a critical look into stapedotomy learning curve influence of patient characteristics and different criteria defining success

Purpose: To evaluate stapedotomy learning curve with cumulative summation methodology using different success criteria (ie, air-bone gap [ABG] ≤10 dB, ABG ≤15 dB, restoration of interaural symmetry, or hearing threshold gain >20 dB), and to assess patient characteristics influencing or modifying the learning curve. Methods: Retrospective chart review of primary and revision stapedotomy cases performed by surgeon 1 (S1, n = 78) and surgeon 2 (S2, n = 85). Results: Using the classic criterion for a successful stapedotomy (ABG ≤10 dB), patients with preoperative ABG >34 dB were associated with unsuccessful procedures (S1 P = .02; S2 P = .07). Revision surgery was associated with unsuccessful outcomes (S1 P = .005; S2 P = .0012). Cumulative summation plots using different criteria did not show a linear trend of association between stapedotomy success and number of operations, but preoperative characteristics of the patients who underwent stapedotomy significantly influenced the plots. Cumulative summation plots showed an initial increasing tendency with improving results, but when ear surgeons got more skilled, they operated on more complex cases (ie, patients with higher preoperative ABG or revision stapedotomy) and they could not meet the success criteria. Conclusions: Cumulative summation plots do not seem useful to evaluate the stapedotomy learning curve, as they do not correctly deal with heterogeneous case series. The increasing complexity of the stapedotomy patients during the surgeons' career impacts on the outcome of stapedotomy and confounds the evaluation of the growing skills of the surgeon. Stapedotomy audiological success rates are strongly influenced by the success criteria used

Standard Outpatient Re-Evaluation for Patients Not Admitted to the Hospital After Emergency Department Evaluation for Acute Abdominal Pain

The aim of the present study was to investigate the efficacy and safety of standard outpatient re-evaluation for patients who are not admitted to the hospital after emergency department surgical consultation for acute abdominal pain. All patients seen at the emergency department between June 2005 and July 2006 for acute abdominal pain were included in a prospective study using a structured diagnosis and management flowchart. Patients not admitted to the hospital were given appointments for re-evaluation at the outpatient clinic within 24 h. All clinical parameters, radiological results, diagnostic considerations, and management proposals were scored prospectively. Five-hundred patients were included in this analysis. For 148 patients (30%), the final diagnosis was different from the diagnosis after initial evaluation. Eighty-five patients (17%) had a change in management after re-evaluation, and 20 of them (4%) were admitted to the hospital for an operation. Only 6 patients (1.2%) had a delay in diagnosis and treatment, which did not cause extra morbidity. Standard outpatient re-evaluation is a safe and effective means of improving diagnostic accuracy and helps to adapt management for patients that are not admitted to the hospital after surgical consultation for acute abdominal pain at the emergency department.Vascular Surger

A new class of glycomimetic drugs to prevent free fatty acid-induced endothelial dysfunction

Background: Carbohydrates play a major role in cell signaling in many biological processes. We have developed a set of glycomimetic drugs that mimic the structure of carbohydrates and represent a novel source of therapeutics for endothelial dysfunction, a key initiating factor in cardiovascular complications. Purpose: Our objective was to determine the protective effects of small molecule glycomimetics against free fatty acid­induced endothelial dysfunction, focusing on nitric oxide (NO) and oxidative stress pathways. Methods: Four glycomimetics were synthesized by the stepwise transformation of 2,5­dihydroxybenzoic acid to a range of 2,5­substituted benzoic acid derivatives, incorporating the key sulfate groups to mimic the interactions of heparan sulfate. Endothelial function was assessed using acetylcholine­induced, endotheliumdependent relaxation in mouse thoracic aortic rings using wire myography. Human umbilical vein endothelial cell (HUVEC) behavior was evaluated in the presence or absence of the free fatty acid, palmitate, with or without glycomimetics (1µM). DAF­2 and H2DCF­DA assays were used to determine nitric oxide (NO) and reactive oxygen species (ROS) production, respectively. Lipid peroxidation colorimetric and antioxidant enzyme activity assays were also carried out. RT­PCR and western blotting were utilized to measure Akt, eNOS, Nrf­2, NQO­1 and HO­1 expression. Results: Ex vivo endothelium­dependent relaxation was significantly improved by the glycomimetics under palmitate­induced oxidative stress. In vitro studies showed that the glycomimetics protected HUVECs against the palmitate­induced oxidative stress and enhanced NO production. We demonstrate that the protective effects of pre­incubation with glycomimetics occurred via upregulation of Akt/eNOS signaling, activation of the Nrf2/ARE pathway, and suppression of ROS­induced lipid peroxidation. Conclusion: We have developed a novel set of small molecule glycomimetics that protect against free fatty acidinduced endothelial dysfunction and thus, represent a new category of therapeutic drugs to target endothelial damage, the first line of defense against cardiovascular disease

