Hydroxypropyl-β-cyclodextrin impacts renal and systemic hemodynamics in the anesthetized dog

Hydroxypropyl-β-cyclodextrin (HPβCD) is a complexation agent used to enhance drug solubilization and formulation stability. Although its toxicity is well characterized, its cardiovascular effects are less known. To investigate them, HPβCD was infused intravenously over 10 min in anesthetized dogs (10-40% (w/v, i.e. 200-800 mg/kg) in non-denervated animals and at 40% in denervated animals). HPβCD increased renal arteriolar resistance and decreased renal blood flow at all doses, almost immediately after infusion start, more drastically in females. A less pronounced increase in total peripheral resistance occurred in females only due to sex difference in sympathetic tone. Pulmonary hemodynamic parameters remained unaffected, suggesting that the renal effect was rather selective. As a consequence of the increased systemic blood pressure, heart rate decreased in normal animals without direct effect on cardiac conductance. This effect was abolished in denervated animals. This suggests that autonomous nervous feedback loops are functional in normal animals and that HPβCD has no direct chronotropic effect. In conclusion, systemic and renal hemodynamic changes should be considered as potential background effects at 200-400 mg/kg. At higher doses (800 mg/kg), changes are more pronounced and could mask/exacerbate hemodynamic response of drug candidate; such doses should be avoided in nonclinical safety studies.

Comparison of markers of coagulation activation and thrombin generation test in uncomplicated pregnancies

INTRODUCTION

Pregnancy is a well-established risk factor for venous thromboembolism, and is associated with a state of hypercoagulability or parameters of thrombin generation. Currently, there is a lack of consensual data on thrombin generation during pregnancy. This study aimed to find a sensitive and specific biological marker of coagulation activation and to identify parameters of thrombin generation.

PATIENTS AND METHODS

The population included 101 women with uncomplicated pregnancies. The objective of this study was to correlate thrombin generation test (measured at 5pM tissue factor, 4μM lipids and without thrombomodulin), with fibrinogen and markers of blood coagulation activation: D-dimer, prothrombin fragments 1+2 (F1+2), thrombin-antithrombin complexes (TAT) and fibrin monomer complexes (FMC) in these women. Internal quality control was performed in each set of experiments.

RESULTS

Fibrinogen, D-dimer, F1+2, and TAT concentrations increased significantly throughout pregnancy, and were correlated with term of pregnancy. In our study, thrombin generation seemed to increase early on, and then remained stable throughout normal pregnancy, in contrast with other markers of blood coagulation activation, excepting FMC. The latter are subject to large inter-individual variations, especially during second trimester. No correlation was demonstrated between thrombin generation parameters and other activation markers.

CONCLUSION

While markers of coagulation activation significantly increased during pregnancy, thrombin generation increased only early on and remains stable during pregnancy. Finding a sensitive and specific biological marker for vascular pregnancy complications, such as FMC and thrombin generation levels, requires further investigation.

Time to menarche and final height after histrelin implant treatment for central precocious puberty

OBJECTIVE

To compare final height, change in body mass index (BMI), and time from end of treatment until menarche in girls with central precocious puberty treated with the histrelin implant versus depot gonadotropin releasing hormone agonist injections.

STUDY DESIGN

Chart review, interview, and final height measurements of 2 groups of girls with central precocious puberty; triptorelin depot (TD) group: 23 girls were treated from age 8.4 ± 0.3 with monthly injections of TD, for 26.7 ± 2.5 months; histrelin implant group: 11 girls were treated from age 8.7 ± 0.3 years for 28.4 ± 3.7 months, of whom 9 initially received monthly TD injections for 1.5-39 months. Final height, BMI (pretreatment vs recent), and time between either implant removal or last injection to menarche were compared.

RESULTS

Time between removal of implant or last injection and menarche was 9.3 ± 1.5 (histrelin implant group) versus 16.1 ± 1.7 (TD group) months (P = .02). Predicted height at implant insertion was 156.8 ± 2.6 cm, and final height was 161.1 ± 2.0 cm (not significant [NS]). Predicted height for TD was 155.2 ± 1.9 cm and final height was 157.9 ± 1.7 cm (NS). Change from onset of treatment to final BMI-SDS for histrelin implant was -0.41 ± 0.3, and for TD was -0.03 ± 0.2 (NS).

CONCLUSIONS

Menarche occurred sooner after implant removal. There was no difference in final height or BMI outcomes between the 2 treatment modalities.

