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Biomedical subjects

D W Kennedy

Publications and source records attributed to D W Kennedy.

At least 19 recordsLinked to original sources

The utility of magnetic resonance imaging in the diagnosis of intranasal meningoencephaloceles.

We present three patients in whom the diagnosis of intranasal meningoencephalocele was made by magnetic resonance imaging. The initial clinical evaluation and computed tomographic examinations of these patients failed to distinguish between chronic inflammation and intranasal meningoencephalocele. Although both computed tomography and magnetic resonance imaging are used to distinguish between normal, inflammatory, and neoplastic tissue in the nasal cavity and paranasal sinuses, limitations do exist and these are the focus of our communication. A clear understanding of the efficacy of these radiographic modalities will enhance surgical planning and can preclude severe complications.

Encephalocele

Current concepts in the surgical management of chronic and recurrent acute sinusitis.

It was previously believed that sinusitis lasting longer than 3 months might lead to irreversible disease. Experience with functional endoscopic sinus surgery indicates that this is rarely the case. Functional endoscopic sinus surgery describes an approach whereby target areas of obstruction are cleared of disease, which allows for ventilation of secondarily involved sinuses and return of mucociliary function. Although endoscopic sinus surgery is one of the techniques most frequently used to manage chronic sinus disease, it is not a suitable surgical approach for every otolaryngologist or all patient settings. Success with this endoscopic approach for chronic sinus disease is based primarily on rigorous perioperative medical care and postoperative surgical debridement. The greatest advancement that the nasal endoscope has brought to patient care is the ability to diagnose disease and follow objectively the effects of different treatment modalities. This advantage is recognized by allergists and used at several centers.

Acute Disease

Current concepts in the surgical management of nasal polyposis.

One of the most common and occasionally frustrating health care problems is that of nasal polyposis. Patient symptoms are debilitating and have a tendency to recur despite the treatment modality used. Nasal endoscopy is a significant advancement for the early diagnosis and objective assessment of treatment modalities used for nasal polyposis. Surgery used in conjunction with medical therapies offers a safe, thorough means of relieving patient symptoms. It is possible to monitor these patients closely for recurrence with nasal endoscopy as well as debride early recurrences before they become symptomatic.

Endoscopy

Inverted papilloma: evaluation with MR imaging.

The authors examined the magnetic resonance (MR) appearance of inverted papillomas to determine if this histologically benign lesion could be distinguished from malignancies of the sinonasal cavity. MR images in 10 patients with histologically proved inverted papilloma were retrospectively reviewed. The signal intensity of inverted papillomas on short repetition time (TR) images was iso- to slightly hypertintense to muscle in all 10 patients. Inverted papillomas had intermediate signal intensity on the long TR/echo time (TE) images. The tumors were iso- or slightly hypointense to fat on long TR/short TE images. In the seven patients who received gadopentetate dimeglumine, all inverted papillomas showed solid inhomogeneous enhancement. A review of eight sinonasal malignancies showed no distinctive signal intensity or enhancement characteristics to help differentiate inverted papillomas from various malignant tumors. The authors conclude that there is no signature MR appearance for the benign inverted papilloma. The main utility of MR imaging is in defining the extent of the lesion.

Adipose Tissue

Prognostic factors, outcomes and staging in ethmoid sinus surgery.

Although the literature is replete with papers discussing the results of surgery for chronic inflammatory sinus disease, critical comparison of results is difficult due to limited knowledge of the prognostic factors and the variable criteria reported for success. Detailed prospective and retrospective data collection was therefore undertaken to evaluate the results of surgical intervention in 120 patients who underwent endoscopic sinus surgery. Results were evaluated both by symptom questionnaire and by endoscopic follow-up examination. Over 240 data fields were collected on each patient, including information regarding presenting symptoms, endoscopic and computed tomography (CT) findings and surgical procedures performed. In order to reduce potential bias, the results of the follow-up questionnaires were compared to questionnaires from other patients unable to return for follow-up endoscopy. Mean follow-up time was 18 months. Potential prognostic variables were evaluated statistically. A strong correlation was identified between the extent of disease and the surgical outcome. Other identified potential factors appeared to have little or no significance. Therefore, a staging system for inflammatory sinus disease based on the extent of disease is suggested.

Adolescent

Nasal endoscopy in the outpatient clinic.