Classification of cilio-inhibiting effects of nasal drugs

Objective/Hypothesis: Nasal drug formulations are widely used for a local therapeutic effect, but are also used for systemic drug delivery. In the development of new nasal drugs, the toxic effects on the mucociliary clearance and therefore on the ciliated tissue is of importance. In this study, the effect of nasal drugs and their excipients on the ciliary beat frequency (CBF) is investigated. Study Design: Experimental, in vitro. Methods: CBF is measured by a photograph-electric registration method. Excised ciliated chicken trachea tissue is incubated for 15 minutes in the formulation, followed by a reversibility test. To estimate the ciliostatic potential, a classification is given of all tested formulations. According to the CBF, after 60 minutes every drug or excipient could be classified as follows: cilio-friendly: after 60 minutes the CBF has regained 75% or more of its initial frequency; cilio-inhibiting: after 60 minutes the CBF has regained between 25% and 75% of its initial frequency; or ciliostatic: after 60 minutes the CBF has regained 25% or less of its initial frequency. Results: Most formulations used are cilio-friendly or cilio-inhibiting. Only some are ciliostatic. Preservatives have a major role in the cilio-inhibiting effect of the drug. Also, other additives can contribute to the toxicity profile of nasal drug formulations. Conclusion: This classification of the cilio-inhibiting potential of nasal drug formulations is a valuable tool in the design of safe nasal drugs. The number of animal studies in vivo can be reduced substantially by using this in vitro screening technique. This study demonstrates that the effect on ciliary movement of most drug formulations is due to the preservatives and/or additives and mostly not to the drug itself

Direct access of drugs to the human brain after intranasal drug administration?

It has been suggested that intranasal (IN) drug delivery could be used to administer drugs directly to the brain, bypassing the blood-brain barrier. Conclusive evidence of this proposed route of drug transport has not been observed by IN-IV comparison. In eight neurosurgery patients with a CSF drain, the uptake in CSF and plasma after IN and IV drug administration was compared. No evidence of direct access of the drugs from the nose to the CSF was found

Classifications of mastoid and middle ear surgery: A scoping review

OBJECTIVES: The aim of this scoping review was to evaluate existing classifications of surgical procedures of the middle ear and mastoid and find a suitable classification that could serve as an international standard. MATERIALS and METHODS: Scoping review with a systematic literature search using reference tracking and a syntax including all surgical procedures in mastoid and middle ear surgery and their synonyms. Studies were selected based on inclusion and exclusion criteria. RESULTS: Eleven reported classifications were included; six of which focused on middle ear surgery, two on mastoid surgery, and three on both. However, none of the classifications included all current surgical procedures of mastoid and middle ear surgery. CONCLUSION: Many classifications have been proposed for innumerable surgical techniques in middle ear and mastoid surgery. Some are outdated, some are incomplete, most are not widely accepted, and only few correspond with all current surgical techniques

Uptake of melatonin into the cerebrospinal fluid after nasal and intravenous delivery: Studies in rats and comparison with a human study

Purpose. To investigate the possibility of direct transport of melatonin from the nasal cavity into the cerebrospinal fluid (CSF) after nasal administration in rats and to compare the animal results with a human study. Methods. Rats (n = 8) were given melatonin both intranasally in one nostril (40 μg/rat) and intravenously by bolus injection (40 μg/rat) into the jugular vein using a Vascular Access Port. Just before and after drug administration, blood and CSF samples were taken and analyzed by HPLC. Results. Melatonin is quickly absorbed in plasma (Tmax = 2.5 min) and shows a delayed uptake into CSF (Tmax = 15 min) after nasal administration. The melatonin concentration-time profiles in plasma and CSF are comparable to those after intravenous delivery. The AUCCSF/AUCplasma ratio after nasal delivery (32.7 ± 6.3%) does not differ from the one after intravenous injection (46.0 ± 10.4%), which indicates that melatonin enters the CSF via the blood circulation across the blood-brain barrier. This demonstrates that there is no additional transport via the nose-CSF pathway. These results resemble the outcome of a human study. Conclusions. The current results in rats show that there is no additional uptake of melatonin in the CSF after nasal delivery compared to intravenous administration. This is in accordance with the results found in humans, indicating that animal experiments could be predictive for the human situation when studying nose-CSF transport

Dynamic Landau theory for supramolecular self-assembly

Although pathway-specific kinetic theories are fundamentally important to describe and understand reversible polymerisation kinetics, they come in principle at a cost of having a large number of system-specific parameters. Here, we construct a dynamical Landau theory to describe the kinetics of activated linear supramolecular self-assembly, which drastically reduces the number of parameters and still describes most of the interesting and generic behavior of the system in hand. This phenomenological approach hinges on the fact that if nucleated, the polymerisation transition resembles a phase transition. We are able to describe hysteresis, overshooting, undershooting and the existence of a lag time before polymerisation takes off, and pinpoint the conditions required for observing these types of phenomenon in the assembly and disassembly kinetics. We argue that the phenomenological kinetic parameter in our theory is a pathway controller, i.e., it controls the relative weights of the molecular pathways through which self-assembly takes place

Influence of anatomy and head position on intranasal drug deposition

The objective of this study was to determine the influence of individual anatomical differences on intranasal drug deposition. The data of a comparison of seven different administration techniques in ten healthy volunteers was used in this single-blind crossover pilot study. After intranasal administration of a dyed test formulation, endoscopic video imaging was done on seven non-sequential days. The deposition pattern per individual around the head of the middle turbinate was analyzed for each technique and correlated with the individual anatomy. Decreased deposition of dyed test formulation in the target area around the head of the middle turbinate was observed in the presence of minor septal deviations, narrow nasal valve areas, or inferior turbinate hypertrophy; a lateral head position helps to bypass a minor septal deviation. Although results are preliminary, we conclude that anatomy and head position are important factors in the deposition of topical nasal drugs and may be the key to improving individual local nasal (steroid) treatment