Small molecule inhibitors against protein geranylgeranyltransferase-I such as P61A6 have been shown to inhibit proliferation of a variety of human cancer cells and exhibit antitumor activity in mouse models. Development of these inhibitors could be dramatically accelerated by conferring tumor targeting and controlled release capability. As a first step towards this goal, we have encapsulated P61A6 into a new type of liposomes that open and release cargos only under low pH condition. These low pH-release type liposomes were prepared by adjusting the ratio of two types of phospholipid derivatives. Loading of geranylgeranyltransferase-I inhibitor (GGTI) generated liposomes with average diameter of 50-100 nm. GGTI release in solution was sharply dependent on pH values, only showing release at pH lower than 6. Release of cargos in a pH-dependent manner inside the cell was demonstrated by the use of a proton pump inhibitor Bafilomycin A1 that Increased lysosomal pH and inhibited the release of a dye carried in the pH-liposome. Delivery of GGTI to human pancreatic cancer cells was demonstrated by the inhibition of protein geranylgeranylation inside the cell and this effect was blocked by Bafilomycin A1. In addition, GGTI delivered by pH-liposomes induced proliferation inhibition, G1 cell cycle arrest that is associated with the expression of cell cycle regulator p21CIP1/WAF1. Proliferation inhibition was also observed with various lung cancer cell lines. Availability of nanoformulated GGTI opens up the possibility to combine with other types of inhibitors. To demonstrate this point, we combined the liposomal-GGTI with farnesyltransferase inhibitor (FTI) to inhibit K-Ras signaling in pancreatic cancer cells. Our results show that the activated K-Ras signaling in these cells can be effectively inhibited and that synergistic effect of the two drugs is observed. Our results suggest a new direction in the use of GGTI for cancer therapy.

OBJECTIVE

Insulin resistance has been associated with cardiovascular disease in peritoneal dialysis patients. Few studies have addressed the impact of fast transport status or dialysis prescription on insulin resistance. The aim of this study was to test whether insulin resistance is associated with obesity parameters, peritoneal transport rate, and glucose absorption.

METHODS

Insulin resistance was evaluated with homeostasis model assessment method (HOMA-IR), additionally corrected by adiponectin (HOMA-AD). Enrolled patients were prevalent nondiabetics attending at Santo António Hospital Peritoneal Dialysis Unit, who were free of hospitalization or infectious events in the previous 3 months (51 patients aged 50.4 ± 15.9 years, 59% women). Leptin, adiponectin, insulin-like growth factor-binding protein 1 (IGFBP-1), and daily glucose absorption were also measured. Lean tissue index, fat tissue index (FTI), and relative fat mass (rel.FM) were assessed using multifrequency bioimpedance. Patients were categorized according to dialysate to plasma creatinine ratio at 4 hours, 3.86% peritoneal equilibration test, and obesity parameters.

RESULTS

Obesity was present in 49% of patients according to rel.FM. HOMA-IR correlated better with FTI than with body mass index. Significant correlations were found in obese, but not in nonobese patients, between HOMA-IR and leptin, leptin/adiponectin ratio (LAR), and IGFBP-1. HOMA-IR correlated with HOMA-AD, but did not correlate with glucose absorption or transport rate. There were no significant differences in insulin resistance indices, glucose absorption, and body composition parameters between fast and nonfast transporters. A total of 18 patients (35.3%) who had insulin resistance presented with higher LAR and rel.FM (7.3 [12.3, interquartile range] versus 0.7 [1.4, interquartile range], P<0.001, and 39.4 ± 10.1% versus 27.2 ± 11.5%, P=0.002, respectively), lower IGFBP-1 (8.2 ± 7.2 versus 21.0 ± 16.3 ng/ml, P=0.002), but similar glucose absorption and small-solute transport compared with patients without insulin resistance. FTI and LAR were independent correlates of HOMA-IR in multivariate analysis adjusted for glucose absorption and small-solute transport (r=0.82, P<0.001).

CONCLUSIONS

Insulin resistance in nondiabetic peritoneal dialysis patients is associated with obesity and LAR independent of glucose absorption and small-solute transport status. Fast transport status was not associated with higher likelihood of obesity or insulin resistance.

