Smart micro/nanoparticles in stimulus-responsive drug/gene delivery systems.

New achievements in the realm of nanoscience and innovative techniques of nanomedicine have moved micro/nanoparticles (MNPs) to the point of becoming actually useful for practical applications in the near future. Various differences between the extracellular and intracellular environments of cancerous and normal cells and the particular characteristics of tumors such as physicochemical properties, neovasculature, elasticity, surface electrical charge, and pH have motivated the design and fabrication of inventive "smart" MNPs for stimulus-responsive controlled drug release. These novel MNPs can be tailored to be responsive to pH variations, redox potential, enzymatic activation, thermal gradients, magnetic fields, light, and ultrasound (US), or can even be responsive to dual or multi-combinations of different stimuli. This unparalleled capability has increased their importance as site-specific controlled drug delivery systems (DDSs) and has encouraged their rapid development in recent years. An in-depth understanding of the underlying mechanisms of these DDS approaches is expected to further contribute to this groundbreaking field of nanomedicine. Smart nanocarriers in the form of MNPs that can be triggered by internal or external stimulus are summarized and discussed in the present review, including pH-sensitive peptides and polymers, redox-responsive micelles and nanogels, thermo- or magnetic-responsive nanoparticles (NPs), mechanical- or electrical-responsive MNPs, light or ultrasound-sensitive particles, and multi-responsive MNPs including dual stimuli-sensitive nanosheets of graphene. This review highlights the recent advances of smart MNPs categorized according to their activation stimulus (physical, chemical, or biological) and looks forward to future pharmaceutical applications.

Comparison of transversus abdominis plane block vs spinal morphine for pain relief after Caesarean section.

BACKGROUND: Transversus abdominis plane (TAP) block is an alternative to spinal morphine for analgesia after Caesarean section but there are few data on its comparative efficacy. We compared the analgesic efficacy of the TAP block with and without spinal morphine after Caesarean section in a prospective, randomized, double-blinded placebo-controlled trial. METHODS: Eighty patients were randomized to one of four groups to receive (in addition to spinal anaesthesia) either spinal morphine 100 µg (S(M)) or saline (S(S)) and a postoperative bilateral TAP block with either bupivacaine (T(LA)) 2 mg kg(-1) or saline (T(S)). RESULTS: Pain on movement and early morphine consumption were lowest in groups receiving spinal morphine and was not improved by TAP block. The rank order of median pain scores on movement at 6 h was: S(M)T(LA) (20 mm)

A pilot double-blind randomised placebo-controlled trial of the effects of fixed-dose combination therapy ('polypill') on cardiovascular risk factors.

AIM: Our objective was to investigate the effects and tolerability of fixed-dose combination therapy on blood pressure and LDL in adults without elevated blood pressure or lipid levels. METHODS: This was a double-blind randomised placebo-controlled trial in residents of Kalaleh, Golestan, Iran. Following an 8-week placebo run-in period, 475 participants, aged 50 to 79 years, without cardiovascular disease, hypertension or hyperlipidaemia were randomised to fixed-dose combination therapy with aspirin 81 mg, enalapril 2.5 mg, atorvastatin 20 mg and hydrochlorothiazide 12.5 mg (polypill) or placebo for a period of 12 months. The primary outcomes were changes in LDL-cholesterol, systolic and diastolic blood pressure and adverse reactions. Analysis was by intention-to-treat basis. RESULTS: At baseline, there were differences in systolic blood pressure (6 mmHg). Taking account of baseline differences, at 12 months, polypill was associated with statistically significant reductions in blood pressure (4.5/1.6 mmHg) and LDL-cholesterol (0.46 mmol/l). The study drug was well tolerated, but resulted in the modest reductions in blood pressure and lipid levels. CONCLUSION: The effects of the polypill on blood pressure and lipid levels were less than anticipated, raising questions about the reliability of the reported compliance. There is a case for a fully powered trial of a polypill for the prevention of cardiovascular disease.

The effect of the COD: N ratio on mainstream deammonification in an integrated fixed-film activated sludge sequencing batch reactor.

