Environment-sensitive hydrogels for drug delivery

Environmentally sensitive hydrogels have enormous potential in various applications. Some environmental variables, such as low pH and elevated temperatures, are found in the body. For this reason, either pH-sensitive and/or temperature-sensitive hydrogels can be used for site-specific controlled drug delivery. Hydrogels that are responsive to specific molecules, such as glucose or antigens, can be used as biosensors as well as drug delivery systems. Light-sensitive, pressure-responsive and electro-sensitive hydrogels also have the potential to be used in drug delivery and bioseparation. While the concepts of these environment-sensitive hydrogels are sound, the practical applications require significant improvements in the hydrogel properties. The most significant weakness of all these external stimuli-sensitive hydrogels is that their response time is too slow. Thus, fast-acting hydrogels are necessary, and the easiest way of achieving that goal is to make thinner and smaller hydrogels. This usually makes the hydrogel systems too fragile and they do not have mechanical strength necessary in many applications. Environmentally sensitive hydrogels for drug delivery applications also require biocompatibility. Synthesis of new polymers and crosslinkers with more biocompatibility and better biodegradability would be essential for successful applications. Development of environmentally sensitive hydrogels with such properties is a formidable challenge. If the achievements of the past can be extrapolated into the future, however, it is highly likely that responsive hydrogels with a wide array of desirable properties can be made.

Afatinib versus gefitinib in patients with EGFR mutation-positive advanced non-small-cell lung cancer: overall survival data from the phase IIb LUX-Lung 7 trial

Background

In LUX-Lung 7, the irreversible ErbB family blocker, afatinib, significantly improved progression-free survival (PFS), time-to-treatment failure (TTF) and objective response rate (ORR) versus gefitinib in patients with epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC). Here, we present primary analysis of mature overall survival (OS) data.

Patients and methods

LUX-Lung 7 assessed afatinib 40 mg/day versus gefitinib 250 mg/day in treatment-naïve patients with stage IIIb/IV NSCLC and a common EGFR mutation (exon 19 deletion/L858R). Primary OS analysis was planned after ∼213 OS events and ≥32-month follow-up. OS was analysed by a Cox proportional hazards model, stratified by EGFR mutation type and baseline brain metastases.

Results

Two-hundred and twenty-six OS events had occurred at the data cut-off (8 April 2016). After a median follow-up of 42.6 months, median OS (afatinib versus gefitinib) was 27.9 versus 24.5 months [hazard ratio (HR) = 0.86, 95% confidence interval (CI) 0.66‒1.12, P = 0.2580]. Prespecified subgroup analyses showed similar OS trends (afatinib versus gefitinib) in patients with exon 19 deletion (30.7 versus 26.4 months; HR, 0.83, 95% CI 0.58‒1.17, P = 0.2841) and L858R (25.0 versus 21.2 months; HR 0.91, 95% CI 0.62‒1.36, P = 0.6585) mutations. Most patients (afatinib, 72.6%; gefitinib, 76.8%) had at least one subsequent systemic anti-cancer treatment following discontinuation of afatinib/gefitinib; 20 (13.7%) and 23 (15.2%) patients received a third-generation EGFR tyrosine kinase inhibitor. Updated PFS (independent review), TTF and ORR data were significantly improved with afatinib.

Conclusion

In LUX-Lung 7, there was no significant difference in OS with afatinib versus gefitinib. Updated PFS (independent review), TTF and ORR data were significantly improved with afatinib.

Clinicaltrials.gov identifier

NCT01466660.

Rituximab using a thrice weekly dosing schedule in B-cell chronic lymphocytic leukemia and small lymphocytic lymphoma demonstrates clinical activity and acceptable toxicity

PURPOSE

Rituximab has been reported to have little activity in small lymphocytic lymphoma (SLL)/chronic lymphocytic leukemia (CLL) and to be associated with significant infusion-related toxicity. This study sought to decrease the initial toxicity and optimize the pharmacokinetics with an alternative treatment schedule.

PATIENTS AND METHODS

Thirty three patients with SLL/CLL received dose 1 of rituximab (100 mg) over 4 hours. In cohort I (n = 3; 250 mg/m(2)) and cohort II (n = 7; 375 mg/m(2)) rituximab was administered on day 3 and thereafter three times weekly for 4 weeks using a standard administration schedule. Cohort III (n = 23; 375 mg/m(2)) administered rituximab similar to cohort II for the first two treatments and then over 1 hour thereafter.