In the postgenome era, development of novel targeted therapeutics is anticipated to accelerate, with the promise of specifically tailored strategies to treat specific molecularly characterized disease entities. Greater understanding of disease pathophysiology and pharmacologic actions at the molecular, cellular, and tissue levels have provided the basis for expanding the clinical application of available therapies such as recombinant human erythropoietin (r-HuEPO, epoetin alfa). The role of epoetin alfa in anemic cancer patients receiving chemotherapy has grown as our understanding of the relationship between anemia and quality of life in this patient population has evolved. With anemia and tumor hypoxia associated with poorer outcomes in various solid tumors, the potential impact of epoetin alfa on outcomes, as well as quality of life, in patients undergoing radiation or chemoradiation is of considerable interest. Anemia occurs almost universally in critically ill patients, resulting in substantial transfusion requirements. In this setting, the anemia appears to be consistent with anemia of chronic inflammatory disease and is potentially treatable by epoetin alfa. Recent preclinical studies indicate that erythropoietin exhibits neuroprotective effects in models of central nervous system injury, suggesting additional potential novel clinical applications for epoetin alfa worthy of careful investigation. Advances in the understanding of the ras genes and their functional proteins in signaling pathways involved in the development of cancer, particularly hematologic malignancies, over the last decade have prompted development of a new class of agents, farnesyl protein transferase inhibitors (FTIs), designed specifically to inhibit the initial step in Ras protein activation. Initial clinical evaluation of FTIs is ongoing, and preliminary results demonstrate antitumor activity in hematologic malignancies. Further identification and understanding of the function and complex interactions of proteins involved in diseases holds the promise of targeted therapies and improved patient outcomes.

Farnesyl transferase inhibitors (FTIs) are anticancer agents designed to target ras processing and ras-dependent signal pathways. Because oncogenic ras mutations are found in up to 50% of multiple myeloma (MM) specimens, these agents may be effective in this disease. However, some preclinical studies suggest that FTI antitumor responses are unrelated to effects on ras. To address this issue in myeloma, we used the ANBL-6 myeloma cell line where interleukin (IL)-6-dependent cells are stably transfected with mutated N-ras or K-ras genes. Because expression of mutated ras allows for IL-6-independent growth, this is a good model to test whether FTIs specifically target growth-promoting ras-activated pathways in myeloma. Although they had little effect in 10% serum, two separate FTIs induced apoptosis of myeloma cells when cultured in low serum, and mutated ras-expressing cells were more sensitive than wild-type (WT) ras-expressing cells. However, induction of apoptosis did not correlate with inhibition of ras processing. Although they had no effect on AKT activity, under low serum conditions FTIs inhibited constitutive activation of the p70S6kinase and nuclear factor kappaB signal proteins in both mutated ras-expressing MM lines and extracellular signal-regulated kinase (ERK) activity in mutated N-ras-expressing cells. However, in studies where p70, nuclear factor kappaB, and ERK were comparably inhibited by other inhibitors or by gene transfer, we could not identify effects on these pathways as participating in the apoptotic response. FTIs were also able to abrogate the IL-6 proliferative response of WT ras-expressing MM cells, and this was associated with inhibition of IL-6-induced activation of ERK, AKT, and p70. The induction of apoptosis and prevention of the IL-6 response in MM cells containing mutated or WT ras provide support for the therapeutic potential of FTIs in this disease.

Ras oncogenes (K-, H- and N-ras) are known to be involved in signal transduction pathways regulating cell growth and differentiation in many human cancers. These proteins are synthesized as a cytosolic precursor that ultimately localizes to the inner plasma membrane. This process is initiated by the attachment of a farnesyl moiety to the protein and is catalysed by the farnesyl transferase. Since activated (mutated) ras oncogenes have been shown to be essential for the malignant phenotype in many tumors, farnesyl transferase inhibitors (FTIs) have emerged as a novel class of antineoplastic agents. Four FTIs are currently in clinical trials. Two of these agents, R-115777 and SCH-66336, are orally active heterocyclic compounds and already in phase II/III studies. Preliminary results of R-115777 or SCH-66336 in combination with gemcitabine or 5-FU/FA in patients with advanced pancreatic carcinomas have been reported. The dose-limiting toxicity was neutropenia, nausea, diarrhea and fatigue. The recommended doses for phase II studies were 200 mg R-115777 or 2 x 200 mg SCH-66336. Durable objective partial responses were noted in several patients. Furthermore, the FTIs were found to be well tolerated. Ongoing phase III studies in patients with advanced pancreatic cancers will determine the extent of clinical activity and whether these agents can be used as single agents for the treatment of pancreatic carcinomas or have to be used in combination with other cytostatic drugs. In addition, it remains to be clarified whether FTIs may sensitize drug-resistant cancers following conventional chemotherapy.

