Microspheres of essential oil in polylactic acid and poly(methyl methacrylate) matrices and their blends

This study is focussed on micro-encapsulation of essential oils in polylactic acid (PLA) and a poly(methyl methacrylate) (PMMA) matrix as well as blends of the same. Microspheres were prepared by the solvent evaporation technique and characterised by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infra-red spectroscopy (FTIR). The encapsulation efficiencies and release profiles of the essential oils were studied by gas chromatography mass spectrometry (GC-MS) and head-space solid-phase microextraction GC-MS, respectively. Furthermore, the microspheres were tested for antibacterial activity against both Gram-negative and Gram-positive bacterial strains.

The results showed that the microspheres compositions (PLA/PMMA ratio) have significant effect on their characteristics. The process adopted for preparing the microspheres promoted formation of spherical particles at the sizes of 1.5–9.5?µm. The highest encapsulation efficiency of the prepared microspheres was observed in systems consisting of linalool (81.10?±?10.0?wt. % for PLA system and 76.0?±?3.3?wt. % for PMMA system). Confirmation was also made that the release rate of the microspheres was affected by the size of the same.     

Release of soluble transferrin receptor from the surface of human leukemic HL60 cells

Information regarding transferrin (Tf) receptor degradation is largely incomplete. HL60 cells were shown to release to their growth medium a Tf-binding protein which could be immunoprecipitated by anti-Tf receptor monoclonal antibodies (MoAbs) B3/25 and OKT9. Soluble Tf receptor was detected in the medium within one hour of replating of cells, and its release was inhibited at 4 degrees C. The affinity of Tf for the soluble receptor released by cells (kd = 2.3 x 10(-10) mol/L) was slightly lower than its affinity for the detergent-solubilized cellular receptor (kd = 1.2 x 10(-10) mol/L). 125I-Tf internalized and released by cells subsequently bound to Tf receptor released by the same cells, and soluble Tf receptor in the conditioned medium (CM) inhibited 125I-Tf binding to intact cells. The soluble Tf receptor isolated from the CM was smaller (78,000 daltons) than the cell surface receptor (94,000 daltons) when analyzed by gel electrophoresis under reducing conditions. Isolated cell membranes readily released soluble receptor; however, this release could be blocked by protease inhibitors. The soluble Tf receptor may represent the extracytoplasmic domain of the cellular Tf receptor released from the surface of HL60 cells through proteolytic cleavage by a membrane-based protease.     

Endoscopic correction of vesicoureteric reflux--our thirteen years' experience.

AIM OF THE STUDY: We review our thirteen years' experience with the endoscopic treatment of primary vesicoureteric reflux (VUR). METHODS: We retrospectively reviewed the charts of 81 patients with primary vesicoureteric reflux who were treated endoscopically. The study included 61 girls and 20 boys aged 3 - 15 years. Twenty-eight patients had unilateral reflux, and 53 patients had bilateral reflux. Endoscopic correction with Teflon paste was done in 64 patients, and endoscopic treatment with Deflux was done in 17 patients. A total of 134 ureters were treated. RESULTS AND CONCLUSION: Reflux was corrected in 87 ureters (64.9 %) after the first injection. The second injection resolved reflux in an additional 20 ureters (14.9 %). Reimplantation was necessary in 4 patients (4.9 %). Overall success rate of the endoscopic treatment was 85.0 %. Reflux was completely absent in 79.8 % of the treated patients, and 5.2 % of the patients had a decreased grade of reflux after the procedure. Treatment was unsuccessful in 3.0 % of the patients. In seven patients spontaneous resolution of the persisting reflux occurred. Endoscopic correction should be performed in all patients with grade two, three and four reflux. Grade one reflux should be treated conservatively, and grade five reflux should be treated surgically. Since Deflux is a biodegradable material, most of the patients should be treated bilaterally, even if they have only grade one reflux. Endoscopic correction of primary vesicoureteric reflux is an easy, simple, fast and safe procedure that, in most cases, prevents regurgitation of urine from the bladder to the upper parts of the urinary system.     

A case of area-specific stimulus-sensitive postanoxic myoclonus.