RESULTS

A total of 33 CLL/SLL patients were enrolled; only one patient discontinued therapy because of infusion-related toxicity. Thirteen patients developed transient hypoxemia, hypotension, or dyspnea that were associated with significant changes in baseline interleukin-6, interleukin-8, tumor necrosis factor alpha, and interferon gamma compared with those not experiencing such reactions. Infusion-related toxicity occurred more commonly in older (median age 73 v 62 years; P =.02) patients with no other pretreatment clinical or laboratory features predicting occurrence of these events. The overall response rate was 45% (3% CR, 42% PR; 95% CI 28% to 64%). Median response duration for these 15 patients was 10 months (95% CI, 6.8-13.2; range, 3 to 17+).

CONCLUSION

Rituximab administered thrice weekly for 4 weeks demonstrates clinical efficacy and acceptable toxicity. Initial infusion-related events seem to be cytokine mediated and resolve by the third infusion making rapid administration possible. Future combination studies of rituximab with other therapies in CLL seem warranted.

Analysis of the circular dichroism spectrum of proteins using the convex constraint algorithm: a practical guide

Due to the time scale of circular dichroism (CD) measurements, it is theoretically possible to deconvolute such a spectrum if the pure CD spectra differ significantly from one another. In the last decade several methods have been published aiming at obtaining the conformational weights, or percentages (which are the coefficients for a linear combination) of the so-called typical secondary structural elements making up the three-dimensional structure of proteins. Two methods that can be used to determine the secondary structures of proteins are described here. The first method, called LINCOMB, is a simple algorithm based on a least-squares fit with a set of reference spectra representing the known secondary structures and yielding an estimation of weights attributed to alpha-helix, beta-pleated sheet (mainly antiparallel), beta-turns, unordered form, and aromatic/disulfide (or nonpeptide) contributions of the protein being analyzed. This method requires a "template" or reference curve set, which was obtained from the second method. The second method, "convex constraint analysis," is a general deconvolution method for a CD spectra set of any variety of conformational type. The algorithm, based on a set of three constraints, is able to deconvolute a set of CD curves to its common "pure"-component curves and conformational weights. To analyze a single CD spectrum with this method, the spectrum is appended to the data set used as a reference data set. As a way to determine the reliability of the algorithm and provide a guideline to its usage, some applications are presented.

Isolation of a candidate repressor/activator, NF-E1 (YY-1, delta), that binds to the immunoglobulin kappa 3' enhancer and the immunoglobulin heavy-chain mu E1 site

We have determined that the developmental control of immunoglobulin kappa 3' enhancer (kappa E3') activity is the result of the combined influence of positive- and negative-acting elements. We show that a central core in the kappa E3' enhancer is active at the pre-B-cell stage but is repressed by flanking negative-acting elements. The negative-acting sequences repress enhancer activity in a position- and orientation-independent manner at the pre-B-cell stage. We have isolated a human cDNA clone encoding a zinc finger protein (NF-E1) that binds to the negative-acting segment of the kappa E3' enhancer. This protein also binds to the immunoglobulin heavy-chain enhancer mu E1 site. NF-E1 is encoded by the same gene as the YY-1 protein, which binds to the adeno-associated virus P5 promoter. NF-E1 is also the human homologue of the mouse delta protein, which binds to ribosomal protein gene promoters. The predicted amino acid sequence of this protein contains features characteristic of transcriptional activators as well as transcriptional repressors. Cotransfection studies with this cDNA indicate that it can repress basal promoter activity. The apparent dual function of this protein is discussed.

Genetic changes in the transforming growth factor beta (TGF-beta) type II receptor gene in human gastric cancer cells: correlation with sensitivity to growth inhibition by TGF-beta

We have found several genetic changes in the TGF-beta-type II receptor gene in human gastric cancer cell lines resistant to the growth inhibitory effect of TGF-beta. Southern blot analysis showed deletion of the type II receptor gene in two of eight cell lines and amplification in another two lines. The single cell line we studied that is sensitive to growth inhibition by TGF-beta showed no structural abnormalities of the type II receptor gene. Some of the gastric cancer cells resistant to the growth inhibitory effect of TGF-beta express either truncated or no detectable TGF-beta type II receptor mRNAs, whereas the one that retains responsiveness to the growth inhibitory effect of TGF-beta expresses a full-size type II receptor mRNA. Immunoprecipitation followed by Western blot analysis showed parallel changes in TGF-beta type II receptor expression. Our results suggest that one of the possible mechanisms of escape from autocrine or paracrine growth control by TGF-beta during carcinogenesis could involve genetic changes in the TGF-beta type II receptor gene itself or altered expression of its mRNA.