For eight months, a sequencing batch reactor (SBR) with integrated fixed-film activated sludge (IFAS) was operated in ambient temperature to study engineering and practical aspects of application of deammonification for mainstream conditions. For biofilm formation, K3 Kaldnes carriers were used, where the anaerobic ammonium oxidation (anammox) process can occur in deep layers of biofilm, while partial nitritation occurs in oxygen-rich outer layers. After the initial running phase of the reactor (Phase 1) to provide time for microorganisms to adapt, the COD: N ratio increased to around 2.6 in Phase 2 through reducing the ammonium concentration and increasing COD in synthetic wastewater to get closer to mainstream conditions. The total reaction time in each half-day batch cycle was kept 625 min throughout various phases, but the duration of intermittent aeration was regulated at 4 ± 1 min. While final nitrogen removal efficiency (NRE) for Phase 1 was 43%, at the end of Phase 2, it decreased to 37%. However, a maximum NRE at 90% was achieved during Phase 2. The identification of the responsible microorganisms was made through Fluorescence in situ hybridization (FISH), while Mixed Liquor Suspended Solid (MLSS) and Mixed Liquor Volatile Suspended Solid (MLVSS) was used to estimate the physical presence of bacteria. Ammonium oxidizing bacteria (AOB) and anaerobic ammonia-oxidizing bacteria (AnAOB) were dominant bacteria, respectively. The adverse effects of a gradual increase of COD: N ratio from 0.17 to more than 2.0 caused a decline in NRE to around 15%.

Safety and efficacy of new glyceryl trinitrate suppository formula: first double blind placebo-controlled clinical trial.

PURPOSE: This study was designed to assess the safety and efficacy of 0.2 percent glyceryl trinitrate suppository form in the healing of chronic anal fissure. METHODS: Thirty-four patients with symptomatic chronic anal fissures were assigned to 0.2 percent glyceryl trinitrate suppository (n = 21) or placebo (n = 13) in a double blind design. Patient's symptom scores were registered at first visit. A validated daily chart was given to assess their symptoms on a daily basis. Both groups received psyllium from the beginning of the study. They were assessed at two-week intervals for six weeks. Then, they started a washout period of one month and after that were crossed over for another six weeks. Chi-squared, t-tests, and analysis of variance were used for statistical analysis. RESULTS: Complete healing at six weeks was achieved in 12 of 21 patients (57 percent) in the glyceryl trinitrate group and 5 of 13 patients (38 percent) in the placebo (P < 0.05). The overall healing rates at the end of study were 15 of 21 (71 percent) vs. 11 of 13 (84 percent) in the glyceryl trinitrate and placebo groups, respectively (P > 0.05). CONCLUSIONS: Application of 0.2 percent glyceryl trinitrate suppository form represents a new, promising, and effective treatment for chronic anal fissure.

Theoretical optimal cricothyroidotomy incision length in female subjects, following identification of the cricothyroid membrane by digital palpation.

BACKGROUND: Misidentification of the cricothyroid membrane is frequent in females, placing them at risk of difficult or failed cricothyroidotomy in the event of failed oxygenation. If anatomy is impalpable, the current guidelines of the Difficult Airway Society, based on expert opinion, recommend an 8-10 cm vertical incision to facilitate access to the cricothyroid membrane. At present no evidence-based guideline exists regarding optimum site or length. We investigated the likelihood of inclusion of the cricothyroid membrane, within hypothetical vertical midline incisions, in a female population. METHODS: We asked clinicians to identify the cricothyroid membrane in both the neutral and extended head positions using palpation, the point identified acting as the theoretical midpoint of a cricothyroidotomy incision. We then identified the cricothyroid membrane using ultrasound. We determined the minimum incision length that would be required to ensure that the cricothyroid membrane lay within its boundaries, if clinician digital palpation was the method of cricothyroid membrane localisation. RESULTS: Ninety female subjects were recruited. Theoretical incisions of 7 and 8 cm were required for successful cricothyroidotomy in the neutral and extended head positions respectively. This was necessary because of the high failure rate of cricothyroid membrane identification (80.9%) and the wide range of error (7.2 cm in a vertical plane). CONCLUSIONS: Based on clinical estimation of the location of the cricothyroid membrane, an incision length of 8 cm, using the clinician's best estimate as its midpoint, would overlie all cricothyroid membrane locations. Our data support the current Difficult Airway Society guidelines for cricothyroidotomy incision length.

