Improved methodology for identifying the teratogenic potential in early drug development of hERG channel blocking drugs

Drugs blocking the potassium current IKr of the heart (via hERG channel-inhibition) have the potential to cause hypoxia-related teratogenic effects. However, this activity may be missed in conventional teratology studies because repeat dosing may cause resorptions. The aim of the present study was to investigate an alternative protocol to reveal the teratogenic potential of IKr-blocking drugs. The IKr blocker astemizole, given as a single dose (80 mg/kg) on gestation day (GD) 13 to pregnant rats caused digital defects. In whole rat embryo culture (2h) on GD 13, astemizole caused a decrease in embryonic heart rate at 20 nM, and arrhythmias at 200-400 nM. Cetirizine, without IKr-blocking properties, did not affect the rat embryonic heart in vitro. The present study shows that single dose testing on sensitive days of development, together with whole embryo culture, can be a useful methodology to better characterize the teratogenic potential of IKr-blocking drugs.

Esophageal stenting in children: indications, application, effectiveness, and complications

BACKGROUND

Use of esophageal stents is uncommon in children, and there are few reports. We report the first experience in predominantly small children and infants with retrievable, flexible stents designed for tracheobronchial use.

OBJECTIVE

Evaluation of initial experience with placement of esophageal stents for benign esophageal disorders in children.

DESIGN

A retrospective study.

SETTING

A pediatric, academic, tertiary-referral center.

PATIENTS

This study involved 7 pediatric patients.

INTERVENTIONS

Covered tracheobronchial stents were endoscopically placed in pediatric patients with benign esophageal conditions. Removal involved using forceps to pull the purse-string suture into the endoscope channel and collapsing the top of the stent for easy removal.

MAIN OUTCOME MEASUREMENTS

To evaluate the safety and feasibility of performing endoscopic stent placement in children and to establish criteria for early stent removal.

RESULTS

Six of 7 patients benefitted from stenting. There were no complications of placement. Novel techniques were developed for difficult retrievals. One patient did not benefit from esophageal stent placement, because the stent migrated downward from the uppermost part of the esophagus. One patient had some gagging, which led to early removal of the stent. A stent was removed emergently in 1 patient for respiratory distress.

LIMITATION

Small number of patients.

CONCLUSIONS

Retrievable, covered stents are easily placed and removed from the esophagus in small children. They should be considered for severe unrelenting strictures, especially when associated with esophageal leaks. A need exists for development of esophageal stents designed for pediatric use.

Effect of chronic treatment with a cyclooxygenase inhibitor on reproductive parameters in male rat

BACKGROUND

Indomethacin is a member of non-steroidal anti-inflammatory drugs (NSAIDs) commonly used for treatment of gout, arthritis, and other inflammatory conditions. It has been shown to inhibit ovarian prostaglandins synthesis in mammals, birds, fish and reptiles. However, the effects of its chronic administration on male reproductive functions remain largely unknown. Using rat as a model, we studied the effect of chronic treatment with indomethacin on the male reproductive system.

METHODS

Testosterone was measured in the serum, testicular tissue, and testicular interstitial fluid by radioimmunoassay. Moreover, we also studied the direct effect of indomethacin in vitro on luteinizing hormone stimulated testosterone secretion from the Leydig cells isolated from various treatment groups.

RESULTS

Indomethacin treatment for 50 days caused a significant but reversible decrease in prostate weight, epididymal sperm reserves and sperm motility score compared with control rats (p < 0.05). In vitro stimulation of Leydig cells isolated from treated rat's testes with luteinizing hormone (250 microIU) produced significantly reduced testosterone compared with cells from control groups (p < 0.05). Furthermore, stimulatory effect of luteinizing hormone on the control Leydig cells was significantly reduced when these cells were challenged with luteinizing hormone in the presence of indomethacin, (p < 0.05). Testosterone concentration in the testicular tissue and testicular interstitial fluid reduced after indomethacin treatment (p < 0.05).

CONCLUSION

Due to its significant inhibition of key reproductive hormones, indomethacin effectively inhibits reproductive functions if used on a long-term basis. In his study, we have identified potential risks in the long-term use ofcyclooxygenase inhibitors.

Achievement of feeding milestones after primary repair of long-gap esophageal atresia

OBJECTIVES

To determine the pattern of feeding milestones following primary repair of long-gap esophageal atresia (EA).

METHOD

A questionnaire based upon well established feeding milestones was used. Children after long-gap EA repair, n=40, were compared from after primary repair to healthy children from birth, n=102.