Synthesis of superporous hydrogels: hydrogels with fast swelling and superabsorbent properties

We have been interested in the synthesis of hydrogels with fast swelling kinetics and superabsorbent properties. To increase the water absorption rate, interconnected pores were introduced to the hydrogels. Since the pore size in the dried hydrogels is in the order of hundreds of micrometers, these hydrogels are called "superporous" hydrogels. Superporous hydrogels were synthesized by crosslinking polymerization of various vinyl monomers in the presence of gas bubbles formed by the chemical reaction of acid and NaHCO3. The polymerization process was optimized to capture the gas bubbles inside the synthesized hydrogels. The use of the NaHCO3/acid system allowed easy control of timing for gelation and foam formation. We found that PF127 was the best foam stabilizer for most of the monomer systems used in our study. Scanning electron microscope (SEM) pictures showed interconnected pores forming capillary channels. The capillary channels, which were critical for fast swelling, were preserved during drying by dehydrating water-swollen hydrogels with ethanol before drying. The ethanol-dehydrated superporous hydrogels reached equilibrium swelling within minutes. The equilibrium swelling time could be reduced to less than a minute with the use of a wetting agent. In our study, water moisture was used as a wetting agent since the amount of moisture content in the dried hydrogels easily could be controlled. Preparation of superporous hydrogels using the right blowing system, foam stabilizer, drying method, and wetting agent makes it possible to reduce the swelling time to less than a minute regardless of the size of the dried gels. The superporous hydrogels can be used where fast swelling and superabsorbent properties are critical.

Prevention of protein adsorption and platelet adhesion on surfaces by PEO/PPO/PEO triblock copolymers

Fibrinogen adsorption and platelet adhesion on to dimethyldichlorosilane-treated glass and low-density polyethylene were examined. The surfaces were treated with poly(ethylene glycol) and poly(ethylene oxide)/poly(propylene oxide)/poly(ethylene oxide) triblock copolymers (Pluronics). Poly(ethylene glycol) could not prevent platelet adhesion and activation, even when the bulk concentration for adsorption was increased to 10 mg/ml. Pluronics containing 30 propylene oxide residues could not prevent platelet adhesion and activation, although the number of ethylene oxide residues varied up to 76. However, Pluronics containing 56 propylene oxide residues inhibited platelet adhesion and activation, even though the number of ethylene oxide residues was as small as 19. Fibrinogen adsorption on the Pluronic-coated surfaces was reduced by more than 95% compared to the adsorption on control surfaces. The ability of Pluronics to prevent platelet adhesion and activation was mainly dependent on the number of propylene oxide residues, rather than the number of ethylene oxide residues. The large number of propylene oxide residues was expected to result in tight interaction with hydrophobic dimethyldichlorosilane-treated glass and low-density polyethylene surfaces and thus the tight anchoring of Pluronics to the surfaces. The presence of 19 ethylene oxide residues in the hydrophilic poly(ethylene oxide) chains was sufficient to repel fibrinogen and platelets by the mechanism of steric repulsion.

Congestion of right liver graft in living donor liver transplantation

BACKGROUND

Left liver graft from a small donor will not meet the metabolic demands of a larger adult recipient. One solution to this problem is to use a right liver graft without a middle hepatic vein (MHV). However, the need for drainage from the MHV tributaries has not yet been described.

METHODS

Five right liver grafts without a MHV were transplanted in patients including two hepatitis B virus-cirrhosis, two fulminant hepatic failure and one secondary biliary cirrhosis. The graft weight ranged from 650 to 1,000 g, corresponding to 48 to 83% of the standard liver volume of the recipients.

RESULTS

Two of five recipients were complicated with severe congestion of the right median sector immediately after reperfusion, followed by prolonged massive ascites and severe liver dysfunction. One of the patients died of sepsis with progressive hepatic dysfunction 20 days after the operation.

CONCLUSIONS

Preservation and reconstruction of the MHV tributaries is recommended to prevent congestion of the right liver graft without MHV.

CHOP followed by involved field radiation: is it optimal for localized nasal natural killer/T-cell lymphoma?

