Can subcentimetre ultrasound detected angiomyolipomas be safely disregarded?

AIM: To optimise follow-up by dismissing lesions on baseline ultrasound (US) if renal lesions conform to US criteria of an angiomyolipoma (AML). METHOD AND MATERIALS: The present study was a 10-year retrospective review of patients who were found to have incidental hyperechoic renal lesions on US to ascertain the outcome from subsequent imaging, clinical encounters, and cancer registrations. Exclusions included renal calculi, tuberous sclerosis, Von-Hippel-Lindau, or a known cancer. RESULTS: After excluding 39 patients, 1,493 patients were identified. One hundred and sixty had more than one lesion with 87 patients having bilateral lesions. Regardless of indication, 889 patients had subsequent imaging within 5 years (59.5%). The average size of all AMLs was 13.2 mm. In the group with lesions that were <10 mm (807), 438 had imaging follow-up with an average follow-up time of 1.5 years. Mean lesion size in this group was 7 mm, with an average increase of <0.5 mm on follow-up. No lesions were found to be malignant on subsequent imaging nor did any of these patients have a subsequent renal cancer diagnosis registered at local multidisciplinary team meetings. CONCLUSION: No incidental subcentimetre hyperechoic renal lesion with imaging characteristics of an AML demonstrated significant growth or developed into a malignancy on follow-up.

Characterization of Near-Infrared and Raman Spectroscopy for In-Line Monitoring of a Low-Drug Load Formulation in a Continuous Manufacturing Process.

Reflectance spectroscopy is an excellent candidate for process analytical technology (PAT) applications in continuous manufacturing of pharmaceutical tablets. Spectroscopic methods provide a real-time, nondestructive measurement of the active pharmaceutical ingredient (API) concentration in order to ensure product quality and uniformity. Of particular challenge is the powder blends with low drug loads (<5% w/w) where the measurement of the signal-to-noise and, in turn, precision limit the ability of the method. We evaluate both near-infrared (NIR) and Raman spectroscopy for use in PAT applications by measuring pharmaceutical blends of varying active ingredient concentrations. Both spectrometers are equipped with a fiber-optically coupled probe head for noncontact measurement of powder blends. A mockup of the interface between the spectrometer and powders within the feed frame of a rotary tablet press is used to simulate the movement of powder blends from the mixer to the press. A port on the feed frame allows measurement by NIR or Raman spectroscopy of the blends just before tablet compression. For our model compound, Raman spectroscopy is shown to have a lower limit-of-detection and less day-to-day variability than NIR spectroscopy. Raman spectroscopy was chosen as the PAT platform to support process development, and working distance and spot size were both optimized for use in the feed-frame of a tablet press. Sufficient limit-of-detection was achieved for monitoring active pharmaceutical ingredient concentrations (API) down to 1% w/w during a semicontinuous manufacturing of tablets. An innovative optimization-based model (EIOT) was used to trend API concentration and demonstrated that the process could be capable of detecting out-of-trend material.

Alteration of blood clotting and lung damage by protamine are avoided using the heparin and polyphosphate inhibitor UHRA.

Anticoagulant therapy-associated bleeding and pathological thrombosis pose serious risks to hospitalized patients. Both complications could be mitigated by developing new therapeutics that safely neutralize anticoagulant activity and inhibit activators of the intrinsic blood clotting pathway, such as polyphosphate (polyP) and extracellular nucleic acids. The latter strategy could reduce the use of anticoagulants, potentially decreasing bleeding events. However, previously described cationic inhibitors of polyP and extracellular nucleic acids exhibit both nonspecific binding and adverse effects on blood clotting that limit their use. Indeed, the polycation used to counteract heparin-associated bleeding in surgical settings, protamine, exhibits adverse effects. To address these clinical shortcomings, we developed a synthetic polycation, Universal Heparin Reversal Agent (UHRA), which is nontoxic and can neutralize the anticoagulant activity of heparins and the prothrombotic activity of polyP. Sharply contrasting protamine, we show that UHRA does not interact with fibrinogen, affect fibrin polymerization during clot formation, or abrogate plasma clotting. Using scanning electron microscopy, confocal microscopy, and clot lysis assays, we confirm that UHRA does not incorporate into clots, and that clots are stable with normal fibrin morphology. Conversely, protamine binds to the fibrin clot, which could explain how protamine instigates clot lysis and increases bleeding after surgery. Finally, studies in mice reveal that UHRA reverses heparin anticoagulant activity without the lung injury seen with protamine. The data presented here illustrate that UHRA could be safely used as an antidote during adverse therapeutic modulation of hemostasis.

