Effect of phospholipase C and protein kinase C following cholinergic denervation and hippocampal sympathetic ingrowth in rat hippocampus.

Following cholinergic denervation of the hippocampus by medial septal lesions, an unusual neuronal reorganization occurs in which peripheral adrenergic fibers arising from the superior cervical ganglia grow into the hippocampus (hippocampal sympathetic ingrowth). We have reported previously that cholinergic denervation and hippocampal sympathetic ingrowth differentially affected cholinergically stimulated phosphoinositide hydrolysis, concentration and affinity of muscarinic receptors, Go-protein level and protein kinase C activity. To complete these studies, we determined whether cholinergic denervation and hippocampal sympathetic ingrowth influenced phospholipase C and protein kinase C expression in dorsal hippocampal membranes and cytosol. Using immunoblotting methods, the results showed that the 100,000 mol. wt subunit of phospholipase Cbeta was increased in the membrane fraction in the hippocampal sympathetic ingrowth group by 45% compared to controls and the 150,000 mol.wt subunit was increased by 75% and 59% compared to controls and cholinergic denervation, respectively. For protein kinase C detection, immunoblots were prepared using antibodies selective for "classical" protein kinase C members (alpha, beta, gamma) and for the "novel" protein kinase C subfamily members (delta, θ). Membrane protein kinase Cbeta was decreased in hippocampal sympathetic ingrowth by 35% compared to controls and by 41% compared to cytosolic hippocampal sympathetic ingrowth. Membrane protein kinase Cbeta was decreased in cholinergic denervation by 28% compared to controls. When compared to membranes from controls and the cholinergic denervation group, and to cytosolic fractions from the hippocampal sympathetic ingrowth groups, respectively, the following membrane protein kinase isoforms were found to be decreased by hippocampal sympathetic ingrowth: gamma by 55%, 40% and 57%; delta by 91.5%, 70% and 120%; theta; by 95%, 100% and 86%.In conclusion, our results may indicate the connection between the previously reported differential influence of hippocampal sympathetic ingrowth and cholinergic denervation on cholinergically stimulated phosphoinositol hydrolysis. The "normalization" of phosphoinositol hydrolysis found in hippocampal sympathetic ingrowth may be due to the increase in phospholipase Cbeta expression in hippocampal sympathetic ingrowth membrane fractions. Since the activation of protein kinase C is known to block phosphoinositol hydrolysis, hippocampal sympathetic ingrowth "normalization" of phosphoinositol hydrolysis may result from a reduction in protein kinase expression in hippocampal sympathetic ingrowth membranes.

Densitometric analysis of Galphao protein subunit levels from postmortem Alzheimer disease hippocampal and prefrontal cortical membranes.

An immunoblotting method using prefrontal cortical and hippocampal membranes from control and Alzheimer disease postmortem brains was employed to detect three subtypes of Galphao protein. In the membranes from control subjects, the density of Galphao1 in hippocampus and cortex was the highest, whereas the density of Galphao2 was the lowest and that of Galphao3 was intermediate. In the Alzheimer disease membranes from hippocampus, the density of total Galphao and all three subtype forms was not changed significantly when compared with control values. There were statistically significant alterations in Galphao in cortical membranes from Alzheimer disease when compared with controls. The density of Galphao1 was decreased by approximately 85%, density of Galphao3 was decreased by approximately 95%, and total Galphao density was decreased by approximately 84% of control value. However, Galphao2 density was decreased by approximately 44% but was found not to be statistically different from controls.

Effects of pertussis toxin and galpha-protein-specific antibodies on phosphoinositide hydrolysis in rat brain membranes after cholinergic denervation and hippocampal sympathetic ingrowth.