Comparative structural analysis by [1H,31P]-NMR and restrained molecular dynamics of two DNA hairpins from a strong DNA topoisomerase II cleavage site.

The structural analysis of two single-stranded DNAs d(AGCTTATCATCGATAAGCT) (ATC-19) and d(AGCTTATCGATGATAAGCT) (GAT-19) was performed by NMR and restrained molecular dynamics. These oligonucleotides reproduce the 15-33 segment of phage pBR322 DNA, which contains a strong cleavage site for topoisomerase II coupled to the antitumor drugs VP-16 and ellipticine. Because of their partial palindromic nature, the two oligonucleotides ATC-19 and GAT-19 may fold back into stable hairpin structures, consisting of a stem of eight base-pairs and a loop of three residues. NMR assignments and conformational parameters were determined from combined 2D NOESY, COSY and 1H-31P spectra. Conformations of ATC-19 and GAT-19 hairpins were calculated using the X-PLOR 3.1 program. Structures were generated through simulated annealing procedures starting from 50 structures with randomized torsion angles. A good convergence was observed for ATC-19 molecules, while no consensus was found for GAT-19. Within the GAT-19 loop, the base stacking was poor and no hydrogen bond could be detected. In contrast, ATC-19 displayed a well-defined three residue loop stabilized by both extensive base stackings and hydrogen bonding between the N3 atom of the adenine ring and the amino group of the cytosine ring. The results confirm our earlier ATC-19 structure obtained by a completely different calculation procedure (JUMNA) and the higher thermal stability of ATC-19 compared to GAT-19. Moreover, due to its mismatched base-pair, the ATC-19 loop may be better described as a single residue loop rather than a three residue loop. Comparison of this loop to those containing sheared purine.purine base-pairs revealed striking resemblances, particularly on the backbone angle combination. Finally, the differences observed between the ATC-19 and GAT-19 structures could help toward understanding the sequential cleavage of DNA strands by topoisomerase II.

The hairpin structure of a topoisomerase II site DNA strand analyzed by combined NMR and energy minimization methods.

We report on the structural study of the single-stranded 19mer oligonucleotide d(AGCTTATC-ATC-GATAAGCT) 22(+). This corresponds to the 15-to-33(+) strand of pBR322 DNA belonging to a strong cleavage site (site 22) for topoisomerase II coupled to antitumor drugs VP-16 or ellipticine. The partially self-complementary nature of this oligonucleotide makes likely its folding into a hairpin structure. To assess this property we carried out a quantitative analysis based on joint calculations and NMR experiments. The latter required two-dimensional (NOESY, P-COSY, TOCSY and proton-detected 1H-31P), and three-dimensional (NOESY-TOCSY) spectra to achieve the assignment of the overcrowded sugar H4' ad H5'/H5" proton region. For molecular modeling, the JUMNA program was used together with NMR constraints; namely, the distances and the backbone torsion angles provided by NOEs and homo- and heteronuclear coupling constants. Experimental results proved that the 19mer oligonucleotide adopted a stable hairpin structure characterized by an eight base-pair stem and a three-membered loop (central-ATC-segment). Homonuclear 1H-1H and heteronuclear 1H-31P coupling constant measurements provided information on the conformational heterogeneity of the sugar and phosphate groups within both the stem and the loop. Restrained energy minimizations starting with different structures resulted in a family of closely related structures. All low-energy molecules presented the same, rather compact, folded structure with the base-stacking continuing into the loop, a sharp turn occurring between residues T10 and C11, and strong backbone distortions at the loop-stem junction.

Determination of skeletal muscle and fat-free mass by nuclear and dual-energy x-ray absorptiometry methods in men and women aged 51-84 y (1-3).

