Epidemiology, etiology, genetic variants in non- syndromic hearing loss in Iran: A systematic review and meta-analysis

OBJECTIVES

Hearing loss is one of the most common heterogeneous complicated disorders worldwide. We previously analyzed the results of published data on non-syndromic hearing loss in the Iranian population systematically. A broad range of genes is a challenge for molecular screening and clinical diagnosis in our populations on the ground of distinct genetics. The aim of this study was to analyze the role and frequency of the variants accountable for non-syndromic hearing loss (NSHL) in the Iranian population. These were identified with different methods including whole exome sequencing (WES), next-generation sequencing (NGS), targeted genomic enrichment and massively parallel sequencing (TGE + MPS), autozygosity mapping, STR markers, linkage analysis, and direct sequencing. This is the comprehensively study focusing on classifying 13 common NSHL genes according to their frequencies. Previous studies have not studied different regions and the Iranian population, and this is the definitive study on the topic.

METHODS

We searched Scopus, PubMed, Science Direct databases, and Google Scholar. After a systematic review of the evidence 95 studies were considered then 31 studies were eligible for meta-analysis. In total, 6995 families, 358 variants, and 117 novel variants were included. Statistical analyses were conducted using Stata SE version 11 software. The inverse variance method enjoyed combining data. Heterogeneity of the preliminary results was assessed using Q (Cochrane test), and I square index. Random effects or fixed models were applied to combine the results, relying on the degree of heterogeneity. Point and pooled prevalence of variants acting on different regions were illustrated by forest plots.

RESULTS

The total prevalence of at least one variant of GJB2 and SLC26A genes was estimated at 26% and 5%, respectively. Variant c.35delG accounted for 18% of the GJB2 variants while 1% of these variants were novel ones. The next most common variants in the GJB2 gene were c.109G>A at 3.5% and c.-23+1G>A at 2.3%. Moreover, the prevalence of GJB2 gene variants varied on average 0.002% from one region to another in Iran (p=0.849). Our meta-analysis also showed that the frequency of at least one variant of MYO15A varied between 1.2% and 12.5%. Corresponding prevalences for the other variants were as follows: ILDR1 (3.5%-3.7%), CDH23 (2%-10%), PJVK (1.4%-33%), TECTA (1.3%-6.7%), MYO6 (2%-4.8%), TMC1 (1.8%-2%), MYO7A (0.7%-5%), MARVELD2 (0.7-5%), OTOF (0.7%-4%), LRTOMT (0.7%-2.5%). Finally, we did not find any relationship between geographic area and the presence of these variants.

CONCLUSION

GJB2 gene variants were the most common cause of NSHL in Iran. Understanding the prevalence of NSHL gene frequency in Iran may be the foundation for future studies in an Iranian population which may lead to future NSHL therapy.

COVID-19 and anosmia in Tehran, Iran

Patients with acute olfactory disorders typically present to the otolaryngologist with both acute hyposmia and less often with anosmia. With the onset of COVID-19 we have noticed an increase in the number of patients who have presented with new onset of complete smell loss to the senior author's practice in Tehran, Iran. This anosmia and the frequency with which patients present is highly unusual. Coronaviruses have been known to cause common cold symptoms. COVID-19 infections have been described as causing more severe respiratory infections and the symptoms reported by authors from Wuhan, China have not specifically included anosmia. We describe patients who have presented during a two-week period of the COVID-19 pandemic with complete loss of sense of smell. Most had either no symptoms or mild respiratory symptoms. Many had a normal otolaryngologic exam. A relationship between COVID-19 and anosmia should be considered during the pandemic. We hypothesize that the mechanism of injury is similar to that of other coronavirus infections that cause central and peripheral neurologic deficits.

Improvement of sinonasal mucociliary function by endoscopic sinus surgery in patients with chronic rhinosinusitis

OBJECTIVES

Mucociliary clearance is an important defense mechanism for upper and lower airway. Chronic rhinosinusitis has been frequently associated with mucociliary dysfunction. Endoscopic sinus surgery (ESS) is recommended for treatment-resistant sinusitis in order to improve mucociliary function. The present study investigated the effect of ESS on the saccharin time (mucociliary clearance time) in relation to symptom profile assessed by the Sino-nasal Outcome Test (SNOT)-22, and disease severity based on the Lund-Kennedy endoscopic scores and Lund-Mackay computed tomographic (CT) scores.

METHOD

The present cohort study included 22 patients with chronic rhinosinusitis who were considered a candidate for ESS due to lack of response to medical treatment. Saccharin test was used before and 3 months after ESS to evaluate changes in mucociliary function. The CT scan was used for preoperative assessment of sinonasal anatomy. In addition, diagnostic nasal endoscopy was performed before and 3 months after ESS. The CT scan and nasal endoscopy findings were respectively analyzed based on the Lund-Mackay and the Lund-Kennedy staging systems recommended for chronic rhinosinusitis. Symptom severity was assessed from before to 3 months after ESS using SNOT-22.

RESULTS

The present study showed decreased saccharin time in patients with chronic rhinosinusitis three months after ESS. The mean pre-operative and post-operative saccharin time were 23.4 and 16.9 min, respectively. There was also a trend toward significance for the effect of changes in the SNOT-22 scores on changes in saccharin time. By contrast, no effects of age, gender, pre-operative Lund-Mackay CT scores, and changes in Lund-Kennedy endoscopy scores were observed on post-ESS saccharin time.

CONCLUSION

The study confirms that ESS in patients with treatment-resistant chronic rhinosinusitis confers improvement in performance on the saccharin test of mucociliary function.

Endonasal Endoscopic Treatment of Parasellar Arachnoid Cyst: Report of a Case

A 40-year-old man presented with intractable headache of 5-year duration and a 1-month history of intermittent cerebrospinal fluid (CSF) rhinorrhea. Magnetic resonance imaging showed a cystic lesion with signal characteristics similar to that of CSF. The patient underwent endonasal endoscopic surgery of the sphenoid sinus and the fistula was reinforced with facia, muscle, cartilage, and posterior septal flap while performing cystocisternostomy. The postoperative course was uneventful, CSF leakage stopped, and headache improved. Postoperative imaging revealed total collapse of the cyst cavity. Based on our findings, endonasal endoscopic treatment of the sellar and parasellar arachnoid cysts, if presenting into the sphenoid sinus, could be an acceptable minimally invasive alternative to the conventional modalities.

