroid axis measures, once during the follicular and once during the luteal phase of the menstrual cycle. While PMS and control women did not differ in mean hormone values during either phase of the menstrual cycle, PMS women showed significantly greater variability in hormone measures including TSH, T3 uptake, T4, and FTI relative to controls. These findings are consistent with the conceptualization that, for a subset of women with PMS, thyroid axis abnormalities may contribute to their disorder. Additionally, when analyzed in the sample as a whole, the menstrual cycle exerted a significant effect on reverse T3 with greater levels observed in the luteal relative to the follicular phase of the cycle.
Publication
Journal: Haematologica
July/17/2014
Abstract
Although farnesyltransferase inhibitors have shown promising activity in relapsed lymphoma and sporadic activity in acute myelogenous leukemia, their mechanism of cytotoxicity is incompletely understood, making development of predictive biomarkers difficult. In the present study, we examined the action of tipifarnib in human acute myelogenous leukemia cell lines and clinical samples. In contrast to the Ras/MEK/ERK pathway-mediated Bim upregulation that is responsible for tipifarnib-induced killing of malignant lymphoid cells, inhibition of Rheb-induced mTOR signaling followed by dose-dependent upregulation of Bax and Puma occurred in acute myelogenous leukemia cell lines undergoing tipifarnib-induced apoptosis. Similar Bax and Puma upregulation occurred in serial bone marrow samples harvested from a subset of acute myelogenous leukemia patients during tipifarnib treatment. Expression of FTI-resistant Rheb M184L, like knockdown of Bax or Puma, diminished tipifarnib-induced killing. Further analysis demonstrated that increased Bax and Puma levels reflect protein stabilization rather than increased gene expression. In U937 cells selected for tipifarnib resistance, neither inhibition of signaling downstream of Rheb nor Bax and Puma stabilization occurred. Collectively, these results not only identify a pathway downstream from Rheb that contributes to tipifarnib cytotoxicity in human acute myelogenous leukemia cells, but also demonstrate that FTI-induced killing of lymphoid versus myeloid cells reflects distinct biochemical mechanisms downstream of different farnesylated substrates. (ClinicalTrials.gov identifier NCT00602771).
Publication
Journal: Neoplasia
January/25/2001
Abstract
Ras-transformed intestinal epithelial cells are resistant to the growth inhibitory actions of TGFbeta and have a marked decrease in expression of the TGFbeta type II receptor (TGFbetaRII). Rat intestinal epithelial cells (RIE) were stably transfected with activated Ras, Sos and Raf constructs and tested for expression of TGFbetaRII and sensitivity to growth inhibition by TGFbeta. The parental RIE line and the RIE-Raf cells were non-transformed in morphology and were sensitive to TGFbeta (70-90% inhibited). In contrast, the RIE-Ras and RIE-Sos lines were transformed, resistant to TGFbeta and expressed 5- to 10-fold decreased levels of the TGFbetaRII mRNA and protein. Cyclin D1 protein expression was repressed by TGFbeta treatment in parental RIE and RIE-Raf cells, whereas levels of cyclin D1 in RIE-Ras and RIE-Sos cells remained unchanged. Treatment of RIE-Ras cells with 25 microM farnesyl transferase inhibitor, FTI L739,749, for 48 hours restored expression of TGFbetaRII to levels equivalent to control cells. In addition, treatment of RIE-Ras cells for 48 hours with PD-98059, a specific MAPKK inhibitor, also increased expression of TGFbetaRII to control levels. Collectively these results suggest that downregulation of TGFbetaRII and loss of sensitivity to growth inhibition by TGFbeta in Ras-transformed intestinal epithelial cells is not mediated exclusively by the conventional Ras/Raf/MAPKK/MAPK pathway. However, activation of MAPK, perhaps by an alternate Ras effector pathway, appears to be necessary for Ras-mediated downregulation of TGFbetaRII.
Publication
Journal: Journal of Molecular and Cellular Cardiology
April/3/2003
Abstract
The negative chronotropic response of the heart to parasympathetic stimulation is mediated via the interaction of M(2) muscarinic receptors, Galpha(i2) and the G-protein coupled inward rectifying K(+) channel, GIRK1. Here TGFbeta(1) is shown to decrease the expression of Galpha(i2) in cultured chick atrial cells in parallel with attenuation of the negative chronotropic response to parasympathetic stimulation. The response to the acetylcholine analogue, carbamylcholine, decreased from a 95+/-2% (+/-SEM, n=8) inhibition of beat rate in control cells to 18+/-2% (+/-SEM,n =8) in TGFbeta(1) treated cells. Data support the conclusion that TGFbeta regulation of Galpha(i2) expression was mediated via an effect on Ras. TGFbeta(1) inhibited Galpha(i2) promoter activity by 56+/-6% (+/-SEM, n=4) compared to control. A dominant activating Ras mutant reversed the effect of TGFbeta on Galpha(i2) expression and stimulated Galpha(i2) promoter activity 1.7 fold above control. A dominant negative Ras mutant mimicked the effect of TGFbeta(1) on Galpha(i2) promoter activity. TGFbeta had no effect on the ratio of GDP/GTP bound Ras, but markedly decreased the level of membrane associated Ras and increased the level of cytoplasmic Ras compared to control. Furthermore, farnesol, a precursor to farnesylpyrophosphate, the substrate for the farnesylation of Ras, not only reversed TGFbeta(1) inhibition of Ras localization to the membrane, but also reversed TGFbeta(1) inhibition of Galpha(i2)promoter activity. FTI-277, a specific inhibitor of the farnesylation of Ras, mimicked the effect of TGFbeta(1) on Ras localization and Galpha(i2) promoter activity. These data suggest a novel relationship between TGFbeta signaling, regulation of Ras function and the autonomic response of the heart.