Cholinergic denervation of the hippocampal formation, via medial septal lesions, induces peripheral noradrenergic fibers, originating from the superior cervical ganglion, to grow into the hippocampus. We have previously reported that cholinergic denervation and hippocampal sympathetic ingrowth differentially affect guanosine-5'-O-(3-thiotriphosphate)- as well as guanosine-5'-O-(3-thiotriphosphate) + carbachol-stimulated polyphosphoinositide hydrolysis, suggesting an alteration in G proteins and/or the entire receptor complex. To examine the type of G protein which may be involved in these effects, rat dorsal hippocampal membranes were preincubated with pertussis toxin in the presence of guanosine-5'-O-(3-thiotriphosphate) and guanosine-5'-O-(3-thiotriphosphate) + carbachol. Pertussis toxin reduced guanosine-5'-O-(3-thiotriphosphate) in all groups, while guanosine-5'-O-(3-thiotriphosphate) + carbachol-stimulated phosphoinositide hydrolysis was reduced in controls and animals without sympathetic ingrowth but not in animals with hippocampal sympathetic ingrowth. This suggests that pertussis toxin-sensitive G proteins may be involved in the mediation of phosphoinositide hydrolysis. To confirm this hypothesis, membranes were preincubated with antibodies to Galphao and Gq/11. The Go antibody significantly decreased guanosine-5'-O-(3-thiotriphosphate) in all groups, while guanosine-5'-O-(3-thiotriphosphate) +carbachol-stimulated phosphoinositide hydrolysis was reduced only in hippocampal sympathetic ingrowth. Impairment of guanosine-5'-O-(3-thiotriphosphate) and carbachol-stimulated phosphoinositide hydrolysis was also decreased in all groups when preincubated with Gq/11 antibody. To determine whether hippocampal sympathetic ingrowth or cholinergic denervation altered the concentration of various G proteins, immunoblotting methodology was utilized. Gq/11 concentrations were found to be equivalent among groups. The density of Go1, Go2, and Go3 isoforms was significantly increased in the cholinergic denervation, while in the hippocampal sympathetic ingrowth only group Go3 was significantly increased. When assessed as total Go protein, density was increased significantly only in the cholinergic denervation group. Overall, these results suggest that hippocampal sympathetic ingrowth and cholinergic denervation induce alterations in phosphoinositide hydrolysis through both the Gq/11 and the Go proteins and that the coupling between muscarinic receptor and G protein is the possible site which affects changes in phosphoinositide turnover. Our results also suggest that cholinergic denervation and hippocampal sympathetic ingrowth may mediate phosphoinositide hydrolysis through an effect on different isoforms of the same G protein.

Outcome of reflux therapy on pediatric chronic sinusitis.

OBJECTIVE: The cause of pediatric chronic sinusitis is multifactorial, but nasal edema appears to be the initial pathologic step. The objective of this study is to evaluate gastronasal reflux as a possible cause of pediatric sinusitis. METHODS: Thirty children with chronic sinusitis were believed to be appropriate candidates for functional endoscopic sinus surgery. Children were evaluated retrospectively for their response to reflux therapy with regard to their sinus symptoms and avoidance of sinus surgery. RESULTS: Two of the 30 children were eventually excluded because they were taken to surgery for the specific purpose of contact point release. Chart review at 24-month follow-up indicated that 25 of the 28 children (89%) avoided sinus surgery. CONCLUSION: After reflux treatment, the number of children requiring sinus surgery was dramatically reduced. The results of this preliminary pediatric study indicate that gastronasal reflux should be evaluated and treated before sinus surgical intervention.

Functional endoscopic sinus surgical outcomes for contact point headaches.

Headaches secondary to sinonasal anatomic abnormalities continue to remain a difficult entity to diagnose and to manage. This retrospective study analyzed the outcome of care for 34 patients who presented with headaches as one of their primary sinonasal complaints and were subsequently found to have contact points between the nasal septum and one or more turbinates on nasal endoscopy and/or computed tomography scan. Following functional endoscopic sinus surgery to relieve the contact points, these patients were interviewed regarding preoperative and postoperative intensity and frequency of the headaches and the overall response of the chronic sinusitis and headaches to surgery, after a mean follow-up period of 13.9 months. After surgery, reduction in intensity and frequency of headaches was experienced in 91% and 85% of the patients, respectively. This investigation demonstrates that surgical management of contact point headaches can make a significant impact on the headache symptomatology in children and adults.

Type I posterior laryngeal clefts.

Posterior laryngeal clefts (PLCs) are described in the literature as rare laryngeal abnormalities. The authors believe type I clefts are much more common than previously reported. In two busy pediatric tertiary care centers, such clefts are the second most common congenital laryngeal finding at rigid endoscopy, second only to laryngomalacia. PLCs frequently present with symptomatology that can be attributed to other common disease processes and are often undiagnosed unless the surgeon maintains a high index of suspicion and specifically examines the posterior glottis by palpation during microlaryngoscopy. This report presents a series of 41 patients with type I PLCs, reviews their subtle and often confusing presenting signs and symptoms, and describes a simple yet reliable method of diagnosis.

