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Biomedical subjects

D A Leopold

Publications and source records attributed to D A Leopold.

At least 19 recordsLinked to original sources
PubMed1992

Evaluation of poly(L-lactic acid) as a material for intravascular polymeric stents.

Poly(L-lactic acid) (PLLA) monofilaments were evaluated for use as intravascular polymeric stents. The PLLA monofilaments were extruded and drawn to different draw ratios. They were then subjected to different thermal treatments and their mechanical properties characterized. Stents constructed with similar monofilaments were tested under hydrostatic pressure, and the results correlated with the properties of the monofilaments. Stent collapse pressure was a decreasing function of stent diameter and filament draw ratio.

Biocompatible Materials↗
PubMed1992

Congenital lack of olfactory ability.

Twenty-two patients, all of whom reported never having been able to smell anything, were studied to determine the particular features that distinguish individuals with congenital anosmia. The clinical evaluation on these patients included a thorough medical and chemosensory history, physical examination, nasal endoscopy, chemosensory testing, olfactory biopsies, and imaging studies. There was no evidence to indicate that these patients ever had a sense of smell. The results of olfactory testing suggested that these patients had an inability to detect both olfactory and trigeminal odorants; however, many of the patients in the group seemed to have a slight ability to perceive at least some component of trigeminal odorants. The olfactory epithelium, if it was present at all on biopsy, was abnormal in appearance.

Adolescent↗
PubMed1992

Pollution: the nose and sinuses.

The nose and sinuses are constantly exposed to the huge quantities of gases needed to maintain life. Not only is the human nose well-equipped to warm and humidify this inhaled air, but it is also uniquely able to clean much of it. Any material other than physiologic amounts of oxygen, nitrogen, carbon dioxide, and water that accompanies the airstream can be considered a pollutant, and this pollutant could potentially injure the individual. The following discussion will review the defense mechanisms that allow the nose and sinuses to protect the lower airways. The effects of pollutants on the respiratory mucosa will then be described, including some recent trends in those effects. These trends include specific population consequences of indoor and outdoor air pollution, and changes in risk for individuals in several occupations. Throughout these discussions, specific areas that would benefit from further research will be mentioned.

Airway Resistance↗
PubMed1991

Successful treatment of phantosmia with preservation of olfaction.

A 26-year-old woman had an 8-year history of phantosmia in her left nostril. The phantosmia could be eliminated by nostril occlusion or cocainization of the olfactory epithelium on the involved side. Because her symptoms and testing suggested a peripheral problem, a full-thickness "plug" of olfactory epithelium from under the cribriform plate (including all the fila olfactoria) was excised. At 5 weeks postoperatively, the phantosmia was completely gone, and her olfactory ability had returned to preoperative levels. Either the removal of abnormal peripheral olfactory neurons from the nose or the interruption of incoming signals to the olfactory bulb eliminated the phantosmia. This form of therapy for phantosmia offers an alternative to more radical procedures such as olfactory bulbectomy and may offer a significant sparing of olfactory ability.

Adult↗
PubMed1991

Disorders in taste and smell.

Although many conditions and medications have been associated with chemosensory disturbances, data from major chemosensory clinical research centers support three major disorders as being causative: nasal and paranasal sinus disease (21%), post-upper respiratory tract viral infection (19%), and head trauma (14%). Despite extensive evaluation, 22% of patients do not demonstrate identifiable causation.

Craniocerebral Trauma↗
PubMed1990

Fish-odor syndrome presenting as dysosmia.

We describe a patient who had perceived an unpleasant odor or taste for at least 20 years. Several other physicians had unsuccessfully treated her for infections, mucus membrane dryness and inflammation, chronic tonsillitis, and psychiatric disorders. Her workup at the State University of New York Health Science Center at Syracuse Olfactory Referral Center included a thorough history, examinations (including endoscopic studies of her nose, pharynx, and lungs), roentgenograms, taste testing, olfactory testing, and selective anesthesia of her chemosensory areas. The perception occurred only during exhalation, and appeared to be binasal. These findings, together with her morning mucus sample having a strong fishlike odor, prompted us to suspect a metabolic problem. Further testing at the Monell-Jefferson Chemosensory Clinical Research Center, Philadelphia, Pa, confirmed that she had trimethylaminuria. It is important to consider this and other treatable conditions when evaluating individuals with olfactory complaints.

