Clinical characteristics of patients with exercise-induced ST-segment elevation without prior myocardial infarction.

BACKGROUND: Exercise-induced ST-segment elevation is a relatively uncommon problem and occurs more frequently in patients who have had a myocardial infarction. Data is limited on the characteristics of Taiwanese patients without prior myocardial infarction who develop exercise-induced ST-segment elevation. METHODS AND RESULTS: Exercise-induced ST-segment elevation developed in 9 of 6,147 consecutive patients without myocardial infarction who underwent treadmill exercise testing at out institution over a 4-year period. The clinical and angiographic characteristics of these patients were studied. Angiographically normal coronary arteries with coronary vasospasm were found in 5 patients, hemodynamically significant coronary stenosis was found in 3 patients, and coexisting spasm in angiographically normal coronary arteries combined with hemodynamically significant coronary stenosis in the different vessel was found in 1 patient. During a median follow-up of 71 months, 2 patients with coronary vasospasm developed recurrent angina after self-discontinuation of calcium antagonists and 2 patients (1 with coronary vasospasm and 1 with hemodynamically significant coronary stenosis) died of cardiac causes before arrival at the emergency department. CONCLUSION: Coronary vasospasm was a more common underlying pathology of exercise-induced ST-segment elevation in this Taiwanese cohort. Coronary angiography +/- intracoronary ergonovine provocation testing is necessary in these patients to identify the underlying pathology and appropriate treatment.     

Magnetic nanoparticle labeling of mesenchymal stem cells without transfection agent: cellular behavior and capability of detection with clinical 1.5 T magnetic resonance at the single cell level.

The purpose of this work was to evaluate the efficacy of labeling human mesenchymal stem cells (hMSCs) by ionic superparamagnetic iron oxide (SPIO) without a transfection agent and verifying its capability to be detected with clinical 1.5 T magnetic resonance (MR) at the single-cell level. Human hMSCs were incubated for 24 h with an ionic SPIO, Ferucarbotran. The labeling efficiency of hMSCs was determined by iron content measurement spectrophotometrically, and the influence of labeling on cell behavior was ascertained by examination of cell viability using the trypan blue exclusion method, cell proliferation analysis using MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, mitochondrial membrane potential (MMP) change, differentiation capacity, and reactive oxygen species (ROS) production measured by dichlorofluorescein diacetate (DCFDA) fluorescent probe. Labeled hMSCs were scanned under 1.5 T MRI with three-dimensional (3D) and two-dimensional (2D) T(2)-weighted gradient echo (GRE) pulse sequences. Human hMSC labeling without transfection agent was efficient. The iron content in hMSCs was 23.4 pg Fe/cell. No significant change was found in viability, proliferation, MMP change, ROS production, or differentiation capacity. About 45.2% of the hMSCs could be detected using 1.5 T MRI at the single cell level with 3D GRE and four repetitions.     

Outcomes of laparoscopic incisional hernia repair: A prospective evaluation

Objective: Although laparoscopic incisional hernioplasty has been gaining in popularity, the best approach for the repair of incisional hernia remains controversial. The present study was undertaken to evaluate the medium‐term outcomes of laparoscopic incisional hernioplasties utilizing onlay GORE‐TEX DualMesh (GORE‐TEX DualMesh Biomaterial; W.L. Gore and Associates, Flagstaff, Arizona, TX, USA). Methodology: Between June 2000 and July 2004, 42 patients underwent laparoscopic incisional hernioplasties at our institution. Perioperative data and postoperative outcomes were collected prospectively and analyzed. Results: Laparoscopic incisional hernioplasty was successfully performed on 39 (93%) patients. Conversion to open repair was required in three patients. The overall mean operative time was 108 min. Sixteen patients (37%) were found to have more than one hernial defect after reduction of the hernial contents. Postoperative morbidity included seroma (n = 8), urinary retention (n = 3), ileus (n = 1), pneumonia (n = 1), fever (n = 1), wound infection (n = 1), and prolonged suture site pain (n = 1) in 13 patients. All these morbidities resolved spontaneously without intervention. Two‐thirds of the patients were discharged within 2 days after surgery. With a median follow up of 2 years, two clinical recurrences (4.8%) were detected. Conclusion: Laparoscopic approach was a safe and efficacious technique for the repair of incisional hernia. Medium‐term outcomes were promising with low postoperative morbidity and recurrence rates. This technique allows clear identification of multiple hernial defects and confers the advantages of minimal access surgery.     

Effects of continuous distraction on cartilage in a moving joint: An investigation on adult rabbits

An animal model, using distraction force on adult rabbits, was developed to study the effects of nonweight-bearing on articular cartilage in a moving joint. Histologic evaluation was used to compare the morphology of chondrocytes, safranin O intensity, cartilage thickness, and structural changes between the test and contralateral joints. At 3 and 6 weeks, the chondrocytes in superficial and intermediate zones were round, with an increase in cellular volume density and mean cell volume and with less metachromasia; the safranin O intensity and cartilage thickness were the same as in the controls. In cartilage of the 9-week group, mean cell volume decreased with cell cloning in the superficial zone, while numerical density increased and mean matrix volume per cell decreased in the superficial and intermediate zones. The cartilage, with a 34% reduction in thickness and a 53–72% decrease in safranin O intensity from the superficial to the deep zone, had superficial fibrotic proliferation, suface erosion or depression, ard tidemark irregularity. Continuous distraction in a moving joint caused morphological changes in chondrocytes prior to degeneration of cartilage. These results support the hypothesis that the forces perceived by cells may dictate their shape and then stimulate alterations in cellular biochemistry and matrix metabolism.     