Long-term follow-up of aviators after functional endoscopic sinus surgery for sinus barotrauma.

Prior to endonasal endoscopic advances for the treatment of sinus disease, surgical results for aviators with recurrent sinus barotrauma (RSB) were inconsistent. Between 1988 and 1992, 54 aviators, who were permanently or temporarily grounded, underwent functional endoscopic sinus (FES) surgery in an attempt to return them to active flying status. Follow-up in the immediate postoperative period revealed that 98% of these aviators returned to active flight duty. A questionnaire was mailed to each of these aviators to compare their preoperative and long-term postoperative symptoms and determine their current flying status. Long-term follow-up time ranged from 20 to 72 mo with average of 48 mo. Of the aviators who responded to the survey, 92% have continued their flying duties and do not report difficulties with RSB. We conclude that FES surgery is effective in the short- and long-term management RSB in aviators.

Botryomycosis: improved therapy for a difficult infection.

Botryomycosis is a chronic bacterial granulomatous disease often involving the skin and subcutaneous tissue. Head and neck involvement is rare. Botryomycosis presents with clinical and histological features similar to actinomycosis or mycetoma, but the causative organism is usually Staphylococcus aureus. Microscopically the organisms appear to be encapsulated in granules, which are thought to protect them from the effects of standard courses of antibiotics. Botryomycosis usually requires surgical intervention for cure. Major debilitating surgery has been required for most patients, because the infection has been unresponsive to seemingly appropriate medical therapy. We present an 8-month-old male with periorbital botryomycosis. Surgical specimens for diagnosis were obtained, but complete resection would have created debilitating functional and cosmetic defects. The lesion failed to respond to nafcillin alone or combination therapy with hyperbaric oxygen, but showed slow, steady improvement with long-term clindamycin. The patient has been disease free for more than 4 years, with minimal scarring and no functional impairment. Prolonged medical therapy for botryomycosis may be a viable alternative to the traditionally recommended surgical resection, thereby reducing cosmetic and functional morbidity.

Cholinergic denervation and sympathetic ingrowth result in persistent changes in hippocampal muscarinic receptors.

Our laboratory has been utilizing the model of hippocampal sympathetic ingrowth, which has been suggested to occur in Alzheimer's disease, to investigate the effects of cholinergic denervation and hippocampal rearrangements. After cholinergic denervation by medial septal lesions, peripheral sympathetic fibres originating from the superior cervical ganglia grow into the rat hippocampus. This hippocampal sympathetic ingrowth can be prevented by superior cervical ganglionectomy. We examined the long-term effects of these treatments on muscarinic receptors by comparing [3H]quinuclidinyl benzilate binding in rat dorsal hippocampus four and 12 weeks post lesion. Four groups of animals were employed, including controls (sham lesion+sham ganglionectomy), animals with ingrowth (medial septal lesion+ sham ganglionectomy), animals with cholinergic denervation alone (medial septal lesion+ ganglionectomy), and ganglionectomy alone (sham lesion+ganglionectomy) animals. In dorsal hippocampus four weeks post lesion, binding affinity was similar among all groups, while muscarinic receptor number was increased in ingrowth animals as compared to both the control (P<0.0002) and ganglionectomy animals (P<0.01). By 12 weeks, receptor affinity was significantly decreased in ingrowth (P<0.0001) and cholinergic denervation (P<0.0003) groups, and receptor number remained significantly elevated in ingrowth animals as compared to control (P<0.01), ganglionectomy (P<0.02) and cholinergic denervation (P<0.01) groups. The decrease in muscarinic receptor affinity may provide some insight into the ineffectiveness of cholinomimetic therapies in Alzheimer's disease, in that agonist efficacy would be reduced at the receptor.

Stevens-Johnson syndrome and respiratory failure in a 9-year-old boy.

The etiology of respiratory failure associated with Stevens-Johnson syndrome may be multifactorial, including upper airway involvement, pneumothorax/pneumomediastinum, and direct involvement of the respiratory mucosa. Respiratory failure from direct involvement of the respiratory mucosa is relatively uncommon. We describe a 9-year-old boy who had respiratory failure associated with Mycoplasma pneumoniae-induced Stevens-Johnson syndrome. Bronchoscopic examination of the airways revealed sloughed mucosa, ulcerative lesions, and inspissated secretions indicative of lower airway involvement with Stevens-Johnson syndrome. Although the mainstay of therapy is supportive care with controlled ventilation, rigid bronchoscopy with bronchoalveolar lavage to clear the airways of the debris was an invaluable adjunct to this patient's care.