The clinical value of four laboratory methods of assessing free thyroxine status was compared in 82 consecutive patients newly referred to a thyroid clinic with suspected thyroid dysfunction. The methods of determining free thyroxine used were: (1) free thyroxine index using a thyroid hormone uptake test (FTI (THUT)); (2) a free thyroxine index using thyroxine binding globulin (FTI (TBG)); (3) a kinetic radioimmunoassay (Immophase); and (4) an equilibrium dialysis method. The definitive thyroid status was evaluated by a combination of clinical assessment (including Wayne index), routine tests of thyroid function (total T4, T3, TSH, and TRH tests where appropriate), and by therapeutic trial in one case. The diagnostic efficiency of the tests was markedly dependent upon the method of determining the reference range for euthyroid patients. Best efficiency for each test was achieved using an amended range after excluding outliners. Test efficiency was then 97.6% for FTI (THUT) and the kinetic RIA and 96.8% for FTI (TBG). Misclassification by one or more of these tests occurred in only four patients (mild hypothyroid, euthyroid on phenytoin, euthyroid on oral contraceptive and valium, T3 hyperthyroid). In contrast, free T4 by equilibrium dialysis was much less efficient (86.6%) and was technically the most complex. Overall the kinetic T4 RIA provided similar diagnostic information to the indirect indices. However, further studies of cost benefit in settings other than a thyroid clinic are required to assess whether this method might replace total T4 and/or FTI as a first-line test of thyroid function.

BACKGROUND

Hyperthyroxinemia does not always equate to hyperthyroidism. Laboratory tests should always be correlated with the clinical picture. A mismatch should make one doubt true hyperthyroidism. The purpose of our study was to assess the etiology of euthyroid hyperthyroxinemia not associated with estrogen use or pregnancy and to review the outcome of those erroneously treated.

METHODS

The medical records of thirteen euthyroid patients with non estrogen associated hyperthyroxinemia were reviewed. They had a complete set of thyroid function tests including free T3 and free T4 by membrane dialysis, TRH stimulation test and thyroid hormone binding panel.

RESULTS

Two diagnostic groups were identified: Hyperthyroxinemia secondary to binding abnormalities (7/13), better known as familial dysalbuminemic hyperthyroxinemia (FDH) and hyperthyroxinemia secondary to Thyroid Hormone Resistance (THR) (6/13). The FDH group had an elevated T4 and FTI, with normal T3RU, TSH, TRH stimulation test but an abnormal thyroid hormone binding panel which was used to confirm the diagnosis. The THR group had two laboratory presentations: Four patients presented with all the thyroid hormone tests elevated (T4, T3, T3RU, FTI) including a free T3 and free T4 by membrane dialysis with a normal TSH and TRH stimulation test and a normal T4 binding panel. This presentation is typical for a TRH patient with a nuclear receptor defect where all the precursos to the defect accumulate. Two patients with THR presented elevated T4 and free T4 but normal T3 and free T3, localizing the defect at the level of the active T4 transport mechanism across the cellular membrane. These two patients had a normal TSH, TRH stimulation test and T4 binding panel. Two patients were treated erroneously with radioactive iodine and became extremely hypothyroid in spite of normal TFTs. Very high dose of thyroid hormone replacement were required to restore euthyroidism.

CONCLUSIONS

One must suspect these two entities in patients clinically euthyroid who have elevated T4 but non-suppressed TSH. A normal TSH and TRH test confirm euthyroidism. A thyroid hormone binding panel differentiates FDH from THR. Neither group require treatment. If treated erroneously and T4 drops to normal values, one must again induce hyperthyroxinemia to restore euthyroidism in these patients.