The present study aimed to analyse the treatment outcome of four cycles of CHOP (cyclophosphamide-vincristine-doxorubicin-prednisolone) followed by involved field radiation therapy (IF RT) for the treatment of stage I-II nasal natural killer (NK)/T-cell lymphoma. From March 1995 to December 1999, 17 patients (median age 41 years; range 30-66) with localized nasal NK/T-cell lymphoma were enrolled. B symptoms were noted in five patients (31%). Sixteen of seventeen patients (94%) were of low risk when classified according to the International Prognostic Index (IPI). The treatment plan consisted of four cycles of CHOP chemotherapy followed by IF RT of 45 Gy. Two patients received radiation during the first or second cycle of CHOP because of bleeding from the primary tumour site. Both patients achieved complete responses (CRs). In the remaining 15 patients, after 4 cycles of CHOP, 6 CRs and 3 partial responses (PRs) were achieved (53% of response rate). IF RT was given to six patients (four in CR, one in PR and one in PD), and all six patients achieved CR. Overall, CR was achieved in 10 of 17 patients (58%). The planned sequential chemoradiotherapy was completed in only 6 of 17 patients (35%) because of the progression during chemotherapy. None of the patients who achieved CR experienced relapse of lymphoma during follow-up. The estimated overall three-year survival rate was 59%. In univariate analysis, B symptoms and stage were significant prognostic factors for response and overall survival (P < 0.05). The present study suggests that four cycles of CHOP followed by IF RT is not satisfactory for treating patients with localized nasal NK/T-cell lymphoma, and that further exploration for improved therapy is needed.

Multicenter phase II trial of Genexol-PM, a novel Cremophor-free, polymeric micelle formulation of paclitaxel, with cisplatin in patients with advanced non-small-cell lung cancer

BACKGROUND

Genexol-PM is a novel Cremophor EL (CrEL)-free polymeric micelle formulation of paclitaxel (Taxol). This multicenter phase II study was designed to evaluate the efficacy and safety of the combination of Genexol-PM and cisplatin for the treatment of advanced non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients with advanced NSCLC received Genexol-PM 230 mg/m(2) and cisplatin 60 mg/m(2) on day 1 of a 3-week cycle as first-line therapy. Intrapatient dose escalation of Genexol-PM to 300 mg/m(2) was carried out from the second cycle if the prespecified toxic effects were not observed after the first cycle.

RESULTS

Sixty-nine patients were enrolled in this study. Overall response rate was 37.7%. The median time to progression was 5.8 months and the median survival period was 21.7 months. The major non-hematologic toxic effects included grade 3 peripheral sensory neuropathy (13.0%) and grade 3/4 arthralgia (7.3%). Four patients (5.8%) experienced grade 3/4 hypersensitivity reactions. The major hematological toxic effects were grade 3/4 neutropenia (29.0% and 17.4%, respectively).

CONCLUSION

Genexol-PM plus cisplatin combination chemotherapy showed significant antitumor activity. The use of CrEL-free, polymeric micelle formulation of paclitaxel allowed administration of higher doses of paclitaxel compared with the CrEL-based formulation without significant increased toxicity.

Surface modification of polymeric biomaterials with poly(ethylene oxide), albumin, and heparin for reduced thrombogenicity

Appropriate surface modification has significantly improved the blood compatibility of polymeric biomaterials. This article reviews methods of surface modification with water-soluble polymers, such as polyethylene oxide (PEO), albumin, and heparin. PEO is a synthetic, neutral, water-soluble polymer, while albumin and heparin are a natural globular protein and an anionic polysaccharide, respectively. When grafted onto the surface, all three macromolecules share a common feature to reduce thrombogenicity of biomaterials. The reduced thrombogenicity is due to the unique hydrodynamic properties of the grafted macromolecules. In aqueous medium, surface-bound water-soluble polymers are expected to be highly flexible and extend into the bulk solution. Biomaterials grafted with either PEO, albumin, or heparin are able to resist plasma protein adsorption and platelet adhesion predominantly by a steric repulsion mechanism.

Pan-Asian adapted Clinical Practice Guidelines for the management of patients with metastatic non-small-cell lung cancer: a CSCO-ESMO initiative endorsed by JSMO, KSMO, MOS, SSO and TOS

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of metastatic non-small-cell lung cancer (NSCLC) was published in 2016. At the ESMO Asia Meeting in November 2017 it was decided by both ESMO and the Chinese Society of Clinical Oncology (CSCO) to convene a special guidelines meeting immediately after the Chinese Thoracic Oncology Group Annual Meeting 2018, in Guangzhou, China. The aim was to adapt the ESMO 2016 guidelines to take into account the ethnic differences associated with the treatment of metastatic NSCLC cancer in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with metastatic NSCLC representing the oncological societies of China (CSCO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence, and was independent of both the current treatment practices and the drug availability and reimbursement situations in the six participating Asian countries. During the review process, the updated ESMO 2018 Clinical Practice Guidelines for metastatic NSCLC were released and were also considered, during the final stages of the development of the Pan-Asian adapted Clinical Practice Guidelines.

