The arden syntax for medical logic modules

The Arden Syntax for sharing medical knowledge bases is described. Its current focus is on knowledge that is represented as a set of independent modules that can provide therapeutic suggestions, alerts, diagnosis scores, etc. The syntax is based largely upon HELP and the Regenstrief Medical Record System. Each module, called a Medical Logic Module or MLM, is made of slots grouped into maintenance, library, and knowledge categories. The syntax has provisions for querying a clinical database and representing time. Several clinical information systems were analyzed and appear to be compatible with the syntax. The syntax has been tested for syntactic ambiguities using the tools lex and yacc. Seventeen institutions are currently in the process of adopting the Arden Syntax for their decision-support systems. A subcommittee of ASTM has been formed to develop standards for sharing medical knowledge bases. The Arden Syntax has been published by ASTM as a initial standard for sharing medical knowledge.     

Natural history and treatment of anorectal strictures complicating Crohn's disease

Forty-four patients seen between 1975 and 1985 with anorectal strictures complicating Crohn's disease have been reviewed to determine the natural history and outcome of surgical treatment. Proctitis was present in 98 per cent, and 93 per cent of patients had sever perianal disease. The site of strictures was rectal in 22, anal in 15 and anorectal in 11 (4 patients had a stricture at 2 sites). Initial treatment was by rectal excision alone in 6, dilatation in 33, and 5 needed no treatment at all. Single dilatation was effective in 15, 8 required two dilatations and in 10 repeated dilatation was necessary. Proctocolectomy was eventually required in 19 patients, 2 have a loop ileostomy and 1 has an ileostomy with a rectal stump in situ. Only 21 remain asymptomatic while 3 continue to need dilatation. Perineal wound healing was delayed in 9 of 19 patients having a proctocolectomy and in 3 the perineal wound has never healed.     

Adenylate cyclase activity as a predictor of thyroid tumor aggressiveness

Prior studies in our laboratory have shown that human thyroid neoplasms have a greater adenylate cyclase activity in response to thyroid stimulating hormone (TSH) than does the adjacent histologically normal thyroid tissue. However, there is little information relating activity of the TSH receptor-adenylate cyclase system to the type of thyroid neoplasm. Thyroid tissue from 67 patients was divided by clinical and histological criteria into 6 categories: normal (59), benign tumors (20), stage 1 carcinoma—intrathyroidal involvement only (25), stage 2 carcinomaregional lymph node involvement (6), stage 3 and 4 carcinoma—tissue invasion or distant metastasis (11), and medullary carcinoma (3). Adenylate cyclase activity in an 8,000 x g thyroid membrane preparation was determined in the basal state and when maximally stimulated with 300 mU/ml TSH. The cyclase responsiveness was the ratio of TSH stimulated adenylate cyclase activity compared to basal adenylate cyclase activity. The cyclase responsiveness by category is: normal, 2.8±0.2 (mean ± SEM); benign, 17.9±2.4; stage 1 carcinoma, 9.2±1.9; stage 2 carcinoma, 4.0±1.0; stage 3 and 4 carcinoma, 1.6±0.4; and medullary carcinoma, 1.05±0.04 (for the neoplasms,p <0.02 by ANOVA). Tumor stage was the only correlate with this trend as other prognostic risk factors (age, sex, a history of neck irradiation, or papillary versus follicular histology) showed no difference in cyclase responsiveness. These studies demonstrate a consistent inverse correlation between adenylate cyclase responsiveness and tumor stage or aggressiveness. Cyclase responsiveness appears to have clinical application for predicting which thyroid tumors will behave aggressively.

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Resumen Estudios previos en nuestro laboratorio han demostrado que los neoplasmas tiroideos humanos poseen una mayor actividad de adenilato ciclasa en respuesta a la administración de hormona estimulante de la tiroides (TSH) que el tejido tiroideo histológicamente normal adyacente. Sin embargo, existe muy poca información sobre la relation de la actividad del sistema receptor de TSH-adenilato ciclasa y el tipo del neoplasma tiroideo. Tejido tiroideo proveniente de 67 pacientes fue dividido mediante criterios chlínicos e histológicos en 6 categorias: normal (59), tumores benignos (20), extensión intratiroidea solamente en estado 1 (25), carcinoma-extensión ganglionar regional en estado 2 (6), carcinoma-invasión tisular o metástasis distantes en estados 3 y 4 (11), y carcinoma medular (3). La actividad de la adenilato ciclasa en una preparación de membrana tiroidea de 8,000 × g fue determinada en el estado basai y en estado de maxima estimulación con 300 mU/ml TSH. El grado de respuesta de la ciclasa fue la tasa de actividad de la adenilato ciclasa estimulada por TSH comparada con la actividad basai de la adenilato ciclasa. El grado de respuesta por categorías fue: normal, 2.8±0.2; tumor benigno, 17.9±2.4; carcinoma estado 1, 9.2±1.9; carcinoma estado 2, 4.0±1.0; carcinoma estados 3 y 4, 1.6±0.4; y carcinoma medular, 1.05±0.04 (para los neoplasmas,p < 0.02 por ANOVA). El estado del tumor apareció como el único factor de correlatión con esta gradación, ya que otros factures de pronóstico (edad, sexo, historia de irradiación cervical, histología papilar versus folicular) no demostraron diferencia en cuanto al grado de respuesta de la ciclasa. Estos estudios demuestran una consistente relación inversa entre el grado de respuesta de la adenilato ciclasa y el estado o agresividad tumoral. El grado de respuesta de la ciclasa parece tener aplicación clínica para predecir qué tumores tiroideos se habrán de comportar en forma agresiva.