Thyroid function was evaluated in 24 children (aged 4-18 years) with chronic renal failure either before institution of hemodialysis or after more than 3 months of hemodialysis. 22 patients were clinically euthyroid and 2 were hypothyroid; in one case hypothyroidism was secondary to cystinosis and in the other it followed radiation therapy. The 2 hypothyroid patients had subnormal levels of T4, T3, FTI and FT4 as well as elevated serum TSH levels. Mean values for T4, T3, FTI and FT4 for the remaining 22 patients were within the normal range, but were significantly decreased, (all p values less than 0.01) when compared to controls. TSH and TBG levels were not significantly different from those of the normal population. Eleven of the euthyroid patients (50%) had either T3 or FT4, but not both, below the normal range without elevation of their TSH levels. These findings suggest that in the absence of other causes of hypothyroidism, children with chronic renal failure are able to maintain a clinically euthyroid state with either normal FT4 or T3 serum levels and can respond to primary gland failure with elevated TSH secretion.

In the present study, a nanoporous metal organic framework (MOF) based on iron metal and amino terephthalate ligand MIL-101-NH₂-Fe has been used as a carrier for loading and in-vitro release of 5-flurouracil (5-FU) anticancer drug. The 5-FU drug loaded MOF was 13 wt % by using thermogravimetric analysis (TGA). The 5-FU release was monitored under physiological condition at 37 °C, pH 7.4 in simulated body fluid (SBF) by using spectrophotometry. The drug demonstrated a slow release profile where 98% of the drug was released in 4 days. Loading of drug was characterized by Fournier transform infrared (FTI-IR) and thermogravimetric analysis (TGA). The crystalline structure was monitored by using X-ray powder diffraction (XRD) and after loading of drug in the MOF, the pattern of samples was remained the same. The morphology and size of samples were showed by using scanning electron microscopy (SEM) and based on the MOF has a length of 500 nm and an average diameter of 200 nm. These structural characterizations were performed to verify the 5-FU drug loading in MIL-101-NH₂-Fe. The MOF stability was studied by measuring the iron concentration in the SBF solution with atomic absorption spectroscopy (AAS). The MTT assay method was assessed the ability of this drug delivery system on overcoming MCF-7 breast cancer cells in comparison with the free drug and the carrier alone. Based on the results, this drug loaded nanoparticle could achieve more cell death as compared to the free 5-FU drug.

Oncogenic Ras proteins have been seen as an important target for novel anticancer drugs. Due to the functional role of Ras farnesylation, fanesyltransferase (FTase) inhibition was thought to be a strategy for interfering with Ras-dependent transformation. When farnesylation is blocked, the function of Ras protein is severely impaired because of the inability of the nonfarnesylated protein to anchor to the membrane. Although it has been clearly demonstrated that FTase inhibitors (FTIs) inhibit Ras farnesylation, it is uncertain whether the antiproliferative effects of these compounds result exclusively from the effects on Ras. Moreover, no consensus has been reached as to the relevant targets(s) of FTIs that can explain their mosaic pharmacology. In searching for downstream targets for FTIs effects, CENP-E and CENP-F/mitosin were identified. Different studies showed that the inhibition of farnesylation interferes with CENP-E-microtubule association. In the presence of FTIs, chromosome alignment to the metaphase plate is delayed, suggesting that farnesylated proteins are involved in a step critical to bipolar spindle formation and chromosome alignment. An important question is whether these biological effects might contribute to the chemotherapeutic effects of the FTIs. However, FTIs, triggering the spindle checkpoint, might elevate the rate of cellular missegregation to levels that are incompatible with cell viability, as well as have a reduced (but still significant?) effect on checkpoint-proficient normal cells. As an example, RPR-115135 induced micronuclei (MN) increase in cancer cells displaying high chromosome instability (CIN) levels, whereas in normal cells it is devoid of activity. Cancer cells showing high CIN level might represent an ideal target for the activity of some FTIs.

The Ras proteins are low molecular weight GTP binding proteins that function in the regulation of the transduction of growth proliferative signals from the membrane to the nucleus. Oncogenically mutated ras genes are found in approximately 25% of all human cancers. Localization of the Ras oncoproteins to the inner surface of the plasma membrane is essential for their biological activity. This observation suggested that the enzyme that mediates the membrane localization, farnesyl-protein transferase (FPTase), would be a target for the development of novel anticancer agents. We have developed potent, cell-active inhibitors of FPTase that exhibit antiproliferative activity in cell culture and block the morphologic alterations associated with Ras-induced transformation of mammalian cells in monolayer cultures. In vivo, these compounds block the growth of ras-transformed fibroblasts in a nude mouse xenograft model and block the growth and, in some cases, cause regression of mammary and salivary tumors in several strains of ras transgenic mice in the absence of any detectable side effects. The results of our preclinical studies and those of others suggest that FTIs may have utility against a variety of human cancers, a hypothesis that is currently being tested in the clinic.