Adult↗
PubMed1988

Hospital mortality for otolaryngologic disorders in New York State.

Hospital mortality in New York State during 1983, 1984, and 1985 for diagnosis related groups (DRGs) that addressed principal diagnoses of otolaryngologic disorders was evaluated. Inpatient data from 291 acute care hospitals in the state indicated that 66.6% of hospital mortality for these conditions was produced in a single category, DRG 64--Ear, Nose, and Throat Malignancy (treated medically). Other otolaryngologic DRGs that were sources of hospital mortality in New York State addressed otitis media and upper respiratory tract infections for elderly persons and patients with complications who were treated medically, a wide range of ear, nose, and throat diagnoses that were treated medically, major head and neck surgical procedures, and a wide range of other surgical procedures for malignant neoplasms. This information should contribute to the evaluation of disease trends that cause mortality in individual hospitals, statewide and nationwide, as well as to efforts at evaluation of quality of care in otolaryngology.

Adolescent↗
PubMed1988

The relationship between nasal anatomy and human olfaction.

The relationship between nasal anatomy and olfactory ability was evaluated by correlating measurements from nasal cavity CT scans with the results of an established clinical measure of olfactory function (Odorant Confusion Matrix, or OCM). The most appropriate mathematical model of this relationship was developed by analyzing the logarithms of 30 anatomical measures and a logistic transform of the OCM percent correct score. Two nasal cavity regions were found to be the most important factors in accounting for the olfactory test results, with a third region modifying the effects of the first two. The results of this study suggest that nasal anatomy may play a role in controlling the access of an odorant to the olfactory receptor area. The conclusions of this study have implications for nasal surgeons who, when possible, should make attempts to repair or preserve these nasal regions which seem to be so important to olfactory function.

Humans↗
PubMed1987

Airflow patterns in a human nasal model.

Nasal airflow patterns were studied by using xenon 133 gas to image the course taken by air as it flowed through a plastic model of the human nasal cavity. The model was produced from the head of a human cadaver, and was anatomically correct. A needle catheter was used to infuse the radioactive xenon into a continuous flow of room air maintained through the model by a variable vacuum source connected to the nasopharynx. The radioactive gas was infused at one of five release sites in the nostril, and the distribution of the radioactivity was imaged in the sagittal plane with a scintillation camera. The data were organized to show the activity in six contiguous regions of the midnose. For each catheter, release site activity patterns were determined for three flow rates. The results of this experiment showed that both catheter position and flow rate had significant and reproducible effects on the distribution of radioactivity within the model.

Catheterization↗
PubMed1986

Patterns of otolaryngologic surgery utilization in Syracuse, NY.

Utilization of otolaryngologic surgical procedures performed in Syracuse, NY, during 1983 and 1984 was evaluated. Both inpatient and outpatient procedures were included; classification was according to diagnosis related groups. The system-wide portion of the analysis demonstrated that 62.5% of otolaryngologic operations carried out during the study were performed in outpatient settings. Total utilization was highest for myringotomies, tonsillectomies, and adenoidectomies, over 80% of which were performed on an outpatient basis. The program-specific portion of the analysis indicated that the highest volumes for these procedures were produced by a free-standing ambulatory surgery program with dedicated facilities and staff. However, a hospital-integrated program, which made use of inpatient resources, also served a majority of total hospital cases for several types of procedures.

Adenoidectomy↗
PubMed1985

Components of the alternative pathway of complement in otitis media with effusion.

