Search PubMed⌕ Search

Biomedical subjects

R C Kern

Publications and source records attributed to R C Kern.

17 recordsLinked to original sources

Chronic sinusitis and anosmia: pathologic changes in the olfactory mucosa.

OBJECTIVES: To evaluate histological changes in the olfactory mucosa of patients with chronic rhinosinusitis These results are analyzed in light of current understanding of the pathophysiology of anosmia secondary to nasal and sinus disease. STUDY DESIGN: Prospective study of olfaction on patients undergoing sinus surgery for the management of chronic rhinosinusitis. METHODS: Thirty patients, aged 22 to 39 years, underwent olfactory biopsy at the time of surgery with evaluation by a pathologist. Inflammatory changes were graded as mild (normal), moderate, or severe. Clinical olfactory function was evaluated using the University of Pennsylvania Smell Identification Test (UPSIT). The results correlated with the degree of olfactory dysfunction. RESULTS: Of the 30 patients 19 had unequivocal olfactory mucosa in the biopsy specimen. Eleven had only respiratory or indeterminate mucosa. Nine patients demonstrated normal olfactory mucosa and normal olfactory function (UPSIT > 35). Ten patients demonstrated pathological changes in the olfactory mucosa with an influx of lymphocytes, macrophages, and eosinophils Of these 10 patients, 7 had olfactory deficits as determined by UPSIT. The remaining three patients had normal olfactory function despite moderate chronic inflammation. These studies indicate that the olfactory mucosa is capable of mounting an inflammatory response similar to that seen in the respiratory mucosa of patients with chronic sinusitis These data suggest that the olfactory deficits in these patients may be the result of inflammatory changes within the olfactory mucosa in addition to any alteration in airflow to the olfactory cleft.

Adult↗

Post-traumatic olfactory dysfunction.

OBJECTIVES: This study demonstrates histopathologic and immunocytochemical changes in the olfactory bulb of a patient with post-traumatic olfactory dysfunction. These results are analyzed in light of current understanding of the pathophysiology of anosmia and dysosmia following head trauma. Emphasis is placed on potential mechanisms of human regeneration and recovery. STUDY DESIGN: The current study documents the history of a patient with the initial complaint of complete anosmia following minor head trauma. Two months after the injury the patient developed persistent, severe dysosmia with debilitating weight loss. Neurosurgical treatment, including removal of the olfactory bulbs and tracts, resulted in permanent resolution of dysosmia. METHODS: Histopathologic and immunocytochemical analysis of the olfactory bulbs was undertaken and compared with age-matched control tissue. RESULTS: Pathological analysis of the olfactory bulb revealed a marked reduction in the number of nerve processes with few intact olfactory glomeruli compared with an age-matched control. Specific immunohistochemical staining for the olfactory neuron-specific protein OMP, however, demonstrated the presence of intact axonal projections between the olfactory mucosa and the bulb. CONCLUSIONS: These results support the hypothesis that post-traumatic anosmia involves, at least in part, damage to peripheral olfactory nerve fibers with histological changes in the olfactory bulb. Potential mechanisms for the development of post-traumatic dysosmia are also discussed.

Adult↗

Olfactory secretion and sodium, potassium-adenosine triphosphatase: regulation by corticosteroids.

OBJECTIVES: To investigate the cellular distribution and relative intensity of the immunoreactivity associated with the expression of sodium, potassium-adenosine triphosphatase (Na, K-ATPase) in cells of the olfactory mucosa. Second, changes in the activity of this enzyme in the olfactory mucosa are correlated with changes in the circulating corticosteroid aldosterone. METHODS: Combination of immunohistochemical and biochemical techniques were employed to examine the olfactory Na, K-ATPase. RESULTS: Within the olfactory epithelium, the Na, K-ATPase immunoreactivity was greatest at the supranuclear region of sustentacular cells and/or dendrites of olfactory receptor neurons (ORNs). Cell bodies of ORNs demonstrated moderate immunoreactivity, whereas the duct cells of Bowman's gland exhibited moderate to intense immunoreactivity. Acinar cells of the Bowman's gland were the most intensely stained components of the lamina propria, exhibiting strong immunoreactivity at the basolateral plasma membrane domains of the acinar cells and less within the cytoplasm. Binding of ouabain, a specific inhibitor of Na, K-ATPase, was significantly elevated for aldosterone-injected versus sham-injected controls. CONCLUSION: These results suggest that olfactory Na, K-ATPase is regulated by the systemic corticosteroid aldosterone. The results are consistent with the hypothesis that corticosteroids regulate olfactory secretion.