The authors report a case of area-specific stimulus-sensitive postanoxic myoclonus and discuss possible pathophysiology. A 71-year-old man sustained cardiorespiratory arrest that lasted 10 minutes and remained unresponsive. On the first EEG obtained 8 hours after the arrest there was no cerebral electrical activity before stimulation of the trigeminal-innervated areas. Periorbital stimulation was associated with bursts of spike-wave activity and generalized myoclonic jerks, whereas other types of stimulation did not elicit any response. A second EEG obtained 32 hours later showed a nonreactive alpha coma pattern. The patient died 7 days after the arrest. Area-specific stimulus-sensitive postanoxic myoclonus is very rare. The regularity of generalized bursts of spike-wave activity (cortical response) in response to stimulation of trigeminal-innervated areas suggests that the resting EEG electrocerebral silence may have been a result of cortical suppression with disinhibition of stimulus-sensitive brainstem-generated myoclonus.     

The discriminative stimulus effects of MK-801: Generalization to other N-methyl-D-aspartate receptor antagonists

Rats were trained to discriminate a dose of the NMDA antagonist MK-801 from saline using a standard, two-lever, operant procedure. The acquisition of this discrimination was rapid, rats reaching criterion performance in a mean of 32 sessions. The discriminative stimulus produced by MK-801 generalized to phencyclidine and (+)N-allylnormetazocine but only low levels of generalization were seen with (-)N-allylnormetazocine and with the anti- ischaemic drug ifenprodil and its derivative SL 82.0715. The MK-801 stimulus was partially antagonized by haloperidol. The results show that MK-801 can produce a discriminative stimulus which is shared by other non-competitive NMDA antagonists which have similar behavioural effects in other procedures. However, ifenprodil and SL 82.0715, which have also been shown to antagonize the effects of NMDA, do not produce similar behavioural effects or discriminative stimuli presumably because they act through a different site.     

Expression and potential role of fibroblast growth factor 2 and its receptors in human embryonic stem cells

Although the detection of several components of the fibroblast growth factor (FGF) signaling pathway in human embryonic stem cells (hESCs) has been reported, the functionality of that pathway and effects on cell fate decisions are yet to be established. In this study we characterized expression of FGF-2, the prototypic member of the FGF family, and its receptors (FGFRs) in undifferentiated and differentiating hESCs; subsequently, we analyzed the effects of FGF-2 on hESCs, acting as both exogenous and endogenous factors. We have determined that undifferentiated hESCs are abundant in several molecular-mass isoforms of FGF-2 and that expression pattern of these isoforms remains unchanged under conditions that induce hESC differentiation. Significantly, FGF-2 is released by hESCs into the medium, suggesting an autocrine activity. Expression of FGFRs in undifferentiated hESCs follows a specific pattern, with FGFR1 being the most abundant species and other receptors showing lower expression in the following order: FGFR1 --> FGFR3 --> FGFR4 --> FGFR2. Initiation of differentiation is accompanied by profound changes in FGFR expression, particularly the upregulation of FGFR1. When hESCs are exposed to exogenous FGF-2, extracellular signal-regulated kinases are phosphorylated and thereby activated. However, the presence or absence of exogenous FGF-2 does not significantly affect the proliferation of hESCs. Instead, increased concentration of exogenous FGF-2 leads to reduced outgrowth of hESC colonies with time in culture. Finally, the inhibitor of FGFRs, SU5402, was used to ascertain whether FGF-2 that is released by hESCs exerts its activities via autocrine pathways. Strikingly, the resultant inhibition of FGFR suppresses activation of downstream protein kinases and causes rapid cell differentiation, suggesting an involvement of autocrine FGF signals in the maintenance of proliferating hESCs in the undifferentiated state. In conclusion from our data, we propose that this endogenous FGF signaling pathway can be implicated in self-renewal or differentiation of hESCs.     

Interaction between the amino and carbonyl groups in copoly(2-dimethylaminoethyl methacrylate/N-phenylmaleimide)

Interactions between the carbonyl and amino groups in copolymers of 2-dimethylaminoethyl methacrylate with N-phenylmaleimide are reported. The existence of interactions ensues from potentiometric measurements and UV-VIS spectra. Interactions in these copolymers result in the formation of energetically very advantageous chromophores, reflected in an intense red colour of the substances obtained.     

