Synthesis of boron nitride nanotubes from unprocessed colemanite

Colemanite (Ca2B6O11·5H2O) is a natural and new precursor material for the synthesis of boron nitride nanotubes (BNNTs). BNNTs have been synthesized from unprocessed colemanite for the first time. The reaction parameters such as time, catalyst type, catalyst amount and temperature were optimized. It was found that the BNNT formation follows the base growth mechanism, which was initiated with a complex of boron nitride (BN) and iron atoms. The obtained BNNTs were characterized by using SEM, TEM, and spectroscopic techniques such as UV-vis, Raman, FTIR and XRD. The BNNTs were randomly oriented and multi-walled with an outer diameter of 10-30 nm and a wall thickness of 5 nm. This novel BNNT synthesis method can be used to obtain high yield, low cost and pure BNNTs.

The effects of Losartan on oxidative stress and inflammation in non-diabetic patients undergoing chronic hemodialysis

INTRODUCTION

We aimed to evaluate the effects of Losartan, an angiotensin receptor blocker, on serum inflammatory markers, plasma thiol groups, and oxidative stres indexes among patients undergoing hemodialysis (HD) treatment.

PATIENTS AND METHODS

Fiftytwo end-stage renal disease (ESRD) patients undergoing chronic HD programme for at least 12 months, and thirty age and gender matched healthy volunteers were enrolled into this prospective clinical trial. Plasma levels of thiol groups (SH), total antioxidant capacitiy (TAC), and total oxidant status (TOS) were studied. Oxidative stress index (OSI) was calculated by TOS/TAC. Firstly results of patients were compared with healthy subjects and then patients were treated by Losartan 50-100 mg and followed up for three months.

RESULTS

Among patients, SH Groups, TAC, TOS, and OSI were statistically higher than controls. Also the inflammatory markers were significantly higher in patients than controls and albumin was lower among patients. At the end of the 3 months among all patients the mean value of TAC was increased to 1.7±0.4 micromol Trolox Eqv./L. from 1.4±0.2, and SH groups to 0.33±0.02 mmol/L from 0.22±0.01, (p < 0.001) while TOS decreased to 7.2±1.1 micromol H(2)O(2) Eqv./L from 9.5±4.5, and OSI decreased to 5.0±0.8 from 7.1±3.2 (p < 0.001).

CONCLUSIONS

Losartan was effective in controlling blood pressure, and decreasing OSI, a marker of elevated oxidative stress, and increasing plasma levels of SH groups, an antioxidant, in ESRD patients undergoing hemodialysis. So, it may not be only a hypotensive drug, but also improves OS, particularly in patients with ESRD.

A comparative study of the effect of icodextrin based peritoneal dialysis and hemodialysis on lipid metabolism

Dyslipidemia is frequent in patients with end stage renal disease. Excessive peritoneal glucose absorption from high glucose-containing peritoneal dialysis solutions may enhance disturbances on the lipid metabolism of patients on peritoneal dialysis. We compared the effect of icodextrin-based peritoneal dialysis therapy with hemodialysis (HD) therapy on lipid metabolism. A total of 157 non-diabetic patients on dialysis at least for 3 months; 78 patients on Icodextrin-based continuous ambulatory peritoneal dialysis (CAPD) (44 M, 34 F) and 79 patients in HD group (47M, 32F) were included into the study. After 12 h of fasting and before the dialysis session, serum urea, creatinin, glucose, Sodium, potasium, and albumin, total cholesterol (TC), triglycerides (TG), very low density lipoprotein (VLDL), low density lipoprotein (LDL)-C, high-density lipoprotein (HDL)-C, apolipoprotein A (Apo A), apolipoprotein B, and lipoprotein a were measured. TG (P = 0018) and VLDL (P = 0.022) were lower in CAPD group than HD group, HDL-C (P < 0.001) and Apo A (P = 0.001) were higher in CAPD group than in HD group. A total of 24.4% in CAPD group and 11.4% in HD group (P < 0.034) had normal serum levels of TG, LDL-C, and HDL-C. More patients in CAPD group (47.4%) had high serum Apo A levels than in HD group (21.5%) (P = 0.001). We suggest that patients receiving icodextrin-based CAPD may have better TG, HDL-C, and Apo A levels than patients on HD.