An evaluation of the alternative pathway of complement was undertaken in patients with otitis media with effusion (OME). Middle ear fluid (MEF) and serum specimens were obtained from 34 patients at the time of elective myringotomy for OME. Bacterial, viral, and mycoplasma cultures were made for all specimens of the fluids. Immunochemical determinations by radial immunodiffusion were performed for C3, C5, factor B, properdin, factor H, factor I, and albumin. Each patient's recent clinical course and past history were reviewed. The results of all viral and mycoplasma cultures were negative. Three of 55 bacterial cultures were positive for type B Haemophilus influenzae. All components of the alternative pathway measured were found to be present in varying amounts in MEF. When the levels of the complement components were compared to the clinical factors studied, there were no observable differences. These data suggest that components of the alternative pathway of complement are present in OME and are not useful in predicting the clinical course or outcome of this disorder.

Adolescent↗
PubMed1984

Benign osteoblastoma. Report of a case and review of the literature.

Benign osteoblastoma is a rare lesion of bone, usually confined to the long bones and the vertebrae. There have been 16 cases reported in the calvarium and only four in the frontal bone. We treated a patient with benign osteoblastoma of the frontal bone (supraorbital ridge and roof of orbit), and we review the literature. The histologic and radiologic characteristics are described and the treatment modalities are reviewed.

Adolescent↗
PubMed1984

Diagnosis-related groups analysis of medical care in four American cities.

The introduction of diagnosis-related groups (DRGs) into American medical care is having a considerable impact on hospital finance and utilization. Patterns of patient care for individual physicians will also be assessable with this system. We evaluated a one-year sample of data on hospital admissions for ear, nose, and throat disorders in four comparable American cities for length of stay variations. The trends from city to city included a wide variation in rates of admission per population of 100,000, especially in the major head and neck surgery category. Patterns of disease, specifically with regard to dysequilibrium and childhood salivary glands, may be a potentially unknown problem for the communities involved. Even though the present DRG system may be an oversimplified method of describing medical care, it does provide useful information for otolaryngologists-head and neck surgeons.

Costs and Cost Analysis↗
PubMed1984

Local excision and radiotherapy for cancer of the oral tongue. A preliminary report.

A group of 18 patients with squamous cell carcinoma of the mid one-third of the tongue was treated by local resection and planned postoperative radiotherapy between 1976 and 1980. Tumors 0.5 cm or greater in thickness were included; no patients had cervical adenopathy. Six were categorized as T1, 10 as T2 and two as T3. In eight patients, histologic review showed tumor extension at or near the resection margin, despite a tumor-free margin at frozen section, while in 10 patients the margins were clear. Local tumor control was achieved in 16 patients (89%). Two failures were evident within 3 months after completion of treatment. The relatively short follow-up of such a small series limits the conclusions from this preliminary study, but the excellent results thus far merit further study.

Adult↗
PubMed1983

Laryngeal trauma. A historical comparison of treatment methods.

In the last 20 years, several authors have reported their experience with the treatment of laryngeal trauma. Over 200 cases of laryngeal trauma in the literature were reviewed and compared with the experience at Upstate Medical Center, Syracuse, NY. Special attention was paid to surgical v medical treatment, type and duration of stenting techniques, and time interval between injury and surgery. Results were compared in terms of voice and airway status. If surgical treatment is not required, the results for airway and voice are generally excellent. In those cases requiring open surgical treatment, the adequacy of airway was independent of the use or method of stenting. Superior voice results were obtained when stenting was not used. In general, better results were obtained when treatment was carried out within the first 24 hours.

Airway Obstruction↗
PubMed1982

Paradoxical vocal cord motion: an important cause of stridor.

Paradoxical vocal cord motion (PVCM) is an important cause of laryngeal stridor and dysphonia; however, only two previous cases have been reported. We report three additional cases, one of which was tracheotomized on two occasions before the diagnosis was made. These patients, typically young females who have had a recent upper respiratory infection, present with stridor. They can phonate weakly, but they cannot cough. Indirect laryngoscopy reveals smooth, symmetric vocal cord adduction on inspiration and abduction on expiration. Laboratory values are normal. PVCM appears to be self-limited (up to 72 hours), and patients respond to supportive care and sedation. Tracheotomy appears to be unnecessary. The etiology is obscure and may be functional; however, a case is discussed in which PVCM was seen in association with chronic aspiration in a patient with organic brain syndrome. An awareness of this entity and a high index of suspicion can prevent unnecessary tracheotomy.

Adolescent↗