Optimising MRI small bowel techniques.

Magnetic resonance imaging (MRI)-based techniques have emerged as the preferred technique for the diagnostic evaluation of the small intestine, particularly in the adult population. The lack of ionising radiation makes MRI ideal for use in younger patients or in cases that require repeated follow-up investigations. Imaging of the small intestine may be carried out using the intubation (enteroclysis) or the ingestion (enterography) techniques. Enterography examinations are more acceptable to patients and may provide similar diagnostic accuracy compared to intubation methods. In this review, methods of improving and optimising MRI of the small intestine are described.

PI-RADS version 2.1: one small step for prostate MRI.

Multiparametric (mp) prostate magnetic resonance imaging (MRI) is playing an increasingly prominent role in the diagnostic work-up of patients with suspected prostate cancer. Performing mpMRI before biopsy offers several advantages including biopsy avoidance under certain clinical circumstances and targeting biopsy of suspicious lesions to enable the correct diagnosis. The success of the technique is heavily dependent on high-quality image acquisition, interpretation, and report communication, all areas addressed by previous versions of the Prostate Imaging-Reporting and Data System (PI-RADS) recommendations. Numerous studies have validated the approach, but the widespread adoption of PI-RADS version 2 has also highlighted inconsistencies and limitations, particularly relating to interobserver variability for evaluation of the transition zone. These limitations are addressed in the recently released version 2.1. In this article, we highlight the key changes proposed in PI-RADS v2.1 and explore the background reasoning and evidence for the recommendations.

Should mini percutaneous nephrolithotomy (MiniPNL/Miniperc) be the ideal tract for medium-sized renal calculi (15-30 mm)?

INTRODUCTION: Reducing the percutaneous nephrolithotomy (PCNL) tract size reduces the morbidity associated with the procedure. Prolonged procedure time is a concern. Modification in technique required is to fragment the stone into smaller particles and remove them using the vacuum cleaner effect. This prospective study compares the efficacy and morbidity of reducing the tract size from the standard 24-16.5 Fr for stones sized from 16 to 30 mm. METHODS: 123 patients were enrolled in this prospective study and distributed into 2 groups based on the tract size used (group A 16.5/17.5 Fr Miniperc, N = 61 and group B: 22/24 Fr standard PCNL, N = 62). Critical factors assessed were procedure time, fluoroscopy time, blood loss, pain score, stone clearance status and complications. RESULTS: Both the groups were comparable with respect to age, creatinine and stone size. The blood loss (hemoglobin and PCV drop) was significantly less for group A (p < 0.001). Both the groups were comparable with regards to the pain score (p > 0.05). Nephrostomy was placed in 3 patients in group A and 14 patients in group B (p = 0.01). There was no significant difference in the procedure time amongst the 2 groups. A total of 9 patients (4 in group A and 5 in group B) had residual fragments greater than 3 mm. CONCLUSION: The 16.5 Fr Miniperc tract offers lower morbidity in terms of blood loss and maintains stone clearance comparable to larger 24 Fr tract size. It should be the ideal size used for medium sized renal stones.

Nontransformed and Cancer Cells Can Utilize Different Endocytic Pathways To Internalize Dendritic Nanoparticle Variants: Implications on Nanocarrier Design.