Interest in Aesthetic Rhinoplasty Scale

Interest in cosmetic surgery is increasing, with rhinoplasty being one of the most popular surgical procedures. It is essential that surgeons identify patients with existing psychological conditions before any procedure. This study aimed to develop and validate the Interest in Aesthetic Rhinoplasty Scale (IARS). Four studies were conducted to develop the IARS and to evaluate different indices of validity (face, content, construct, criterion, and concurrent validities) and reliability (internal consistency, split-half coefficient, and temporal stability) of the scale. The four study samples included a total of 463 participants. Statistical analysis revealed satisfactory psychometric properties in all samples. Scores on the IARS were negatively correlated with self-esteem scores (r = –0.296; p < 0.01) and positively associated with scores for psychopathologic symptoms (r = 0.164; p < 0.05), social dysfunction (r = 0.268; p < 0.01), and depression (r = 0.308; p < 0.01). The internal and test–retest coefficients of consistency were found to be high (α = 0.93; intraclass coefficient = 0.94). Rhinoplasty patients were found to have significantly higher IARS scores than nonpatients (p < 0.001). Findings of the present studies provided evidence for face, content, construct, criterion, and concurrent validities and internal and test–retest reliability of the IARS. This evidence supports the use of the scale in clinical and research settings.

When Aesthetics, Surgery, and Psychology Meet: Aesthetic Nasal Proportions in Patients Having Rhinoplasty and Normal Adults

The aesthetic nasal proportions have played a significant role in rhinoplasty practice. On the other hand, psychological variables also play a crucial role in rhinoplasty. It is of paramount importance for facial plastic surgeons to consider both sides to achieve a more satisfactory outcome. The present study aimed to compare aesthetic nasal proportions between primary rhinoplasty candidates and a demographically matched control group to determine whether patients having rhinoplasty have different aesthetic nasal proportions compared with healthy adults who are not interested in rhinoplasty. Sixty patients having rhinoplasty were selected consecutively from a surgical clinic. A control group ( n  = 60) with the same demographic characteristics was selected. Photographs were taken using a digital camera on a fixed zoom setting. All images were captured at a distance of 1.5 m. Frontal and right lateral views were used to compare nasolabial angle, nasofrontal angle, nasofacial angle, alar width, intercanthal distance, nasal length, and width-to-length ratio. Independent t tests were used for comparisons. Independent t tests verified that nasofrontal angle, nasal length, and width-to-length ratio were significantly different between the two groups ( p  < 0.01). Effect sizes ranged between 0.11 and 0.69. Aesthetic proportions were not significantly different in four factors. Nasolabial angle, nasofacial angle, alar width, and intercanthal distance were not different ( p  > 0.05). Four major aesthetic nasal proportions were statistically similar in a group of patients having rhinoplasty and a control group with no interest in rhinoplasty. Surprisingly, the patients having rhinoplasty showed a mean width-to-length ratio closer to aesthetic ideal. Therefore, applying for rhinoplasty may have strong psychological reasons (e.g., body dysmorphic symptoms) compared with realistic aesthetic appraisals.

De Sanctis-Cacchione syndrome: A case report and literature review

De Sanctis–Cacchione (DSC) syndrome is one of the rarest, most severe forms of xeroderma pigmentosum (XP). These patients with XP are of short stature, have mental disabilities, and develop progressive neurologic degeneration because of a severe inability to repair damaged DNA. Herein, we will present the case of a 9-year-old boy who had DSC syndrome with microcephaly, severe psychomotor retardation, ataxia, and hearing loss. The cutaneous manifestations included giant squamous cell carcinoma (SCC) that covered the eye, multiple facial SCCs, and pigment changes on sun-exposed areas. In addition, we include a review of reported rare cases and a brief discussion of disease management.

A comparison of depression scores between aesthetic and functional rhinoplasty patients

Depression is a mood state of sadness, gloom, and pessimistic ideation with loss of interest or pleasure in normal activities. This mood disorder has been reported to occur more frequently among cosmetic surgery patients. The purpose of the current study was to compare the score of depression among aesthetic rhinoplasty candidates and functional rhinoplasty patients as control group. The Beck Depression Inventory (BDI) and Depression (DE) subscale of Symptom Check List-90-Revised (SCL-90-R) were administered on a sample of aesthetic rhinoplasty patients (n=21) as well as a sample of functional rhinoplasty patients (n=21). Those with both cosmetic and functional purposes were categorized regarding their primary objective. Questionnaires were given to patients preoperatively. Cohen's d was also calculated as a measure of Effect Size (ES). BDI and SCL-90-R-DE scores were analyzed using t-test for independent groups. Statistical analyses suggested that the mean BDI and SCL-90-R-DE scores of aesthetic surgery patients were significantly higher than those of functional surgery patients (P<0.05). The results showed that age, sex, and Socio-Economic Status (SES) were not significantly different between the two groups as they can be capable of influencing the depression score. Effect size was above the moderate level: d=0.51, d=0.72 for BDI and SCL-90-R-DE, respectively. Using two different depression instruments, the findings of this study showed that aesthetic rhinoplasty patients were more depressed in comparison with functional rhinoplasty patients. The measures of ES also supported the hypothesis that aesthetic rhinoplasty candidates had higher scores in depression.

Management of advanced intracranial intradural juvenile nasopharyngeal angiofibroma: combined single-stage rhinosurgical and neurosurgical approach

BACKGROUND

Although intracranial extension of juvenile nasopharyngeal angiofibroma (JNA) occurs commonly, intradural penetration is extremely rare. Management of such tumors is a challenging issue in skull-base surgery, necessitating their removal via combined approaches. In this work, we share our experience in management of extensive intradural JNA.

METHODS

In a university hospital-based setting of 2 tertiary care academic centers, retrospective chart of 6 male patients (5 between 15 and 19 years old) was reviewed. Patients presented chiefly with nasal obstruction, epistaxis, and proptosis. One of them was an aggressive recurrent tumor in a 32-year-old patient. All cases underwent combined transnasal, transmaxillary, and craniotomy approaches assisted by the use of image-guided endoscopic surgery, with craniotomy preceding the rhinosurgical approach in 3 cases.

RESULTS

Adding a transcranial approach to the transnasal and transmaxillary endoscopic approaches provided 2-sided exposure and appreciated access to the huge intradural JNAs. One postoperative cerebrospinal fluid leak and 1 postoperative recurrence at the site of infratemporal fossa were treated successfully. Otherwise, the course was uneventful in the remaining cases.

CONCLUSION

Management of intracranial intradural JNA requires a multidisciplinary approach of combined open and endoscopic-assisted rhinosurgery and neurosurgery, because of greater risk for complications during the dissection. Carotid rupture and brain damage remain 2 catastrophic complications that should always be kept in mind. A combined rhinosurgical and neurosurgical approach also has the advantage of very modest cosmetic complications.

Evaluation of pediatric voice handicap index and pediatric voice related quality of life before and after adenotonsillectomy in pediatric population

OBJECTIVE

To study changes in Pediatric Voice Handicap Index (PVHI) and Pediatric Voice Related Quality of Life (PVRQOL) before and after adenotonsillectomy in short term follow up.