Lack of tau proteins rescues neuronal cell death and decreases amyloidogenic processing of APP in APP/PS1 mice

Lack of tau expression has been reported to protect against excitotoxicity and to prevent memory deficits in mice expressing mutant amyloid precursor protein (APP) identified in familial Alzheimer disease. In APP mice, mutant presenilin 1 (PS1) enhances generation of Aβ42 and inhibits cell survival pathways. It is unknown whether the deficient phenotype induced by concomitant expression of mutant PS1 is rescued by absence of tau. In this study, we have analyzed the effect of tau deletion in mice expressing mutant APP and PS1. Although APP/PS1/tau(+/+) mice had a reduced survival, developed spatial memory deficits at 6 months and motor impairments at 12 months, these deficits were rescued in APP/PS1/tau(-/-) mice. Neuronal loss and synaptic loss in APP/PS1/tau(+/+) mice were rescued in the APP/PS1/tau(-/-) mice. The amyloid plaque burden was decreased by roughly 50% in the cortex and the spinal cord of the APP/PS1/tau(-/-) mice. The levels of soluble and insoluble Aβ40 and Aβ42, and the Aβ42/Aβ40 ratio were reduced in APP/PS1/tau(-/-) mice. Levels of phosphorylated APP, of β-C-terminal fragments (CTFs), and of β-secretase 1 (BACE1) were also reduced, suggesting that β-secretase cleavage of APP was reduced in APP/PS1/tau(-/-) mice. Our results indicate that tau deletion had a protective effect against amyloid induced toxicity even in the presence of mutant PS1 and reduced the production of Aβ.

Evaluation of trigeminal nerve injuries in relation to third molar surgery in a prospective patient cohort. Recommendations for prevention

Trigeminal nerve injury is the most problematic consequence of dental surgical procedures with major medico-legal implications. This study reports the signs and symptoms that are the features of trigeminal nerve injuries caused by mandibular third molar (M3M) surgery. 120 patients with nerve injury following M3M surgery were assessed. All data were analysed using the SPSS statistical programme and Microsoft Excel. 53 (44.2%) inferior alveolar nerve (IAN) injury cases and 67 (55.8%) lingual nerve injury (LNI) cases were caused by third molar surgery (TMS). Neuropathy was demonstrable in all patients with varying degrees of paraesthesia, dysaesthesia (in the form of burning pain), allodynia and hyperalgesia. Pain was one of the presenting signs and symptoms in 70% of all cases. Significantly more females had IAN injuries and LNIs (p<0.05). The mean ages of the two groups of patients were similar. Speech and eating were significantly more problematic for patients with LNIs. In conclusion, chronic pain is often a symptom after TMS-related nerve injury, resulting in significant functional problems. Better dissemination of good practice in TMS will significantly minimize these complex nerve injuries and prevent unnecessary suffering.

Investigation of in vivo radioprotective and in vitro antioxidant and antimicrobial activity of garlic (Allum sativum)

OBJECTIVE

In this study, we aimed to assess the in vivo antioxidant potential via evaluating radioprotective effects in kidney and liver tissues of rats and in vitro antimicrobial and radical scavenger activity of garlic extract.

MATERIALS AND METHODS

Thirty-two mature female Wistar rats were divided into four groups, each consisting of eight rats. Experimental groups were control group (1), GE group (2), irradiation group (3) and both GE and irradiation group (4). For the rats in two groups (group 3 and 4), irradiation was performed on a Cobalt-60 unit using a single fraction of 20 Gy. The GE was given to rats once a day during the month before irradiation and continued for five days after irradiation. The garlic cloves were peeled on crushed ice and 50 g of garlic was cut into small pieces and homogenized in 75 mL of 0.9% NaCI. The concentration of this garlic preparation was considered to be 500 mg/mL on the basis of weight of the starting material (0.5 g/mL). This extract was administered to rats by oral gavage.