Inflammatory breast cancer (IBC) is an aggressive and poorly managed disease that accounts for up to 6% of new breast cancer cases in the United States annually. Recent preclinical findings suggest that IBC might be treated with farnesyltransferase inhibitors (FTIs), a novel class of experimental therapeutics that are currently in clinical trials. FTIs exhibit considerable selectivity and efficacy against tumors in preclinical models, and they have been well-tolerated in Phase I human trials. How FTIs target cancer cells has emerged as an important question, with the somewhat disappointing results from initial Phase II efficacy trials. FTI development was predicated on Ras inhibition but there is considerable evidence that other mechanisms are important for mediating the antineoplastic activities of these drugs. One important mediator that has emerged is RhoB, a small GTPase that is recruited by FTIs to trigger growth inhibition and apoptosis. Recently, van Golen and Merajver and their colleagues have demonstrated that FTIs will recruit RhoB to suppress IBC cell phenotypes or neoplastic transformation of human mammary epithelial cells by RhoC, a key oncogenic driver in IBC. A mechanistic implication of this study is that RhoB can interfere with RhoC-dependent signals required for neoplastic pathophysiology. Further preclinical and clinical investigations to test the potential therapeutic utility of FTIs for treating RhoC-driven breast cancers such as IBC would seem warranted.

The development of farnesyltransferase inhibitors (FTIs) has been one of the most active areas of anticancer drug development for the past ten years. Numerous potent FTIs have been developed and extensively evaluated in preclinical model biological systems. Emphasis is given here to the discovery of new, more potent FTIs, and in particular to the results seen with agents currently being evaluated in clinical trials. The emerging, surprising differences between the proposed and actual anticancer mechanisms of the FTIs are discussed. Recent indications that the phenomenon of protein prenylation has broad therapeutic implications, beyond the potential anticancer applications of the FTIs, are presented. Finally, other components of the cellular prenylation or posttranslational modification machinery may prove to be therapeutic targets, and recent discoveries in this area are summarized.

The fact that proteins such as Ras require farnesylation to induce malignant transformation prompted many investigators to design farnesyl transferase inhibitors (FTI) as novel anticancer drugs. FTIs inhibit the growth of ras transformed cells in vitro and induce tumor regression in ras dependent tumor in vivo. Moreover, FTIs inhibit tumor progression in human tumor xenograft models. Currently, FTIs are undergoing phase I and II trials in various cancer types. They show impressive antitumour efficacy and they lack toxicity. Despite these promising results, the development of such molecules in hindered by the absence of appropriate clinical endpoints and of surrogate biological markers. Indeed, it seems likely that Ras is not the critical target of FTIs and that inhibition of the farnesylation of proteins such as RhoB, might also contribute to the observed antitumour properties. Identification of targets that underlie their biological effect is essential in order to predict and evaluate their efficacy.

Ras proteins belong to the monomeric GTPases familly. They control cell growth, differentiation, proliferation, and survival. Ras mutations are frequently found in human cancers and play a fundamental role in tumorigenesis. Ras requires localization to the plasma membrane to exert its oncogenic effects. This subcelllular localization is dependent of protein farnesylation which is a post translational modification catalysed by the farnesyl transferase enzyme. Farnesyl transferase Inhibitors (FTI) were then designed ten to twelve years ago to inhibit ras processing and consequently the growth of ras mutated tumor. Preclinical data show that FTIs inhibit cell proliferation and survival in vitro and in vivo of a wide range of cancer cell lines, many of which contain wild type ras suggesting that mutated Ras is not the only target of the FTIs effects. Four FTIs went then through clinical trials and three of then are still developed in the clinic. Phase I et II clinical trials confirmed a relevant antitumor activity and a low toxicity. Phase III clinical trials are currently undergoing for both solid and hematologic tumors. The expected results should allow to define the position of FTIs as anticancer drugs, particularly in combination with conventional chemotherapy, hormone therapy, radiotherapy or any other new targeted compound.