Aldosterone↗

Mineralocorticoid receptors in the mammalian olfactory mucosa.

Mineralocorticoid hormones regulate secretion and absorption in a wide variety of epithelial tissues, although specific mechanisms in the olfactory mucosa are currently unknown. Utilizing reverse transcription-polymerase chain reaction (RT-PCR) analysis, we have demonstrated the expression of mineralocorticoid (type I) receptor messenger RNA in the rodent olfactory mucosa. Amplification products of predicted size were obtained with nucleotide sequences corresponding to respective mineralocorticoid receptor (MR) kidney transcripts. Immunocytochemistry, using an antibody with known specificity for MRs, was then utilized in order to localize the cellular site(s) of MR protein expression in the olfactory mucosa. The highest levels of MR immunoreactivity were localized to the supranuclear region of sustentacular cells, as well as the acinar cells of the Bowman's glands. The respiratory regions of the nasal cavity were devoid of appreciable MR immunoreactivity. This study demonstrates both MR transcript and protein expression in the olfactory mucosa. We hypothesize that the mineralocorticoid hormones may have a role in modulation of olfactory secretion and/or sensory transduction in the peripheral olfactory system.

Animals↗

Expression of glucocorticoid receptor mRNA and protein in the olfactory mucosa: physiologic and pathophysiologic implications.

OBJECTIVES: Define the presence and distribution of glucocorticoid receptors (GRs) within the olfactory mucosa in order to assess potential physiologic and pathophysiologic effects of these hormones on olfaction. STUDY DESIGN: The olfactory mucosa was harvested from adult male rats and guinea pigs. Kidney tissue was utilized as a known positive control. METHODS: The techniques of reverse transcriptase-polymerase chain reaction (RT-PCR) and immunocytochemistry were utilized to examine the expression of GR mRNA and protein. To assure the presence of olfactory mucosa in the nasal tissue samples, RT-PCR was utilized to identify the olfactory marker protein (OMP). RESULTS: The presence of GR mRNA was confirmed in both the olfactory mucosa and kidney. GR-like immunoreactivity associated with the olfactory epithelium was greatest at the apical surface, a position corresponding to the dendrites, knobs, and cilia of olfactory receptor neurons, as well as the supranuclear region of sustentacular cells. Weaker GR-like immunoreactivity was associated with the region of the cell bodies of the olfactory receptor neurons. Within the lamina propria, acinar cells of the Bowman's glands and olfactory nerve bundles were intensely immunoreactive. CONCLUSIONS: The presence of GR mRNA and protein within the olfactory mucosa is consistent with a functional role for glucocorticoid hormones in the systemic regulation of olfaction. Furthermore, these studies suggest that corticosteroid medications may have direct effects on the cells of the olfactory mucosa in the pathologic state. The potential mechanisms whereby these hormones may act are discussed.

Animals↗

Mineralocorticoid (type I) receptors in the olfactory mucosa of the mammal: studies with [3H]aldosterone and the anti-mineralocorticoid spironolactone.

High-affinity, specific binding sites to mineralocorticoids, with characteristics of mineralocorticoid (type I) receptors, have been found in the mammalian olfactory mucosa. In the presence of RU 28362, which blocks low-affinity binding of the labeled hormone to glucocorticoid (type II) receptors, Scatchard analysis of the specific [3H]aldosterone binding indicates that aldosterone binds to a single class of high-affinity (type I) sites with a dissociation constant, Kd, of 1.2 x 10(-9) M and a maximum number of binding sites, Bmax, of 63 fmol/mg dry tissue. Time course of association of [3H]aldosterone and its binding sites showed maximal binding by 30 min at 25 degrees C which remained unchanged up to 90 min. Competition studies performed with 1 x 10(-7)-1 x 10(-5) M spironolactone, a competitive mineralocorticoid antagonist, showed a dose-response reduction of [3H]aldosterone binding, implying that in the olfactory mucosa this compound behaves as an aldosterone antagonist. These results demonstrate significant [3H]aldosterone binding to receptors of high affinity and mineralocorticoid specificity and suggest that the olfactory mucosa is a target site for mineralocorticoid action.

