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Biomedical subjects

M Landay

Publications and source records attributed to M Landay.

10 recordsLinked to original sources
PubMed2000

Promotion of growth and apoptosis in c-myc nullizygous fibroblasts by other members of the myc oncoprotein family.

c-myc nullizygous fibroblasts (KO cells) were used to compare the abilities of c-myc, N-myc and L-myc oncoproteins to accelerate growth, promote apoptosis, revert morphology, and regulate the expression of previously described c-myc target genes. All three myc oncoproteins were expressed following retroviral transduction of KO cells. The proteins all enhanced the growth rate of KO cells and significantly shortened the cell cycle transition time. They also accelerated apoptosis following serum deprivation, reverted the abnormal KO cell morphology, and modulated the expression of previously described c-myc target genes. In most cases, L-myc was equivalent to c-myc and N-myc in restoring all of the c-myc-dependent activities. These findings contrast with the previously reported weak transforming and transactivating properties of L-myc. Myc oncoproteins may thus impart both highly similar as well as dissimilar signals to the cells in which they are expressed.

Animals↗
PubMed1997

Intensive radiation therapy concurrent with up to 7-week continuous-infusion paclitaxel for locally advanced solid tumors: phase I studies.

Patients with locally advanced solid tumors of the lung, head and neck, and malignant astrocytomas usually succumb to their disease despite aggressive standard therapy. Laboratory data suggest that the addition of 1.0 to 10 nmol/L paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ), a microtubule stabilizing drug, to radiation therapy may result in significant radiation sensitization, perhaps due to accumulation of cells at G2/M. Relatively low concentrations (1.0 to 10 nmol/L) appear to be optimal for direct cytotoxicity and radiosensitization in vitro. Within this dose range, more prolonged exposure seems to result in higher response rates. The phase I trials reported here are designed to test the combination of paclitaxel, administered by continuous intravenous infusion (24 hours a day, 7 days a week), and standard, curative-intent radiation therapy. The ultimate goal of this study is to improve local and systemic control and survival for patients with these three tumor types. To date, 39 evaluable patients are enrolled in this study; there has been no dose-limiting toxicity up to 6.5 mg/m2/d. Observed toxicities include anemia, lymphopenia, mucositis, and cutaneous toxicities.

Antineoplastic Agents, Phytogenic↗
PubMed1996

Application of a classical model of competitive business strategy to orthodontic practice.

This study explored how market forces might affect the business aspects of orthodontic practices; in particular, profitability. The forces identified were (1) intensity of rivalry, (2) threat of new entrants, and (3) bargaining power of buyers and suppliers. A mail survey instrument was used to collect the data. Results showed that more than half the surveyed practices show an increase in new case starts despite weak economic conditions. Although satellite offices and marketing increase the overhead, they do not add to net profit. New entrants are a threat to existing practices, as are the substitute discretionary spending by the consumer. Interestingly, while some orthodontic practices have joined the managed care programs, a majority of them realize neither increased patient load nor profit. Our data seem to indicate that orthodontic practices have not been successful in "cost containment" with their marketing, number of employees, computerization or inventory. Collectively, the results of this study suggest that success in an orthodontic office is primarily dependent on the practitioner's personality traits, rather than rigidly applied business principles.

Attitude of Health Personnel↗
PubMed1988

Benign esophagorespiratory fistulas in adults.

Four benign esophagorespiratory fistulas, three secondary to granulomatous disease and one presumed to be congenital, have been diagnosed in adults at the authors' institution in the past year. The patients had symptoms of chronic or recurrent pulmonary infections, and two experienced coughing after swallowing. Chest radiographs demonstrated refractory consolidation, with or without cavitation and frequently accompanied by an air-distended esophagus. Barium studies were diagnostic. All patients responded well to antibiotic and surgical therapy.

Bronchial Fistula↗
PubMed1987

Dental benefits and reimbursements.

This article analyzes and compares the various dental benefit reimbursement methodologies currently available in the dental marketplace. Emphasis is placed on the advantages and disadvantages of the capitation/HMO approach from the point of view of the patient, dentist, plan administrator, and purchaser/employer.

Capitation Fee↗
PubMed1978

Evaluation of ultrasound in the diagnosis of acute and chronic biliary tract disease.

Oral cholecystography and intravenous cholangiography are the two studies most frequently used to confirm the diagnosis of biliary tract disease. Since it is not always practical to obtain these in acutely ill patients, gray scale sonography was evaluated to determine its accuracy. One hundred eight patients had sonography performed prior to operation. The sonogram was correct in 96 of the 108 patients (89%). There were four false-negatives (3.7%), one false-positive (0.9%), and seven patients (6.4%) in whom the study was nondiagnostic. Stones were seen in 88 patients and confirmed in 87 patients for an accuracy of 98.9% Sonography is a simple, noninvasive procedure by which cholelithiasis can be accurately detected. Because of the high correlation between sonography and operative findings, we suggest that cholecystosonography be used as the initial screening study in patients suspected of having biliary tract disease.

Acute Disease↗