NS5A inhibitors in the treatment of hepatitis C

Hepatitis C virus infection is a major health problem worldwide and no vaccine has yet been developed against this virus. In addition, currently approved pharmacotherapies achieve suboptimal cure rates and have side effects that result in non-compliance and premature treatment discontinuation. Significant research has been devoted to developing direct-acting antiviral agents that inhibit key viral functions. In particular, several novel drug candidates that inhibit the viral non-structural protein 5A (NS5A) have been demonstrated to possess high potency, pan-genotypic activity, and a high barrier to resistance. Clinical trials using combination therapies containing NS5A inhibitors have reported results that promise high cure rates and raise the possibility of developing interferon-free, all-oral regimens.

Treatment with everolimus is associated with a procoagulant state

INTRODUCTION

Renal transplant recipients are at increased risk of venous thromboembolic events, which is in part caused by their treatment with maintenance immunosuppressive drugs. Because we observed an increased incidence of venous thromboembolic events in renal transplant recipients treated with the mTOR inhibitor (mTORi) everolimus, we aimed to identify prothrombotic mechanisms of this immunosuppressive drug.

MATERIALS AND METHODS

In a single center study, nested in a multi-center randomized controlled trial, we measured parameters of coagulation, anti-coagulation and fibrinolysis in renal transplant recipients, receiving the mTORi everolimus (n=16, mTOR group) and compared them to a similar patient group, receiving a calcineurin inhibitor and/or mycophenolate sodium (n=20, non-mTOR group). All patients were at least 6 months following transplantation with a stable transplant function.

RESULTS

The use of an mTORi was associated with significantly higher levels of von Willebrand factor, prothrombin fragment 1+2, thrombin-activatable fibrinolysis inhibitor and plasminogen activator inhibitor-1 as compared to a non-mTORi based immunosuppressive regimen.

CONCLUSIONS

Treatment with an mTORi leads to increased endothelial activation, thrombin formation and impaired fibrinolysis in renal transplant recipients. This suggests an increased risk of thrombotic events in renal transplant recipients treated with mTOR inhibitors. A prospective study to establish the precise risk of thrombotic events in these patients is urgently needed.

Cooperation of binding sites at the hydrophilic domain of cell-surface sulfatase Sulf1 allows for dynamic interaction of the enzyme with its substrate heparan sulfate

BACKGROUND

Sulf1 is a cell-surface sulfatase removing internal 6-O-sulfate groups from heparan sulfate (HS) chains. Thereby it modulates the activity of HS-dependent growth factors. For HS interaction Sulf1 employs a unique hydrophilic domain (HD).

METHODS

Affinity-chromatography, AFM-single-molecule force spectroscopy (SMFS) and immunofluorescence on living cells were used to analyze specificity, kinetics and structural basis of this interaction.

RESULTS

Full-length Sulf1 interacts broadly with sulfated glycosaminoglycans (GAGs) showing, however, higher affinity toward HS and heparin than toward chondroitin sulfate or dermatan sulfate. Strong interaction depends on the presence of Sulf1-substrate groups, as Sulf1 bound significantly weaker to HS after enzymatic 6-O-desulfation by Sulf1 pretreatment, hence suggesting autoregulation of Sulf1/substrate association. In contrast, HD alone exhibited outstanding specificity toward HS and did not interact with chondroitin sulfate, dermatan sulfate or 6-O-desulfated HS. Dynamic SMFS revealed an off-rate of 0.04/s, i.e., ~500-fold higher than determined by surface plasmon resonance. SMFS allowed resolving the dynamics of single dissociation events in each force-distance curve. HD subdomain constructs revealed heparin interaction sites in the inner and C-terminal regions of HD.

CONCLUSIONS

Specific substrate binding of Sulf1 is mediated by HD and involves at least two separate HS-binding sites. Surface plasmon resonance KD-values reflect a high avidity resulting from multivalent HD/heparin interaction. While this ensures stable cell-surface HS association, the dynamic cooperation of binding sites at HD and also the catalytic domain enables processive action of Sulf1 along or across HS chains.

GENERAL SIGNIFICANCE

HD confers a novel and highly dynamic mode of protein interaction with HS.