A review of quality of life in chronic renal failure.

The quality of life of patients with end-stage renal disease (ESRD) has become an area of intensive investigation because of the high costs of renal-replacement therapy (dialysis or renal transplantation) and the rising prevalence of renal failure. Studies comparing quality of life of patients using different forms of renal-replacement therapy are flawed by deficiencies in study design, such as lack of randomisation. Nevertheless, in both retrospective and prospective studies, transplantation has been shown to offer the highest levels of functional ability, employment and subjective quality of life. After case-mix adjustment, there is little difference between peritoneal dialysis and haemodialysis in terms of quality-of-life (QOL) outcomes. Vocational rehabilitation is an important aim of therapy; for patients below retirement age, pre-dialysis education and counselling are important in maintaining employment. The elderly comprise the fastest-growing group of dialysis recipients; multiple comorbidities add to functional impairment in these patients. Subjective quality of life remains surprisingly high in many elderly patients, despite poor objective quality of life. The quality of life of patients with diabetes mellitus and ESRD is lower than that of nondiabetic patients with ESRD. For selected patients with insulin-dependent diabetes mellitus, combined renal and pancreatic transplantation offers the advantage of freedom from insulin injections. Unfortunately, available evidence suggests only small improvements in quality of life with combined transplantation versus kidney-only transplantation, probably because many patients have developed multiple diabetic complications by the time of transplantation. Epoetin alfa (erythropoietin) has been shown to improve quality of life in a number of trials. The optimal target haematocrit is a subject of controversy, but on current evidence, a target of 34 to 37% is reasonable. The degree of improvement in quality of life must be balanced against the additional costs of achieving a higher haematocrit. Further study is necessary to clarify the optimal target haematocrit for epoetin alfa therapy, as well as the possible effects of nutritional support, growth hormone in paediatric patients, and combined renal and pancreatic transplantation in improving quality of life.

Mucociliary clearance and buffered hypertonic saline solution.

Nasal irrigations have been used for centuries without any scientific data to determine efficacy. For 10 years, the senior author has used buffered hypertonic saline nasal irrigation for patients with acute/chronic sinusitis and for those having undergone sinus surgery. A simple study was undertaken using volunteers without any significant sinonasal disease. Patients served as their own control using a saccharin clearance test before any nasal irrigation was used. Patients then used one of two solutions to irrigate their nose-buffered normal saline or buffered hypertonic saline-and were then retested. On a separate day, the control test was repeated, followed by irrigation with the alternate solution and a second saccharin clearance test. The outcome showed buffered hypertonic saline nasal irrigation to improve mucociliary transit times of saccharin, while buffered normal saline had no such effect.

Effect of hippocampal sympathetic ingrowth and cholinergic denervation on hippocampal phospholipase C activity and G-protein function.

Following cholinergic denervation of the hippocampal formation, via medial septal lesions, peripheral noradrenergic fibers, originating from the superior cervical ganglion, grow into the hippocampus. In previous studies, we have found that hippocampal sympathetic ingrowth and cholinergic denervation alone (animals with concurrent medial septal lesions and superior cervical ganglionectomy) alter phosphoinositide turnover and muscarinic cholinergic receptors in such a way as to suggest an alteration in coupling between the muscarinic cholinergic receptors and phosphoinositol turnover. To test this hypothesis we examined the effect of hippocampal sympathetic ingrowth and cholinergic denervation on phospholipase C activity, G-protein function and the whole receptor complex by measuring the amount of phosphoinositide hydrolysed in hippocampal membranes of the rat. Neither hippocampal sympathetic ingrowth nor cholinergic denervation was found to alter phospholipase C activity when activated by increasing concentrations of Ca2+. In dorsal hippocampus, cholinergic denervation, when compared to hippocampal sympathetic ingrowth and controls, was found to decrease the amount of phosphoinositol hydrolysed when stimulated with the GTP analog, guanosine-5'-O-(3-thiotriphosphate). When guanosine-5'-O-(3-thiotriphosphate) plus carbachol (1 mM) was utilized to stimulate the entire receptor complex, phosphoinositol hydrolysis was found to be decreased in the cholinergic denervation group as compared to both hippocampal sympathetic ingrowth and control groups. This effect was maximum at 3 microM guanosine-5'-O-(3-thiotriphosphate). These results suggest that both hippocampal sympathetic ingrowth and cholinergic denervation affect the efficiency of coupling between the muscarinic cholinergic receptors and phosphoinositol turnover, with cholinergic denervation decreasing and hippocampal sympathetic ingrowth "normalizing" efficiency. Further, they suggest that the G-protein is the site at which hippocampal sympathetic ingrowth and cholinergic denervation mediate their effects. The results of these experiments are also discussed within the context of recent findings demonstrating G-protein abnormalities in Alzheimer's disease.