Farnesyltransferase inhibitors (FTIs) have emerged as a novel class of anti-cancer agents. Analogs of the potent FTI, 1-benzyl-5-(3-biphenyl-2-yl-propyl)-1H-imidazole, were synthesized and tested in vitro for their inhibitory activities. The most promising compound identified from this series is analog 29 that possesses potent enzymatic and cellular activities.

BACKGROUND

Thrombospondin-1 (TSP-1) induces vascular smooth muscle cell (VSMC) migration and is important in the development of intimal hyperplasia. HMG-CoA reductase inhibitors, such as lovastatin, reduce the incidence of vascular restenosis after angioplasty by both cholesterol lowering and pleiotropic effects. Inhibition of the mevalonate pathway is largely responsible for these pleiotropic properties. This inhibition prevents isoprenylation of the small G proteins, Rho and Ras, by geranylgeranyl and farnesyl pyrophosphate, respectively. Isoprenylation is required for Ras and Rho activation, which is relevant for cell migration.

OBJECTIVE

Lovastatin inhibits TSP-1-induced VSMC chemotaxis by inhibiting small G proteins via the mevalonate pathway.

METHODS

Chemotaxis was assessed using a modified Boyden chamber. Quiescent VSMCs were pretreated with serum free media (SFM), lovastatin with or without mevalonate farnesyl (FTI), geranylgeranyl transferase inhibitors (GGTI), farnesyl transferase inhibitor (FPT), or the Rho kinase inhibitor (Y-27632). Chemoattractants were SFM or TSP-1. Comparisons were made by ANOVA followed by post-hoc testing (P<0.05). The effect of lovastatin on Ras activation was evaluated using cells pretreated with SFM or lovastatin, with or without mevalonate prior to TSP-1 exposure. Western blot for Ras activation was performed.

RESULTS

Lovastatin dose-dependently inhibited TSP-1-induced chemotaxis, which was reversed by mevalonate. Mevalonate did not induce chemotaxis independently. FTI and FPT, but not GGTI or Y-27632, inhibited TSP-1-induced Ras activation and TSP-1-induced chemotaxis. Lovastatin inhibition of Ras activation was reversed with mevalonate.

CONCLUSIONS

Ras, not Rho, is relevant for TSP-1-induced VSMC chemotaxis. These data suggest that lovastatin suppresses TSP-1-induced chemotaxis by inhibition of Ras.

Neuromuscular electrical stimulation (NMES) is typically used with older adults receiving rehabilitation therapies, but little is known about the stimulation patterns that maximize force output and minimize fatigue in this population. The purpose of this study was to apply variable patterns of stimulation to the thenar muscles of the hand in younger and older adults to determine if force production and neuromuscular fatigue effects were similar. Three submaximal stimulation patterns were administered: A 20Hz constant frequency pattern, a pattern that increased from 20 to 40Hz, and a pattern that incorporated two closely spaced (5ms) doublet pulses. The doublet stimulation produced significantly higher average forces and force-time integrals (FTIs) than the constant frequency and increasing frequency patterns in both age groups. Additionally, older adults showed less fatigue than the younger group during isometric contractions performed after the fatiguing stimulation patterns. These results suggest that variable pulse NMES patterns enhance force production in the hand in both younger and older individuals better than constant frequency patterns, which are typically used in clinical applications. Also, greater fatigue resistance to electrical stimulation protocols may exist in the older population; this is critical information for the design and application of NMES rehabilitation regimens used with older adults.

OBJECTIVE

The signaling mechanisms controlling organ damage in the pancreas in severe acute pancreatitis (AP) remain elusive. Herein, we examined the role of farnesyltransferase signaling in AP.

METHODS

Pancreatitis was provoked by the infusion of taurocholate into the pancreatic duct in C57BL/6 mice. Animals were treated with a farnesyltransferase inhibitor FTI-277 (25 mg/kg) before pancreatitis induction.

RESULTS

FTI-277 decreased the blood amylase levels, pancreatic neutrophil infiltration, hemorrhage, and edema formation in the pancreas in mice challenged with taurocholate. Farnesyltransferase inhibition reduced the myeloperoxidase levels in the pancreas and lungs in response to taurocholate infusion. However, FTI-277 had no effect on the taurocholate-provoked formation of macrophage inflammatory protein-2 in the pancreas. Interestingly, farnesyltransferase inhibition abolished the neutrophil expression of macrophage-1 antigen in mice with pancreatitis. In addition, FTI-277 decreased the taurocholate-induced activation of the rat sarcoma protein in the pancreas. An important role of farnesyltransferase was confirmed in L-arginine-induced pancreatitis.