METHODS

Quasi-experimental (before and after study). Eighty-six children aged 3-13 years (58 boys, 28 girls) with adenotonsillar problems (whether with obstructive or infectious surgical indications) who were admitted for adenotonsillectomy procedure. Parents of children were asked to complete PVHI and PVRQOL questionnaires prior to surgery and 1 month after it.

RESULTS

Reliability of the PVRQOL and PVHI was established by evaluation of Cronbach α value. Cronbach α for PVHI was 0.92 and for PVRQOL it was 0.83. Preoperative values for the PVHI were: mean±SD; 14.39±14.65. Preoperative values for the PVRQOL were: mean±SD; 92.60±10.82. PVHI showed significant improvement after surgery: mean±SD; 2.93±6.98 (P<0.001). Postoperative PVRQOL had a significant improvement: mean±SD; 98.11±5.82 (P<0.001).

CONCLUSION

Adenotonsillectomy improved PVHI and PVRQOL scores in children with adenotonsillar problems, regardless of obstructive or infectious surgical indications.

Comparison of patterns of psychopathology in aesthetic rhinoplasty patients versus functional rhinoplasty patients

OBJECTIVES

To determine whether candidates for aesthetic rhinoplasty show more severe symptoms of psychopathology in comparison with functional rhinoplasty patients.

STUDY DESIGN

Case-control study. Aesthetic rhinoplasty candidates were taken as cases and functional rhinoplasty patients comprised the control group.

SETTING

A surgical center for rhinoplasty.

SUBJECTS AND METHODS

Forty-two patients seeking either aesthetic rhinoplasty (n = 21) or functional rhinoplasty (n = 21) were included in this study in winter 2012 using a convenience sampling method. All patients were asked to complete the Symptom Check List-90-Revised (SCL-90-R) preoperatively. An independent t test was performed for each subscale of the instrument. Cohen's d was calculated as a measure of effect size. Pearson's correlation was also performed between the subscales.

RESULTS

Independent t test verified that aesthetic rhinoplasty patients scored significantly higher in 8 subscales of the SCL-90-R in comparison with functional rhinoplasty patients as control group. Aesthetic rhinoplasty seekers showed more severe symptoms in obsessive-compulsive disorder (P < .01), depression (P < .01), interpersonal problems (P < .01), psychoticism (P < .05), paranoia (P < .05), hostility (P < .05), phobia (P < .01), and general psychopathology (P < .01). All subscales were correlated strongly in the current sample.

CONCLUSION

This study demonstrated that a sample of patients seeking aesthetic rhinoplasty had higher symptoms in various components of psychopathology compared with a control group. Therefore, preoperative psychological screening of aesthetic rhinoplasty candidates may be useful.

Comparison of Self-Esteem Status in Aesthetic and Functional Rhinoplasty Patients

Objectives:

Self-esteem is one’s attitude toward oneself. It is one of the most important psychological aspects of rhinoplasty. Some findings indicate the improvement of patient self-esteem after the operation. The aim of this study was to compare self-esteem in patients seeking aesthetic or functional rhinoplasty.

Methods:

A total of 45 patients ranging in age from 17 to 36 filled out the Rosenberg Self-Esteem Scale (RSES) over a 3-month period. RSES consists of 10 items measuring general self-esteem. The subjects took a validated form of RSES preoperatively. Twenty-one aesthetic surgery patients and 21 functional surgery patients had filled out the questionnaire and 3 patients had left it blank.

Results:

Using t-test for independent groups, the analysis of the data demonstrated that the mean self-esteem score in the aesthetic surgery group was significantly lower than that of the functional surgery group ( P < .05). Age, sex, socioeconomic status (SES), and educational backgrounds were analyzed as potential extraneous variables and comparative analysis of each showed no significance between the 2 groups. Cohen’s d was also calculated as a measure of effect size (ES). The value of ES measure was high ( d = 0.78).

Conclusions:

The findings of the present study showed that aesthetic rhinoplasty patients had lower self-esteem in comparison with functional rhinoplasty patients.

Nonsurgical Radiofrequency Volumetric Reduction of Adenoidal Hypertrophy

Objectives:

Adenoidal hypertrophy (AH) is the most common cause of pathologic mouth breathing in children. Medical treatment of adenoid hypertrophy includes treatment of allergies, nasal sprays, and antibiotics. However, in some cases AH continues to produce symptoms despite maximal medical therapy. Potential risks of anesthesia and complications of surgical procedures have led to the promotion of non-surgical alternatives. During the past 3 years, advances in expertise and technology led to the new advent of using office based setting for nonsurgical procedures by the author as an innovative method for treatment of AH.

Methods:

Sixty five children who were definitive candidates for surgical adenoidectomy were managed with radiofrequency treatment under endoscopy control without any need of general anesthesia. The age range was between 4 and 15. All children underwent direct endoscopic examination of adenoid before and after procedure.

Results:

The period of follow-up was from 2 to 32 months. Patients experienced different degrees of improvement after nonsurgical procedure, according to a researcher-based questionnaire. The results were impressive for some parents because of marked improvement by very simple procedure as compared to surgery.

Conclusions:

Nonsurgical radiofrequency reduction of adenoid size has multiple advantages: excellent magnified view of adenoid area, accurate reduction of central obstructing part of adenoid, nonbleeding, evaluation and treatment of other nonadenoid obstructing problems, complete preservation of normal nasopharyngeal structures, no general anesthesia, no operating room stress, no hospitalization, high safety, no complications, and better patient tolerance using this fast and easy procedure.

Combined Rhinosurgical and Neurosurgical Management of Intradural Angiofibromas

Objectives:

Although intracranial extension of angiofibromas is not uncommon, intradural penetration is rare. Management of such rare tumors is a challenging issue in skull base surgery, necessitating tumor removal via combined approaches in most cases. In this paper we present our experience for management of extensive intradural angiofibromas.

Methods:

Six cases were male patients, 5 between 15 and 19 years old, presenting with nasal obstruction and epistaxis and proptosis. One of them was an aggressive recurrent tumor in a 32-year-old patient. They were scheduled for combined approaches with assistance of image-guided endoscopic surgery.

Results:

Six cases underwent combined transnasal, tramaxillary, and craniotomy approaches with assistance of image-guided endoscopic surgery. Craniotomy preceded rhinologic approach in 3. CSF leak and skull base defect was repaired by temporalis muscle flap and pericranial flap in 4 and fascia lata in 2. One postoperative leak was repaired with fascia lata transcranially. Otherwise the course was uneventful in all cases.