Three hyperbranched polyglycerol nanoparticle (HPG NP) variants were synthesized and fluorescently labeled for the study of their cellular interactions. The polymeric nanoparticle that contains a hydrophobic core and a hydrophilic HPG shell, HPG-C10-HPG, is taken up faster by HT-29 cancer cells than nontransformed cells, while similar uptake rates are observed with both cell types for the nanoparticle HPG-C10-PEG that contains a hydrophobic core and a polyethylene glycol shell. The nanoparticle HPG-104, containing neither the hydrophobic core nor the polyethylene glycol shell, is taken up faster by nontransformed cells than HT-29 cells. Importantly, cancer and normal cells can utilize different endocytic mechanisms for the internalization of these HPG NPs. Both HPG-C10-HPG and HPG-C10-PEG are taken up by HT-29 cells through clathrin-mediated endocytosis and macropinocytosis. Nontransformed cells, however, take up HPG-C10-HPG and HPG-104 through macropinocytosis, while these cells utilize both clathrin-mediated endocytosis and macropinocytosis to internalize HPG-C10-PEG.

A Polymer Therapeutic Having Universal Heparin Reversal Activity: Molecular Design and Functional Mechanism.

Heparins are widely used to prevent blood clotting during surgeries and for the treatment of thrombosis. However, bleeding associated with heparin therapy is a concern. Protamine, the only approved antidote for unfractionated heparin (UFH) could cause adverse cardiovascular events. Here, we describe a unique molecular design used in the development of a synthetic dendritic polycation named as universal heparin reversal agent (UHRA), an antidote for all clinically used heparin anticoagulants. We elucidate the mechanistic basis for the selectivity of UHRA to heparins and its nontoxic nature. Isothermal titration calorimetry based binding studies of UHRAs having different methoxypolyethylene glycol (mPEG) brush structures with UFH as a function of solution conditions, including ionic strength, revealed that mPEG chains impose entropic penalty to the electrostatic binding. Binding studies confirm that, unlike protamine or N-UHRA (a truncated analogue of UHRA with no mPEG chains), the mPEG chains in UHRA avert nonspecific interactions with blood proteins and provide selectivity toward heparins through a combined steric repulsion and Donnan shielding effect (a balance of Fel and Fsteric). Clotting assays reveal that UHRA with mPEG chains did not adversely affect clotting, and neutralized UFH over a wide range of concentrations. Conversely, N-UHRA and protamine display intrinsic anticoagulant activity and showed a narrow concentration window for UFH neutralization. In addition, we found that mPEG chains regulate the size of antidote-UFH complexes, as revealed by atomic force microscopy and dynamic light scattering studies. UHRA molecules with mPEG chains formed smaller complexes with UFH, compared to N-UHRA and protamine. Finally, fluorescence and ELISA experiments show that UHRA disrupts antithrombin-UFH complexes to neutralize heparin's activity.

Assessment of the inferior mesenteric vein diameter as a surrogate marker to evaluate response to neoadjuvant chemoradiotherapy for locally advanced rectal adenocarcinoma.

AIM: Neoadjuvant chemoradiotherapy for locally advanced rectal cancer aims to downstage prior to definitive management. Repeat imaging assessment of the tumour post-therapy has implications for treatment. Our aim was to assess if the inferior mesenteric vein (IMV) diameter measured on CT can be used as a surrogate marker for evaluation of tumour response to neoadjuvant treatment. METHOD: IMV diameter was assessed in patients with and without locally advanced rectal cancer, pre- and post-radiotherapy, to ascertain if IMV diameter is a surrogate marker of tumour response. RESULTS: IMV diameter was 5.9 mm in patients with rectal cancer vs 4.7 mm in patients without (P = 0.0001). The baseline IMV diameter was significantly higher for cases with local lymphadenopathy [N0 5.2 mm vs N1/2 6 mm (P = 0.0059)] and extramural venous invasion (EMVI) [negative 5.4 mm vs positive 6.4 mm (P = 0.0001)]. Post-radiotherapy there was a significant decrease in the IMV diameter in cases with treatment response compared to non-responders: the percentage change in IMV diameter was a 17.54% decrease vs 1.39% increase (P = 0.0001). These results were reproduced on comparing between magnetic resonance tumour regression grades using ANOVA (P = 0.0001). There was also a significant decrease in IMV diameter when assessing lymph node (LN) and EMVI response vs non-responders (P = 0.0001 and 0.0001 respectively). CONCLUSION: Patients with rectal cancer have a dilated IMV compared with patients without rectal cancer. We confirm that IMV diameter is a potential surrogate marker of LN status and EMVI at baseline. IMV diameter is also a marker of tumour, LN and EMVI response to chemoradiotherapy.