BMP-Smad 1/5/8 signalling in the development of the nervous system

The transcription factors, Smad1, Smad5 and Smad8, are the pivotal intracellular effectors of the bone morphogenetic protein (BMP) family of proteins. BMPs and their receptors are expressed in the nervous system (NS) throughout its development. This review focuses on the actions of Smad 1/5/8 in the developing NS. The mechanisms by which these Smad proteins regulate the induction of the neuroectoderm, the central nervous system (CNS) primordium, and finally the neural crest, which gives rise to the peripheral nervous system (PNS), are reviewed herein. We describe how, following neural tube closure, the most dorsal aspect of the tube becomes a signalling centre for BMPs, which directs the pattern of the development of the dorsal spinal cord (SC), through the action of Smad1, Smad5 and Smad8. The direct effects of Smad 1/5/8 signalling on the development of neuronal and non-neuronal cells from various neural progenitor cell populations are then described. Finally, this review discusses the neurodevelopmental abnormalities associated with the knockdown of Smad 1/5/8.

Extraction, chemical characterization and biological activity determination of broccoli health promoting compounds

Broccoli (Brassica oleracea L. var. Italica) contains substantial amount of health-promoting compounds such as vitamins, glucosinolates, phenolic compounds, and dietary essential minerals; thus, it benefits health beyond providing just basic nutrition, and consumption of broccoli has been increasing over the years. This review gives an overview on the extraction and separation techniques, as well as the biological activity of some of the above mentioned compounds which have been published in the period January 2008 to January 2013. The work has been distributed according to the different families of health promoting compounds discussing the extraction procedures and the analytical techniques employed for their characterization. Finally, information about the different biological activities of these compounds has been also provided.

Scratching inhibits serotonin-evoked responses of rat dorsal horn neurons in a site- and state-dependent manner

Scratching inhibits pruritogen-evoked responses of neurons in the superficial dorsal horn, implicating a spinal site for scratch inhibition of itch. We investigated if scratching differentially affects neurons depending on whether they are activated by itchy vs. painful stimuli, and if the degree of inhibition depends on the relative location of scratching. We recorded from rat lumbar dorsal horn neurons responsive to intradermal (id) microinjection of serotonin (5-hydroxytryptamine, 5-HT). During the response to 5-HT, scratch stimuli (3mm, 300 mN, 2 Hz, 20s) were delivered at the injection site within the mechanosensitive receptive field (on-site), or 4-30 mm away, outside of the receptive field (off-site). During off-site scratching, 5-HT-evoked firing was significantly attenuated followed by recovery. On-site scratching excited neurons, followed by a significant post-scratch decrease in 5-HT-evoked firing. Most neurons additionally responded to mustard oil (allyl isothiocyanate). Off-site scratching had no effect, while on-site scratching excited the neurons. These results indicate that scratching exerts a state-dependent inhibitory effect on responses of spinal neurons to pruritic but not algesic stimuli. Moreover, on-site scratching first excited neurons followed by inhibition, while off-site scratching immediately evoked the inhibition of pruritogen-evoked activity. This accounts for the suppression of itch by scratching at a distance from the site of the itchy stimulus.

A West Nile virus NS4B-P38G mutant strain induces adaptive immunity via TLR7-MyD88-dependent and independent signaling pathways

Prior work shows that an attenuated West Nile virus (WNV), the nonstructural (NS)4B-P38G mutant infection in mice induced strong immune responses and protected host from subsequent lethal wild-type WNV infection. Here, we investigated NS4B-P38G mutant infection in myeloid differentiation factor 88-deficient (MyD88(-/-)) and Toll-like receptor 7-deficient (TLR7(-/-)) mice and found they had enhanced susceptibility compared to wild-type mice. Both groups had lower WNV-specific IgM response and reduced effector T cell functions. Dendritic cells (DCs) also exhibited a reduced maturation and impaired antigen-presenting functions compared to wild-type DCs. Moreover, infection with NS4B-P38G mutant in TLR7(-/-) and MyD88(-/-) mice provided full and partial protection respectively from subsequent challenge with lethal wild-type WNV. There were reduced T cell responses in MyD88(-/-) and interleukin-1 receptor deficient (IL-1R(-/-)) mice during secondary challenge with wild-type WNV. In contrast, TLR7(-/-) mice displayed normal T cell functions. Collectively, these results suggest that TLR7-dependent MyD88 signaling is required for T cell priming during NS4B-P38G mutant infection, whereas the TLR7-independent MyD88 signaling pathways are involved in memory T cell development, which may contribute to host protection during secondary challenge with wild-type WNV.