BACKGROUND: Skeletal muscle mass (SMM) and fat-free mass (FFM) are important variables in nutritional studies. Accurate techniques for measuring these variables have not been thoroughly validated in elderly subjects. OBJECTIVES: The objectives of this study were to 1) compare SMM values derived from dual-energy X-ray absorptiometry (DXA) with those calculated by a nuclear method from total body potassium (TBK) and total body nitrogen (TBN) measurement (both: KN) in older subjects, and 2) assess the accuracy of FFM measurement by DXA in these subjects. DESIGN: TBK, TBN, DXA (model XR36; Norland, Fort Atkinson, WI), bioimpedance, and anthropometric measurements were performed on healthy women (n = 50) and men (n = 25) aged 51-84 y. RESULTS: Mean SMM by KN was not significantly different from SMM by DXA in either sex. SMM by KN predicted SMM by DXA with an SEE of 2.1 kg (r = 0.95, P < 0.0001 for women and men together). In the men, FFM by DXA agreed well with FFM estimated by TBK, skinfold thicknesses, bioimpedance analysis, and a multicompartment model. In women, FFM by DXA was 4-5 kg less than that by the other methods (P < 0.01). Truncal fat was related to intermethod FFM differences (r = 0.58, P < 0.0001). CONCLUSIONS: These data indicate that 1) either the nuclear or the DXA method can be applied to estimate SMM in healthy older subjects, and 2) the Norland DXA instrument significantly underestimates FFM in older women, in part, because of the influence of truncal adiposity.

Magnetic resonance imaging with implanted neurostimulators: an in vitro and in vivo study.

OBJECTIVE: The goal was to assess the safety of magnetic resonance imaging (MRI) with implanted neurostimulators, in an in vitro and in vivo study. METHODS: Two different implantable pulse generators (IPGs) (ITREL II and 3; Medtronic, Minneapolis, MN) and different leads (separately and connected to an IPG) were tested in three different MRI scanners (0.2, 0.25, and 1.5 T). Measurements of the induced voltages (using an external oscilloscope) and the induced heat (using an infrared camera) were performed in an in vitro study. Finally, 38 patients with implanted neurostimulator systems (leads and IPGs) underwent MRI in 50 examinations, with continuous monitoring by a physician with uninterrupted visual and vocal contact with the patient. Twenty-five patients were studied prospectively, with documented printouts of the parameter settings before and after MRI. RESULTS: An induced voltage of 2.4 to 5.5 V was measured in the experimental configuration with a lead connected to an IPG. The voltage was higher with the leads alone, compared with the leads connected to the IPG, and was dependent on the MRI scanner, the sequences, and the type of lead. No heat induction was observed in any part of the hardware. No change of pulse shape or change of IPG parameters was observed during MRI. No adverse effects occurred in patients with chronically implanted deep brain leads connected to an IPG. CONCLUSION: MRI can be safely performed in patients with implanted neurostimulation systems with the tested deep brain leads connected to an IPG (ITREL II and 3), with running parameters. No heat induction was detected, and the experimentally measured induced voltage did not seem to harm the patients. Only the reed switch of the IPGs was activated; the other parameters remained unchanged. Further investigations must be performed to study the local electrical effects in larger plate electrodes; these effects might cause slight discomfort. There is no danger with any type of electrode during MRI examinations if the electrodes lie outside the region of interest. These observations are restricted to the tested devices. A conscientious estimation of the risks and benefits of MRI for patients with implanted devices is recommended. If the type of device is not known to the examiner, MRI should still be considered to be contraindicated.

Addition of misoprostol to ranitidine in non-responders to H2-blockers and pirenzepine.

In the present study, which comprised 14 patients in whom 300 mg and 900 mg of ranitidine as well as in combination with pirenzepine had failed to suppress acid secretion, we tested the effect of adding misoprostol. Night-time intragastric pH was continuously monitored, a rise in the intragastric pH above 4.0 h more than 6 h following the oral dose at 18.00 h being considered a response. In only 1 of the 7 patients with cirrhosis, and in 1 of the 7 control patients, did the combination of 300 mg ranitidine and 400 micrograms of misoprostol result in sufficient acid suppression. Mean pH profiles during the four study periods were not significantly different and the effect of misoprostol was similar in cirrhotics and controls. The inefficacy of the addition of misoprostol in this selected group of patients who did not respond even high doses of ranitidine (+/- pirenzepine) does not favour the hypothesis that gastric mucosal prostaglandin efficiency may be an important factor in the non-response to H2-receptor antagonists. It appears unlikely that the cause is localized solely at the site of H2-receptors.

A method to simultaneously investigate histamine-induced cyclic AMP and aminopyrine accumulation in isolated gastric mucosal cells from human biopsies.