Taste masking of azithromycin by resin complex and sustained release through interpenetrating polymer network with functionalized biopolymers.

OBJECTIVE: The objective was to evaluate taste masking of azithromycin (AZI) by ion exchange resins (IERs) and the formation of covalent semi interpenetrating polymer network (IPN) beads using chitosan (CS) and sodium carboxylated agarose (SCAG) for sustained release of drug. METHODS: Methacrylic acid (MAA)-based IERs were prepared by suspension polymerization method. Drug release complexes (DRCs) were prepared by different drug:resin ratios i.e. 1:1, 1:2 and 1:4. The resultant DRCs were characterized using DSC, FTIR, PXRD, in vivo and in vitro taste masking, and in vitro drug release at gastric pH. IPN beads were prepared by entrapping DRCs with bio polymers and cross linked with trisodium citrate (NaCIT), and further cross-linked with glutaraldehyde (GA) for sustained release of AZI. RESULTS: In vitro and in vivo taste masking studies showed that MD1:4 DRC formulation was optimal. The release of AZI from DRC was found to be very fast at gastric pH i.e. 97.37 ± 1.02% within 45 min. The formation of IPN beads was confirmed by FTIR. The release of drug from IPN beads at gastric and intestinal pH was found to be "<28% and <60%", respectively. The release kinetics showed Fickian diffusion profile for ionically cross-linked beads and zero-order release mechanism for GA cross-linking beads. CONCLUSIONS: DRCs can be effectively used for taste masking and newly formulated IPN beads demonstrated sustained release of AZI.

In vivo and in vitro taste masking of ofloxacin and sustained release by forming interpenetrating polymer network beads.

Drug-resin complexes (DRCs) of ofloxacin and ion-exchange resins (IERs) were prepared in different ratios of drug/IERs, that is, 1:1, 1:2 and 1:4 (w/w) and investigated for taste masking by in vivo and in vitro release studies. Human volunteers graded AD1:4 (DRC) as tasteless with an average value of 0.3 ± 0.03 and in vitro study showed that AD 1:4 released only 1.70 ± 0.86% of drug at salivary pH within 30s. Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (P-XRD) and differential scanning calorimetry (DSC) studies of AD 1:4 showed the change in the morphology of the drug, that is, from crystalline phase to amorphous phase during complex formation. The release of drug from AD 1:4 was completed within 30 min at gastric pH 1.2 and to extend the release time of drug at gastric pH, it was entrapped with different biopolymers, such as sodium alginate (SA) and sodium carboxymethyl cellulose (SCMC), in the presence of ferric chloride and glutaraldehyde (GA) to form interpenetrating polymer network (IPN) beads. FTIR studies revealed that IPN beads were crosslinked with Fe3+ and GA. The release of drug at gastric and intestinal pH was 14.53 ± 1.52% and 65.86 ± 1.29%, respectively, for a contact time of 10 h. The kinetics release study shows fickian diffusion for ionically crosslinked beads and zero-order release for GA crosslinking beads.

Anticoagulation inhibits tumor cell-mediated release of platelet angiogenic proteins and diminishes platelet angiogenic response.

