The development of an interactive game-based tool for learning surgical management algorithms via computer.

Background: We have previously demonstrated the potential efficacy of a computer-assisted board game as a tool for medical education. The next logical step was to transfer the entire game on to the computer, thus increasing accessibility to students and allowing for a richer and more accurate simulation of patient scenarios.

Methods: First, a general game model was developed using Microsoft Visual Basic.

Removal of microorganisms in different stages of wastewater treatment for Mexico City.

In this study the removal of a diversity of microorganisms during different stages of treatment was evaluated. The process scheme consisted of Advanced Primary Treatment (APT), sand filtration, and chlorine disinfection. During the first 2 stages, fecal coliforms were reduced from 1.

Identification of women with T1-T2 breast cancer at low risk of positive axillary nodes.

Background And Objectives: The diagnostic and therapeutic significance of axillary dissection has been questioned. We sought to define a subgroup of patients with early-stage breast cancer who are at low risk for positive axillary nodes.

Methods: Between 1970 and 1995, 1,598 women with stage I and II breast cancer underwent level I-II axillary dissection with a minimum of 10 nodes removed.

Activation of Raf-1 in human pancreatic adenocarcinoma.

Point mutations in the Ras oncogene cause Ras to remain in its active GTP-bound state sending signals downstream continuously. Since 75 to 90% of all human pancreatic ductal adenocarcinomas harbor activating mutations at codon 12 of the K-ras oncogene it was our belief that Raf-1-MEK-MAPK will be activated in the majority of human pancreatic cancers. The aim of this study was to confirm activation of Raf-1 in K-ras mutant human pancreatic cancer.

Factors associated with a positive reexcision after excisional biopsy for invasive breast cancer.

Background: Breast-conserving therapy followed by adjuvant radiotherapy represents an alternative to mastectomy as a treatment for invasive breast cancer. When excisional biopsy has been performed outside the parent institution, reexcision is often performed, with tumor being identified in 32% to 62% of the subsequent specimens. We analyzed not only the factors associated with a positive reexcision but also those factors associated with final surgical margins that are positive for tumor.

Raf-1 protein expression in human breast cancer cells.

Background: The Raf-1 kinase, a 72-kDa cytoplasmic serine-threonine kinase, plays a central role as a second messenger in signal transduction. After ligand binding to a variety of transmembrane tyrosine kinase growth factor receptors including epidermal growth factor (EGF) receptor, the 72-kDa kinase is activated through phosphorylation to a 74-kDa phosphoprotein. The Raf-1 kinase is constitutively activated in many transformed cells either directly, by mutations within its amino-terminus regulatory region, or indirectly, due to overstimulation by autocrine growth factors or activated proximal oncogenes.

The influence of young age on outcome in early stage breast cancer.

Purpose: To assess the impact of young age on outcome in women with early stage breast cancer undergoing conservative surgery and radiation.

Methods And Materials: Between 1981 and 1991, 980 patients with Stage I and II breast cancer underwent excisional biopsy, axillary dissection, and radiation. The median follow-up was 4.

Malignant granular cell tumors: report of a case and review of the literature.

Background: Granular cell tumors are uncommon soft tissue tumors and are more commonly benign. Malignant granular cell tumors are extremely rare, may be confused with other soft tissue sarcomas, and can be diagnosed only when metastatic disease that has the same histologic features as the primary tumor has been identified. Metastases are more commonly seen in lymph nodes and lungs; however, often the metastatic disease is not identified at the time of initial diagnosis and presents anywhere from 3 to 37 months after initial treatment.

Enteroenteric intussusception due to a metastatic malignant fibrous histiocytoma.

Intussusception secondary to metastatic sarcoma is an unusual cause of small bowel obstruction. When a patient who has no history of a previous laparotomy, and has a known malignancy which metastasized hematogenously, presents with small bowel obstruction, the diagnosis of intussusception should be considered. The patient should be evaluated and treated accordingly.

The role of mastectomy in patients with stage I-II breast cancer presenting with gross multifocal or multicentric disease or diffuse microcalcifications.

Purpose: Women with Stage I-II invasive breast cancer who present with gross multicentric disease or diffuse microcalcifications have a significant risk of breast recurrence when treated with conservative surgery and radiation. The purpose of this report is to present the results of mastectomy in this group of patients.

Methods And Materials: Between 1982 and 1989, 88 patients with clinical Stage I-II breast cancer who presented with clinical and mammographic evidence of gross multicentric disease or diffuse microcalcifications underwent modified radical mastectomy.

Recurrent breast cancer: presentation, diagnosis, and treatment.

Patients must be followed up closely after primary therapy for invasive breast cancer so that locoregional recurrences can be detected early. Once a recurrence has been detected, a thorough evaluation is indicated to exclude distant metastatic disease. If none is found, the patient may be a candidate for aggressive surgical intervention to render the patient disease-free.

Conservative surgery and radiation for early-stage breast cancer.

In selected patients with early-stage breast cancer, conservative surgery and radiation represent an alternative equal to mastectomy in terms of local recurrence, distant metastasis, survival, and long-term complications. Patients with early-stage breast cancer who are candidates for conservative surgery and radiation include those whose primary tumor is less than 4 to 5 cm in size without evidence of gross multicentricity or diffuse microcalcifications. Patients with an extensive intraductal component may be appropriate candidates provided that margins of resection are negative.

Acalculous cholecystitis in bone marrow transplant patients.

Background: Acalculous cholecystitis (ACC) is an uncommon disorder of the biliary tract, accounting for approximately 6% of acute cholecystitis cases. In this study, cholecystitis was seen in 8 of 770 bone marrow transplant recipients, with ACC occurring in five (63%).

Methods: Records of 592 allogenic and 150 autologous BMT patients were reviewed for risk factors associated with ACC.

neu(c-erbB-2/HER2) and the epidermal growth factor receptor (EGFR) in breast cancer.

One hundred and eighty thousand new cases of invasive breast cancer were diagnosed in 1992 within the United States. This disease affects approximately 1 out of 8 women in the US. Chemotherapy and/or hormonal therapy have shown some improved disease-free and/or overall survival rates.

Nutritional support of patients with cancer of the gastrointestinal tract.

Malnutrition is extremely common in patients with malignant disease. Whereas the causes are multifactorial, the predominant factor is the imbalance between nutrient intake and host nutrient requirements. Furthermore, the evidence suggests that cachexia is related to abnormal changes in host intermediary metabolism induced by host-tumor interactions, and endogenous peptides such as TNF may be important mediators.

A G4-DNA/B-DNA junction at codon 12 of c-Ha-ras is actively and asymmetrically methylated by DNA(cytosine-5)methyltransferase.

Oligodeoxynucleotides spanning codon 12 of the human c-Ha-ras gene were found to be exceptionally good substrates for de novo methylation by human DNA(cytosine-5)methyltransferase. In the complex formed by two complementary 30mers, only the C-rich strand was methylated by the enzyme. Guanines at the 3' end of the G-rich strand of the complex could not be completely modified by dimethyl sulfate [corrected] suggesting tetrameric bonding at these G-residues.