Aldosterone↗

Localization of 11 beta-hydroxysteroid dehydrogenase: specific protector of the mineralocorticoid receptor in mammalian olfactory mucosa.

The enzyme 11 beta-hydroxysteroid dehydrogenase (11 beta HSD) plays a major role in the protection of the mineralocorticoid (type I) receptor. The cellular mechanism of aldosterone selectivity relies on the coexpression of mineralocorticoid receptors and 11 beta HSD in the same cells. In the current study, 11 beta HSD activity was localized in the mammalian olfactory mucosa by a histochemical technique which links steroid metabolism with the deposition of formazan. The histochemical reaction results from oxidation of the synthetic substrate 11 beta-hydroxyandrostenedione and is dependent on nicotine-adenine dinucleotide (NAD). This demonstrates the presence of a dehydrogenase activity separate from the nicotineamide-adenine dinucleotide phosphate (NADP)-dependent 11 beta HSD. In the olfactory mucosa, the presence of NAD-dependent 11 beta HSD activity is localized to the sustentacular cells and acinar cells of Bowman's glands. No definite NAD-dependent activity was demonstrated in the olfactory receptor neurons. These data suggest that mineralocorticoid receptors present in acinar cells and sustentacular cells are aldosterone selective.

11-beta-Hydroxysteroid Dehydrogenases↗

Cytochemical localization of adenylyl cyclase activity within the sensory epithelium of the trout saccule.

Adenylyl cyclase, the enzyme of synthesis of cAMP, the second messenger molecule mediating signal transduction in response to sensory, neurotransmitter and hormonal stimuli, has been localized in the sensory epithelium of the rainbow trout (Salmo gairdneri R.) saccule by cytochemical detection of enzyme activity. In the sensory receptor cell, or hair cell, reaction product has been visualized in the stereocilia in close association with the outer cell membrane and also at the apical surface of the cuticular plate. A diffuse distribution of precipitate was observed within the cytoplasm of terminal endings of nerve fibers presumed to be efferent on the basis of characteristic synaptic specializations including presynaptic vesicles and a postsynaptic cistern lying within the hair cell. Occasionally, reaction product was observed to be associated with the external cell membrane of these nerve terminals. There appeared to be little or no adenylyl cyclase activity associated with the plasma membrane at the base of the hair cell or in presumptive afferent nerve endings. However, a subpopulation of nerve fiber endings which exhibited both efferent and afferent synaptic specializations contained precipitate. A concentration of adenylyl cyclase activity in hair cell stereocilia and efferent nerve terminals in the sensory epithelium is suggestive of a role for cAMP in second messenger action at these sites, possibly related to mechanosensory transduction and efferent neuromodulation, respectively.

Adenylyl Cyclases↗

Serum immunoglobulins specific for intracellular proteins of squamous cell carcinoma.

OBJECTIVE: To determine an autologous humoral immune response to squamous cell carcinoma (SCC) intracellular proteins in patients with SCC. DESIGN: Intracellular proteins were isolated from 25 different cultured SCC lines. The proteins were used as a source of antigens to measure IgA, IgE, and IgG responses in the serum samples of patients and controls. Antibody response was assessed in both unfractionated and fractionated intracellular proteins. PATIENTS: The serum samples of 65 patients with SCC and of 65 age- and gender-matched controls were tested. RESULTS: Antibodies to SCC intracellular proteins were detected in the serum samples of 40 (62%) of the 65 patients with SCC and in the serum samples of 46 (71%) of 65 controls. Thirty (46%) of the patients with SCC and 40 (62%) of the controls had IgE responses, 18 (28%) of the patients and one (2%) of the controls had IgA responses, and 17 (26%) of the patients and 14 (22%) of the controls had IgG responses. An inverse relation was noted between detectable IgE responses and IgA or IgG responses in the patients and the controls. The analysis of antibody response indicated that 28 molecules were recognized predominantly by the serum samples of patients with SCC, but not by the serum samples of controls. CONCLUSIONS: A substantial proportion of patients with SCC and of controls exhibited an autologous humoral immune response to SCC intracellular proteins. The IgE responses to SCC intracellular proteins were inversely related to IgA or to IgG responses. Different antibody isotypes normally cause markedly different immune functions, and may suggest different roles for the existent immune responses to SCC antigens. We identified many tumor-associated antigens that were selectively recognized by the serum samples of patients with SCC. These antigens could be used to define molecular studies of immune surveillance and selection, and may represent appropriate targets for immunotherapy.

