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Biomedical subjects

J J Pappas

Publications and source records attributed to J J Pappas.

At least 19 recordsLinked to original sources
PubMed2000

RARbeta involvement in enhancement of lung tumor cell immunogenicity revealed by array analysis.

The retinoid receptors (RARs and RXRs) are mediators of the multiple effects of retinoic acid. Of these, the retinoic acid receptor beta2 (RARbeta2) has frequently been shown to be the principal mediator of the growth and tumor suppressive effects of retinoic acid; this gene is inactivated in many epithelial tumors and their derived cell lines. We have searched for genes that are regulated by this isoform and are potentially involved in tumor suppression. Using the Atlas human cDNA array I, we identified 27 genes (not counting RARbeta itself) that are regulated, directly or indirectly, by RARbeta2 when it is transfected into Calu-1, a lung tumor-derived line that does not normally express RARbeta. Several of the affected genes code for proteins whose functions would augment the process of apoptosis and/or the host's immune response. The latter group included ICAM-1 and MHC class I heavy chain, whose protein products play particularly important roles in the mounting of an effective anti-tumor response. We then confirmed by flow cytometry that the observed increases in message levels were reflected in increased cell surface protein levels for ICAM-1 and MHC class I in RARbeta2 transfectants of two RARbeta-deficient lines, Calu-1 and the epidermoid lung cancer-derived line SK-MES. Finally, we showed that RARbeta2 transfection of Calu-1 cells enhanced the heterologous CTL response in both the induction and the effector phases by up to threefold. These results support the hypothesis that down-regulation of these genes (and possibly others) in RARbeta-deficient tumor cells contributes to immune system evasion, and suggest a novel therapeutic approach for this disease.

Apoptosis↗
PubMed1996

Implementing a Web-based clinical information system using EMR middle layer services.

The Clinical Summary is a Web-based application for accessing the clinical database at the Massachusetts General Hospital. The application has been developed to give physicians in our health care community access to clinical information for patients they refer to our hospital. "Middle layer" services, written previously for the hospital's clinical workstation, supply much of the application's functionality. Employment of reusable services together with a Web-based front end has afforded a rapid and inexpensive means for developing a new clinical information system. This paper discusses the system's design, function, and methods of implementation.

Computer Communication Networks↗
PubMed1996

A component-based, distributed object services architecture for a clinical workstation.

Attention to an architectural framework in the development of clinical applications can promote reusability of both legacy systems as well as newly designed software. We describe one approach to an architecture for a clinical workstation application which is based on a critical middle tier of distributed object-oriented services. This tier of network-based services provides flexibility in the creation of both the user interface and the database tiers. We developed a clinical workstation for ambulatory care using this architecture, defining a number of core services including those for vocabulary, patient index, documents, charting, security, and encounter management. These services can be implemented through proprietary or more standard distributed object interfaces such as CORBA and OLE. Services are accessed over the network by a collection of user interface components which can be mixed and matched to form a variety of interface styles. These services have also been reused with several applications based on World Wide Web browser interfaces.

Computer Communication Networks↗
PubMed1984

Small fenestra stapedectomy: technique and advantages.

We discuss the rationale and advantages of the small fenestra technique (SFT) of stapedectomy. When results from conventional stapedectomy techniques are compared with those of SFT, the small fenestra technique shows improved hearing in the high frequencies of 2,000, 4,000, and 8,000 Hz, improved speech discrimination, reduced vestibular disturbance, and reduced iatrogenic trauma to the cochlea.

Auditory Threshold↗
PubMed1983

Small fenestra stapedectomy technique: reducing risk and improving hearing.

During the past 25 years many variations have emerged in stapedectomy, most of which centered around either a change in the prosthesis itself or in the type of oval window seal. The small fenestra stapedectomy technique (SFT) represents a change in surgical procedure rather than in prosthetic design. This technique offers the opportunity to improve hearing results while reducing risks in stapedectomy surgery. Four areas of significant improvement are seen in patients in whom the SFT was used: (1) improved hearing in the high frequencies of 2000, 4000, and 8000 Hz, (2) improved speech discrimination scores, (3) a significant reduction in the number of reported vestibular complaints, and (4) a reduction in the number of serious postoperative sensorineural hearing losses.