RESULTS

The age when surveyed of the EA group and controls was different: 6.2+/-4.7 (mean+/-standard deviation) years, range 1.1-20.9, versus 2.5+/-2.4 years, range 0.0-12.1, p=0.00. The esophageal gap length in the EA group was 5.1+/-1.2 cm and age at repair was 5.5+/-5.0 months. There was no statistically significant difference between the atresia group and controls for feeding milestones; Self feeding finger foods approached significance. There was, however, greater variability in the timing of milestones in the atresia group compared to controls. Feeding milestones were negatively correlated with age at primary repair: drinking with a covered sippy cup, rho=-0.51, p=0.01 and self feeding finger foods, rho=-0.36, p=0.04 were statistically significant. Drinking from a cup correlated with gestational age, rho=0.38, p=0.04, and negatively correlated to esophageal gap length, rho=-0.45, p=0.01.

CONCLUSIONS

Despite delayed onset of feeding, major milestones after EA repair occurred in similar pattern to normal infants. An early referral for primary repair is beneficial for earlier acquisition of milestones for infants with long-gap EA.

Mechanotherapy: how physical therapists' prescription of exercise promotes tissue repair

Mechanotransduction is the physiological process where cells sense and respond to mechanical loads. This paper reclaims the term “mechanotherapy” and presents the current scientific knowledge underpinning how load may be used therapeutically to stimulate tissue repair and remodelling in tendon, muscle, cartilage and bone.

The purpose of this short article is to answer a frequently asked question “How precisely does exercise promote tissue healing?” This is a fundamental question for clinicians who prescribe exercise for tendinopathies, muscle tears, non-inflammatory arthropathies and even controlled loading after fractures. High-quality randomised controlled trials and systematic reviews show that various forms of exercise or movement prescription benefit patients with a wide range of musculoskeletal problems.1^–4 But what happens at the tissue level to promote repair and remodelling of tendon, muscle, articular cartilage and bone?

The one-word answer is “mechanotransduction”, but rather than finishing there and limiting this paper to 95 words, we provide a short illustrated introduction to this remarkable, ubiquitous, non-neural, physiological process. We also re-introduce the term “mechanotherapy” to distinguish therapeutics (exercise prescription specifically to treat injuries) from the homeostatic role of mechanotransduction. Strictly speaking, mechanotransduction maintains normal musculoskeletal structures in the absence of injury. After first outlining the process of mechanotransduction, we provide well-known clinical therapeutic examples of mechanotherapy–turning movement into tissue healing.

Long-gap esophageal atresia treated by growth induction: the biological potential and early follow-up results

This study had two purposes. The first was to determine whether the growth procedure would allow true primary repairs of the most severe end of the esophageal atresia (EA) spectrum with the longest gaps (LG) and most rudimentary lower esophageal segments. The second goal was to provide the first short- to mid-term (3-12 years) follow-up data on the esophageal function and quality of life (QOL) data on the patients in this series. From our series of 60 LG-EA patients who underwent a growth procedure, 42 had the true primary esophageal repair completed 3 years ago. Among these, 18 had gaps over 6 cm, and for 6, only a rudimentary lower esophagus existed well below the diaphragm. No patient was turned down and all had primary repairs. These results suggest that even the most rudimentary segment has the potential to achieve normal size and that the full EA spectrum can have a primary repair. Our follow-up studies indicated that the esophageal function of these previously grown segments was very good. All contacted (40) were eating normally with only 3 receiving supplemental g-tube feeds because of other significant defects. We have actively treated significant reflux and 41/42 had fundoplication. By endoscopy (N = 15) no esophagitis was visible, but on biopsy, mild inflammation was found in 3. No conditions were found which would suggest that there would be a late deterioration or adverse consequences would arise. Based on these ongoing evaluations, the outlook seems very favorable for a good long-term QOL.

Facile, economical and direct synthesis of 9-anilinoacridines

Acridines are well-known group of compounds with a wide variety of biological properties. We describe herein an expeditious approach to prepare anilinoacridine derivatives from mefenamic acid. It is the first report of a one-pot approach to anilinoacridines in good to excellent yields.

Muscle power is related to tibial bone strength in older women

We enrolled 65 to 75 year-old community-dwelling women and measured muscle power, strength, physical activity using accelerometry and tibial bone strength using peripheral quantitative computed tomography (pQCT). Muscle power contributed 6.6% of the variance in the bone strength-strain index and 8.9% in the section modulus after accounting for age, height, weight, and physical activity; moderate to vigorous physical activity was related to muscle power in the lower extremity.

INTRODUCTION

Muscle power is associated with DXA measurements of bone mass, but it is not known whether muscle power is associated with bone strength. There are no reports of investigations that have tested the effect of muscle power on bone compartments using advanced imaging.

