Analytical and computational studies of the nonlinear vibrations of SWCNTs embedded in viscous elastic matrix using KBM method

The forced vibration analysis of single wall carbon nanotubes (SWCNTs) embedded in the viscous elastic matrix subjected to axial parametric excitation has been investigated. The Euler Bernoulli beam model of the non-local continuum theory is used. The resonant and non-resonant solutions are analytically studied using the Krylov Bogoliubov and Mitropolsky method. It has been seen that the amplitude remains constant up to the second order of approximation. The resonant solutions are also found to analyze the possibility of chaos in the neighborhood of resonance. The computational techniques are used, and plots of time series, phase plot, and Poincaré surface of section are also drawn to confirm the chaotic behavior for certain values of parameters of SWCNTs, which may lead the aging process in the SWCNTs after a long time.

Internal carotid artery injury during endonasal sinus surgery: our experience and review of the literature

Iatrogenic internal carotid artery injury is a catastrophic but uncommon complication of endonasal sinus surgery. We present our experience in managing this emergency situation. A 52-year-old man underwent revision endoscopic repair of recurrent cerebrospinal fluid leak that was complicated with profuse haemorrhage during removal of the anterior wall of sphenoid sinus using a Hajek sphenoid punch forceps. Immediate packing of the sphenoid sinus controlled the haemorrhage. Urgent angiography revealed injury at the paraclival segment of the left internal carotid artery. An endovascular stent was initially placed but thrombosed; it was subsequently converted to coil embolisation. The patient had watershed cerebral infarct with hemiparesis post procedure but made full recovery within 6 weeks. Immediate nasal packing followed by urgent angiography and endovascular stent placement is the least invasive definitive treatment. If stenting is unsuccessful, endovascular balloon occlusion or coil embolisation is the next preferred treatment, if there is adequate cross-cerebral circulation. The success of treatment relies on its immediate management by a multidisciplinary team.

Differential gene expression in trigeminal ganglia of male and female rats following chronic constriction of the infraorbital nerve

BACKGROUND

The mechanisms underlying sex-based differences in pain and analgesia are poorly understood. In this study, we investigated gene expression changes in trigeminal ganglia (TG) of male and female rats exposed to infraorbital nerve chronic constriction injury (IoN-CCI).

METHODS

Somatosensory assessments were performed prior to IoN-CCI and at selected time points postsurgery. Selected gene expression changes were examined with real-time quantitative polymerase chain reaction (RT-PCR) in ipsilateral TG at 21 days postsurgery.

RESULTS

Rats exposed to IoN-CCI developed significant mechanical allodynia and hyperalgesia on days 19 and 21 postsurgery. During this period, females developed significantly more allodynia but not hyperalgesia compared to males. At 21 days postsurgery, expression levels of 44 of the 84 investigated pain-related genes in ipsilateral TG were significantly regulated relative to naïve rats in either sex. Csf1 and Cx3cr1 were up-regulated in both sexes, but the magnitude of regulation was significantly higher in females (p = 0.02 and p = 0.001, respectively). Htr1a and Scn9a were down-regulated in both sexes, but the down-regulation was significantly more pronounced in males (p = 0.04 and p = 0.02, respectively). Additionally, Cck, Il1a, Pla2g1b and Tnf genes were significantly regulated in females but not in males, and Chrna4 gene was significantly down-regulated in males but not in females.

CONCLUSIONS

Our findings suggest sex-dependent gene regulation in response to nerve injury, which may contribute to sex dimorphism of trigeminal neuropathic pain. Further studies are needed to establish gene expression changes over time and correlate these with hormonal and other physiological parameters in male and female.

SIGNIFICANCE

We present novel sex-specific transcriptional regulation in trigeminal ganglia that may contribute to male-/female-based differences in trigeminal neuropathic pain. These findings are expected to open new research horizons, particularly in male versus female targeted therapeutic regimens.

Management of rhinosinusitis in adults in primary care

Rhinosinusitis is a common health problem encountered in primary care. It is due to mucosal inflammation of the nose and paranasal sinuses. Less than 2% of the cases are associated with bacterial infections. Diagnosis is based on clinical symptoms and supported by nasal endoscopy and imaging studies. Intranasal corticosteroids and normal saline irrigation are important treatments. Antibiotics are seldom indicated.