Surface modification using silanated poly(ethylene glycol)s

Surface-grafted poly(ethylene glycol) (PEG) molecules are known to prevent protein adsorption to the surface. The protein-repulsive property of PEG molecules are maximized by covalent grafting. We have synthesized silanated monomethoxy-PEG (m-PEG) for covalent grafting of PEG to surfaces with oxide layers. Two different trialkoxysilylated PEGs were synthesized and characterized. The first trialkoxysilylated PEG was prepared by direct coupling of m-PEG with 3-isocyanatopropyltriethoxysilane through a urethane bond (silanated PEG I). The other silanated PEG (silanated PEG II) containing a long hydrophobic domain between PEG and a silane domain was prepared by reacting m-PEG with 1,6-diisocyanatohexane and 10-undecen-1-ol in sequence before silylation with 3-mercaptopropyl trimethoxysilane. Silanated PEGs I and II were grafted onto glass, a model surface used in our study. The PEG-grafted glass surfaces were characterized by contact angle, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Although contact angle did not change much as the bulk concentration of silanated PEG used for grafting increased from 0.1 to 20 mg/ml for both PEGs I and II, the surface atomic concentrations from XPS measurements showed successful PEG grafting. Surface PEG grafting increased concentration of surface carbon but decreased silicone concentration. The high resolution C1s spectra showed higher ether carbon with lower hydrocarbon compositions for the PEG-grafted surfaces compared to the control surface. AFM images showed that more PEG molecules were grafted onto the surface as the bulk concentration used for grafting was increased. AFM images of the dried surfaces showed that the surfaces were not completely covered by PEG molecules. After hydration, however, the surface appears to be covered completely probably due to the hydration of the grafted PEG chains. Glass surfaces modified with silanated PEGs reduced fibrinogen adsorption by more than 95% as compared with the control surface. Silanated PEGs provides a simple method for PEG grafting to the surface containing oxide layers.

Size-Resolved Kinetic Measurements of Aluminum Nanoparticle Oxidation with Single Particle Mass Spectrometry

Aluminum nanoparticles are being considered as a possible fuel in advanced energetic materials application. Of considerable interest therefore is a knowledge of just how reactive these materials are, and what the effect of size on reactivity is. In this paper we describe results of size resolved oxidation rate using a recently developed quantitative single particle mass spectrometer (SPMS). Aluminum nanoparticles used were either generated by DC Arc discharge or laser ablation, or by use of commercial aluminum nanopowders. These particles were oxidized in an aerosol flow reactor in air for specified various temperatures (25-1100 degrees C), and subsequently sampled by the SPMS. The mass spectra obtained were used to quantitatively determine the elemental composition of individual particles and their size. We found that the reactivity of aluminum nanoparticles is enhanced with decreasing primary particle size. Aluminum nanoparticles produced from the DC Arc, which produced the smallest primary particle size (approximately 19 nm), were found to be the most reactive (approximately 68% aluminum nanoparticles completely oxidized to aluminum oxide at 900 degrees C). In contrast, nanopowders with primary particle size greater than approximately 50 nm were not fully oxidized even at 1100 degrees C (approximately 4%). The absolute rates observed were found to be consistent with an oxide diffusion controlled rate-limiting step. We also determined the size-dependent diffusion-limited rate constants and Arrehenius parameters (activation energy and pre-exponential factor). We found that as the particle size decreases, the rate constant increases and the activation energy decreases. This work provides a quantification of the known pyrophoric nature of fine metal particles.

Mouse down-regulated in adenoma (DRA) is an intestinal Cl(-)/HCO(3)(-) exchanger and is up-regulated in colon of mice lacking the NHE3 Na(+)/H(+) exchanger

Mutations in human DRA cause congenital chloride diarrhea, thereby raising the possibility that it functions as a Cl(-)/HCO(3)(-) exchanger. To test this hypothesis we cloned a cDNA encoding mouse DRA (mDRA) and analyzed its activity in cultured mammalian cells. When expressed in HEK 293 cells, mDRA conferred Na(+)-independent, electroneutral Cl(-)/CHO(3)(-) exchange activity. Removal of extracellular Cl(-) from medium containing HCO(3)(-) caused a rapid intracellular alkalinization, whereas the intracellular pH increase following Cl(-) removal from HCO(3)(-)-free medium was reduced greater than 7-fold. The intracellular alkalinization in Cl(-)-free, HCO(3)(-)-containing medium was unaffected by removal of extracellular Na(+) or by depolarization of the membrane by addition of 75 mM K(+) to the medium. Like human DRA mRNA, mDRA transcripts were expressed at high levels in cecum and colon and at lower levels in small intestine. The expression of mDRA mRNA was modestly up-regulated in the colon of mice lacking the NHE3 Na(+)/H(+) exchanger. These results show that DRA is a Cl(-)/HCO(3)(-) exchanger and suggest that it normally acts in concert with NHE3 to absorb NaCl and that in NHE3-deficient mice its activity is coupled with those of the sharply up-regulated colonic H(+),K(+)-ATPase and epithelial Na(+) channel to mediate electrolyte and fluid absorption.

