Human hnRNP Q re-localizes to cytoplasmic granules upon PMA, thapsigargin, arsenite and heat-shock treatments.

Eukaryotic gene expression is regulated on different levels ranging from pre-mRNA processing to translation. One of the most characterized families of RNA-binding proteins is the group of hnRNPs: heterogenous nuclear ribonucleoproteins. Members of this protein family play important roles in gene expression control and mRNAs metabolism. In the cytoplasm, several hnRNPs proteins are involved in RNA-related processes and they can be frequently found in two specialized structures, known as GW-bodies (GWbs), previously known as processing bodies: PBs, and stress granules, which may be formed in response to specific stimuli. GWbs have been early reported to be involved in the mRNA decay process, acting as a site of mRNA degradation. In a similar way, stress granules (SGs) have been described as cytoplasmic aggregates, which contain accumulated mRNAs in cells under stress conditions and present reduced or inhibited translation. Here, we characterized the hnRNP Q localization after different stress conditions. hnRNP Q is a predominantly nuclear protein that exhibits a modular organization and several RNA-related functions. Our data suggest that the nuclear localization of hnRNP Q might be modified after different treatments, such as: PMA, thapsigargin, arsenite and heat shock. Under different stress conditions, hnRNP Q can fully co-localize with the endoplasmatic reticulum specific chaperone, BiP. However, under stress, this protein only co-localizes partially with the proteins: GW182-GWbs marker protein and TIA-1 stress granule component.

Association of 3-methyleneindolenine, a toxic metabolite of 3-methylindole, with acute interstitial pneumonia in feedlot cattle.

OBJECTIVE: To compare concentrations of 3-methyleneindolenine (3MEIN) in lung tissues obtained from feedlot cattle that died as a result of acute interstitial pneumonia (AIP) and cattle that died as a result of other causes and to compare blood concentrations of 3MEIN in healthy feedlot cattle and feedlot cattle with AIP. STUDY POPULATION: Blood samples and lung tissues collected from 186 cattle housed in 14 feedlots in the western United States. PROCEDURE: Samples of lung tissues were collected during routine postmortem examination and submitted for histologic, microbiologic, and toxicologic examination. Blood samples were collected from cattle with clinical manifestations of AIP and healthy penmates. Histologic diagnoses were categorized as AIP, bronchopneumonia (BP), control samples, and other disorders. Concentrations of 3MEIN were determined in lung tissues and blood samples, using an ELISA. RESULTS: Concentrations of 3MEIN in lung tissues were significantly greater in AIP and BP samples, compared with control samples. Absorbance per microgram of protein did not differ between BP and AIP samples. Blood concentrations of 3MEIN were significantly greater in cattle with AIP, compared with healthy cattle or cattle with BP. Odds of an animal with AIP being a heifer was 3.1 times greater than the odds of that animal being a steer. CONCLUSIONS AND CLINICAL RELEVANCE: Increased pulmonary production of 3MEIN may be an important etiologic factor in feedlot-associated AIP.

Selective dehydrogenation/oxygenation of 3-methylindole by cytochrome p450 enzymes.

