The presence of K-12 ras mutations in duodenal adenocarcinomas and the absence of ras mutations in other small bowel adenocarcinomas and carcinoid tumors.

Background: Adenocarcinomas and carcinoid tumors are the most common malignant tumors of the small intestine. K-ras oncogene mutations at codon 12 are common in gastric, pancreatic, and colon carcinomas, with an incidence of 35-88%. K-ras mutations have not been extensively studied in either adenocarcinomas or carcinoid tumors of the small bowel.

A three-dimensional finite element method for large elastic deformations of ventricular myocardium: II--Prolate spheroidal coordinates.

A three-dimensional finite element method for nonlinear finite elasticity is presented using prolate spheroidal coordinates. For a thick-walled ellipsoidal model of passive anisotropic left ventricle, a high-order (cubic Hermite) mesh with 3 elements gave accurate continuous stresses and strains, with a 69 percent savings in degrees of freedom (dof) versus a 70-element standard low-order model. A custom mixed-order model offered 55 percent savings in dof and 39 percent savings in solution time compared with the low-order model.

Modification of the Radiation Response by the Administration of Exogenous Genes.

Gene therapy combined with radiotherapy represents a new approach for cancer treatment to selectively radio-sensitize malignant cells or protect normal tissues. Examples of gene therapy strategies that modify the biological response to radiation include cytokine-mediated gene therapy and virally directed enzyme/pro-drug therapy (VDEPT). We have proposed the concept of gene therapy targeted by ionizing radiation, whereby a cDNA encoding a cytotoxin or an immunogenic protein that modifies the cellular radiation response is ligated downstream from a radiation inducible promoter.

Tumor necrosis factor alpha (TNF-alpha) gene therapy targeted by ionizing radiation selectively damages tumor vasculature.

Intratumoral injection of an adenoviral vector containing radiation-inducible DNA sequences of the Egr-1 promoter linked to a cDNA encoding tumor necrosis factor (TNF) alpha (Ad.Egr-TNF) enhances the tumoricidal action of ionizing radiation in a human epidermoid carcinoma xenograft (SQ-20B). The dominant histopathological feature in tumor-bearing animals treated with Ad.

The effects of mental health factors on ambulatory care visits by rural teens.

This study sought to determine the effects of mental health variables on rural adolescents' use of ambulatory health care services and whether these effects varied across common outpatient settings. Using a cross-sectional survey design, 2,297 adolescents who attended public schools in grades 7 through 12 in one isolated rural Mississippi River Delta county were assessed via a standardized health behavior survey. This self-report measure inquired about relevant health behaviors such as alcohol use, depressive symptoms, and health service use.

Contribution of the deltoid ligament to ankle joint contact characteristics: a cadaver study.

Changes in ankle biomechanics lead to altered load transmission through the ankle joint, possibly predisposing it to osteoarthritis. Contributions of the different bands of the deltoid ligament to the contact characteristics in the ankle were examined. Fifteen normal cadaveric lower extremities were axially loaded to 445 N after intra-articular Fuji film placement.

Spatial and temporal control of gene therapy using ionizing radiation.

Activation of transcription of the Egr-1 gene by X-rays is regulated by the promoter region of this gene. We linked the radiation-inducible promoter region of the Egr-1 gene to the gene encoding the radiosensitizing and tumoricidal cytokine, tumour necrosis factor-alpha (TNF-alpha) and used a replication-deficient adenovirus to deliver the Egr-TNF construct to human tumours growing in nude mice. Combined treatment with Ad5.

Load partitioning influences the mechanical response of articular cartilage.

The role of the fluid within articular cartilage as affected by the load-sharing mechanism and its potential, beneficial effects were assessed with the u-p finite element method. The mechanical behavior of cartilage as it covers the surface of a diarthrodial joint was evaluated when the partitioning of an applied stress to the solid and fluid phases of the tissue was varied. Comparisons were made in the response of the cartilage when 0%, 25%, 50%, or 75% of the applied stress was supported by the fluid at the surface.

TCR selection and allelic exclusion in RAG transgenic mice that exhibit abnormal T cell localization in lymph nodes and lymphatics.

RAG-1 and RAG-2 are developmentally regulated genes that are essential for V(D)J recombination and lymphocyte development. Expression of RAG-1 and RAG-2 by thymocytes is normally limited to cells that have not completed selection. We have previously documented that persistent expression of the recombinase activating genes (RAG) in transgenic mice results in aberrant thymic development, altered lymphatic microanatomy, and a profound immunodeficiency.

Transformation by homeobox genes can be mediated by selective transcriptional repression.

Altered transcription is a recurrent theme in the field of cancer biology. But despite the central role of transcription in transformation, little is known about the mechanism by which dominant nuclear oncogenes induce malignancies. Homeobox family proteins are prominent examples of transcriptional regulators which control development and can function as oncogenes.

Gender differences in rural adolescent drinking patterns.

Purpose: The purpose of this study was to examine differences in rural adolescent male and female drinking patterns, problem drinking behavior, and the factors associated with problem drinking behavior.

Methods: An anonymous written survey was administered to 2,297 adolescents, aged 12 to 18 years, in a rural Mississippi River Delta county. Potential risk factors for problem drinking behavior examined included demographic, behavioral, peer, and parental characteristics.