Conclusions:

The intradural intracranial extensions of angiofibroma require meticulous approach in terms of surgery because of their greater risk for complications during the dissection. Carotid rupture and brain damage are 2 catastrophic complications which should be kept in mind. In cases with extensive intradural involvement of the middle cranial fossa by angiofibroma, craniotomy with intradural approach could help to decrease complications.

Effect of thermal interface on heat flow in carbon nanofiber composites

The thermal transport process in carbon nanofiber (CNF)/epoxy composites is addressed through combined micromechanics and finite element modeling, guided by experiments. The heat exchange between CNF constituents and matrix is studied by explicitly accounting for interface thermal resistance between the CNFs and the epoxy matrix. The effects of nanofiber orientation and discontinuity on heat flow and thermal conductivity of nanocomposites are investigated through simulation of the laser flash experiment technique and Fourier's model of heat conduction. Our results indicate that when continuous CNFs are misoriented with respect to the average temperature gradient, the presence of interfacial resistance does not affect the thermal conductivity of the nanocomposites, as most of the heat flow will be through CNFs; however, interface thermal resistance can significantly alter the patterns of heat flow within the nanocomposite. It was found that very high interface resistance leads to heat entrapment at the interface near to the heat source, which can promote interface thermal degradation. The magnitude of heat entrapment, quantified via the peak transient temperature rise at the interface, in the case of high thermal resistance interfaces becomes an order of magnitude more intense as compared to the case of low thermal resistance interfaces. Moreover, high interface thermal resistance in the case of discontinuous fibers leads to a nearly complete thermal isolation of the fibers from the matrix, which will marginalize the contribution of the CNF thermal conductivity to the heat transfer in the composite.

Effect of twist and porosity on the electrical conductivity of carbon nanofiber yarns

This study focuses on the effect of twist and porosity on the electrical conductivity of carbon nanofiber (CNF) yarns. The process of fabrication of CNF yarns included the synthesis of aligned ribbons of polyacrylonitrile (PAN) nanofibers via electrospinning. The PAN ribbons were twisted into yarns with twist levels ranging from zero twist to high twists of 1300 turn per meter (tpm). The twist imposed on the ribbons substantially improved the interactions between nanofibers and reduced the porosity. The PAN yarns were subsequently stabilized in air, and then carbonized in nitrogen at 1100 °C for 1 h. Compressive stresses developed between the PAN nanofibers as a result of twist promoted interfusion between neighboring nanofibers, which was accelerated by heating the yarns during stabilization to temperatures above the glass transition of PAN. The electrical conductivity of the yarns was measured with a four point probe measurement technique. Although increasing the twist promotes electrical conductivity between nanofibers by forming junctions between them, our results indicate that the electrical conductivity does not continuously increase with increasing twist, but reaches a threshold value after which it starts to decrease. The causes for this behavior were studied through experimental techniques and further explored using a yarn-equivalent electrical circuit model.

Are Those Who Seek Rhinoplasty Really More Depressed?

Objective: 1) To study whether the prevalence of depression in rhinoplasty candidates is more than the patients of non-cosmetic surgeries. 2) To define the importance of depression screening as a factor in rhinoplasty patient selection.

Method: The Beck depression inventory has been used to screen the state of depression in both patients seeking rhinoplasty and those who were supposed to undertake routine non-cosmetic otorhinolaryngologic surgeries in the same hospital. 45 patients in each group were evaluated, and the results were analyzed through chi-square and Student t tests.

Results: Overall 54.4% of patients were female and 45.6% were male, among which 62% of females were in the rhinoplasty group (p:0.02). The mean age in the rhinoplasty group was at least 1 decade younger than the patients undertaking non-cosmetic surgeries (24.89 vs 36.27). Six rhinoplasty patients and 3 non-cosmetic surgery patients were categorized in the mild depression group ( P: 0.39). None of the patients seeking rhinoplasty were scored as having moderate and severe depression, while 2 patients of noncosmetic surgeries were categorized in these groups.

Conclusion: Despite the existing social image of a large prevalence of depressive symptoms in rhinoplasty seekers, which would lead to the terms of concern about the operation result, patients undertaking rhinoplasty, both males and females, seem to be as depressed as other patients of the same socioeconomic status.

Quality of life comparison in common rhinologic surgeries

Various questionnaires are used in patients who undergo rhinologic surgeries but a unique comprehensive questionnaire is needed to evaluate quality of life (QOL) in rhinologic surgeries. The purpose of this study was to prepare a comprehensive questionnaire and compare QOL among four common rhinologic surgeries including functional endoscopic sinus surgery, septoplasty, septorhinoplasty, and septoplasty with turbinoplasty preoperatively and 6 months postoperatively. This was a prospective interventional before-and-after study. Preoperative and 6 months postoperative evaluations were performed with a Modified Health-Related Quality of Life (HRQL) questionnaire designed to cover all needed QOL aspects and the 22-item Sino-nasal Outcome Test questionnaire to cover all needed QOL aspects. The Modified HRQL included 33 items in six subgroups (nasal symptoms, sleep problems, headache, nonnasal symptoms, and practical and emotional problems) and general feeling. From 202 patients who completed the questionnaire before the procedures, 146 (72% of all patients) who were interviewed 6 months postoperatively were included in this study. Comparing preoperative data between followed up patients and missed patients showed no statistical difference among surgeries (p = 0.90). Comparison of patient's pre- and postoperative QOL showed a significant improvement in global QOL and in all questionnaire items (p < 0.0001 in all comparisons). Comparison of QOL changes before and after surgery among different surgeries revealed no statistical difference (p = 0.282). Our data showed a significant improvement in each surgery but the amount of improvement in different surgeries was almost constant.

Tension pneumocephalus: a life-threatening complication of septoplasty and septorhinoplasty

PROBLEMS/ OBJECTIVES: Septoplasty and septorhinoplasty are two important surgical operations in otorhinolaryngology. Tension pneumocephalus is a rare, but potentially fatal, intracranial complication of these operations.

METHODOLOGY

We present two cases of tension pneumocephalus following nasal surgery. Both patients had tension pneumocephalus, meningitis, and defects in the skull base.

RESULTS

One patient underwent endoscopic repair of the defect, while the second case expired despite medical and neurosurgical management.

Association between the functional polymorphism C-159T in the CD14 promoter gene and nasal polyposis: potential role in asthma

BACKGROUND

Nasal polyposis (NP) is a chronic inflammatory disease that is frequently associated with allergy and asthma. Corticosteroid therapy and surgical removal of polyps are the 2 most common treatment strategies for NP. Various allergic and inflammatory mediators are thought to play a major role in the pathophysiology of this disorder. The CD14 gene is located on chromosome 5q31-32, which is considered a critical region for several allergic and atopic diseases, including asthma. Consequently, variations in CD14 could have functional effects on the etiology and severity of allergy and asthma. The aim of this study was to investigate the association between the polymorphism C-159T in the CD14 gene of patients with NP and controls.