Development of sesquiterpenes from Alpinia oxyphylla as novel skin permeation enhancers.

To improve the drug permeation into and/or across the skin, essential oils extracted from Alpinia oxyphylla (AO) were evaluated using in vitro and in vivo permeation techniques with Wistar rats as the animal model. Hydrocarbons and oxygenated sesquiterpenes were the major components in the lower-polarity fraction (AO-1) and higher-polarity fraction (AO-2), respectively. Permeation of indomethacin was significantly enhanced after treatment with AO-1 and AO-2 in the in vitro and in vivo studies. AO-2 generally showed a higher ability to promote drug permeation compared to AO-1. The increment of skin/vehicle partitioning may be the predominant mechanism for this enhancing activity. Both transepidermal water loss (TEWL) and colorimetric evaluation showed limited irritation to skin by AO essential oils at the macroscopic level. Human skin fibroblasts were used to investigate the in vitro screening of skin toxicity. AO-1 slightly increased prostaglandin E(2) (PGE(2)) formation from skin fibroblasts. A striking result was observed with AO-2, which greatly inhibited the release of PGE(2). Moreover, both AO essential oils had no statistically significant effect on PGE(2) release by human lung epithelial cells. The results of this study indicate that skin disruption and inflammation do not necessary correspond to the enhancing efficiency of the enhancers tested.     

A six-week, parallel, randomized, double-blind study comparing the efficacy and safety of the 0.5% timolol/2.0% MK-507 combination b.i.d. to the concomitant administration of 0.5% timolol b.i.d. and 2.0% MK-507 b.i.d.

This was a 6-week, parallel, randomized, double-blind study comparing the efficacy and safety of the 0.5% timolol/2.0% MK-507 combination b.i.d. to the concomitant administration of 0.5% timolol b.i.d. and 2.0% MK-507 b.i.d. Patients with ocular hypertension or open-angle glaucoma from 21 to 85 years of age were enrolled in this study. Each of them should have intraocular pressure (IOP) of 20 mmHg or more in the study eye after they completed the wash-out period. The patients enrolled were randomly assigned to either combination (0.5% timolol/2.0% MK-507 b.i.d. and placebo b.i.d.) or concomitant (0.5% timolol b.i.d. and 2.0% MK-507 b.i.d.) treatment. During the study, no systemic or topical medication affecting IOP other than test drugs were allowed. A total of 20 randomized patients were included in the intention-to-treat population for analysis of data. The ten were assigned to the combination treatment and others were assigned to the concomitant treatment. There was no statistically significant difference between the two study treatments in terms of gender distribution, average age, and average IOP at the trough and the peak before starting the test medications. Mean reduction of the IOP from baseline to the final visit at the trough was 5.04 mmHg in the combination treatment and was 2.73 mmHg in the concomitant treatment. Mean reduction of the IOP at the peak was 2.19 mmHg in the combination treatment and was 2.53 mmHg in the concomitant treatment. There were no statistically significant differences in the above analyses between the two treatments. Safety evaluation was carried out, and number of adverse events in each treatment group did not differ substantially. Ocular signs and symptoms were evaluated in each visit, and all of the between-treatment values were not different significantly, either. Laboratory tests were performed, and showed no significant differences between pre- and post-treatment periods. None of these was found to be clinically serious, either. We concluded that the 0.5% timolol/2.0% MK-507 combination b.i.d. is equivalent in the efficacy of lowering IOP as well as safety compared to the concomitant administration of 0.5% timolol b.i.d. and 2.0% MK-507 b.i.d. in patients with ocular hypertension or open-angle glaucoma.     

Synthesis of polymers containing pseudohalide groups by cationic polymerization, 13. “Living” polymerization of 2-methylpropene initiated by the system 1,4-bis(1-azido-1-methylethyl)benzene/BCl3/dimethyl sulfoxide

Polymerizations of 2-methylpropene (MP) initiated by the system 1,4-bis(1-azido-1-methylethyl)benzene (DAMEB)/BCl₃ in the presence of DMSO were carried out by “all monomer in” (AMI) technique at ?70°C in CH₂Cl₂ solution. FT-IR, ¹H NMR and SEC analyses of polymers (PMP) showed that the M _n versus weight of PMP plot is a straight line without intercept and azide F_n3 and aromatic ring F_? functionalities are close to the theoretical values of 2 and 1, respectively. A polymerization of MP initiated by the system α,ω-diazido-PMP/BCl₃/DMSO led to a final poly(2-methylpropene) (PMP) with an increase of M _n corresponding to the amount of MP introduced and presenting the same functionalities F_N3 and F_? as the starting PMP. These results indicate that the polymerization system MP/DAMEB/BCl₃/DMSO is a “living” one, because in an acceptably large range of molecular weight (M _n < 50000) the Mayo plot 1/DP versus 1/DP ₀ is a straight line. The intercept gives k_trM/k_p = 4 · 10^?5, showing the transfer reaction proceeds at very low rate.