Publication
Journal: Journal of Orthopaedic Science
November/12/2017
Abstract
BACKGROUND
Detailed information regarding differences in plantar pressure distribution between hallux valgus and healthy feet is unavailable. The purposes of the present study were to clarify the characteristics of the plantar pressure distribution in patients with hallux valgus compared with healthy matched controls and to determine whether hallux valgus leads to dysfunction of the great toe during walking.
METHODS
The study consisted of 25 patients with symptomatic moderate-to-severe hallux valgus (HV group) and 13 healthy matched volunteers (C group) without hallux valgus. All patients and volunteers were women. The HV and C groups did not differ significantly in age, height, weight, and body mass index. Plantar pressure during walking was measured using F-scan. The plantar aspect of the foot was divided into eight regions. The peak pressure (Peak-P), maximum force (Max-F), contact time (Con-T), contact area (Con-A), and force time integral (FTI) were measured in each region.
RESULTS
The Peak-P of the great toe did not differ significantly between the HV and C groups. However, all other parameters: Max-F, Con-T, Con-A, and FTI of the great toe in the HV group were significantly lower than in the C group. In the central forefoot, the Peak-P and Max-F in the HV group were significantly higher than in the C group.
CONCLUSIONS
The present study demonstrated that a moderate-to-severe hallux valgus deformity leads to dysfunction of the great toe during walking and may increase mechanical loading on the central forefoot.
Publication
Journal: Aging
February/6/2013
Abstract
Small increases in the expression of wild-type prelamin A are sufficient to recapitulate the reduced cell proliferation and altered nuclear membrane morphology observed in cells expressing progerin, the mutant lamin A associated with progeria. We hypothesized that the manifestation of these phenotypes in cells expressing elevated levels of wild-type prelamin A or progerin is caused by the same molecular effectors, which play a central role in the onset of the progeroid phenotype. To experimentally test this hypothesis, we compared the transcriptomes of isogenic diploid fibroblasts expressing progerin or elevated levels of wild-type prelamin A with that of wild-type fibroblasts. We subsequently used the reversion towards normal of two phenotypes, reduced cell growth and dismorphic nuclei, by treatment with farnesyltransferase inhibitor (FTI) or overexpression of ZMPSTE24, as a filtering strategy to identify genes linked to the onset of these two phenotypes. Through this analysis we identified the gene encoding for the transcription factor FOXQ1, as a gene whose expression is induced in both cells expressing progerin and elevated levels of wild-type prelamin A, and subsequently reduced in both cell types upon conditions that ameliorate the phenotypes. We overexpressed FOXQ1 in normal fibroblasts and demonstrated that increased levels of this factor lead to the development of both features that were used in the filtering strategy. These findings suggest a potential link between this transcription factor and cell dysfunction induced by altered prelamin A metabolism.
Publication
Journal: Journal of Cellular and Molecular Medicine
November/5/2012
Abstract
Matrix metalloproteinase-1 (MMP-1) activity has been linked to numerous disease processes from arthritis to ulcer. Its proteolytic activity has been implicated inconsistently in different steps of tumourigenesis and metastasis. The discrepancies may be attributable to our limited understanding of MMP-1 production, cellular trafficking, secretion and local activation. Specifically, regulation of MMP-1 directional delivery versus its general extracellular matrix secretion is largely unknown. Inhibition of prenylation by farnesyl transferase inhibitor (FTI-276) decreased extracellular MMP-1 and subsequently reduced invasiveness by 30%. Parallel, stable cell line RNAi knockdown of MMP-1 confirmed its role in cellular invasiveness. The prenylation agonist farnesyl pyrophosphate (FPP) partially normalized FTI-276 inhibited extracellular MMP-1 levels and invasion capacity while transiently delayed its cellular podia distribution. MMP-1 directional delivery to these structures were confirmed by combination of a MMP-1-specific fluorogenic substrate, a MMP1-Ds-Red fusion protein construct expression and DQ-collagen degradation, which demonstrated coupling of directional delivery and activation. MetaMorph analysis of cellular lamellipodia structures indicated that FTI-276 inhibited formation and delivery to these structures. Farnesyl pyrophosphate partially restored lamellipodia area but not MMP-1 delivery under the time frame investigated. These results indicate that MMP-1 directional delivery to podia structures is involved in the invasive activity of sarcoma cells, and this process is prenylation sensitive.