Autoradiography↗

Direct laryngoscopy with provocation: a useful method to distinguish acute laryngeal edema from nonorganic disease.

BACKGROUND: Acute laryngeal edema is a manifestation of anaphylaxis, is frequently sudden in onset and requires immediate treatment to prevent further airway compromise. Nonorganic disease such as globus hystericus may present with symptoms similar to acute laryngeal edema. Distinguishing life-threatening acute laryngeal edema from non-life-threatening disease may be difficult. OBJECTIVE: We present a patient in which direct laryngoscopy was used to distinguish acute laryngeal edema from nonorganic disease. METHODS: A case report of a woman who had presented to numerous emergency rooms with symptoms of cough, sensation of throat closing, and hoarseness when exposed to odors such as nail polish remover and musk cologne. She was treated repeatedly with subcutaneous epinephrine, oral diphenhydramine and intravenous methylprednisolone. Her history was not classic for IgE-mediated anaphylaxis and we challenged her with nail polish remover while visualizing her vocal cords with direct laryngoscopy. RESULTS: Upon challenge with an offending agent, her symptoms were again suggestive of life-threatening laryngeal edema. Direct laryngoscopy, however, revealed no objective evidence of airway obstruction. CONCLUSION: Direct laryngoscopy with provocation is useful in distinguishing acute laryngeal edema from nonorganic disease.

Bronchial Provocation Tests↗

Bacterial allergy in nasal polyposis. A new method for quantifying specific IgE.

OBJECTIVES: To determine (1) if bacteria-specific serum IgE levels can be more effectively measured by first absorbing competing IgG antibodies from serum and (2) if patients with chronic paranasal sinus disease exhibit a high positive prevalence of bacteria-specific serum IgE. DESIGN: A modified radioallergosorbent test method was employed wherein each serum sample was absorbed with recProtein A to remove competing non-IgE antibodies, and purified proteins extracted from 16 individual bacteria were used as potential allergens. PARTICIPANTS: Twenty-four patients with nasal polyposis and 14 with chronic sinusitis, all refractory to conventional medical therapy and requiring endoscopic sinusotomies, were tested. Tested as controls were 10 subjects with chronic allergic rhinitis, without a history of chronic sinus disease, and possessing total serum IgE and inhalant-specific IgE levels equal to or higher than the patient group. RESULTS: (1) Pretreatment of serum samples with recProtein A resulted in an increase of bacteria-specific radioallergosorbent test sensitivity. (2) Seventeen of 24 patients with polyps, eight of 14 with chronic sinusitis, and one of 10 with chronic allergic rhinitis were determined to be IgE positive when tested with this assay. CONCLUSIONS: (1) Bacteria-specific serum IgE can be quantified; (2) most patients with nasal polyposis and/or chronic sinusitis possess bacteria-specific IgE in their serum, while subjects with only allergic rhinitis do not; and (3) multiple bacterial species isolated from chronically infected sinuses are capable of inducing IgE-mediated sensitization.

Antibodies, Bacterial↗

Successful in vitro growth of human respiratory epithelium on a tracheal prosthesis.