Supplementation with Octacosanol Affects the Level of PCSK9 and Restore Its Physiologic Relation with LDL-C in Patients on Chronic Statin Therapy

Dietary supplementation with sugar cane derivates may modulate low-density lipoprotein cholesterol (LDL-C) and proprotein convertase subtilisin/kexin type 9 (PCSK9) levels. The purpose of this study was to determine if dietary supplement (DS), containing Octacosanol (20 mg) and vitamin K2 (45 µg), could restore the disrupted physiologic relation between LDL-C and serum PCSK9. Double-blind, randomized, placebo-controlled, single-center study including 87 patients on chronic atorvastatin therapy was conducted. Eighty-seven patients were randomized to receive DS (n = 42) or placebo (n = 45), and followed for 13 weeks. Serum PCSK9 levels, lipid parameters and their relationship were the main efficacy endpoints. The absolute levels of PCSK9 and LDL-C were not significantly different from baseline to 13 weeks. However, physiologic correlation between % change of PCSK9 and % change of LDL-C levels was normalized only in the group of patients treated with DS (r = 0.409, p = 0.012). This study shows that DS can restore statin disrupted physiologic positive correlation between PCSK9 and LDL-C. Elevated PCSK9 level is an independent risk factor so controlling its rise by statins may be important in prevention of cardiovascular events.     

Point-of-care measured serum cholinesterase activity predicts patient outcome following severe burns

Risk stratification is of utmost importance in burn therapy. However, suitable bedside biomarkers to evaluate the emerging inflammatory response following burn injuries are missing. Serum cholinesterase (butyrylcholinesterase, BChE) has been shown to be a clinically relevant biomarker in acute inflammatory diseases including burns.In this observational cohort study BChE activity was measured by using point-of-care testing (POCT), a novel method in acute burn care. POCT measurements were performed at emergency room admission (ERA) of 35 patients and repeated 12, 24 and 48 h later. All patients or their legal designees gave informed consent.Patients with burn injuries showed sustained BChE activity reduction following hospital admission. BChE activity correlated negatively with burn injury severity, organ failure severity and intensive care unit resource requirements. BChE activity measured at ERA and 12 h later identified survivors and predicted 28-day patient outcome with noninferior efficacy compared to the abbreviated burn severity index (ABSI) scoring. Finally, POCT-measured BChE activity might complement ABSI scoring and possibly improve early risk stratification in acute burn care therapy.     

Pelvic floor exercise alone or with vaginal cones for the treatment of mild to moderate stress urinary incontinence in premenopausal women

The authors compared intensive pelvic floor exercise alone (A) with intensive pelvic floor exercise plus vaginal cones (B) in premenopausal women with mild to moderate stress urinary incontinence. Forty-six patients (mean 43±6 years) were randomized into two training groups and treated for 3 months. Pre- and post-therapy urethral pressure profiles at rest and under stress and subjective results were obtained from 29 patients. The subjective improvement rate of the compliant patients after 12 weeks was 85% in group A and 84% in group B. When the dropouts (9 in group A and 8 in group B) were included in the subjective results an overall improvement rate of 48% in group A and 52% in group B was obtained. In group A one pressure transmission ratio (PTR) improved significantly at 6 weeks and the position of maximum urethral closure pressure was shifted proximally at 12 weeks. In group B one PTR in the midurethra was improved significantly at 6 weeks. The other urodynamic parameters were unchanged. There were no differences between groups A and B in subjective results or urodynamic findings. These results suggest that intensive pelvic floor exercise with or without vaginal cones improves the symptoms of mild to moderate stress incontinence in about 85% of premenopausal women, but that it has little effect on urodynamic parameters. Vaginal cones provided no additional benefit but may be useful for women for whom closely supervised pelvic floor exercise is not available.Editorial Comment: It is becoming increasingly clear from the literature that pelvic floor muscle exercises are effective in improving continence in many women with straightforward stress incontinence. An appropriate quest continues to determine how the exercises can best be taught and done. This article demonstrates that with frequent supervision, similar continence status is achieved both with and without the use of vaginal cones. It would be interesting to compare outcomes with and without cones in women who saw a health care provider only once for their initial teaching. If cones were found to be more effective in this setting, that would be a great aid to primary care physicians.The authors state that there was no correlation between the cone weight and the degree of improvement of symptoms: however, only 2 of the subjects progressed to the next heaviest cone weight. My understanding of the principles of athletic muscles training is that as one increases the resistance the muscle fibers hypertrophy and strengthen. This is the principle behind building biceps. Body-builders or power-lifters continue to increase the amount of weight (resistance) they lift in order to increase bulk and strength. I wonder if this same principle is the reason for the differences in results between this study and the one by Peattie et al. quoted by the authors. My major concern is that people begin to devalue the amount of effort required to perform effective pelvic floor exercises and make assumptions that such exercises are not as good as a permanent surgical cure. I believe that we have not yet begun to develop really effective muscle strengthening regimens for the pelvic floor, and attitudes such as the above will only serve to inhibit our progress.