METHODS

The study population comprised 106 patients with NP diagnosed based on computed tomography scan of the paranasal sinus, endoscopy, and histological examination. Findings were compared with those from 87 controls. The frequency of C-159T was determined using polymerase chain reaction-restriction fragment length polymorphism analysis. DNA was extracted using the salting out technique.

RESULTS

A significant association was observed between C-159T and NP (P = .04). Patients with the CC genotype at position -159 of the CD14 promoter region had an increased risk of asthma (OR, 3.83, 95% CI, 0.99-13.91; P < .02). However, we did not find an association between the distribution of C-159T and serum immunoglobulin E level.

CONCLUSIONS

A genetic variation in the CD14 promoter might play a role in the pathogenesis of NP and in the incidence of asthma.

Endonasal endoscopic dacryocystorhinostomy: how to achieve optimal results with simple punch technique

Endonasal endoscopic dacryocystorhinostomy (EEDCR) has been popularized as a minimally invasive technique. Although preliminary reports revealed less success in comparison with external approaches, recent endonasal endoscopic surgeries on various types of DCR have preserved advantages of this technique while diminishing the failures. We described our experience on EEDCR, including the main advantages and disadvantages of it. Hundred consecutive cases of lachrymal problems underwent EEDCR utilizing simple punch removal of bone, instead of powered instrumentation or lasers. The medial aspect of the sac was removed in all of patients, while preserving normal mucosa around the sac. Hundred cases of EEDCR were performed on 81 patients, with 19 bilateral procedures. Nine procedures were performed under local anesthesia. Based on a mean 14 months follow-up, 95 cases were free of symptoms, revealing 95% success rate. The punch technique diminishes the expenses of powered or laser instrumentation with comparable results. It seems that preserving normal tissues and creating a patent rhinostomy with least surgical trauma and less subsequent scar, plays the most important role in achieving desirable results.

Regression of Polypoid Nasal Mucosa after Systemic Corticosteroid Therapy: A Proteomics Study

Background

Nasal polyposis (NP) treatment and pathophysiology have always been challenging for otolaryngologists. Among the medical treatments for NP, glucocorticoids (GCs) have been always one of the mainstays but the mechanisms of their action are not well defined. Identifying and comparing the protein profile of chronic rhinosinusitis (CRS) with NP before and after treatment with GCs can help to clarify NP pathogenesis and mechanisms of corticosteroid effects on NP.

Methods

Samples of nasal polyps were taken from selected NP patients in workup for endoscopic sinus surgery. None of the patients used local or systemic GCs within 30 days before the sampling. The patients were given prednisone, 30 mg/day, for 4 days before the surgery to shrink the NP tissue. Nasal polyp samples were collected during surgery. Proteins from samples were extracted and separated by immobilized pH gradient–based two-dimensional difference gel electrophoresis (2D DIGE). Resulting 2D-gel images were statistically analyzed using Delta2D software and differently expressed protein spots were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Results

A reference map of 1963 proteins could be established. Expression of 20 proteins changed significantly (twofold, p < 0.05) after treatment of NP with GCs. Heat shock proteins and retinoic acid were induced by GCs. Ingenuity pathway analysis of all identified proteins indicated that apoptosis pathway is triggered in NP after GC administration.

Conclusion

Identifying the changes of NP proteome due to GCs and the biological functions of proteins can lead to new ways of treatment and open new fields in NP research.

Nitric oxide metabolites as biomarkers for follow-up after chronic rhinosinusitis surgery

BACKGROUND

Nitric oxide (NO) has a variety of effects on the pathophysiology of the nasal cavity and seems to play an important role in inflammation. It is increased in the common cold but decreased in acute and chronic rhinosinusitis (CRS). Exhaled NO increases after endoscopic sinus surgery in CRS. In our previous study we showed that NO metabolite (nitrate and nitrite) levels are increased in the sinus cavity of CRS patients. We hypothesized that NO metabolite levels are increased to normal in the nasal lavage of CRS patients after endoscopic sinus surgery and NO metabolites in the nasal lavage can be used as indicators of the disease status after surgery.

METHODS

This study was performed on 52 patients with CRS who did not respond to medical therapy and who underwent surgery. NO metabolite levels were measured in nasal lavages of the patients before surgery and 2 months after surgery.

RESULTS

NO metabolite levels (mean +/- SEM) were 18.11 +/- 3.08 micromol/L and 35.97 +/- 4.64 micromol/L in nasal lavages of patients before and after surgery, respectively. The levels of NO metabolites were increased significantly (p < 0.01) after surgery in nasal lavages and patients reported significant improvement based on the visual analog scoring after the operation.

CONCLUSION

NO metabolite levels were decreased in nasal lavages of CRS patients and were increased to normal levels after surgery along with improvement of the disease. NO metabolite levels may be used as an indicator for the follow-up of patients after endoscopic sinus surgery.

Immunologic evaluation of patients with recurrent ear, nose, and throat infections

PURPOSE

In this study, we aimed to study the frequency of possible underlying immunodeficiency responsible for susceptibility to ear, nose, and throat (ENT) infection.

MATERIALS AND METHODS

One hundred three (72 males and 31 females) consecutive children and adult patients with history of recurrent or chronic ENT infections, referred by otolaryngologists to the Department of Allergy and Clinical Immunology, Children's Medical Center, Tehran University of Medical Sciences (Tehran, Iran), were enrolled to the study from March 2003 to March 2006. For each patient, demographic information and medical histories of any ENT infections were collected by reviewing the patient's records. We measured immunoglobulin isotype concentrations and immunoglobulin (Ig) G subclasses by nephelometry and enzyme-linked immunosorbent assay methods, respectively. Of 103 patients, 75 received unconjugated pneumococcus polyvalent vaccine, and blood samples were taken before and 21 days after vaccination. Specific antibodies against whole pneumococcal antigens were measured using enzyme-linked immunosorbent assay method. Existence of bronchiectasis was confirmed in each patient using high resolution computed tomography scan.

RESULTS

Among 103 patients, 17 (16.5%) patients were diagnosed to have defects in antibody-mediated immunity including 6 patients with immunoglobulin class deficiency (2 common variable deficiency and 4 IgA deficiency), 3 with IgG subclass deficiency (2 IgG2 and 1 IgG3), and 8 with specific antibody deficiency against polysaccharide antigens. In our series, bronchiectasis was detected in 5 cases associated with primary immunodeficiency.

CONCLUSIONS

Long-standing history of ENT infections could be an alarm for ENT infections associated with primary antibody deficiency.