Development of specific dengue virus 2'-O- and N7-methyltransferase assays for antiviral drug screening

Dengue virus (DENV) protein NS5 carries two mRNA cap methyltransferase (MTase) activities involved in the synthesis of a cap structure, (7Me)GpppA(2'OMe)-RNA, at the 5'-end of the viral mRNA. The methylation of the cap guanine at its N7-position (N7-MTase, (7Me)GpppA-RNA) is essential for viral replication. The development of high throughput methods to identify specific inhibitors of N7-MTase is hampered by technical limitations in the large scale synthesis of long capped RNAs. In this work, we describe an efficient method to generate such capped RNA, GpppA(2'OMe)-RNA₇₄, by ligation of two RNA fragments. Then, we use GpppA(2'OMe)-RNA₇₄ as a substrate to assess DENV N7-MTase activity and to develop a robust and specific activity assay. We applied the same ligation procedure to generate (7Me)GpppA-RNA₇₄ in order to characterize the DENV 2'-O-MTase activity specifically on long capped RNA. We next compared the N7- and 2'-O-MTase inhibition effect of 18 molecules, previously proposed to affect MTase activities. These experiments allow the validation of a rapid and sensitive method easily adaptable for high-throughput inhibitor screening in anti-flaviviral drug development.

Protein tyrosine phosphatases as novel targets in breast cancer therapy

Breast cancer is linked to hyperactivation of protein tyrosine kinases (PTKs), and recent studies have unveiled that selective tyrosine dephosphorylation by protein tyrosine phosphatases (PTPs) of specific substrates, including PTKs, may activate or inactivate oncogenic pathways in human breast cancer cell growth-related processes. Here, we review the current knowledge on the involvement of PTPs in breast cancer, as major regulators of breast cancer therapy-targeted PTKs, such as HER1/EGFR, HER2/Neu, and Src. The functional interplay between PTKs and PTK-activating or -inactivating PTPs, and its implications in novel breast cancer therapies based on targeting of specific PTPs, are discussed.

Protein tyrosine phosphatase variants in human hereditary disorders and disease susceptibilities

Reversible tyrosine phosphorylation of proteins is a key regulatory mechanism to steer normal development and physiological functioning of multicellular organisms. Phosphotyrosine dephosphorylation is exerted by members of the super-family of protein tyrosine phosphatase (PTP) enzymes and many play such essential roles that a wide variety of hereditary disorders and disease susceptibilities in man are caused by PTP alleles. More than two decades of PTP research has resulted in a collection of PTP genetic variants with corresponding consequences at the molecular, cellular and physiological level. Here we present a comprehensive overview of these PTP gene variants that have been linked to disease states in man. Although the findings have direct bearing for disease diagnostics and for research on disease etiology, more work is necessary to translate this into therapies that alleviate the burden of these hereditary disorders and disease susceptibilities in man.

Yearly variations of demographic indices and mortality data in Italy from 1901 to 2008 as related to the caloric intake

The aim of the present study was to evaluate, by Join Point regression method, the yearly variations in demographic indices and mortality data in Italy from 1901 to 2008, as related to the caloric intake. The relationships between mortality and caloric intake were studied by time series. The results showed that, from 1901 to 2008, the Italian population grew from 32.5 to 59.6 millions; the live births rates decreased from 31.8 to 10.1‰ (males) and from 33.3 to 9.0‰ (females); the infant mortality rates fell from 184.1 to 3.7‰ (males) and from 149.4 to 3.2‰ (females); males and females gained 35.7 and 40.6 years in life expectancy at birth, respectively. In 1901 the 61% of deaths occurred in the youngest, whereas in 2008 the elderly accounted for the 80%. In 1901, in terms of age-adjusted data, other and undefined causes overcame the specific causes of death, whose rank was: respiratory, digestive, infectious, cardiovascular, cerebrovascular, cancers, accidents, endocrine, and nervous system diseases. In 2008, undefined causes ranked 3rd (males) and 4th (females), while cancers became the leading cause of death, followed by cardiovascular, cerebrovascular, accidental, respiratory, endocrine, digestive, nervous system, and infectious diseases. The caloric intake showed a negative correlation with all-cause mortality, infant mortality, and mortality for a number of specific causes. These patterns reflect the progress in average nutritional status, lifestyle quality, socioeconomic level, and hygienic conditions.

Men with low preoperative sexual function may benefit from nerve sparing radical prostatectomy

PURPOSE

We determined the effect of nerve sparing radical prostatectomy on sexual and urinary function in men at various levels of pretreatment sexual function.