3-Methylindole (3 MI) is a selective pulmonary toxicant, and cytochrome P450 (P450) bioactivation of 3 MI, through hydroxylation, epoxidation, or dehydrogenation pathways, is a prerequisite for toxicity. CYP2F1 and CYP2F3 exclusively catalyze the dehydrogenation of 3 MI to 3-methyleneindolenine, without detectable formation of the hydroxylation or epoxidation products. It was not known whether 3 MI is simply an excellent dehydrogenation substrate for all P450 enzymes, or whether certain cytochrome P450s responsible for 3 MI bioactivation have unique active sites that only catalyze the dehydrogenation of the molecule, while other P450s would catalyze only the oxygenation of 3 MI. Therefore, the kinetics of product formation by the CYP2F1 and CYP2F3 enzymes were compared with other cytochrome P450 enzymes. The enzymes tested were CYP1A1, CYP1A2, CYP1B1, and CYP2E1. The CYP1A1 and CYP1A2 enzymes produced all three 3 MI metabolites: the dehydrogenation product, 3-methyleneindolenine (V(max)/K(m) = 4 and 22, respectively); the hydroxylation product, indole-3-carbinol (V(max)/K(m) = 42 and 100, respectively); and the epoxidation product, 3-methyloxindole (V(max)/K(m) = 4 and 72, respectively). These CYP1A enzymes catalyzed oxygenation of 3 MI at much faster rates than dehydrogenation. CYP1B1 produced indole-3-carbinol (V(max)/K(m) = 85) and 3-methyloxindole (V(max)/K(m) = 7), and CYP2E1 only produced 3-methyloxindole (V(max)/K(m) = 98), but neither enzyme catalyzed the formation of the dehydrogenated product. Six additional P450 enzymes that were tested formed none of the dehydrogenation product. The ability of the various CYP1 family enzymes to catalyze the formation of all three major 3 MI metabolites, along with the specific oxygenation by CYP2E1, illustrates that dehydrogenation of 3 MI is not a substrate-directed process, but that the members of the CYP2F family possess unique active sites that specifically catalyze only the dehydrogenation mechanism.

Clinically relevant frontal sinus anatomy and physiology.

Management of frontal sinus disease has evolved considerably with the advent of endoscopic paranasal sinus instrumentation. With this evolution has come the increased demand for anatomic competence among otolaryngologists. Armed with a better understanding of the complex frontal sinus and anterior ethmoid complex anatomy, the otolaryngologist can target the anatomic abnormalities that predispose an individual to frontal sinus disease and limit the effectiveness of medical and surgical management.

The five year experience with endoscopic trans-septal frontal sinusotomy.

Endoscopic trans-septal frontal sinusotomy (TSFS) represents a unique surgical approach to the floor of the frontal sinus. Although the final result can have similarities to the modified Lothrop procedure in that the intersinus septum may be drilled out, endoscopic TSFS represents a novel approach that can be valuable in patients with certain anatomic configurations. Endoscopic TSFS represents an alternate approach to the frontal sinus that may be used by the experienced endoscopist to augment treatment of refractory frontal sinus disease. This procedure is best considered for patients with favorable anatomy who have significant frontal sinus disease and cannot be managed adequately through an endoscopic frontal sinusotomy.

Benign lesions of the frontal sinus.

Benign tumors of the frontal sinus including fibro-osseous lesions and inverted papillomata present unique problems for the rhinologist. Because of the bony cavity surrounding the frontal sinus and relatively small portal into the nose, conventional techniques including the osteoplastic flap, frontal trephination, and lynch procedure have provided useful approaches to these tumors. The advent of endoscopic techniques in the management of chronic inflammatory disease of the paranasal and, specifically, frontal sinuses, has led to these traditional techniques being augmented successfully, and, in some cases, surpassed by newer endoscopic techniques. This article reviews the diagnosis and management of the two most common types of benign tumors of the frontal sinus, bony tumors and inverted papillomata, with emphasis on the usefulness of the endoscope in managing such lesions.

[Integration of new nurses in nursing units in a university hospital]. / L'intégration des nouvelles infirmières dans les unités de soins d'un hôpital universitaire.

The study presented in this article raises the problems of the integration of recently graduated nurses in the hospital from the point of view of a culture difference between the two socialisation worlds: more reflexive standards of behaviour and culture in the schools (emphasis on analysis, knowledge, care actions argumentation...) and more instrumental ones in the hospitals (emphasis on efficiency, work organisation, operationality...). An enquiry by means of interviews with recent graduates from different schools (open, semi-open and closed questions) enables to successively analyse the skills they consider to have acquired at school, the ones they consider as required by the hospital and the differences they feel between hospital and school concerning the enhanced skills. The results show a significant discrepancy between the ideal of the interviewed nurses and the reality of their work within the institutional constraints of the hospital.