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Résumé Les études antérieures provenant de nos laboratoires ont démontré une augmentation de l'activité enzymatique de l'adénylate-cyclase en réponse à la thyroïd stimulating hormone (TSH) dans le tissu thyroïdien humain tumoral, par rapport au tissu thyroïdien adjacent normal. Cependant il existe peu de données concernant l'activité du système récepteur TSH/adénylatecyclase par rapport au type de tumeur de la thyroïde. Les tissus thyroïdiens provenant de 67 patients différents ont été repartis en 6 groupes selon des critères cliniques et histologiques: normal (59), tumeur bénigne (20), cancer stade 1 (intrathyroïdien uniquement) (25), cancer stade 2 (envahissement ganglionnaire régional) (6), cancer stade 3 et 4 (envahissement tissulaire avoisinant ou métastases à distance (11), et cancer médullaire (3). A partir d'une préparation de membrane thyroïdienne centrifugée à 8,000 × g, l'activité de l'adénylate-cyclase a été déterminée en l'état basai et après stimulation maximale par 300 mU/ml de TSH. La réponse enzymatique a été mesurée comme étant le rapport de l'activité stimulée par la TSH/activité basale. Les résultats selon les 6 groupes étaient (moyen±ET): tissu normal, 2.8±0.2; tumeur bénigne, 17.9±2.4; cancer stade 1, 9.2±1.9; cancer stade 2, 4.0±1.0; cancers stade 3 et 4, 1.6±0.4; et cancer médullaire, 1.05±0.04 (p < 0.02 par l'analyse de variance pour les néoplasies). Le stade tumoral était la seule variable corrélée avec l'activité enzymatique. L'activité enzymatique n'était pas corrélée avec l'âge, le sexe, les antécédents d'irradiation cervicale antérieure ou l'histologie (papillaire vs. folliculaire). Ces études montrent un rapport inversement proportionnel entre l'activité d'adénylate-cyclase et le degré d'agressivité tumorale ou le stade. La réponse d l'adénylate-cyclase paraît avoir une application clinique: prévoir quelles tumeurs thyroïdiennes auront une évolution agressive.

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Presented at the International Association of Endocrine Surgeons in Sydney, Australia, September, 1987.

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Supported in part by the Medical Research Service of the Veterans Administration.     

Variation in evoked potential measures over the menstrual cycle: A pilot study

Nancy Kluck, Scan J. O'Connor, Victor M. Hesselbrock, Allan Tasman and Donald Maier, Lance Bauer: Variation in Evoked Potential Measures Over the Menstrual Cycle: A Pilot Study. Prog. Neuro. Psychopharmacol. Biol. Psychiat. 1992. 16(6): 901–911.

1. 1. The P3 component of a visual event related potential (ERP) was studied for five consecutive weeks in six women with normal menstrual cycles. Serum concentrations of luteinizing hormone (LH), estradiol (E2) and progesterone were studied during the same period.

2. 2. Increases in P3 amplitude, although nonsignificant, were noted in the week preceding onset of menses.

3. 3. No significant changes in reaction times to target/nontarget stimuli were noted over the same time period.

Uncomplicated amebic liver abscess: prospective evaluation of percutaneous therapeutic aspiration.

The performance of therapeutic aspiration in the treatment of amebic liver abscess, advocated and practiced in many centers, is controversial. Previously, this practice has been evaluated in retrospective analyses. To test the potential benefit of therapeutic aspiration, the authors undertook a prospective randomized trial in 57 patients admitted for suspected amebic liver abscess during a 15-month period. Sixteen patients were excluded from the trial. The remaining 41 patients were randomly included in one of two study groups to receive amebicidal therapy alone or amebicidal therapy coupled with image-guided percutaneous therapeutic aspiration. All patients in the trial recovered. No statistically significant benefit was demonstrated in the aspiration group for the two objective parameters evaluated: length of hospitalization and duration of time to becoming afebrile. Subjective improvement in symptoms after aspiration was greater in the aspiration group at a marginally statistically significant level. These data do not support the adjunctive performance of percutaneous therapeutic aspiration in the treatment of uncomplicated amebic liver abscess. Amebicidals alone were equally efficacious in treating the group studied.     

Ossification of the posterior longitudinal ligament: a report of nine cases in non-Oriental patients

Ossification of the posterior longitudinal ligament (OPLL) is a progressive disorder of the spine which may result in spinal cord compression and myelopathy. While prevalent among Japanese, its occurrence in non-Orientals has been infrequently reported. Nine patients with OPLL have been diagnosed and followed at the Emory Clinic Spine Center over a 5-year period. All of the patients had been misdiagnosed before presentation. Five of the nine had undergone a total of eight ineffective operations. Failure to distinguish OPLL from other more common causes of myelopathy can result in delayed or inappropriate treatment. Illustrative cases and radiographic studies are presented.     

Link protein shows species variation in its susceptibility to proteolysis.

Human cartilage link protein exists as three native components, while equine, bovine, and porcine cartilage link protein exist as two and Swarm rat chondrosarcoma link protein exists as only one component. These nonhuman link protein components represent intact protein structures, and there is little evidence for proteolytically modified forms in nonhuman tissues. In human cartilage, the proteolytic production of modified link proteins increases with age, whereas high amounts of such products were not seen in the nonhuman tissues. However, the small amounts of link protein fragments that were observed in the nonhuman cartilages were of a similar size to their human counterparts. On digestion of human proteoglycan aggregate with stromelysin, rapid modification of the link protein components occurred, whereas the aggregates from nonhuman cartilages showed incomplete cleavage of their link protein components. The relative resistance of nonhuman link protein to stromelysin may in part be due to a unique amino acid substitution present near the enzymic cleave site.