Nitric oxide: a new concept in chronic sinusitis pathogenesis

PURPOSE

Exhaled NO is produced mainly in paranasal sinuses and nasal mucosa. Nasal NO has been suggested to have a variety of effects in nasal cavity. Decreased exhaled NO is found in chronic sinusitis, and NO metabolite levels are increased in animal models of chronic sinusitis, suggesting a role for them in sinusitis pathogenesis. There was no data available on human NO metabolite level.

MATERIALS AND METHODS

We lavaged maxillary sinuses in a control and 2 patient groups. The control group was patients who underwent functional endoscopic sinus surgery (FESS) due to any other reason than chronic sinusitis. The patient groups had chronic rhinosinusitis with and without polyposis who underwent FESS. Maxillary sinuses were lavaged during FESS, and NO metabolites (nitrate and nitrite) were lavaged in the lavage fluid.

RESULTS

Nitric oxide metabolite levels (mean +/- SEM) were 8.085 +/- 1.43 mumol/L in healthy maxillary sinus lavage fluid and 18.04 +/- 3.51 and 16.78 +/- 2.91 mumol/L in chronic rhinosinusitis with and without polyposis, respectively. Lavage fluid of sinuses with chronic sinusitis had elevated levels of NO metabolites, which were significantly higher than the control group. The difference between the chronic sinusitis with and without polyposis groups was not significant.

CONCLUSIONS

Nitric oxide metabolites were significantly higher in maxillary sinuses of patients with chronic sinusitis. Elevated levels of NO and NO metabolites in sinusitis might damage healthy sinus epithelium. NO metabolites may have an important role in sinusitis pathogenesis.

Endonasal endoscopic resection of ethmoido-orbital osteoma compressing the optic nerve

Osteomas are the most common benign tumors of the paranasal sinuses. Open procedures for removal of ethmoid osteomas have been the method of choice, but debate over optimal treatment continues. We report resection of a large ethmoido-orbital osteoma via endonasal endoscopic approach with minimal morbidity. A 42-year-old man presented with a 1-year history of slowly progressive proptosis and lateral gaze diplopia. Imaging studies of orbits and sinuses revealed a large bony mass in left ethmoid sinus extending into the left orbit. The mass had compressed and slightly diverted the optic nerve. The patient had also bilateral extensive polyposis for which bilateral ethmoidectomy and sphenoidotomy were performed. Using a curved blunt elevator, the osteoma was gently and meticulously detached from adjacent structures. Finally, frontal recesses were cleaned form the polyps. The postoperative period was uneventful. After 18 months, he is still free of symptoms. The previously used management modality of symptomatic osteomas has mostly consisted of open approaches. Endonasal endoscopic approach provides a safe and effective alternative to open approaches, offering cosmetic advantages and lowering the morbidity. This approach could be judiciously used in large ethmoido-orbital osteomas in selected cases.

Endoscopic resection of nasopharyngeal angiofibromas by combined transnasal and transoral routes

PURPOSE

To determine the role of endoscopic surgery in decreasing intraoperative bleeding, morbidity, and hospitalization period of juvenile nasopharyngeal angiofibroma resection and to describe combined endoscopic transnasal and transoral approaches.

PATIENTS AND METHODS

Twelve cases of juvenile nasopharyngeal angiofibroma diagnosed by endoscopic examination, computed tomography, and angiography were selected for endoscopic resection. Tumor staging ranged from stage I(A) to II(B). Ten patients underwent preoperative selective arterial embolization, and in 1 case selective arterial ligation was used. In general, the tumors were approached endoscopically through nasal and oral cavities with 0 degrees and 30 degrees 4-mm telescopes without any incision and no packing at their termination.

RESULTS

The patients were followed by endoscopy and computed tomography. There was a dramatic decrease in intraoperative bleeding and postoperative morbidity. No early postoperative complications were seen. Two recurrences were observed in 12 patients up to a mean follow-up of 15 months.

CONCLUSIONS

Minimal bleeding, decreased morbidity, and shorter hospitalization period were the main reasons that prompted us to use endoscopic technique for the removal of juvenile nasopharyngeal angiofibroma. Adding transoral endoscopic approach to the transnasal endoscopic approach provides 2-sided exposure and appreciate access to angiofibroma.

Endonasal endoscopic treatment of medial orbital wall fracture via rotational repositioning

Various surgical approaches have been employed to treat the medial orbital wall fracture. It has been necessary to use grafts or splints in these approaches. We introduced a new technique to treat our patient with diplopia resulting from medial orbital fracture. In this new method, rotational repositioning of the fractured segment eliminates the use of any graft or synthetic material in the nose, ethmoid sinuses, or the orbit. The procedure could be done under local anesthesia, which facilitates intraoperative monitoring of the ocular movements to evaluate improvement of diplopia. Rotational repositioning technique could be an effective alternative method to previous approaches in treatment of selected medial orbital wall fractures.

Endonasal endoscopic treatment of parasellar arachnoid cyst: report of a case

A 40-year-old man presented with intractable headache of 5-year duration and a 1-month history of intermittent cerebrospinal fluid (CSF) rhinorrhea. Magnetic resonance imaging showed a cystic lesion with signal characteristics similar to that of CSF. The patient underwent endonasal endoscopic surgery of the sphenoid sinus and the fistula was reinforced with facia, muscle cartilage, and posterior septal flap while performing cystocisternostomy. The postoperative course was uneventfiul CSF leakage stopped, and headache improved. Postoperative imaging revealed total collapse of the cyst cavity. Based on our findings, endonasal endoscopic treatment of the sellar and parasellar arachnoid cysts, if presenting into the sphenoid sinus, could be an acceptable minimally invasive alternative to the conventional modalities.

Two-dimensional determination of the cellular Ca2+ binding in bovine chromaffin cells