Distribution of obstructive intimal lesions and their cellular phenotypes in chronic pulmonary hypertension. A morphometric and immunohistochemical study

We investigated the distribution of pulmonary arteriopathy in chronic pulmonary hypertension (PH) in a quantitative histopathologic study, using computer-assisted image analysis. We also examined the histologic manifestations and cellular phenotypes of various obstructive intimal lesions in PH with an immunohistochemical method. A total of 53 lungs removed at autopsy or explantation were obtained for the study from 51 documented cases of moderate to severe PH (15 cases of primary pulmonary hypertension [PPH], eight cases of Eisenmenger's syndrome [EISEN], 22 cases of chronic major-vessel thromboembolic disease [CTED], and three cases of PH associated with other known causes), and two unused donor lungs served as normal controls. Intimal thickening in PPH was most prominent in small pulmonary arteries and arterioles less than 200 micrometer in diameter. Plexiform lesions in PPH were associated with significantly smaller arteries than in EISEN. Arteries larger than 400 micrometer showed a significant intimal thickening only in CTED. Obstructive intimal lesions in PH comprised a morphologic spectrum with frequent intermediate forms between plexiform and thrombotic lesions. Most cells within various intimal lesions showed an immunoprofile of myofibroblasts that were positive for vimentin and alpha-smooth muscle actin, but negative for desmin and endothelial markers including Factor VIII, clonal designator (CD)31, and CD34. Endothelial markers were positive only in the single layer of cells lining slitlike lumens, when the latter were present. In conclusion, major types of PH had characteristic distribution patterns of obstructive intimal lesions, showing mainly a myofibroblastic phenotype and variable endothelial/vascular differentiation.

Is juvenile obsessive-compulsive disorder a developmental subtype of the disorder? A review of the pediatric literature

OBJECTIVE

To examine the clinical correlates of obsessive-compulsive disorder (OCD) in children and adolescents.

METHOD

A systematic review of the extant literature on juvenile OCD was conducted examining age at onset, gender distribution, symptom phenomenology, psychiatric comorbidity, neurological and perinatal history, family psychiatric history, cognitive and neuropsychological profiles, and treatment and outcome in juvenile OCD subjects.

RESULTS

Juvenile OCD was associated with a unique peak of age at onset indicating a bimodal incidence of the disorder, male preponderance, a distinct pattern of comorbidity with attention-deficit/hyperactivity disorder and other developmental disorders as well as frequent associated neuropsychological deficits, an increased familial loading for OCD, and frequent absence of insight.

CONCLUSION

These findings show that juvenile OCD is associated with a unique set of correlates that appear to differ from findings reported in studies of adult OCD subjects. Although in need of confirmation, these findings suggest that juvenile OCD may be a developmental subtype of the disorder. Since juvenile OCD is likely to continue into adulthood, these findings stress the importance of considering age at onset in clinical and research studies of adults with OCD.

Vandetanib in pretreated patients with advanced non-small cell lung cancer-harboring RET rearrangement: a phase II clinical trial

Background

Chromosomal rearrangements involving RET, which are found in about 1% of non-small cell lung cancer (NSCLC), define a unique molecular subset. We performed this study to examine the efficacy and safety of vandetanib 300 mg daily in this patient population.

Patients and methods

This study was a multi-center, open-label, phase II clinical trial. Patients were enrolled if they had metastatic or recurrent NSCLC with a RET rearrangement, which was confirmed by fluorescence in situ hybridization, had progressive disease against platinum-based doublet chemotherapy, and had a performance status of 0-2. The primary endpoint was the objective response rate.

Results

A total of 18 patients were enrolled in this study between July 2013 and October 2015. Patients were aged 35-71 years; three had a performance status of 2, and the majority were a heavily pretreated population (≥ two different previous chemotherapy regimens in 72% of the patients). Among the 17 evaluable patients, three had a partial response (objective response rate = 18%) and eight had a stable disease (disease control rate = 65%). Among these patients, the partial response or disease stabilization was durable for more than 6 months in eight patients. Vandetanib also showed a progression-free survival of 4.5 months, and an overall survival of 11.6 months during a median follow-up duration of 14 months. The safety profile was comparable with previous studies of vandetanib. Most vandetanib-related adverse events were mild with prevalent hypertension and rash (in >70% of patients). Grade 3 toxicity included hypertension (n = 3), QT prolongation (2), and elevation of aminotransferases (1), and as a consequence the dose was reduced in four patients. There were no adverse events associated with grade 4 or 5 toxicity.