Platelets are a reservoir for angiogenic proteins that are secreted in a differentially regulated process. Because of the propensity for clotting, patients with malignancy are often anticoagulated with heparin products, which paradoxically offer a survival benefit by an unknown mechanism. We hypothesized that antithrombotic agents alter the release of angiogenesis regulatory proteins from platelets. Our data revealed that platelets exposed to heparins released significantly decreased vascular endothelial growth factor (VEGF) in response to adenosine 5'-diphosphate or tumor cells (MCF-7 cells) and exhibited a decreased angiogenic potential. The releasate from these platelets contained decreased proangiogenic proteins. The novel anticoagulant fondaparinux (Xa inhibitor) demonstrated a similar impact on the platelet angiogenic potential. Because these anticoagulants decrease thrombin generation, we hypothesized that they disrupt signaling through the platelet protease-activated receptor 1 (PAR1) receptor. Addition of PAR1 antagonists to platelets decreased VEGF release and angiogenic potential. Exposure to a PAR1 agonist in the presence of anticoagulants rescued the angiogenic potential. In vivo studies demonstrated that platelets from anticoagulated patients had decreased VEGF release and angiogenic potential. Our data suggest that the mechanism by which antithrombotic agents increase survival and decrease metastasis in cancer patients is through attenuation of platelet angiogenic potential.

Nontoxic polyphosphate inhibitors reduce thrombosis while sparing hemostasis.

Polyphosphate (polyP) is secreted by activated platelets and has been shown to contribute to thrombosis, suggesting that it could be a novel antithrombotic target. Previously reported polyP inhibitors based on polycationic substances, such as polyethylenimine, polyamidoamine dendrimers, and polymyxin B, although they attenuate thrombosis, all have significant toxicity in vivo, likely due to the presence of multiple primary amines responsible for their polyP binding ability. In this study, we examined a novel class of nontoxic polycationic compounds initially designed as universal heparin reversal agents (UHRAs) to determine their ability to block polyP procoagulant activity and also to determine their utility as antithrombotic treatments. Several UHRA compounds strongly inhibited polyP procoagulant activity in vitro, and 4 were selected for further examination in mouse models of thrombosis and hemostasis. Compounds UHRA-9 and UHRA-10 significantly reduced arterial thrombosis in mice. In mouse tail bleeding tests, administration of UHRA-9 or UHRA-10 was associated with significantly less bleeding compared with therapeutically equivalent doses of heparin. Thus, these compounds offer a new platform for developing novel antithrombotic agents that target procoagulant anionic polymers such as polyP with reduced toxicity and bleeding side effects.

In Vivo Biological Evaluation of High Molecular Weight Multifunctional Acid-Degradable Polymeric Drug Carriers with Structurally Different Ketals.

Understanding the influence of degradable chemical moieties on in vivo degradation, tissue distribution, and excretion is critical for the design of novel biodegradable drug carriers. Polyketals have recently emerged as a promising therapeutic delivery platform due to their ability to degrade under mild acidic intracellular compartments and generation of nontoxic degradation products. However, the effect of chemical structure of the ketal groups on the in vivo degradation, biodistribution, and pharmacokinetics of water-soluble ketal-containing polymers has not been explored. In the present work, we synthesized high molecular weight, water-soluble biodegradable hyperbranched polyglycerols (BHPGs) through the incorporation of structurally different ketal groups into the main chain of highly biocompatible polyglycerols. BHPGs showed pH and ketal group structure dependent degradation in buffer solutions. When the polymers were intravenously administered in mice, a strong dependence of in vivo degradation, biodistribution, and clearance on the ketal group structure was observed. All the BHPGs demonstrated degradation and clearance in vivo, with minimal tissue accumulation. Interestingly, an unanticipated degradation behavior of BHPGs with structurally different ketal groups was observed in vivo in comparison to their degradation in buffer solutions. BHPGs with cyclohexyl ketal (CHK) and cyclopentyl ketal (CPK) groups degraded much faster and were cleared from circulation much rapidly, while BHPG with glycerol hydroxy butanone ketal (GHBK) group degraded at a much slower rate and exhibited similar plasma half-life as that of nondegradable HPG. BHPG-GHBK also showed significantly lower tissue accumulation than nondegradable HPG after 30 days of administration. The difference in in vivo degradation may be attributed to the difference in hydrophobic characteristics of different ketal containing polymers, which may change their interaction with proteins and cells in vivo. This is the first study that demonstrates the influence of chemical structure of ketal groups on in vivo degradation and circulation profile of polymers, and through proper surface modifications, these polymers would be useful as multifunctional drug carriers.