Differential gene expression in trigeminal ganglia of male and female rats following chronic constriction of the infraorbital nerve

BACKGROUND

The mechanisms underlying sex-based differences in pain and analgesia are poorly understood. In this study, we investigated gene expression changes in trigeminal ganglia (TG) of male and female rats exposed to infraorbital nerve chronic constriction injury (IoN-CCI).

METHODS

Somatosensory assessments were performed prior to IoN-CCI and at selected time points postsurgery. Selected gene expression changes were examined with real-time quantitative polymerase chain reaction (RT-PCR) in ipsilateral TG at 21 days postsurgery.

RESULTS

Rats exposed to IoN-CCI developed significant mechanical allodynia and hyperalgesia on days 19 and 21 postsurgery. During this period, females developed significantly more allodynia but not hyperalgesia compared to males. At 21 days postsurgery, expression levels of 44 of the 84 investigated pain-related genes in ipsilateral TG were significantly regulated relative to naïve rats in either sex. Csf1 and Cx3cr1 were up-regulated in both sexes, but the magnitude of regulation was significantly higher in females (p = 0.02 and p = 0.001, respectively). Htr1a and Scn9a were down-regulated in both sexes, but the down-regulation was significantly more pronounced in males (p = 0.04 and p = 0.02, respectively). Additionally, Cck, Il1a, Pla2g1b and Tnf genes were significantly regulated in females but not in males, and Chrna4 gene was significantly down-regulated in males but not in females.

CONCLUSIONS

Our findings suggest sex-dependent gene regulation in response to nerve injury, which may contribute to sex dimorphism of trigeminal neuropathic pain. Further studies are needed to establish gene expression changes over time and correlate these with hormonal and other physiological parameters in male and female.

SIGNIFICANCE

We present novel sex-specific transcriptional regulation in trigeminal ganglia that may contribute to male-/female-based differences in trigeminal neuropathic pain. These findings are expected to open new research horizons, particularly in male versus female targeted therapeutic regimens.

Voriconazole and squamous cell carcinoma after lung transplantation: A multicenter study

This study evaluated the independent contribution of voriconazole to the development of squamous cell carcinoma (SCC) in lung transplant recipients, by attempting to account for important confounding factors, particularly immunosuppression. This international, multicenter, retrospective, cohort study included adult patients who underwent lung transplantation during 2005-2008. Cox regression analysis was used to assess the effects of voriconazole and other azoles, analyzed as time-dependent variables, on the risk of developing biopsy-confirmed SCC. Nine hundred lung transplant recipients were included. Median follow-up time from transplantation to end of follow-up was 3.51 years. In a Cox regression model, exposure to voriconazole alone (adjusted hazard ratio 2.39, 95% confidence interval 1.31-4.37) and exposure to voriconazole and other azole(s) (adjusted hazard ratio 3.45, 95% confidence interval 1.07-11.06) were associated with SCC compared with those unexposed after controlling for important confounders including immunosuppressants. Exposure to voriconazole was associated with increased risk of SCC of the skin in lung transplant recipients. Residual confounding could not be ruled out because of the use of proxy variables to control for some confounders. Benefits of voriconazole use when prescribed to lung transplant recipients should be carefully weighed versus the potential risk of SCC. EU PAS registration number: EUPAS5269.

Effect of an antimicrobial stewardship programme on antimicrobial utilisation and costs in patients with leukaemia: a retrospective controlled study

OBJECTIVES

To examine the effectiveness of an antimicrobial stewardship programme on utilization and cost of antimicrobials in leukaemia patients in Canada.

METHODS

We conducted a multisite retrospective observational time series study from 2005 to 2013. We implemented academic detailing as the intervention of an antimicrobial stewardship programme in leukaemia units at a hospital, piloted February-July 2010, then fully implemented December 2010-March 2013, with no intervention in August-November 2010. Internal control was the same hospital's allogeneic haematopoietic stem-cell transplantation unit. External control was the combined leukaemia-haematopoietic stem-cell transplantation unit at another hospital. Primary outcome was antimicrobial utilization (antibiotics and antifungals) in defined daily dose per 100 patient-days (PD). Secondary outcomes were antimicrobial cost (Canadian dollars per PD); cost and utilization by drug class; length of stay; 30-day inpatient mortality; and nosocomial Clostridium difficile infection. We used autoregressive integrated moving average models to evaluate the impact of the intervention on outcomes.