The introduction of the nasal endoscope has greatly advanced the diagnostic and therapeutic capability of otolaryngologists in the office setting. With continued technologic developments in endoscopic equipment and topical intranasal anesthesia, further advances are expected that undoubtedly will expand endoscopic diagnosis treatment in the office setting. Presently otolaryngologists are beginning to use endoscopes in the evaluation and treatment of nasolacrimal duct obstruction, and we are aware of one case of cerebrospinal fluid leak that has been repaired in the office setting with nasal endoscopic technique. (Lanza D: personal communication, 1991).

Ambulatory Care

Ostiomeatal complex risk factors for sinusitis: CT evaluation.

The ostiomeatal complex was prospectively evaluated in 100 consecutive patients referred for CT scanning. The degree of nasal septal angulation, uncinate process deviation (U-VS angle), infundibular and middle meatus opacification were correlated with maxillary and ethmoid sinus opacification. Patients with more severe nasal septal deviation and more horizontally-oriented uncinate processes had a higher frequency of sinus opacification. However, the differences between patients with and without CT evidence of sinus disease were very small (1.7 degrees to 3.4 degrees). Infundibular opacification most accurately predicted maxillary (76%), and middle meatus opacification most accurately predicted ethmoid sinus disease (78%). There is a small but statistically significant decrease in U-VS angulation and increase in nasal septal deviation in patients with sinusitis. However, the value of performing these measurements is limited. The evaluation of the degree of nasal septal deviation and uncinate process angulation will be most useful in preoperative planning.

Causality

Alterations in ruminal utilization of magnesium and zinc in lambs fed different ratios of concentrate: forage.

Twelve wether lambs were used to study the effects of concentrate level on ruminal utilization of Mg and Zn. Treatments consisted of concentrate: forage ratios (C:F) of 10:90, 40:60, and 70:30. Ruminal pH.hours (pH x hours area below 6.7 in 24-hour period) increased (P less than .01; linear) with increasing C:F. Bacterial intestinal Mg flow increased (P less than .01; linear) with increasing C:F and was strongly correlated with pH.hours (r = .75, P = .008). Ruminal Mg absorption was not affected (P greater than .05) by C:F, but correlated well with bacterial intestinal Mg flow (r = .66; P = .026). As with Mg, intestinal flow of bacterial Zn increased (P less than .01; linear) with increasing C:F and was highly correlated with pH.hours (r = .76, P = .006). Ruminal Zn absorption declined (P less than .05; linear) with increasing C:F and correlated well with bacterial Zn flow (r = -.82, P = .002). Data suggest that ruminal pH and (or) bacterial accumulation of Mg and Zn may compromise ruminal absorption of these minerals.

Animal Feed

Applied nasal anatomy & embryology.

The embryology & anatomy of the nose as it is applied to rhinoplasty is surveyed so that the surgeon in training can develop a basis from which to review the literature. This review demonstrates the need for the consolidation and clarification of the nomenclature associated with the complex anatomy of the nasal pyramid.

Humans

Monoclonal antibody and synthetic peptide inhibitors of human tumor cell migration.

The processes of migration and invasion by human tumor cells are likely to involve specific cell surface receptors, such as receptors for the extracellular matrix molecules fibronectin, laminin, and collagen. We have examined the roles of several of these receptors using a set of monoclonal antibodies directed against the beta 1 integrin family, as well as a series of synthetic peptides reported to inhibit various interactions of each of these proteins with the cell surface. The most general inhibitor of tumor cell migration was found to be the anti-beta 1 monoclonal antibody 13, which inhibited the migration of human HT-1080 fibrosarcoma cells, 5637 bladder carcinoma cells, VA13 viral transformants, and HCT 116 colon carcinoma cells when fibronectin was the migration substrate. Moreover, this antibody was particularly effective in blocking cell migration on laminin, as well as migration within 3-dimensional collagen gels. It also inhibited in vitro invasiveness in a reconstituted basement membrane invasion assay (Matrigel assay) at concentrations as low as 1 microgram/ml. Integrins of the beta 1 class thus appear to play a central role in several types of migration by a variety of human tumor cell lines. Anti-alpha 5 fibronectin receptor monoclonal antibody 16 also significantly inhibited migration on fibronectin, but not on other substrates, in 3 of the 4 cell lines. Conversely, anti-alpha 2 monoclonal antibody F17 strikingly inhibited migration in 3-dimensional collagen gels, but not on other substrates, implicating the alpha 2 beta 1 integrin system in migration of tumor cells within collagenous matrices. A series of synthetic peptides previously reported to inhibit interactions of normal cells with fibronectin, laminin, and collagen were also tested as inhibitors of tumor cell migration. Peptides containing the Arg-Gly-Asp adhesive recognition signal were partially inhibitory, but with occasional exceptions, most other peptides had no effects on migration. Our results indicate the central importance of several specific beta 1 integrins in human tumor cell migration and show the effectiveness of monoclonal antibody treatment in blocking this process in vitro.