The spatiotemporal profile of intracellular calcium signals is determined by the flux of calcium ions across different biological membranes as well as by the diffusional mobility of calcium and different calcium buffers in the cell. To arrive at a quantitative understanding of the determinants of these signals, one needs to dissociate the flux contribution from the redistribution and buffering of calcium. Since the cytosol can be heterogeneous with respect to its calcium buffering property, it is essential to assess this property in a spatially resolved manner. In this paper we report on two different methods to estimate the cellular calcium binding of bovine adrenal chromaffin cells. In the first method, we use voltage-dependent calcium channels as a source to generate calcium gradients in the cytosol. Using imaging techniques, we monitor the dissipation of these gradients to estimate local apparent calcium diffusion coefficients and, from these, local calcium binding ratios. This approach requires a very high signal-to-noise ratio of the calcium measurement and can be used when well-defined calcium gradients can be generated throughout the cell. In the second method, we overcome these problems by using calcium-loaded DM-nitrophen as a light-dependent calcium source to homogeneously and quantitatively release calcium in the cytosol. By measuring [Ca2+] directly before and after the photorelease process and knowing the total amount of calcium being released photolytically, we get an estimate of the fraction of calcium ions which does not appear as free calcium and hence must be bound to either the indicator dye or the endogenous calcium buffer. This finally results in a two-dimensional map of the distribution of the immobile endogenous calcium buffer. We did not observe significant variations of the cellular calcium binding at a spatial resolution of approximately 2 micron. Furthermore, the calcium binding is not reduced by increasing the resting [Ca2+] to levels as high as 1.1 microM. This is indicative of a low calcium affinity of the corresponding buffers and is in agreement with a recent report on the affinity of these buffers (Xu, T., M. Naraghi, H. Kang, and E. Neher. 1997. Biophys. J. 73:532-545). In contrast to the homogeneous distribution of the calcium buffers, the apparant calcium diffusion coefficient did show inhomogeneities, which can be attributed to restricted diffusion at the nuclear envelope and to rim effects at the cell membrane.

Two dye two wavelength excitation calcium imaging: results from bovine adrenal chromaffin cells

We tested a mixture of Calcium-Green-1 (CG-1) and Brilliantsulfaflavine (BS) for dual excitation ratiometric measurements of the intracellular free calcium concentration ([Ca2+]i) in bovine adrenal chromaffin cells. Dyes were coloaded (without being molecularly linked to each other) in the whole-cell configuration of the patch clamp technique. We compared the loading time-courses of CG-1 and BS, investigated their intracellular distribution patterns and studied the time course of photobleaching. We determined the apparent dissociation constant of CG-1, both optically and by potentiometric titration. Our findings indicate that: (i) with excitation at 420/488 nm, calibrated fluorescence signals could be derived using a Grynkiewicz-type equation; (ii) BS is an ideal reference dye that displayed no interaction with CG-1 or cellular constituents; and (iii) that calibration requires diffusional equilibration between pipette and the accessible volume of the cell. Spatially resolved recordings of fluorescence excitation spectra revealed elevated fluorescence of CG-1 in the nucleus such that reported [Ca2+]i levels seemed 25% higher compared to cytosolic values. Comparing fluorescence emission from in vitro dye solutions with in vivo values, we could estimate the accessible volume fraction and amount of Ca(2+)-insensitive dye.

T-jump study of calcium binding kinetics of calcium chelators

Recent experimental studies have investigated the kinetic competition between calcium chelators and the secretion apparatus at a fast central synapse. Simultaneously, mathematical modelling studies indicate the importance of a quantitative knowledge of the binding kinetics of the chelators in studying fast physiological processes operating on a millisecond time scale. Using the temperature-jump relaxation method, I have studied the in vitro kinetics of Bis-Fura-2, Furaptra, Fluo-3, Calcium-Green-1, Calcium-Green-5N, Calcium-Orange-5N as well as EGTA, BAPTA and H-EDTA in conditions which are identical to those implemented in our patch clamp recordings, i.e. 100-140 mM CsCl, 20-40 mM Cs-HEPES, 8 mM NaCl, pH = 7.2 at 22 degrees C. The results can be summarized as follows: all fluorescent indicators have on rates in the range of 10(8)-10(9) M-1s-1. They differ significantly with respect to their off-rates from each other according to their affinities, ranging from 100 s-1 up to 26,000 s-1. BAPTA is kinetically almost indistinguishable from Fura-2. EGTA and H-EDTA have small binding rate constants for calcium in the range of 3 x 10(6) M-1s-1 since, at pH 7.20, protons need to be dissociated from the chelators before they can bind calcium ions.

Linearized buffered Ca2+ diffusion in microdomains and its implications for calculation of [Ca2+] at the mouth of a calcium channel

Immobile and mobile calcium buffers shape the calcium signal close to a channel by reducing and localizing the transient calcium increase to physiological compartments. In this paper, we focus on the impact of mobile buffers in shaping steady-state calcium gradients in the vicinity of an open channel, i.e. within its "calcium microdomain." We present a linear approximation of the combined reaction-diffusion problem, which can be solved explicitly and accounts for an arbitrary number of calcium buffers, either endogenous or added exogenously. It is valid for small saturation levels of the present buffers and shows that within a few hundred nanometers from the channel, standing calcium gradients develop in hundreds of microseconds after channel opening. It is shown that every buffer can be assigned a uniquely defined length-constant as a measure of its capability to buffer calcium close to the channel. The length-constant clarifies intuitively the significance of buffer binding and unbinding kinetics for understanding local calcium signals. Hence, we examine the parameters shaping these steady-state gradients. The model can be used to check the expected influence of single channel calcium microdomains on physiological processes such as excitation-secretion coupling or excitation-contraction coupling and to explore the differential effect of kinetic buffer parameters on the shape of these microdomains.

Kinetic studies of Ca2+ binding and Ca2+ clearance in the cytosol of adrenal chromaffin cells

The Ca2+ binding kinetics of fura-2, DM-nitrophen, and the endogenous Ca2+ buffer, which determine the time course of Ca2+ changes after photolysis of DM-nitrophen, were studied in bovine chromaffin cells. The in vivo Ca2+ association rate constants of fura-2, DM-nitrophen, and the endogenous Ca2+ buffer were measured to be 5.17 x 10(8) M-1 s-1, 3.5 x 10(7) M-1 s-1, and 1.07 x 10(8) M-1 s-1, respectively. The endogenous Ca2+ buffer appeared to have a low affinity for Ca2+ with a dissociation constant around 100 microM. A fast Ca2+ uptake mechanism was also found to play a dominant role in the clearance of Ca2+ after flashes at high intracellular free Ca2+ concentrations ([Ca2+]), causing a fast [Ca2+]i decay within seconds. This Ca2+ clearance was identified as mitochondrial Ca2+ uptake. Its uptake kinetics were studied by analyzing the Ca2+ decay at high [Ca2+]i after flash photolysis of DM-nitrophen. The capacity of the mitochondrial uptake corresponds to a total cytosolic Ca2+ load of approximately 1 mM.