A method has been developed to simultaneously measure two parameters of histamine-induced gastric secretion, cyclic AMP and aminopyrine accumulation, in gastric mucosal cells from human biopsies. Histamine stimulated cyclic AMP and aminopyrine accumulation with different time courses. Cyclic AMP production reached a maximum at 30 min, whereas maximal aminopyrine accumulation was obtained after the cells had been incubated for 90 min in presence of 100 mcM histamine. Histamine was more potent in stimulating aminopyrine than cyclic AMP accumulation. The ED50 values for histamine-induced aminopyrine accumulation were estimated to be 0.88 +/- 0.02 and 25.53 +/- 8.75 mcM for cyclic AMP production, respectively. The aminopyrine accumulation was more than half-maximally increased at 1 mcM histamine without significant effects on the cyclic AMP basal level. It remains to be elucidated whether this finding indicates, besides cyclic AMP, the involvement of calcium in histamine stimulus. The histamine H2-receptor antagonists cimetidine and ranitidine inhibited both in vitro parameters, whereas the gastric proton pump inhibitor omeprazole only affected aminopyrine accumulation. Our method might be a valuable tool for in vitro pharmacological and clinical investigations on histamine-induced gastric secretion in human biopsies.

[A rare case of cannabis arteritis]. / Ein seltener Fall von Cannabis-Arteritis.

A 24-year old woman, heavy cannabis smoker with progressive Raynauld's phenomenon and digital necrosis is presented. Systemic sclerosis and other connective tissue disorders as well as arteriosclerosis and arterial emboli were excluded with appropriate laboratory examinations. Arteriography revealed multiple forearm, palmar and digital occlusions with corkscrew-shaped vessels. Based on these characteristic arteriography and clinical findings, the diagnosis of cannabis-arteritis was finally retained. With careful necrectomy, conservative wound dressings and secondary prostacyclin therapy a complete healing of digital necrosis was observed. There was no recurrence during the 6 month-follow-up. This observation demonstrates that cannabis may represent a possible cofactor in the pathogenesis of arteritis in young smokers. Early recognition is important to avoid irreversible complications such as loss of digits.

Plasma sample preparation by ultrafiltration for FTIR analysis.

Total body water (TBW) may be significantly altered with disease. Isotope dilution techniques, considered to be the "gold standard" methods for measuring TBW, are expensive, time consuming and require considerable expertise, especially during the sample preparatory phase. In this study, a new method, ultrafiltration (UF), was hypothesised to be an efficient alternative to vacuum sublimation (VS) in the preparation of plasma samples for Fourier Transform Infra Red (FTIR) determination of TBW. Deuterium Oxide (D2O) concentrations were prepared in human plasma and subjected to both techniques. FTIR analysis was carried out on the resulting VS and UF solutions and on D2O concentrations in distilled water. The resulting absorbance values were then statistically compared. Urea concentrations prepared in D2O-containing plasma were also compared to "blank" plasma to investigate the effect of high plasma urea concentration on the resulting H2O/D2O mixture obtained during UF Paired t-tests showed that the VS plasma samples (p=0.003), but not the UF samples (p=0.9), were significantly different to D2O standards prepared in distilled water. While there was no evidence of an effect of urea on UF at low (0.4 g/L) D2O concentration, a marginal (p=0.04) effect occurred at a higher (1.6 g/L) D2O level. Throughput of samples was much more efficient with the UF technique. These findings indicate that the new UF method is an accurate, more efficient method of plasma sample preparation than the VS method in the FTIR determination of TBW.

Evaluation of the effect of intra-operative intravenous fluid on post-operative pain and pulmonary function: a randomized trial comparing 10 and 30 ml kg(-1) of crystalloid.