Amino Acid Sequence

Endoscopic transnasal orbital decompression.

Orbital decompression for dysthyroid orbitopathy has traditionally been performed through either an external or a transantral approach. The advent of intranasal endoscopes allowed for the development of a transnasal approach for medial and inferior orbital wall decompression. Using this approach, orbital decompressions were performed on 13 orbits in eight patients with severe complicated dysthyroid orbitopathy. Simultaneous bilateral lateral orbitotomies were performed on five patients. Walsh-Ogura decompressions and lateral orbitotomies were performed on two orbits. When combined with lateral orbitotomy, Hertel measurements improved an average of 5.7 mm in orbits decompressed transnasally and 4.5 mm in orbits decompressed with a Walsh-Ogura approach. Transnasal decompression alone improved Hertel measurements an average of 4.7 mm. Visual acuity improved in three of four patients with optic neuropathy, and in all patients with exposure keratopathy. We conclude that the endoscopic transnasal approach provides comparable decompression to traditional methods while avoiding the morbidity of an external ethmoidectomy or Caldwell-Luc antrotomy.

Adult

A comparison of past and future leisure activity participation between spinal cord injured and non-disabled persons.

Leisure activity profiles of 81 male and 21 female SCI subjects were compared with profiles of 135 male and 151 female non-disabled individuals. These profiles, derived from the Leisure Activities Blank (McKechnie, 1985), revealed that SCI subjects had been more physically active (prior to injury) than those in a non-disabled comparison group; however, their post-injury expectations for future leisure activity involvement were considerably lower than a similar study of non-disabled individuals. These reduced expectations were found for both active and sedentary activity categories. It is suggested that awareness of pre-morbid leisure activity profiles, plus recognition that post-injury expectations for leisure activity participation are often reduced, could assist medical personnel to prescribe treatment or offer programmes that enable SCI patients to maintain their pre-morbid lifestyles and enhance future leisure activity expectations.

Adolescent

Comparative biodegradation of alkyl halide insecticides by the white rot fungus, Phanerochaete chrysosporium (BKM-F-1767).

The ability of Phanerochaete chrysosporium to degrade six alkyl halide insecticides (aldrin, dieldrin, heptachlor, chlordane, lindane, and mirex) in liquid and soil-corncob matrices was compared by using 14C-labeled compounds. Of these, only [14C]lindane and [14C]chlordane underwent extensive biodegradation, as evidenced by the fact that 9.4 to 23.4% of these compounds were degraded to 14CO2 in 30 days in liquid cultures and 60 days in soil-corncob cultures inoculated with P. chrysosporium. Although [14C]aldrin, [14C]dieldrin, [14C]heptachlor, and [14D]mirex were poorly mineralized, substantial bioconversion occurred, as determined by substrate disappearance and metabolite formation. Nonbiological disappearance was observed only with chlordane and heptachlor.

Aldrin

First-line management of sinusitis: a national problem? Overview.

Traditional concepts of sinus disease as primarily involving the maxillary sinuses are giving way to understanding of the primary involvement of the ostiomeatal complex. Recognition of predisposing factors is also improving, as is localization of disease in the ethmoid, maxillary, frontal, and sphenoid sinuses. Because of the interdependence of the sinuses, acute sinusitis is rarely limited to one sinus. The diagnosis of acute disease is relatively easy compared with that of chronic sinusitis, which mimics many other conditions. Antibiotics and decongestants typically constitute initial therapy for acute sinusitis, and surgery is reserved for patients with threatened complications. The principal goal of this symposium is to outline the most rational approach to treatment of sinus disease on the basis of currently available diagnostic and therapeutic techniques. Emphasis will be placed on first-line management, on therapeutic response, and on objective evaluation of therapeutic efficiency.

Acute Disease