RESULTS

Our findings suggest that the use of garlic extract could be useful for addressing the limited therapeutic gain due to the radiation sensitivity of normal tissues adjacent to the tumour which are exposed to radiation, by strengthening the antioxidant system. In vitro and in vivo experiments seem to yield similar conclusions.

CONCLUSIONS

It can be stated that garlic is may be recommended to be sufficiently included in the diets of radiotherapy patients considering its antioxidant and antimicrobial efficacy.

Olanzapine versus placebo for out-patients with anorexia nervosa

BACKGROUND

Anorexia nervosa (AN) is a serious psychiatric illness associated with significant morbidity and mortality. There is little empirical support for specific treatments and new approaches are sorely needed. This two-site study aimed to determine whether olanzapine is superior to placebo in increasing body mass index (BMI) and improving psychological symptoms in out-patients with AN.

METHOD

A total of 23 individuals with AN were randomly assigned in double-blind fashion to receive olanzapine or placebo for 8 weeks together with medication management sessions that emphasized compliance. Weight, other physical assessments and measures of psychopathology were collected.

RESULTS

End-of-treatment BMI, with initial BMI as a covariate, was significantly greater in the group receiving olanzapine [F(1, 20)=6.64, p=0.018]. Psychological symptoms improved in both groups, but there were no statistically significant group differences. Of the 23 participants, 17 (74%) completed the 8-week trial. Participants tolerated the medication well with sedation being the only frequent side effect and no adverse metabolic effects were noted.

CONCLUSIONS

This small study suggests that olanzapine is generally well tolerated by, and may provide more benefit than placebo for out-patients with AN. Further study is indicated to determine whether olanzapine may affect psychological symptoms in addition to BMI.

Accelerated human mutant tau aggregation by knocking out murine tau in a transgenic mouse model

Many models of human tauopathies have been generated in mice by expression of a human mutant tau with maintained expression of mouse endogenous tau. Because murine tau might interfere with the toxic effects of human mutant tau, we generated a model in which a pathogenic human tau protein is expressed in the absence of wild-type tau protein, with the aim of facilitating the study of the pathogenic role of the mutant tau and to reproduce more faithfully a human tauopathy. The Tg30 line is a tau transgenic mouse model overexpressing human 1N4R double-mutant tau (P301S and G272V) that develops Alzheimer's disease-like neurofibrillary tangles in an age-dependent manner. By crossing Tg30 mice with mice invalidated for their endogenous tau gene, we obtained Tg30xtau(-/-) mice that express only exogenous human double-mutant 1N4R tau. Although Tg30xtau(-/-) mice express less tau protein compared with Tg30, they exhibit signs of decreased survival, increased proportion of sarkosyl-insoluble tau in the brain and in the spinal cord, increased number of Gallyas-positive neurofibrillary tangles in the hippocampus, increased number of inclusions in the spinal cord, and a more severe motor phenotype. Deletion of murine tau accelerated tau aggregation during aging of this mutant tau transgenic model, suggesting that murine tau could interfere with the development of tau pathology in transgenic models of human tauopathies.

Profiling of patients presenting with posttraumatic neuropathy of the trigeminal nerve

AIMS

To describe the cause, clinical signs, and symptoms of patients presenting to a tertiary care center with iatrogenic lesions to the mandibular branches of the trigeminal nerve.

METHODS

Pain history, pain scores using the visual analog scale, and mechanosensory testing results were recorded from 93 patients with iatrogenic lingual nerve injuries (LNI) and 90 patients with iatrogenic inferior alveolar nerve injuries (IANI). Results were analyzed using the SPSS statistical software. Chi-square tests were applied for nonparametric testing of frequencies, where P ⋜ .05 indicated statistical significance. Appropriate correlations were also carried out between certain data sets.