Effect of esmolol given during cardiopulmonary bypass on fractional area of contraction from transesophageal echocardiography

The infusion of esmolol during hypothermic cardiopulmonary bypass (CPB) has no negative myocardial effects after CPB, despite increased esmolol levels during CPB due to hypothermia. The purpose of this randomized, double-blind, prospective study was to measure the effects of esmolol infused during CPB on cardiac function as measured by calculated indices of cardiac work and by transesophageal echocardiography (TEE). Patients scheduled for CPB were randomized to receive intravenous esmolol (300 micrograms.kg-1.min-1 during CPB after bolus of 2 mg/kg prior to CPB) or placebo. Infusion was stopped at 10 min after release of aortic cross-clamp. Hemodynamics and TEE were recorded during the procedure. Fractional area of contraction (FAC), an approximation of left ventricular ejection fraction, was calculated from end-diastolic and end-systolic areas. Esmolol was administered to 15 patients and placebo to 14. Heart rates in the esmolol group were lower during infusion and prior to CPB (P < 0.05). Stroke volume index and left ventricular stroke work index were higher in the esmolol group at 15 min post-CPB (P < 0.05). FAC was higher in the esmolol group at 15 and 30 min post-CPB (P < 0.05), but no difference was observed between groups at 1 h post-CPB. Esmolol infused during CPB in this series of patients was associated with better left ventricular function during the first 0.5 h post-CPB.

Leak rate of latex gloves after tearing adhesive tape

Anesthesiologists use latex gloves to provide barrier protection against infectious disease or contamination while providing anesthetic services. The performance of these services often involves tearing tape. The purpose of this study was to test the effect of tearing adhesive tape on permeability of latex examination gloves and to test the effect of an adhesive-sparing moisturizing cream on permeability of latex gloves used to tear adhesive tape. In a blinded, randomized, controlled laboratory experiment, 48 nonsterile latex examination gloves (24 pairs) were randomized to 1 of 2 groups. Adhesive-sparing moisturizing cream, 0.1 mL, was applied to 12 glove pairs; the remaining 12 pairs served as controls. Each of the 24 pairs of gloves were used to tear five 4-cm strips of cloth adhesive tape from a standard 1 1/2-inch roll. After initial inspection for obvious tears, each glove was tested for leaks using the watertight test as specified by the American Society for Testing and Materials (ASTM). Data recorded included the identity of the investigator tearing tape, number of holes initially observed, number of holes observed from the ASTM test, location of holes, glove classification as right or left hand, and treatment group. Based on the study, the authors concluded that health care providers who tear adhesive tape while wearing latex gloves should be aware that there is a high probability that the gloves no longer form a protective barrier and that adhesive-sparing moisturizing cream applied before tape is torn increases barrier protection.

Treatment of the cutaneous pain of acute herpes zoster with 9% lidocaine (base) in petrolatum/paraffin ointment

BACKGROUND

Treatment of the pain of acute herpes zoster by local anesthetic injections has drawbacks. Topical percutaneous local anesthesia (TPLA) may offer another strategy of providing regional analgesia in affected patients.

OBJECTIVE

We evaluate the analgesic efficacy and safety of 9% (wt/vol) lidocaine (base) in petrolatum/paraffin ointment in patients with acute herpes zoster.

METHODS

Ointment was applied to the affected skin of 22 patients. Pain, tenderness, sensitivity to pinprick and cold, and blood lidocaine concentration were measured repeatedly during a 20-hour interval and intermittently thereafter.

RESULTS

Mean pain, tenderness, and cutaneous sensation scores were reduced at measurements taken from 4 to 20 hours after ointment application (p < 0.05), but not every patient obtained relief. No patient had local skin irritation or systemic toxic effects related to the local anesthetic.

CONCLUSIONS

TPLA is a promising therapy for control of cutaneous pain of acute herpes zoster. Controlled studies should be performed to prove efficacy, determine optimal TPLA formulation, and define dosage limits.

Odorant-induced oscillations in the mushroom bodies of the locust

Kenyon cells are the intrinsic interneurons of the mushroom bodies in the insect brain, a center for olfactory and multimodal processing and associative learning. These neurons are small (3-8 microns soma diameter) and numerous (340,000 and 400,000 in the bee and cockroach brains, respectively). In Drosophila, Kenyon cells are the dominant site of expression of the dunce, DC0, and rutabaga gene products, enzymes in the cAMP cascade whose absence leads to specific defects in olfactory learning. In honeybees, the volume of the mushroom body neurophils may depend on the age or social status of the individual. Although the anatomy of these neurons has been known for nearly a century, their physiological properties and the principles of information processing in the circuits that they form are totally unknown. This article provides a first such characterization. The activity of Kenyon cells was recorded in vivo from locust brains with intracellular and local field potential electrodes during olfactory processing. Kenyon cells had a high input impedance (approximately 1 G omega at the soma). They produced action potentials upon depolarization, and consistently showed spike adaptation during long depolarizing current pulses. They generally displayed a low resting level of spike activity in the absence of sensory stimulation, despite a large background of spontaneous synaptic activity, and showed no intrinsic bursting behavior. Presentation of an airborne odor, but not air alone, to an antenna evoked spatially coherent field potential oscillations in the ipsilateral mushroom body, with a frequency of approximately 20 Hz. The frequency of these oscillations was independent of the nature of the odorant. Short bouts of oscillations sometimes occurred spontaneously, that is, in the absence of odorant stimulation. Autocorrelograms of the local field potentials in the absence of olfactory stimulation revealed small peaks at +/- 50 msec, suggesting an intrinsic tendency of the mushroom body networks to oscillate at 20 Hz. Such oscillatory behavior could not be seen from local field potential recordings in the antennal lobes, and may thus be generated in the mushroom body, or via feedback interactions with downstream neurons in the protocerebrum. During the odor-induced oscillations, the membrane potential of Kenyon cells oscillated around the resting level, under the influence of excitatory inputs phase-locked to the field activity. Each phasic wave of depolarization in a Kenyon cell could be amplified by intrinsic excitable properties of the dendritic membrane, and sometimes led to one action potential, whose timing was phase-locked to the population oscillations.(ABSTRACT TRUNCATED AT 400 WORDS)

Outpatient spinal opiate analgesia: a case report

Outpatient spinal opiate analgesia for relief of cancer pain has been well-described in the literature. We report a case of a patient with metastatic disease who received epidural morphine using a subcutaneous epidural catheter via home injections. The patient and his family administered the medications. There are several options to choose from when using epidural morphine, and each patient's needs must be evaluated for the appropriate system.

Fatal cardiac perforation caused by the dilator of a central venous catheterization kit

We report a case of cardiac perforation and tamponade caused by the dilator of a central venous catheterization kit. Standards for dilator manufacture and guidelines for safe use of these instruments are suggested.

Elective transtracheal jet ventilation for bronchoscopic removal of tracheal foreign body

We have shown that transtracheal jet ventilation can be used safely and effectively when removing a foreign body from the airway. In some cases, it may be wise to choose this method of ventilation initially, thus avoiding the difficulties associated with more conventional modes of controlled ventilation. This is especially true when the potential for loss of the airway during the procedure is significant. This technique also allows the bronchoscopist the benefit of unimpeded access to the airway and adequate uninterrupted time for his operative procedure.