BACKGROUND: Existing evidence suggests that administration of intravenous fluids has been shown to improve outcomes including pain in gynecological laparoscopic surgery but the optimum fluid dose has not been determined. AIMS: To determine the effect of administration of intravenous fluids on post-operative pain and pulmonary function after gynecological laparoscopy. METHODS: In a prospective randomized double-blinded study 100 ASA 1 and 2 elective patients undergoing gynecological laparoscopy were randomized to receive intravenous compound sodium lactate 10 ml kg(-1) (CSL10-restrictive) or 30 ml kg(-1) (CSL30-liberal) administered intra-operatively. The primary outcome measure was the post-operative pain score at 24, 48 and 72 h, assessed by 0-10 verbal rating scale (VRS). Pulmonary function (FEV1, FVC, PEFR) and oxygen saturation were also measured. RESULTS: Patients who received CSL 30 had lower post-operative pain scores than CSL 10 (ANCOVA-mean difference = 0.47, 95 % CI 0.11-0.83, P = 0.01). Post-operative pain VRS was lower in CSL30 than CSL10 at 48 h (mean difference 0.56, 95 % CI 0.04-1.09, P = 0.036). Patients in CSL30 reported shoulder tip pain less frequently than those in CSL10 (30.4 vs. 43.9 % of assessments, P = 0.03, OR 0.58) but reported wound pain more frequently 39.0 vs. 24.2 %, P = 0.01, OR 2.0). Indices of pulmonary function did not differ between groups at any time. CONCLUSIONS: Liberal compared to restrictive administration of i.v. crystalloid is associated with a clinical modest reduction in pain. Pulmonary dysfunction was not increased with liberal fluid administration.

Anaesthetic outcomes in obese parturients: the effect of assessment in the high-risk clinic.

BACKGROUND: Obese parturients are at high risk of complications during anaesthesia and early use of epidural analgesia in labour has been recommended for obese patients during labour. AIM: To assess the outcome of anaesthesia outpatient consultation for obese parturients. METHODS: We retrospectively compared outcomes of obese patients antenatally and an obese and non-obese control group over a 1-year period. Outcomes included potential airway problems, anaesthetic for caesarean section, use and success of epidural analgesia and cervical dilation at epidural placement. RESULTS: The proportion of obese patients who had predictable intubation difficulty was low (5%). Epidural use analgesia in labour (69 vs 36 vs 66%, P = 0.148) was similar between groups (obese, obese controls and non-obese controls, respectively). Cervical dilation at the time of epidural insertion in the obese group (2.0, 1.0-3.0 cm) was not different from obese controls (3.0, 1.75-5.75 cm). There was no difference in the number of attempts required to site the epidural between groups or the number of patients that required resiting of the epidural catheter. General anaesthesia was not required in any emergency case in this group. CONCLUSION: The outcomes of obese patients attending the anaesthetic clinic were mixed. Not all patients who were to advised have epidurals did so but those who did requested them in early labour and there was no requirement for general anaesthesia during emergency caesarean section and adverse airway events were avoided in this group.

Anaesthetic management of a patient with Liddle's syndrome for emergency caesarean hysterectomy.

We describe the anaesthetic management of a patient with Liddle's syndrome during caesarean section and emergency hysterectomy for placenta accreta associated with significant intrapartum haemorrhage. Liddle's syndrome is a rare autosomal dominant disorder characterised by early onset arterial hypertension and hypokalaemic metabolic alkalosis. Additional issues were the presence of short stature, limb hypertonicity and preeclampsia. Initial management with a low-dose combined spinal-epidural technique was subsequently converted to general anaesthesia due to patient discomfort. The management of Liddle's syndrome in the setting of neuraxial and general anaesthesia in a patient undergoing caesarean section is discussed.

The effect of weight reduction on ultrasonographic findings of nonalcoholic Fatty liver.

BACKGROUND Non-alcoholic fatty liver (NAFL) includes a spectrum of diseases ranging from simple hepatic steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. NAFL is typically seen in association with obesity, diabetes and hypertriglyceridaemia. In order to seek the role of diet therapy in treatment of NAFL, we compared the ultrasonographic findings of patients with fatty liver disease before and after standard diet therapy. METHODS Twenty-three overweight or obese subjects with incidental fatty liver discovered during ultrasonography were included. Subjects underwent 3 months of diet therapy, and anthropometric data including weight, height, BMI, waist circumference, and hip circumference were measured. Ultrasonographic findings were graded from 0 to 3. Changes in ultrasonographic findings and anthropometric data were studied. RESULTS After three months of dieting, the ultrasonographic grade of all patients decreased by one or two grades. Fifteen patients decreased one grade while 8 others decreased by 2 grades. We observed a significant correlation between the decrease in ultrasonographic grade and the decrease in weight and BMI. CONCLUSION Our study indicates that standard diet therapy could be used as an effective treatment for NAFL patients.