RESULTS

Significantly more females were referred than males (P < .05). Overall, third molar surgery (TMS) caused 73% of LNI, followed by local anesthesia (LA) (17%). More diverse procedures caused IANI, including TMS (60%), LA (19%), implants (18%), and endodontics (8%). Approximately 70% of patients presented with neuropathic pain coincident with anesthesia and÷or paresthesia. Neuropathy was demonstrable in all patients with varying degrees of loss of mechanosensory function, paresthesia, dysesthesia, allodynia, and hyperalgesia. Functionally, IANI and LNI patients mostly had problems with speech and eating, where speech was affected amongst significantly more patients with LNI (P < .001). Sleep, brushing teeth, and drinking were significantly more problematic for IANI patients (P < .05, P < .001, and P < .0001, respectively).

CONCLUSION

Neuropathic pain, as well as anesthesia, frequently occurs following iatrogenic trigeminal nerve injury similar to other posttraumatic sensory nerve injuries. This must be acknowledged by clinicians as a relatively common problem and informed consent appropriately formulated for patients at risk of trigeminal nerve injuries in relation to dentistry requires revision.

Cannabinoid receptor CB1-immunoreactive nerve fibres in painful and non-painful human tooth pulp

The cannabinoid receptor CB1 is involved in modulation of neuronal hypersensitivity and pain. The aim of this study was to evaluate CB1 receptor levels for the first time in dental pain. A total of 19 patients due for molar extraction were divided into two groups, those with existing dental pain (n=9), and those with no history of pain (n=10). Immunohistochemistry and computer image analysis was used to evaluate CB1-positive nerve fibres in tooth pulp, with neurofilament-immunostaining as a structural nerve marker. CB1-immunoreactive nerve fibres were scattered throughout the tooth pulp and often seen in nerve bundles, but the fibres did not penetrate the subodontoblastic layer. There was no statistically significant change in the CB1 nerve fibre percentage area in the painful group compared to the non-painful group (p=0.146); the neurofilament fibres were significantly reduced in the painful group compared to the controls (p=0.028), but there was no difference in the ratio of CB1 to neurofilaments between the two groups. Thus, CB1 expression is maintained by nerve fibres in painful human dental pulp, and peripherally-restricted CB1 agonists currently in development may advance the treatment of dental pain.

Sodium channel Na v 1.7 immunoreactivity in painful human dental pulp and burning mouth syndrome

BACKGROUND

Voltage gated sodium channels Na v 1.7 are involved in nociceptor nerve action potentials and are known to affect pain sensitivity in clinical genetic disorders.

AIMS AND OBJECTIVES

To study Na v 1.7 levels in dental pulpitis pain, an inflammatory condition, and burning mouth syndrome (BMS), considered a neuropathic orofacial pain disorder.

METHODS

Two groups of patients were recruited for this study. One group consisted of patients with dental pulpitis pain (n = 5) and controls (n = 12), and the other patients with BMS (n = 7) and controls (n = 10). BMS patients were diagnosed according to the International Association for the Study of Pain criteria; a pain history was collected, including the visual analogue scale (VAS). Immunohistochemistry with visual intensity and computer image analysis were used to evaluate levels of Na v 1.7 in dental pulp tissue samples from the dental pulpitis group, and tongue biopsies from the BMS group.

RESULTS

There was a significantly increased visual intensity score for Na v 1.7 in nerve fibres in the painful dental pulp specimens, compared to controls. Image analysis showed a trend for an increase of the Na v 1.7 immunoreactive % area in the painful pulp group, but this was not statistically significant. When expressed as a ratio of the neurofilament % area, there was a strong trend for an increase of Na v 1.7 in the painful pulp group. Na v 1.7 immunoreactive fibres were seen in abundance in the sub-mucosal layer of tongue biopsies, with no significant difference between BMS and controls.

CONCLUSION

Na v 1.7 sodium channel may play a significant role in inflammatory dental pain. Clinical trials with selective Na v 1.7 channel blockers should prioritize dental pulp pain rather than BMS.