Conclusion

Vandetanib is moderately active in pretreated patients with advanced NSCLC-harboring RET rearrangements.

Comparison of an aprepitant regimen with a multiple-day ondansetron regimen, both with dexamethasone, for antiemetic efficacy in high-dose cisplatin treatment

BACKGROUND

We compared an aprepitant regimen with a control regimen of ondansetron + dexamethasone given for 4 days.

PATIENTS AND METHODS

Patients scheduled to receive cisplatin > or =70 mg/m(2) were randomized to either the aprepitant regimen (aprepitant, ondansetron and dexamethasone on day 1; aprepitant and dexamethasone on days 2-3; dexamethasone on day 4) or control regimen (ondansetron + dexamethasone on days 1-4). Patients recorded vomiting, nausea and rescue therapy use. The primary end point was complete response (no vomiting and no use of rescue therapy) in the overall phase (days 1-5 post-cisplatin).

RESULTS

Complete response rates were higher in the aprepitant than control group in the overall (72% versus 61%; P = 0.003), acute (day 1; 88% versus 79%; P = 0.005) and delayed phases (days 2-5; 74% versus 63%; P = 0.004), as were rates of no vomiting (overall 77% versus 62%, P < or = 0.001; acute 89% versus 81%, P = 0.004; delayed 79% versus 64%, P < or = 0.001). Rates of no rescue therapy were similar between groups.

CONCLUSIONS

Compared with an antiemetic regimen in which ondansetron + dexamethasone were given for 4 days, the aprepitant regimen was superior in the acute, delayed and overall phases of chemotherapy-induced nausea and vomiting. The aprepitant regimen should be considered a new standard of antiemetic therapy for cisplatin-treated patients. www.ClinicalTrials.gov Identifier: NTC00090207.

Effects of castration and androgen replacement on erectile function in a rabbit model

We investigated, in a rabbit model, the effects of castration and testosterone replacement on: 1) the hemodynamics of the corpus cavernosum; 2) alpha-1 adrenergic receptor protein expression; 3) neural NO synthase protein expression and activity; 4) phosphodiesterase type 5 activity; and 5) trabecular smooth muscle/connective tissue balance. One week after bilateral orchiectomy, animals were treated for 7 days with vehicle alone, testosterone, or estradiol. Intact control animals received vehicle only. Systemic arterial blood and intracavernosal pressures (ICP) were measured in each animal before and after electrical stimulation of the cavernosal nerve. Alpha1-adrenergic receptor protein expression was determined by ligand binding studies. NO synthase expression and activity were determined by Western blot analyses and conversion of L-arginine to citrulline, respectively. Phosphodiesterase type 5 activity was determined by hydrolysis of guanosine 3',5'-cyclic monophosphate (cGMP) in tissue extracts in the absence or presence of 100 nM sildenafil. Smooth muscle content was assessed by Masson's trichrome staining and computer-assisted histomorphometry. Castration significantly reduced ICP, but it did not alter systemic arterial blood pressure during stimulation of the cavernosal nerve. Testosterone, but not estradiol, treatment prevented the effects of castration and restored ICP to values similar to those obtained in intact animals. Castration reduced expression of alpha1-adrenergic receptor, and this reduction was prevented or reversed by testosterone replacement. Neural NO synthase protein expression and total activity were not altered significantly by castration or after testosterone replacement. However, phosphodiesterase type 5 activity increased in castrated animals treated with testosterone. Castration significantly reduced trabecular smooth muscle content, and this reduction was restored by testosterone (but not estradiol) treatment. The results of this study demonstrate that androgen deprivation alters the functional responses and structure of erectile tissue.

Vasculogenic female sexual dysfunction: the hemodynamic basis for vaginal engorgement insufficiency and clitoral erectile insufficiency

OBJECTIVE

Organic female sexual dysfunction may be related in part to vasculogenic impairment of the hypogastric-vaginal/clitoral arterial bed. The aim was to develop an animal model of vaginal engorgement insufficiency and clitoral erectile insufficiency.

METHODS

Pelvic nerve stimulated vaginal engorgement and clitoral erection were achieved in control (normal diet, n = 8) and atherosclerotic (balloon injury of aorto-iliac arteries and 0.5% cholesterol diet, n = 7) New Zealand White female rabbits. After 16 weeks, novel hemodynamic variables including vaginal wall and clitoral blood flow, vaginal wall and clitoral intracavernosal pressure, vaginal length, vaginal luminal pressure, blood levels of cholesterol and triglycerides, aorto-iliac angiography and vaginal wall and clitoral erectile tissue histology were recorded in the two groups.