Reconstruction of tracheal defects may be necessary following trauma or oncologic surgery. Defects up to 8 cm can often be repaired using end-to-end anastomosis. Use of a tracheal prosthesis for larger defects has been complicated by recurrent stenosis and infection. Recent animal studies, utilizing a Dacron polyurethane prosthesis suggest that problems with anastomotic stenosis and infection can be controlled. Problems with a central stenosis within the prosthesis persist when used for defects greater than 6 cm. Establishment of a confluent lining of respiratory epithelium is believed to be necessary for successful prosthetic tracheal reconstruction. Using cell culture techniques, we report the first successful seeding and growth of human respiratory epithelium onto a Dacron polyurethane tracheal prosthesis.

Cell Adhesion↗

Ultrastructural localization of Na+/K(+)-ATPase in rodent olfactory epithelium.

The olfactory epithelium is comprised of bipolar sensory neurons, sustentacular cells, and basal cells. The sensory neurons have apical knobs and cilia, which project into the olfactory mucus toward the nasal lumen, and represent presumptive sites of odorant binding. Ionic currents, measured across this epithelium in both the resting and odorant-stimulated states, are known to be sustained, at least in part, by active transport of sodium. Information identifying the cellular sites of ion transport in olfactory sensory epithelium will therefore aid in elucidating the ionic mechanisms associated with olfactory transduction. The membrane-bound enzyme Na+/K(+)-ATPase mediates active ion transport in many other cells and tissues. We have consequently employed the cytochemical technique reported by Ernst (J. Histochem. Cytochem., 20 (1972) 23-38, 1322) to identify possible sites of elevated Na+/K(+)-ATPase activity in olfactory epithelium. This procedure detects inorganic phosphate (Pi) released from an artificial substrate (nitrophenyl phosphate) by enzyme catalytic activity. In the presence of strontium ion. Pi is precipitated near regions of high enzymatic activity, then converted to a product visible in the electron microscope. Parallel control preparations were incubated in media (1) supplemented with the specific Na+/K(+)-ATPase inhibitor ouabain (to abolish formation of specific reaction product); (2) with substrate deleted (to demonstrate possible non-specific binding of Sr2+ and/or Pb2+); or (3) with the necessary cofactor K+ deleted. In tissues incubated for demonstration of Na+/K(+)-ATPase activity, reaction product was associated with apical knobs, cilia and dendrites of olfactory receptor neurons at the apical surface. In the more proximal region of the epithelium, reaction product was associated with cell bodies and axons of the sensory neurons, and with the lateral membranes of sustentacular cells. Reaction product was deposited intracellularly, compatible with the known mechanism of the Na+/K(+)-ATPase enzymatic reaction. In control specimens incubated with ouabain, with substrate deleted, or with K+ deleted, only a small quantity of non-specific precipitate was observed. These results are discussed with reference to the various sodium currents implicated in olfactory transduction and transepithelial transport.

Animals↗

Efficacy of endoscopic sinus surgery in the management of patients with asthma and chronic sinusitis.

An association between chronic sinusitis and asthma has been noted for many years, although the precise nature of the relationship is poorly understood. Earlier studies, using traditional surgical techniques, have demonstrated subjective improvement in asthmatic complaints. Reports demonstrating improvement following endoscopic sinus surgery for chronic sinusitis are rare. To report our experience with endoscopic sinus surgery and asthmatics, we reviewed the charts of 75 consecutive patients with asthma and chronic sinusitis who underwent endoscopic sinus surgery between 1994 and 1996. Study criteria included the following: chronic sinusitis, one year preoperative and one year postoperative follow-up from endoscopic sinus surgery, and asthma requiring inhaled steroids and oral prednisone for control. Many patients required prednisone bursts for control of asthma. Number of days and total dose of oral prednisone were used as objective measures of asthma control. Number of weeks of antibiotics was used as a relative measure of sinusitis. Fourteen of the 15 patients meeting study criteria decreased their postoperative prednisone requirement by total number of days (preoperative 84 versus postoperative 63 days [p < 0.0001]). Postoperatively, patients required an average of 1300 mg less oral prednisone (p < 0.033). Antibiotic use also decreased, with an average use of antibiotic nine weeks preoperatively versus seven weeks postoperatively (p < 0.045). This study provides corroborative objective evidence that, at least in the short term, endoscopic sinus surgery is efficacious in the management of patients with chronic sinusitis and asthma.

Adolescent↗