Diagnosis and management of rhinosinusitis before scheduled immunosuppression: a schematic approach to the prevention of acute fungal rhinosinusitis.

Acute (invasive) fungal rhinosinusitis is an aggressive and potentially lethal complication of insulin dependent diabetes, as well as immunosuppression from chemotherapy and bone marrow transplant. The goal of this article is to describe methods to help with the diagnosis and treatment of sinusitis prior to developing this state of immune-compromise. This will help eliminate a significant risk factor for these patients that can lead to serious morbidity and ultimately mortality.

Applications of in situ hybridization techniques in the diagnosis of chronic sinusitis.

The clinical significance of positive bacterial cultures in chronic sinusitis is often difficult to assess. Contaminants from surface colonization of the sinus mucosa may be difficult to distinguish from true intramucosal or bone involvement. Furthermore, tissue Gram stains are frequently unable to demonstrate the presence of bacteria in tissue despite endoscopic evidence of active sinusitis. In situ hybridization (ISH) techniques using bacterial rRNA probes were applied to evaluate the presence of intramucosal and intraosseous bacteria in chronic sinusitis surgical specimens. A total of 22 specimens of chronically inflamed human ethmoid bone were evaluated by ISH and by Gram stain. In three specimens, ISH identified bacterial rRNA within sinus mucosa and mucin. Notably, in these three ISH-positive specimens, Gram stain was negative in two. No specimen showed evidence of bacterial rRNA within bone. These preliminary results suggest that in situ hybridization may be a useful adjunct to current methods of detecting microorganisms within chronically infected sinus tissue.

The forgotten turbinate: the role of the superior turbinate in endoscopic sinus surgery.

The fate of the middle turbinate in endoscopic sinus surgery has been a subject of debate for some time. The superior turbinate's role, however, has been largely passed over. Past anatomic descriptions and illustrations have given surgeons the incorrect impression that this structure is well superior and out of the field of dissection. Injury to the superior turbinate may account for postoperative hyposmia. The superior turbinate also serves as a constant landmark for the sphenoethmoidal recess, and a limited resection allows the surgeon to identify and include the natural ostium of the sphenoid sinus in the sphenoidotomy. The embryology and anatomy of the superior turbinate are reviewed. An approach to the natural ostium of the sphenoid sinus from the lateral side of the middle turbinate, using the superior turbinate as a guide, is described.

Endoscopically assisted anterior cranial skull base resection of sinonasal tumors.

The traditional approach to sinonasal tumors involving the base of skull has been the anterior craniofacial resection. Endoscopic techniques have created the potential to approach the intranasal aspect of skull base lesions without external incisions and still develop an en bloc resection when removed. We report our initial experience with skull base neoplasms in which the otolaryngic portion of the standard resection was accomplished instead through an endoscopic approach. The nature of lesions favorable for this approach and associated technical issues are discussed. Although we do not consider this approach a replacement for the traditional anterior craniofacial resection, it is an important adjunct in the skull base surgeon's armamentarium.

Endoscopic trans-septal frontal sinusotomy: the rationale and results of an alternative technique.