CONCLUSIONS

These results demonstrate that farnesyltransferase signaling plays a significant role in AP by regulating neutrophil infiltration and tissue injury via the neutrophil expression of macrophage-1 antigen. Thus, our findings not only elucidate novel signaling mechanisms in pancreatitis but also suggest that farnesyltransferase might constitute a target in the management of severe AP.

The 10-bromobenzocycloheptapyridyl farnesyl transferase inhibitor (FTI) Sch-66336 (1) is currently under clinical evaluation for the treatment of human cancers. During structure-activity relationship development leading to 1, 10-bromobenzocycloheptapyridyl FTIs were found to be more potent than analogous compounds lacking the 10-Br substituent. This potency enhancement was believed to be due, in part, to an increase in conformational rigidity as the 10-bromo substituent could restrict the conformation of the appended C(11) piperidyl substituent in an axial orientation. A novel and potent class of FTIs, represented by indolocycloheptapyridine Sch-207758 [(+)-10a], have been designed based on this principle. Although structural and thermodynamic results suggest that entropy plays a crucial role in the increased potency observed with (+)-10a through conformational constraints and solvation effects, the results also indicate that the indolocycloheptapyridine moiety in (+)-10a provides increased hydrophobic interactions with the protein through the addition of the indole group. This report details the X-ray structure and the thermodynamic and pharmacokinetic profiles of (+)-10a, as well as the synthesis of indolocycloheptapyridine FTIs and their potencies in biochemical and biological assays.

Protein prenylation is a post translational modification that is indispensable for Ras-Rho mediated tumorigenesis. In mammals, three enzymes namely protein farnesyltransferase (FTase), geranylgeranyl transferase1 (GGTase1), and geranylgeranyl transferase2 (GGTase2) were found to be involved in this process. Usually proteins of Ras family will be farnesylated by FTase, Rho family will be geranylgeranylated by GGTase1. GGTase2 is exclusive for geranylgeranylating Rab protein family. FTase inhibitors such as FTI- 277 are potent anti-cancer agents in vitro. In vivo, mutated Ras proteins can either improve their affinity for FTase active site or undergo geranylgeranylation which confers resistance and no activity of FTase inhibitors. This led to the development of GGTase1 inhibitors. A well-defined 3-D structure of human GGTase1 protein is lacking which impairs its in silico and rational designing of inhibitors. A 3-D structure of human GGTase1 was constructed based on primary sequence available and homology modeling to which pubchem molecules library was virtually screened through AutoDock Vina. Our studies show that natural compounds Camptothecin (-8.2 Kcal/mol), Curcumin (-7.3 Kcal/mol) have higher binding affinities to GGTase-1 than that of established peptidomimetic GGTase-1 inhibitors such as GGTI-297 (-7.5 Kcal/mol), GGTI-298 (-7.5 Kcal/mol), CHEMBL525185 (-7.2 Kcal/mol).

BACKGROUND

N‑terminal pro‑B‑type natriuretic peptide (NT‑proBNP) is an established biomarker of heart failure in the general population. However, its diagnostic value is unclear in hemodialysis (HD) patients owing to renal insufficiency.

OBJECTIVE

The aim of the study was to establish the usefulness of NT‑proBNP for hydration assessment and the relation of NT‑proBNP to the nutritional state and prognosis of survival.

METHODS

In 321 HD patients (206 men; mean age, 65.1 ±21.4 years), we assessed NT‑proBNP levels, overhydration (OHBIA), and the indices of the nutritional state (using a bioimpedance analysis [BIA]) in relation to cardiac troponin T (cTnT), hemoglobin, albumin, total cholesterol (TC), and C‑reactive protein (CRP) levels. The efficacy of HD was assessed using Kt/V, weekly HD dose, and HD session ultrafiltration. The cohort was divided into NT‑proBNP quartiles. Patients with 2 NT‑proBNP measurements were categorized also into change‑over‑time subgroups. A follow‑up lasted for a median period of 23.8 ±26.3 months.