Publication
Journal: International Journal of Legal Medicine
August/16/2011
Abstract
Venlafaxine (VEN) is an antidepressant found to possess a higher fatal toxicity index (FTI, i.e., deaths in proportion to consumption) than other newer antidepressants and selective serotonin reuptake inhibitors (SSRIs). The aim of this study was to elucidate using post-mortem cases whether the apparent high toxicity of VEN is associated with adverse drug interactions, pharmacogenetic factors and/or the manner of death. Within a 2-year period, a comprehensive post-mortem database and death certificates were searched for cases with laboratory findings of VEN, findings of other drugs, associated background information and the cause and manner of death. In 123 cases, the concentrations of VEN and its two metabolites, O-desmethylvenlafaxine (O-VEN) and N-desmethylvenlafaxine (N-VEN), and the CYP2D6 genotype were determined in post-mortem blood. The median concentrations of VEN, O-VEN and N-VEN were 560, 420 and 49 µg/l, respectively. A prominent feature of the VEN-positive cases was the high abundance of interacting drugs (46%), being more common with higher VEN concentrations. Compared to other common antidepressants, VEN-positive cases showed the highest suicide frequency, but also the proportion of suicidal VEN poisonings of all suicides was substantially higher than that of mirtazapine or SSRIs. Relative CYP2D6 activity did not predispose to high VEN concentrations, and the frequency of the extreme phenotypes followed the general population. In conclusion, the high suicide potential of VEN in combination with the high prevalence of drugs causing adverse interactions could be the reason for the observed high FTI.
Publication
Journal: Current Molecular Medicine
January/31/2006
Abstract
In sum, the FTIs are signal transduction inhibitors that display promising clinical activity against a broad spectrum of malignancies. We are just beginning to explore and elucidate the mechanisms by which transformed cells respond to FTIs and the optimal settings in which they do so. The clinical trials that are currently in progress and under development will provide the critical foundations for defining the optimal roles of FTIs in patients with AML and other hematologic disorders. The correlative laboratory studies to define the mechanisms by which FTIs alter cellular metabolism and modulate the activities of specific signaling pathways in both normal and malignant marrow precursors are a pivotal part of this effort. What we learn about FTIs in the clinic and the laboratory will apply broadly to the effective and safe application of all signal transduction inhibitors.
Publication
Journal: Breast Cancer Research and Treatment
September/15/2003
Abstract
Farnesyl transferase inhibitors (FTIs) serve to specifically inhibit farnesyl isoprenoid lipid modification of proteins. Although originally developed as anti-Ras oncoprotein drugs, it now appears that these compounds function independently of Ras. FTIs have been shown to inhibit transformation by a variety of mechanisms, including apoptosis involving cytochrome c release from mitochondria. Tamoxifen exhibits both anti-estrogenic and estrogenic properties and is widely used as an estrogen antagonist for the treatment of estrogen receptor (ER) positive human breast tumors. Tamoxifen can induce ER-dependent apoptosis in human breast tumor cells by a mechanism involving the Bcl2/mitochondrial arm of the apoptotic machinery. Since tamoxifen and FTIs may stimulate distinct components of the mitochondrial-based apoptotic machinery, we reasoned that their effects might be synergistic. Here we show that anti-estrogens and an FTI (FTI-277) synergize to inhibit cell growth and enhance cell death in ER positive, human breast tumor cell lines. However, the drugs exhibited only additive effects on an ER negative cell line. Analysis of treated ER positive T-47D cells demonstrated that a synergistic increase in apoptosis was induced, as measured by increased caspase 3 activity. Thus, tamoxifen and FTIs may synergize to promote apoptotic cell death in ER positive human breast tumor cells.
Publication
Journal: Hypertension Research
August/24/2014
Abstract
Both norepinephrine (NE) and connective tissue growth factor (CTGF) contribute to vascular fibrosis during hypertension. Recent studies indicate that farnesyl pyrophosphate synthase (FPPS) plays an important role in cardiac remodeling in hypertension. However, the role of FPPS in NE-induced fibrotic responses and related molecular mechanisms is unknown. Vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) were stimulated with NE. The fibrotic responses were assessed by measuring CTGF, hydroxyproline (hyp), and α-1 procollagen I levels using Western blot, a hydroxyproline test kit, and real-time quantitative PCR assays, respectively. Ras activity was determined by a pull-down assay using a Ras activation assay kit and detected by Western blot. NE dose-dependently increased fibrosis in SHR-VSMCs, and this increase was significantly reduced by ibandronate, an inhibitor of FPPS. The addition of farnesol, but not geranylgeraniol, partially reversed the inhibitory effects of ibandronate. Furthermore, the anti-fibrotic effects of ibandronate could be mimicked by FTI-276 but not by GGTI-286. A pull-down assay showed that ibandronate reduced the NE-induced Ras activation. Moreover, ibandronate inhibited the NE-induced activation of p38, JNK, and ERK1/2. Only SB203580 (specific inhibitor of p38) diminished the NE-induced CTGF production. These results demonstrated that inhibiting FPPS prevents NE-induced fibrotic responses in SHR-VSMCs and that the Ras kinase and p38 pathways were the underlying mechanisms involved in this process.
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