RESULTS

The intervention group included 1006 patients before implementation and 335 during full implementation. Correspondingly, internal control had 723 and 264 patients, external control 1395 and 864 patients. Antimicrobial utilization decreased significantly in the intervention group (p <0.01, 278 vs. 247 defined daily dose per 100 PD), increased in external control (p = 0.02, 237.4 vs. 268.9 defined daily dose per 100 PD) and remained stable in internal control (p = 0.66). Antimicrobial cost decreased in the intervention group (p = 0.03; $154.59 per PD vs. $128.93 per PD), increased in external control (p = 0.01; $109.4 per PD vs. $135.97 per PD) but was stable in internal control (p = 0.27). Mortality, length of stay and nosocomial C. difficile rate in intervention group remained stable.

CONCLUSIONS

The antimicrobial stewardship programme reduced antimicrobial use in leukaemia patients without affecting inpatient mortality and length of stay.

Aspergillus galactomannan detection in exhaled breath condensate compared to bronchoalveolar lavage fluid for the diagnosis of invasive aspergillosis in immunocompromised patients

OBJECTIVES

Exhaled breath condensate (EBC) is a noninvasive means of sampling the airways that has shown significant promise in the diagnosis of many disorders. There have been no reports of its usefulness in the detection of galactomannan (GM), a component of the cell wall of Aspergillus. The suitability of EBC for the detection of GM for the diagnosis of invasive aspergillosis (IA) using the Platelia Aspergillus enzyme-linked immunosorbent assay was investigated.

METHODS

Prospective, cross-sectional study of lung transplant recipient and haemotologic malignancy patients at a university centre. EBC samples were compared to concomitant bronchoalveolar lavage (BAL) samples among lung transplant recipients and healthy controls. EBC was collected over 10 minutes using a refrigerated condenser according to the European Respiratory Society/American Thoracic Society recommendations, with the BAL performed immediately thereafter.

RESULTS

A total of 476 EBC specimens with 444 matched BAL specimens collected from lung transplant recipients (n = 197) or haemotologic malignancy patients (n = 133) were examined. Both diluted and untreated EBC optical density (OD) values (0.0830, interquartile range (IQR) 0.0680-0.1040; and 0.1130, IQR 0.0940-0.1383), respectively, from all patients regardless of clinical syndrome were significantly higher than OD values in healthy control EBCs (0.0508, IQR 0.0597-0.0652; p < 0.0001). However, the OD index values did not correlate with the diagnosis of IA (44 samples were associated with IA). Furthermore, no significant correlation was found between EBC GM and the matched BAL specimen.

CONCLUSIONS

GM is detectable in EBC; however, no correlation between OD index values and IA was noted in lung transplant recipients.

Nasal closure for severe hereditary haemorrhagic telangiectasia in 100 patients. The Lund modification of the Young's procedure: a 22-year experience

INTRODUCTION

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disease characterized by recurrent epistaxis, mucocutaneous telangiectasia and visceral arteriovenous malformations. The nosebleeds can be life-threatening and in these circumstances, radical treatment is required.

METHODS

Since 1994, closure of the nose has been undertaken to prevent severe nasal bleeding in patients meeting specific selection criteria. Outcome data collected on this cohort pre- and post-operatively is available for analysis.

RESULTS

From a cohort of 515 HHT patients, 100 have undergone nasal closure, bilateral ab initio in 81%. Fifty patients completed pre- and post-operative epistaxis severity questionnaires and provided information on post-operative problems and 28 completed a Glasgow Benefit Inventory (GBI). Overall most patients derived significant benefit from the procedure with complete cessation of nasal bleeding in 94%, a highly significant improvement in the epistaxis score and a mean GBI score of 53.4. Loss of smell and taste was the most frequent post-operative complaint.

CONCLUSION

HHT can be associated with life-threatening epistaxis significantly affecting patients quality of life. Permanent prevention of airflow is associated with complete or near-total cessation of epistaxis in the majority of patients.