RESULTS

Concerning pelvic nerve stimulated vaginal hemodynamic changes, there was significantly less increase in blood flow (ml/min/100 gm tissue), wall pressure (mmHg) and length changes (mm) in atherosclerotic (9.3 +/- 3.7, 4.8 +/- 3.8, 67.3 +/- 8.3) compared to control (13.9 +/- 4.5, 5.5 +/- 2.6, 74.1 +/- 10.0) animals respectively. Histologic examination of clitoral erectile tissue demonstrated cavernosal artery atherosclerotic changes and diffuse vaginal and clitoral fibrosis. Aorto-iliac angiography in atherosclerotic animals revealed diffuse moderate to severe atherosclerotic occlusion.

CONCLUSIONS

Vaginal engorgement and clitoral erection depend on increased blood inflow. Atherosclerosis is associated with vaginal engorgement insufficiency and clitoral erectile insufficiency.

Synthesis and characterization of superporous hydrogel composites

Recently, we synthesized superporous hydrogels which swell fast with high swelling ratios for development of gastric retention devices. Due to their superabsorbent nature, superporous hydrogels are too mechanically weak for gastric retention application. The mechanical strength of superporous hydrogels was substantially increased by making superporous hydrogel composites. The composite materials used were hydrophilic particulate materials commonly used as disintegrants in pharmaceutical tablets. In this study, Ac-Di-Sol was used as a model composite material. Addition of Ac-Di-Sol resulted in significant improvement in the properties of superporous hydrogels. The dried superporous hydrogels maintained interconnected channels even after drying in the air. Thus, the swelling kinetics and the swelling ratio were not affected by air drying, which normally would have resulted in partial or total collapse of the interconnected pores. The presence of Ac-Di-Sol also increased the mechanical strength substantially. Scanning electron microscopic examination showed that the composite material increased the physical crosslinking density which provided high mechanical strength and prevented polymer chains from collapsing during air drying. The superporous hydrogel composites possess properties suitable for gastric retention.

Connexin26 mutations associated with nonsyndromic hearing loss

OBJECTIVE

Mutations in the GJB2 gene are a major cause of autosomal recessive and sporadic types of congenital deafness. The 35delG mutation is the most frequent type of mutation in white populations. However, several other forms were reported, such as 167delT among Ashkenazi Jews and R143W in Africans. The present study investigated the mutations of connexin26 (Cx26) found in patients with nonsyndromic hearing loss (NSHL) and newborns in the Korean population.

STUDY DESIGN

The sequencing data for 147 unrelated patients with congenital NSHL and 100 audiologically screened newborns were included in this prospective study.

METHODS

Genomic DNA samples from all patients and newborns were sequenced in both directions for detection of Cx26 mutations.

RESULTS

Thirteen different types of mutations were found in the patients and newborns. V27I and E114G are the popular types of polymorphic mutations in both groups. 235delC-deletion and frameshift--was detected in patients (15 in 294 alleles) and newborns (1 in 200 alleles). 35delG was rarely found in both group. In addition to above mutations, several types of mutations--S85P, K41R, S72C, V84A, 176-191del, and 299-300del-were identified. The family study of the 235delC showed a typical autosomal recessive trait of NSHL in their audiological evaluation of hearing threshold.

CONCLUSION

The frequency of 235delC allele showed much higher in the patients (5%) than in newborns (0.5%). We rarely found 35delC mutant in both groups. These results suggest that the different types of Cx26 mutations affect autosomal recessive NSHL according to ethnic background.

Gastric retention properties of superporous hydrogel composites

In many applications, usefulness of conventional hydrogels is limited by their slow swelling. To improve the swelling property of the conventional hydrogels, we have synthesized superporous hydrogels (SPHs) which swell fast to equilibrium size in minutes due to water uptake by capillary wetting through numerous interconnected open pores. The swelling ratio was also large in the range of hundreds. The mechanical strength of the highly swollen SPHs was increased by adding a composite material during the synthesis. The composite material used in the synthesis of SPH composites was Ac-Di-Sol((R)) (croscarmellose sodium). The gastric retention property of the prepared SPH composites was tested in dogs both in fasted and fed conditions. The SPH composites were placed in a hard gelatin capsule (size 000) for oral administration. All dogs tested were fasted for 36 h before experiments. Under the fasted condition, the SPH composite remained in the stomach for 2-3 h after before breaking into two pieces and being emptied. When food was given before the experiment just once following 36 h of fasting, the SPH composite remained in the stomach for more than 24 h, even though the fed condition was maintained only for the first few hours. Our study indicated that SPH composites possessed three properties necessary for gastric retention: fast swelling; superswelling; and high mechanical strength. While more improvements need to be made, the SPH composites provide the basis for the development of effective long-term gastric retention devices.