Kimura's disease: A case presentation of postauricular swelling.

Kimura's disease (KD) is a rare chronic inflammatory disease of subcutaneous tissues and occurs predominantly in head and neck region. It is seen primarily in young Asian males. Typical clinical presentations are painless subcutaneous masses, regional lymph node enlargement, blood and tissue hypereosinophilia, and increased serum IgE levels. Here, we present a case of a 27-year-old female who presented with unilateral single nodular swelling in the right postauricular region. The diagnosis of KD was done based on characteristic histopathologic finding in conjunction with peripheral eosinophilia and increase in serum IgE levels.

Conjugation of aurein 2.2 to HPG yields an antimicrobial with better properties.

Aurein 2.2 is an antimicrobial peptide (AMP) whose mechanism of action is quite well-understood and that has good activity against Gram-positive bacteria. It is, however, highly cytotoxic. Poly(ethylene glycol) (PEG) conjugation (PEGylation) of protein and peptide drugs has been used for decades to improve their in vivo efficacy and blood circulation by enhancing the biocompatibility of the protein or peptide in question. However, the relatively large hydrodynamic size, high intrinsic viscosity, the limited number of functional groups available for conjugation, and immunogenicity of high molecular weight PEG limits its use in bioconjugation applications. Recently, hyperbranched polyglycerol (HPG) has been gaining attention as an alternative to PEG due to its excellent biocompatibility. Here, for the first time, we report the synthesis of HPG conjugates of antimicrobial peptides. Aurein 2.2 peptide was conjugated to high molecular weight HPG with a varying number of peptides per polymer, and the biocompatibility and antimicrobial activity of the conjugates were investigated. The antimicrobial activity of the peptide and its conjugates were determined by measuring the minimal inhibitory concentration (MIC) against Staphylococcus aureus and Staphylococcus epidermidis. The interaction of aurein 2.2 peptide and the conjugates with a model bacterial biomembrane was investigated using CD spectroscopy to understand the mode of action of the conjugates. The biocompatibility of the AMP-polymer conjugates was investigated by measuring red cell lysis, platelet activation and aggregation, complement activation, blood coagulation, and cell toxicity. Our results show that the size of the conjugates and the peptide density influence the biocompatibility of the antimicrobial conjugates. These results will help to further define the properties of HPG-AMP conjugates and set the stage for development of better therapeutic agents.

Structural insight of glitazone for hepato-toxicity: Resolving mystery by PASS.

Troglitazone causes severe hepatic injury in certain individuals and multiple mechanisms related to hepato-toxicity has been reported creating confusion. In the present study, the mechanism for the hepatic injury of glitazones was investigated by PASS. The results suggest that chromane containing glitazones are apoptic agonist (activating p53 by intrinsic pathway leading to the apoptosis) and those which do not contain the chromane are devoid of this. In case of hepato-toxicity by non-chromane glitazone and their metabolite such as M-3, RM-3, rosiglitazone and pioglitazone; PASS suggest that these chemicals are not apoptic agonist but they are the substrate for CYP enzyme (Phase-I Oxidative Enzyme) and Phase-II conjugating enzymes; interfering with bile acid metabolism rendering bile acid more toxic (cholestasis). This unmetabolised bile salt further initiates the process apoptosis via intrinsic and extrinsic pathway leading to the apoptosis. Immunoblot analysis further confirm our hypothesis that troglitazone (chromane containing glitazone), but not rosiglitazone and pioglitazone (non-chromane containing glitazone) increased the levels of p53 in a time-dependent manner. Hence our prediction related to the mechanism of hepato-toxicity by apoptosis and structural insight of glitazone can be helpful in improving the drug profile of this category.