Delayed diagnosis of a laryngotracheoesophageal cleft.

Laryngotracheoesophageal (LTE) clefts are rare anomalies of the airway. Surgical correction has been performed in all cases reported in the literature for clefts diagnosed during life. Posterior laryngeal clefts (PLC) are defined as minor (type I) to severe (type IV), with types III and IV being further described as LTE clefts. Type I clefts have been observed with an increased frequency of up to 6% of all pediatric direct laryngoscopies performed at a tertiary pediatric referral hospital. These can be managed medically and seldom require surgical correction. A case is presented of a boy whose initial diagnosis of LTE cleft (PLC type III) was made at age 7 years. His presenting complaints were chronic airway symptoms without airway distress. He developed only two episodes of pneumonia. Surgical correction was not performed. This young athlete has been followed for more than 6 years without significant problems. This appears to be the only case found in the literature of the successful management of a LTE cleft that has not required surgical correction. Photographic documentation and suggestions on endoscopic diagnosis are presented.

Unique case presentations of acute epiglottic swelling and a protocol for acute airway compromise.

Acute epiglottitis is a well-described life-threatening disease. Since the generalized use of the Haemophilus influenzae type B (HIB) vaccine, presentations of this disorder have decreased dramatically in children. Presentations of this and other acute epiglottic swelling can vary remarkably and may easily be misdiagnosed by physicians who have little or no experience with the acutely obstructed airway. Early suspicion and a proper evaluation is mandatory to prevent a life-threatening crisis. Six patients are presented with unusual presentations of acute epiglottic swelling from differing etiologies; these include the following: case 1, recurrent epiglottitis; case 2, chronic epiglottitis; case 3, traumatic epiglottitis; case 4, caustic ingestion; and cases 5 and 6, simultaneous infection of family members. Because the incidence of acute epiglottitis is decreasing, it has become rare at most institutions. To help primary care and emergency room physicians, a formal written protocol should be available at medical facilities that might be faced with patients presenting with acute airway obstruction. An "acute airway obstruction protocol" used successfully for the last decade is offered. Use of such a written document might be life-saving for patients with impending upper airway obstruction. The otolaryngologist is a key member of the recommended multidisciplinary team.

Chronic sinusitis: a medical or surgical disease?

Chronic sinusitis in children who do not have other underlying medical problems is a medically treatable disease, and surgery is not required often. Allergies, environmental factors, and gastroesophageal reflux are the three most important contributing causes of chronic sinusitis in children. Chronic sinusitis is not a primary infectious disease.

Otitis media and sinusitis: similar diseases.

Otitis media and sinusitis are common pediatric diagnoses and share common features that are described in this article. Although the anatomy, physiology, and disease processes are not identical, knowledge of the basic pathophysiology of middle ear disease often enables a clinician to have a useful working understanding of sinus disease. Recognizing these similarities provides a better understanding of their pathophysiology and treatment.

Anatomy of the paranasal sinuses.

This article portrays the anatomy of the ethmoid bone and lateral nasal wall in a detailed, but easily digested form. Understanding the anatomy of the lateral wall of the nose is the cornerstone of competent paranasal sinus surgery.

Rhinologic uses of powered instrumentation in children beyond sinus surgery.

Powered instrumentation is now available for a variety of sinonasal procedures in children. Microdebriders with continuous suction at the operative site allow increased precision for complex procedures that often were difficult in small, fragile, pediatric noses. These instruments can be used for functional endoscopic sinus surgery in children and for such procedures as benign and malignant sinonasal or base of skull tumors, choanal atresia, complicated adenoidectomies, dacrocytorinostomies, septal spurs, and recurrent respiratory papillomatosis. These instruments can remove mucosa, neoplastic tissue, cartilage, thin bony septations, nasal debris, and blood under continuous endoscopic visualization. Edematous mucosa is not stripped, but trimmed and preserved, allowing much more rapid postoperative healing because exposed bone is avoided.