A regulatory role for recombinase activating genes, RAG-1 and RAG-2, in T cell development.

RAG-1 and RAG-2 are developmentally regulated genes that are essential for the assembly of antigen receptors in lymphoid cells. Here we describe transgenic mice that carry RAG-1 and RAG-2 under the control of the proximal lck promoter. Persistent expression of RAG-1 and RAG-2 was associated with incomplete thymopoiesis and profoundly compromised cellular immunity.

New therapeutic possibilities in primary invasive breast cancer.

Objective: Current therapy for small invasive breast cancer, particularly when discovered mammographically, was re-examined. Axillary dissection may be avoided when lymph node metastases incidence is low (< 10%) or when primary cancer features determine adjuvant therapy. Radiation therapy may be avoided when risk of recurrence is very low.

Continuing trends in the prevalence of right-sided lesions among colorectal carcinomas.

The shift of colorectal carcinoma location toward the proximal colon has been reported. This study documents that this statistically significant trend has continued through 1992. An increase in transverse and descending colon cancers is now apparent also.

The effect of storage on the biomechanical behavior of articular cartilage--a large strain study.

The transplantation of stored shell osteochondral allografts is a potentially useful alternative to total joint replacements for the treatment of joint ailments. The maintenance of normal cartilage properties of the osteochondral allografts during storage is important for the allograft to function properly and survive in the host joint. Since articular cartilage is normally under large physiological stresses, this study was conducted to investigate the biomechanical behavior under large strain conditions of cartilage tissue stored for various time periods (i.

Detection and prevention of colon cancer by colonoscopy.

It is widely accepted that most carcinomas of the colon and rectum develop through the adenoma-to-carcinoma sequence. A recent review characterizes the various relationships between colorectal polyps and carcinoma. Tierney and Associates list several studies that show the frequent coexistence of adenomatous polyps with carcinoma of the colon or rectum.

Application of the u-p finite element method to the study of articular cartilage.

The finite element method using the principle of virtual work was applied to the biphasic theory to establish a numerical routine for analyses of articular cartilage behavior. The matrix equations that resulted contained displacements of the solid matrix (mu) and true fluid pressure (p) as the unknown variables at the element nodes. Both small and large strain conditions were considered.

Classifying patients with burns for hospital reimbursement: diagnosis-related groups and modifications for severity.

This study was designed to evaluate the relative severity and resource consumption of hospitalized patients with burns in a national cross section of hospitals, both with and without burn centers. We investigated to determine whether clinical variables or severity of illness measures not recorded in the Uniform Hospital Discharge Data Set are significant in explaining variation in length of stay, total cost, and mortality for patients with burns. The ability of the six burn diagnosis-related groups (DRGs) to explain variation in patients' length of stay was 20% and their ability to predict total costs was 24%.

Finite element analyses of repaired articular surfaces.

The response to a compressive load of a repaired cartilage surface, consisting of full-thickness repair tissue adjacent to normal cartilage, was predicted by the u-p finite element method and compared to that of a normal cartilage surface under the same loading conditions. By individually varying the aggregate modulus, permeability and Poisson's ratio for the repair tissue, analyses were performed to assess the contributions of each to the changes in mechanical behaviour. In comparing the repaired to normal surfaces, the presence of a softer repair tissue resulted in increased axial and decreased radial deformations at any given time point, while a repaired surface with an increased permeability compressed more easily due to the increased fluid flow and caused equilibrium to occur sooner.

Long-term storage effects on canine osteochondral allografts.

We have studied long-term (to 60 days) effects of 4 degrees C storage in culture media on the histologic, mechanical, and chemical properties of the cartilage from osteochondral shell allografts from the dog. The structural integrity of the cartilage matrix was intact up to 60 days of storage, for the mechanical properties represented by the aggregate modulus and apparent permeability remained normal. These data are supported by normal safranin-O staining as well as normal glycosaminoglycan content and total collagen concentration.

Diazepam versus midazolam (versed) in outpatient colonoscopy: a double-blind randomized study.

Midazolam is a new parenteral benzodiazepine premedication for endoscopy. Consecutive patients were randomized to receive either intravenous midazolam or diazepam as premedication for outpatient total colonoscopy by one endoscopist. Fifty-five patients received diazepam (0.

Histological and biomechanical assessment of articular cartilage from stored osteochondral shell allografts.

Normal and stored articular cartilage from the medial tibial plateaus of mature canine knee joints were evaluated histologically and biomechanically. The medial plateaus from the right knee (control) were assessed fresh, while the left (stored) were preserved in culture media at 4 degrees C for 3, 7, 14, or 28 days and then evaluated. Biomechanically, confined compression tests were performed on all specimens to determine the aggregate modulus and apparent permeability of the articular cartilage.

The cost of burn care and implications for the future on quality of care.

The high cost of health care has become a nationwide concern and there are several national initiatives under way to reduce the rate of increase of these costs. Among the most recent initiatives has been the introduction of Medicare reimbursement based upon Diagnostic Related Groups (DRGs). This paper presents a retrospective analysis of the costs of care of burned patients admitted to the University of Alabama at Birmingham Burn Center and a profile of the financial impact of DRGs.