RESULTS

Relative OHBIA increased across the NT‑proBNP quartiles (Q1/Q2/Q3/Q4, 1.31% ±2.56%/2.06% ±2.35%/2.92% ±2.97%/4.62% ±4.22%; P <0.0001). NT‑proBNP was also closely associated with other OH parameters. In addition, there was a significant correlation between NT‑proBNP and cTnT (r = 0.55; P <0.0001). Body mass index (BMI) and fat tissue index (FTI) decreased across the quartiles (BMI, 28.5 ±7.7/26.0 ±6.6/25.8 ±5.4/23.7 ±5.5 kg/m2; FTI, 14.4 ±9.0/14.1 ±7.3/12.3 ±6.8/11.6 ±6.1; P <0.001). The highest albumin level was present in Q1 (4.10 ±0.63/3.99 ±0.51/3.90 ±0.62/3.97 ±0.78 g/dl; P = 0.006). The TC level was the lowest in Q4 (190 ±60/169 ±56/173 ±51/153 ±56 mg/dl; P = 0.002). The hemoglobin level decreased across the quartiles (11.44 ±1.25/11.15 ±2.50/10.79 ±1.51/10.45 ±1.67 g/dl; P = 0.0006). The differences in CRP levels and HD‑related parameters were nonsignificant. During the follow‑up, 97 deaths were recorded (11/26/21/39, P <0.0001).

CONCLUSIONS

NT‑proBNP seems to be a useful biomarker of hypervolemia in HD patients. Nevertheless, it has to be interpreted with regard to the patient's individual residual renal function and cardiovascular status.

The aims of this study were to analyse body composition, to detect the presence of undernutrition, and to establish a relationship between undernutrition and the biological markers routinely used as indicators of nutritional status in hemodialysis (HD) patients (pts). We used a body composition monitor (BCM) that expresses body weight in terms of lean tissue mass (LTM) and fat tissue mass (FTM) independent of hydration status. From nine HD units, 934 pts were included. Undernutrition was defined as having a lean tissue index (LTI = LTM/height(2)) below the 10th percentile of a reference population. Biochemical markers and parameters delivered by BCM were used to compare low LTI and normal LTI groups. Undernutrition prevalence was 58.8% of the population studied. Low LTI pts were older, were significantly more frequently overhydrated, and had been on HD for a longer period of time than the normal LTI group. FTI (FTI = FTM/ height(2)) was significantly higher in low LTI pts and increased according to BMI. LTI was not influenced by different BMI levels. Albumin and C-reactive protein correlated inversely (r = -0.28). However neither of them was statistically different when considering undernourished and normal LTI pts. Our BCM study was able to show a high prevalence of undernutrition, as expressed by low LTI. In our study, BMI and other common markers, such as albumin, failed to predict malnutrition as determined by BCM.

OBJECTIVE

To develop a quick identification method for the sun-dried and sulfur-fumigated Angelicae Sinensis Radix used by Fourier transform infrared spectroscopy (FTIR) combined with second derivative infrared spectroscopy.

METHODS

The alcoholic and aqueous extracts of sun-dried and sulfur-fumigated Angelicae Sinensis Radix were analyzed by using FTIR, the further analysis was used by second derivative infrared spectroscopy.

RESULTS

There existed differences between their infrared spectra either extracted by ethanol or water, while the distinctions were more obvious after analyzing their alcoholic and aqueous extracts through high resolution of second derivative infrared spectroscopy. Infrared spectra showed that the absorption peaks of Angelicae Sinensis Radix were significantly reduced and a new absorption peak appeared after sulfur-fumigated process in alcoholic extracts, while both of them changed markedly in the "fingerprint region" ranging from 1 000 to 400 cm(-1) in aqueous extracts. Second derivative spectra showed that the absorption peaks of sulfur-fumigated Angelicae Sinensis Radix extracted by ethanol weakened and disappeared at about 3 578 cm(-1) and 3 541 cm(-1), while both of them differed significantly from each other ranging from 1 400 to 1 200 cm(-1) as well as 800 cm(-1) to 600 cm(-1), difference also existed between them extracted by water ranging from about 3 900 to 3 850 cm(-1) and 3 800 to 3 750 cm(-1).

CONCLUSIONS

The FTIS method combined with second derivative can be utilized to distinguish sun-dried and sulfur-fumigated Angelicae Sinensis Radix efficiently, conveniently and accurately, and provide a basis for identification and quality control of Angelicae Sinensis Radix.