Ear, Middle↗
PubMed1981

Small fenestra stapedectomy. A preliminary report.

The small fenestra stapedectomy is based on a rationale of creating a more effective acoustical mechanical transmission system, while reducing potential labyrinthine disturbance. Surgical technique for the small fenestra stapedectomy is described, including the creation of the fenestra and the use of McGee stainless steel piston prosthesis with loose areolar tissue around the piston. Postoperative results are compared in a series of 100 cases, 50 having the small fenestra technique, SFT, and 50 having partial or total footplate removal procedure. Vestibular results demonstrate a noticeable reduction in postoperative complaints of balance disorders in the SFT patients. Hearing results, when compared between the two groups, show a statistically significant advantage for the SFT patients in postoperative high frequency threshold sensitivity and speech discrimination scores. Technical difficulties in creating the fenestra without fracturing the entire footplate are discussed and suggestions made for their avoidance. The advantages of lowered risk, based on reduced trauma to and contamination of the labyrinth, as well as improved high frequency hearing sensitivity and speech discrimination, support the use of this procedure and call for further investigation and development of its clinical potential.

Audiometry↗
PubMed1981

Homograft septal cartilage for attic support in intact canal wall tympanomastoidectomy and tympanoplasty.

The postoperative formation of attic retraction pockets following tympanoplasty, with or without mastoidectomy, has often been a significant cause of recurrent disease accompanied by decreased hearing levels. Nasal septal cartilage is recommended as a successful homograft material for attic support. The basis and indications for its use are discussed. Preparation and storage of the homograft materials and surgical technique are described. Long-term results are reported, including a special group in which the status of the homograft material was assessed during revision surgery. Minimal complications have been encountered. Conclusions support the overall advantages of this technique utilizing homograft septal cartilage as an effective means of posterosuperior canal wall support, an aid in preventing retraction pocket formation.

Adolescent↗
PubMed1979

Round window ultrasonic irradiation: conservative surgery for Meniere's disease.

Ultrasonic irradiation of the labyrinth through the round window approach is a minimally destructive method of surgical management for Meniere's disease. Results of 48 procedures, followed from six months to eight years, are reported. Relief from vertiginous symptoms was obtained in 70 percent of the patients. Hearing was improved in 14 percent; hearing was also significantly worse in 14 percent. These findings resulted in an overall 56 percent of the patients falling into American Academy of Otolaryngology control classes A or B. No significant postoperative complications were observed. Results are difficult to classify on a cause-and-effect basis due to the remissions and exacerbations characteristic of Meniere's disease. Ultrasonic irradiation using the round window approach does not involve the potential risks of such surgical procedures as labyrinthectomy, vestibular neurectomy, and endolymphatic sac procedures. The primary disadvantage of this procedure is securing and servicing the instrumentation. Due to its conservative nature, ultrasonic irradiation through the round window is an attractive surgical consideration until such time when the pathologic processes in Meniere's disease are better understood.

Adult↗
PubMed1978

Total hearing rehabilitation: within-clinic hearing aid dispensing.

Federal (FDA) regulations recently passed require physician clearance before hearing aid sales. Discussed herein are numerous evaluative and rehabilitative procedures necessary for proper hearing aid fittings. A program of total professional management of the hearing rehabilitation process, including the direct dispensing of hearing aids by the otology-audiology team, is described and advocated.

Audiology↗
PubMed1978

O.P.S.C.: improving delivery of otolaryngological surgical care.

Results of over two years' experience with an outpatient surgical center within a private otolaryngology clinic have demonstrated several advantages. Discussed herein are the history of outpatient surgical centers, and the development of our within clinic O.P.S.C. (Outpatient Surgery Center). Developmental stages described include investigation of liability exposure, securing state health department approval, enactment of state legislation, staffing, equipment, and obtaining third party carrier approval. Advantages to the patient, otolaryngologist, community, and third party carriers are enumerated. Statistics regarding types and numbers of procedures performed and types of anesthesia used are included. Experience with the O.P.S.C. indicates that it is a means of improving the delivery of otolaryngological surgical care.

Arkansas↗