Endoscopic transseptal frontal sinusotomy (TSFS) represents an alternate approach to surgical treatment of chronic frontal sinus disease that is refractory to traditional modes of medical and surgical therapy. We retrospectively reviewed our experience with endoscopic TSFS from 1995-1997. Twenty-one procedures were performed through a transseptal approach. One patient was excluded for failure to follow-up, for a total of 20 procedures. Patients were followed with serial endoscopic examinations and a telephone questionnaire with a mean follow-up of 12 months (Range 1-24 months) and 16 months (range 5-31), respectively. The primary indication for surgery was frontal recess stenosis after previous endoscopic frontal sinusotomy in 17/20 (85%). Three patients were considered poor candidates for a primary endoscopic frontal sinusotomy. Patency was maintained in all patients during the follow-up period. A diameter of greater than 3 mm was confirmed by passage of a curved suction in 19/20 (95%). Of the 19 patients that were evaluated via a telephone questionnaire, 17 patients (89.5%) reported some degree of improvement in their nasal/sinus symptoms, and 12/18 patients (67%) felt the frequency of medication requirements was less than that before undergoing endoscopic TSFS. We conclude that endoscopic TSFS represents an alternate approach to the frontal sinus that may be used by the experienced endoscopist, to augment treatment of refractory frontal sinus disease. This procedure seems especially suited for revision surgery in those patients with acquired frontal sinus stenosis. In revision operations with distorted anatomical landmarks, localization of the frontal sinus may be improved with the aid of 3-dimensional computer assisted localization systems. Unlike traditional frontal sinus obliteration, endoscopic TSFS does not preclude radiographic assessment postoperatively, and allows for endoscopic evaluation of the frontal sinus in the office setting.

Long-term impact of functional endoscopic sinus surgery on asthma.

Using objective and subjective criteria, we performed a study to assess the long-term impact of functional endoscopic sinus surgery (FESS) in patients with chronic rhinosinusitis and asthma at an average follow-up of 6.5 years. One hundred twenty patients who underwent FESS for chronic rhinosinusitis were followed up for an average of 6.5 years (range 6.0 to 10.6 years). Seventy-two (60%) patients responded to a follow-up questionnaire, and 30 (42%) of them reported a history of asthma. Subjective levels of improvement and assessments of medication need were evaluated and statistically assessed with parametric and nonparametric methods. Of these 30 patients, 27 (90%) reported that their asthma was better than it had been before FESS, 6.5 years ago. Average reported improvement increased from 49% at 1.1 years after surgery to 65% at 6.5 years after surgery. Asthma attacks declined in 20 of 27 (74.1%). Medication use for asthma showed similar improvement, with approximately half reporting less inhaler usage and nearly two thirds reporting less oral steroid use. This study demonstrates that a combination of FESS, careful postoperative care, and appropriate medical therapy for chronic rhinosinusitis has a favorable long-term effect on asthma in patients with symptomatic chronic sinusitis. In this study asthma severity, frequency of attacks, and medication need were all improved.

The nasal airway and obstructed breathing during sleep.

Nasal obstruction whether partial or complete can influence the quality of sleep and has been strongly linked to the genesis of obstructed breathing during sleep (OBS). The relationship between nasal airflow and the process of upper airway collapse is complex. The first part of this article reviews the nasal anatomy with an emphasis on the sites of nasal obstruction, the effect of the nasal reflexes on the pulmonary system, and the pathophysiology of the development of OBS. The second part reviews the common causes of increased nasal resistance, the assessment of nasal passages, and the treatment options. This article also includes literature in support of and refuting the postulated mechanisms by which nasal obstruction can effect the respiratory system during sleep.

Specific dehydrogenation of 3-methylindole and epoxidation of naphthalene by recombinant human CYP2F1 expressed in lymphoblastoid cells.

