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Biomedical subjects

D W Kennedy

Publications and source records attributed to D W Kennedy.

At least 73 records · Page 4Linked to original sources
PubMed1992

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↗
PubMed1992

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↗
PubMed1991

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↗
PubMed1991

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↗
PubMed1991

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↗
PubMed1990

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↗
PubMed1990

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↗
PubMed1990

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↗
PubMed1990

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↗
PubMed1990

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↗
PubMed1990

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

Radical stripping of diseased sinus mucosa has been considered the correct surgical approach to chronic sinusitis on the basis that severe mucosal thickening was irreversible. Now, nasal endoscopy has disproved this belief by showing that chronic sinusitis is primarily a disease of obstruction, with inflammation as a secondary manifestation. Once obstruction is surgically corrected and ventilation restored, the mucosa may regain near-normal appearance and function. For chronic sinusitis that fails to respond to antibiotic therapy--and for recurrent acute sinusitis associated with abnormalities of the ostiomeatal complex--functional endoscopic sinus surgery offers the patient real hope of permanent relief from symptoms of sinusitis. Careful postoperative follow-up with endoscopic evaluation enhances effectiveness of this more recent approach to sinus surgery. The importance of presurgical evaluation via endoscopy and computed tomography cannot be overemphasized.

Endoscopy↗
PubMed1990

Endoscopic management of cerebrospinal fluid leaks and cephaloceles.

The excellent visualization and atraumatic surgical techniques of endoscopic sinus surgery have been applied to the management of five cerebrospinal fluid leaks and two nasal cephaloceles. In all cases, the exact site of the lesion was identified. Four cerebrospinal fluid leaks were grafted with a free or pedicled septal mucosal graft. The fifth cerebrospinal fluid leak came from a narrow sphenoethmoid recess and stopped after the mucosa was abraded. The two cephaloceles were reduced intranasally and covered with bone and mucosal grafts. Not all cases seen in the same time period were treated endoscopically; two additional cerebrospinal fluid leaks were treated with conventional techniques because of severe nasal inflammatory disease and intracranial complications. The technique and indications for endoscopic management of cerebrospinal fluid leaks and cephaloceles are discussed.

Adult↗
PubMed1989

Reevaluation of maxillary sinus surgery: experimental study in rabbits.

Functional endoscopic sinus surgery concentrates primarily on the removal of ostiomeatal complex disease. When required, maxillary sinus ostioplasty is performed. However, surgical widening of a sinus ostium is contrary to common precepts. A study therefore was performed to reevaluate the effects of antrostomies and of intrasinus mucosal removal. Widening of the natural ostium, a separate antrostomy at some distance from the ostium, or radical mucosal removal was performed on 30 rabbits. Fifteen sinuses were used as controls. After 6 to 8 weeks the status of the sinus mucosa and mucociliary clearance was studied. The study confirmed that mucociliary clearance continued toward the natural ostium following inferior antrostomy. Following widening of the natural ostium, mucociliary clearance through the ostium redeveloped in 11 of 18 sinuses but was typically imperfect. There were no cases of ostial closure; however, the incidence of infection was significantly higher in all three experimental groups than in the control group.

Animals↗
PubMed1989

Endoscopic sinus surgery for mucoceles: a viable alternative.

Functional endoscopic surgery affords the potential for dramatically reducing operative morbidity of surgery for paranasal sinus mucoceles by offering a minimally invasive approach under local anesthesia. Following surgery, direct endoscopic visualization of the area enables accurate follow-up. Unlike sinus obliteration, the ability to accurately image the sinus by CT is also preserved. This paper presents our preliminary experience with 18 mucoceles in which endoscopic sinus surgery was attempted. Five patients had preoperative proptosis and diplopia, three had Pott's puffy tumor and five had erosion of the posterior table of the frontal sinus. Fifteen patients were satisfactorily treated endoscopically, two lesions could not be satisfactorily approached and required external surgery, and one patient had persistent disease. No disease recurrence has been noted to date with endoscopic follow-up of up to 42 months.

Adolescent↗
PubMed1989

Difficult decisions in endoscopic sinus surgery.

Sinus disease, like many other problems in otolaryngology, may run the gamut of being either easily correctable with a clear-cut treatment or completely resistant to any form of treatment. Fortunately, many patients have problems somewhere between these two extremes. Clearly there is no one correct approach for treatment of many problems. Two, three, or even four approaches may be equally effective in some cases. In other cases, one approach may be successful in the hands of one surgeon whereas another approach is more appropriate for a different surgeon. This article presents nine cases that do not have clear-cut solutions. In some, the consultants clearly disagreed, whereas in others there was some uniformity in treatment plans. This flexibility in surgery in general and specifically with a technique that is relatively new is what makes it so exciting and so promising for continued success in treating sinus disease.

Adult↗
PubMed1988

Peripheral but not thymic T cells participate in an autoreactive T cell network.

Splenic T cells proliferate in response to the anti-I-Ab reactive T cell hybridoma T1.203 in an H-2-restricted but MHC antigen-independent manner. We propose that this anti-idiotypic response is mediated by "Type 2 autoreactive" T cells that are induced in peripheral lymphoid tissues following interaction with the particular idiotype expressed by the anti-self-I-A T cells. Thus, we define this phenomenon as an idiotype-restricted MHC-related cell interaction. To study the ontogeny of this response, we examined the distribution of Type 2 autoreactive cells. Spleen and lymph node but not thymic C57BL/6 T cells vigorously proliferate to T1.203. Mature (PNA-) as well as immature (PNA+) thymic T cells respond poorly. The frequency of cells responding to T1.203 is far greater in the spleen than in the thymus. The responding T cells were of both Lyt 1+ and Lyt 2+ T phenotype. The results suggest that Type 2 autoreactive cells are induced in peripheral lymphoid tissues following interaction with anti-I-A autoreactive T cells which escape from the thymus or develop in the periphery.

Age Factors↗