MATERIALS AND METHODS

Men in the CaPSURE™ (Cancer of the Prostate Strategic Urologic Research Endeavor) database who underwent radical prostatectomy and had baseline and 2-year posttreatment UCLA-PCI sexual function and urinary function scores were selected. Nerve sparing was categorized as bilateral, unilateral or none and the level of pretreatment sexual function was divided into quartiles. The cohort was divided into subgroups of nerve sparing technique and pretreatment sexual function. Differences between sexual function and urinary function among subgroups were determined. A test of interaction was performed between preoperative sexual function and degree of nerve sparing on postoperative sexual function and urinary function scores.

RESULTS

A total of 1,322 patients met the study inclusion criteria. Median patient age was 61 years (range 41 to 79). Bilateral, unilateral and no nerve sparing procedures were performed in 899, 200 and 223 men, respectively. The effects of nerve sparing on sexual function differed among the quartiles of preoperative sexual function (p <0.01). Nerve sparing did not have an effect on the sexual function of men in the lowest quartile of preoperative sexual function score (p = 0.15) but did have a significant beneficial effect on sexual function in the higher 3 quartiles (p = 0.04, p <0.01 and p <0.01, respectively). Alternatively, nerve sparing improved urinary function in men in the lowest quartile of baseline sexual function.

CONCLUSIONS

Nerve sparing radical prostatectomy results in better sexual function outcomes than no nerve sparing in most men except those with little baseline function. Urinary function was positively impacted in all men. Men who are suitable candidates for nerve preservation may benefit from nerve sparing surgery. Poorer baseline sexual function should not exclude these men from such surgery.

Coupling of infraslow fluctuations in autonomic and central vigilance markers: skin temperature, EEG β power and ERP P300 latency

Even under thermoneutral conditions, skin temperature fluctuates spontaneously, most prominently at distal parts of the body. These fluctuations were shown to be associated with fluctuations in vigilance: mild manipulation of skin temperature during nocturnal sleep affects sleep depth and the power spectral density of the electroencephalogram (EEG), and fluctuations in skin temperature during daytime wakefulness are related to sleep propensity and task performance. The association of daytime skin temperature fluctuations with EEG markers of vigilance has not previously been investigated. Therefore, the present study aimed to evaluate the association between daytime fluctuations in skin temperature with those in two quantitative EEG measures: the power spectral density of background EEG, and the event related potential (ERP) elicited by visual stimuli. High-density EEG and skin temperature were obtained in eight healthy adults five times a day while they performed a visual sustained-attention task. Assessments were made after a night of normal sleep and after the challenge of a night of total sleep deprivation. Fluctuations in the distal-to-proximal skin temperature gradient measured from the earlobe and mastoid were associated with fluctuations in parieto-occipital high beta band (20-40 Hz) power of the pre-stimulus background EEG, but only after sleep deprivation. The temperature fluctuations were moreover associated with fluctuations in the latency of the P300 elicited by the stimulus. The findings demonstrate close association between fluctuations in an autonomic correlate of the vigilance state (i.e. the distal-to-proximal skin temperature gradient), and fluctuations in central nervous system correlates of the vigilance state (i.e. background EEG and ERP). The findings are of theoretical and practical relevance for the assessment and manipulation of vigilance.

Gasket seal closure for extended endonasal endoscopic skull base surgery: efficacy in a large case series

OBJECTIVE

To assess long-term efficacy of the gasket seal, a method for watertight closure of the cranial base using autologous fascia lata held in place by a rigid buttress, in a large case series.

METHODS

A prospectively acquired database of all endonasal endoscopic surgeries performed over a 5-year period at Weill Cornell Medical College starting in September 2005 was reviewed.

RESULTS

The gasket seal was used in 46 consecutive patients. Mean age was 53 years (range 7-83 years). All patients had extensive intracranial disease with a significant intraoperative cerebrospinal fluid (CSF) leak. Pathology included craniopharyngioma (39.1%), meningioma (23.9%), and pituitary adenoma (17.4%). After a mean follow-up of 28 months (range 3-63 months), two (4.3%) patients had a postoperative CSF leak. Excluding the patients with adenomas, the CSF leak rate was 5.2% (2 of 38 patients). One leak was controlled with reoperation, and the other was stopped with a lumbar drain (LD). The significance of pathology, type of approach, exposure of the ventricular system, use of fat graft, use of nasoseptal (NS) flap, and use of lumbar drain (LD) was examined, and none of these were significant predictors of postoperative CSF leak.

CONCLUSIONS

Gasket seal closure is a reliable long-term effective method for achieving watertight closure of the cranial base. It can be used in association with an intracranial fat graft, NS flap, LD, and tissue sealants. In this series, none of these other factors were significant predictors of postoperative CSF leak.