3-Methylindole (3MI) is a naturally occurring pulmonary toxin that requires metabolic activation. Previous studies have shown that 3MI-induced pneumotoxicity resulted from cytochrome P-450-catalyzed dehydrogenation of 3MI to an electrophilic methylene imine (3-methyleneindolenine), which covalently bound to cellular macromolecules. Multiple cytochrome P-450s are capable of metabolizing 3MI to several different metabolites, including oxygenated products. In the present study, the role of human CYP2F1 in the metabolism of 3MI was examined to determine whether it catalyzes dehydrogenation rather than hydroxylation or ring oxidation. Metabolism was examined using microsomal fractions from human lymphoblastoid cells that expressed the recombinant human CYP2F1 P-450 enzyme. Expression of CYP2F1 in the lymphoblastoid cells proved to be an appropriate expression system for this enzyme. Products were analyzed using HPLC and the mercapturate, 3-[(N-acetylcystein-S-yl)methyl]indole, of the reactive intermediate was identified and quantified. Product analysis showed that human CYP2F1 efficiently catalyzed the dehydrogenation of 3MI to the methylene imine without detectable formation of indole-3-carbinol or 3-methyloxindole. High substrate concentrations of 3MI strongly inhibited production of the dehydrogenated product, a result that may indicate the existence of mechanism-based inhibition of CYP2F1 by 3MI. Recombinant CYP2F1 demonstrated remarkable selectivity for the bioactivation of 3MI to the putative dehydrogenated reactive electrophile. Bioactivation of naphthalene to its pneumotoxic epoxide by CYP2F1 was also demonstrated.

Endoscopic septoplasty: indications, technique, and results.

Endoscopic septoplasty is an attractive alternative to traditional "headlight" approaches to septoplasty. The primary advantage of the technique is the ability to reduce morbidity and postoperative swelling in isolated septal deviations by limiting the dissection to the area of the deviation. This ability to markedly reduce the extent of subperichondrial dissection is particularly valuable in patients who have undergone prior septal cartilage resection. Other advantages include improved visualization, particularly in posterior septal deformities; improved surgical transition between septoplasty and sinus surgery; and its use as an effective teaching tool. We present our experience with endoscopic septoplasty in a series of 111 patients. Surgical indications, technique, and complications are discussed.

Endoscopically guided sinus cultures in normal subjects.

The study of healthy sinus flora has been pursued with Caldwell-Luc, antral puncture, and anterior rhinoscopy. Increasingly, nasal endoscopy has been used to obtain cultures, yet the significance of findings using this technique remains uncertain. Our ability to interpret the growing number of these cultures will be greatly enhanced by determining the results of this technique in patients without sinusitis. The goal of this study is to identify the bacterial flora of the sinuses in 25 healthy volunteers. Gram stain, aerobic, and anaerobic cultures were performed on swabs taken from the middle meatus and sphenoethmoid recesses. Eighteen cultures were sterile for aerobic organisms. Of the remaining 32 cultures, 41 isolates were retrieved. Predominant aerobes were S. aureus, Staphylococcus coagulase-negative, and diphtheroids; P. acnes was the predominant anaerobe.

Use of the superior meatus and superior turbinate in the endoscopic approach to the sphenoid sinus.

Endoscopic surgery of the posterior ethmoid and sphenoid sinuses can present the operator with a considerable challenge. Although endoscopic training and physician experience have increased significantly in the past decade, surgical complications such as optic nerve trauma and cerebrospinal fluid leak still occur. Surgeons reporting such complications cite a lack of orientation within the dissection field as a primary cause. Because endoscopic sinus surgery is now being performed more routinely, surgical strategies designed to reduce the risk of complications are more important than ever. An anatomic landmark that could reliably orient the dissection within the posterior ethmoids and guide the surgeon to the sphenoid sinus could reduce the possibility of such adverse outcomes. In our experience identification of the superior meatus and superior turbinate provides a reliable landmark within the dissection field that can ensure surgical orientation to the operator. This technique allows safe, reliable dissection of the posterior ethmoids and an efficient approach to the sphenoid sinus, especially in patients undergoing revision surgery. In this article our technique for the identification and definition of the superior meatus and superior turbinate is presented, and the advantages of using this landmark in sinus surgery are discussed. In our experience identification of the superior meatus, superior turbinate, posterior skull base, and medial orbital wall defines a parallelogram-shaped box, which delineates the sphenoid face. This box provides the necessary orientation to guide the surgeon's entrance into the sphenoid sinus through the posterior ethmoid sinus (as Messerklinger described). Techniques for identifying the superior turbinate and meatus and for entering the sphenoid are detailed.