METHODS

We enrolled 74 community-dwelling women aged 65-75 years. We measured muscle power and strength of leg extension using Keiser air-pressure resistance equipment. All participants wore a waist-mounted Actigraph accelerometer to record physical activity. We used peripheral quantitative computed tomography (pQCT) to measure tibial mid-shaft (50% of the site) bone strength (strength-strain index, section modulus). We used Pearson correlations and multi-level linear regression to investigate the associations between muscle and bone.

RESULTS

Muscle power contributed 6.6% (p = 0.007) of the variance in the bone strength-strain index and 8.9% (p = 0.001) the variance in the section modulus in older women after accounting for age, height, weight, and physical activity. Moderate to vigorous physical activity was significantly related to muscle power in the lower extremity (r = 0.260; p = 0.041).

CONCLUSION

Muscle power significantly contributed to the variance in estimated bone strength. Whether power training will prove to be a more effective stimulus for bone strength than conventional strength training will require further studies.

Oxovanadium(IV) complexes of hydrazides: Potential antifungal agents

Oxovanadium(IV) -derived antifungals have been prepared by condensing equimolar amounts of vanadyl sulfate with hydrazides. All the synthesized ligands and their metal complexes were characterized by IR, UV-Visible and micro analytical data. These synthesized compounds were screened for their antifungal activity against Aspergillus flavus (A. flavus), Trichophyton longifusus (T. longifusus), Candida albicans (C. albicans), Microsporum canis (M. canis), Fusarium solani (F. solani) and Candida glaberata (C. glaberata) fungal strains. All complexes showed promising antifungal activity against different fungal strains with the exception of F. Solani and C. glaberata. Minimum Inhibitory Concentration (MIC) of different complexes and ligands are in the range of 250 to 400 microg/mL. Complex 7a and ligand 13 exhibit lowest MIC of 250 microg/mL whereas, complex 5a and ligands 2, 7 and 14 showed highest MIC of 400 microg/mL.

Tyrosinase inhibition: Conformational analysis based studies on molecular dynamics calculations of bipiperidine based inhibitors

Two series of variably N-substituted biperidines were synthesized by condensing various acid chlorides, alkyl halides and anhydrides with 1,4-bipiperidine. The new compounds were tested as tyrosinase inhibitors and a structure-activity relationship (SAR) study was carried out. Potent inhibition was observed in the case of the 4'-methylbenzyl substitution on this atom (IC50 = 1.72 microM) with this compound being a lead for future drug design. Additionally, calculations of the important QSAR molecular descriptors were done on the biperidine analogues after their 2 ps molecular dynamics (MD) simulations using molecular mechanics force field (MMFF) approaches. Using MD simulations potential and total energies were calculated for the energy minimized models of bipiperidine and the most active analogs 2, 3, 4, 6, 8 and 10.

Antibacterial cobalt (II), copper (II), nickel (II) and zinc (II) complexes of mercaptothiadiazole—derived furanyl, thienyl, pyrrolyl, salicylyl and pyridinyl Schiff bases

A series of Co (II), Cu (II), Ni (II) and Zn (II) complexes of mercaptothiadiazole-derived furanyl, thienyl, pyrrorlyl, salicylyl and pyridinyl Schiff bases were synthesized, characterized and screened for their in vitro antibacterial activity against four Gram-negative, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi and Shigella fexneri, and two Gram-positive; Bacillus subtilis and Staphylococcus aureous bacterial strains. The results of these studies show the metal complexes to be more antibacterial as compared to the prepared un-complexed Schiff bases.

Isatin-derived Antibacterial and Antifungal Compounds and their Transition Metal Complexes

A series of isatins incorporating thiazole, thiadiazole, benzothiazole and p-toluene sulfonyl hydrazide moieties, along with their cobalt(II), copper(II), nickel(II) and zinc(II) metal complexes have been synthesized and characterized by elemental analyses, molar conductances, magnetic moments, IR, NMR and electronic spectral data. These compounds have been screened for antibacterial activity against Escherichia coli, Bacillus subtillis, Shigella flexneri, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi, and for antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glaberata using the agar-well diffusion method. All the synthesized compounds have shown good affinity as antibacterial and/or antifungal agents which increased in most of the cases on complexation with the metal ions.

Antifungal Cobalt(II), Copper(II), Nickel(II) and Zinc(II) Complexes of Furanyl-,Thiophenyl-, Pyrrolyl-, Salicylyl- and Pyridyl-derived Cephalexins

Some novel cephalexin-derived furanyl, thiophenyl, pyrrolyl, salicylyl and pyridyl Schiff's bases and their cobalt (II), copper (II), nickel (II) and zinc (II) complexes have been synthesized and studied for their antifungal properties against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glaberata. The presence of metal ions in the investigated Schiff's base complexes reported here lead to significant antifungal activity, whereas the parent ligands were generally less active.