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Biomedical subjects

S M Weiss

Publications and source records attributed to S M Weiss.

At least 55 records · Page 3Linked to original sources
PubMed1990

The effects of ethanol and diazepam on reactions to predatory odors.

In a straight alley containing a cat odor stimulus rats show high rates of risk assessment, including flat back approach and stretch attend behaviors oriented toward the threat stimulus and contact with the stimulus. In this situation, diazepam (2.0 and 4.0 mg/kg) significantly reduced risk assessment measures (flat back approach + stretch attend), while not reliably altering control locomotion (curved back). In combination with earlier findings that the same doses of diazepam reliably increased risk assessment from a movement arrest baseline, these results strongly support a behavioral model of anxiety involving predictable nonmonotonic changes in risk assessment as a function of anxiety reduction. In comparison to diazepam, ethanol had less pronounced effects on the Cat Odor Test, as in earlier tasks of reactivity to potential threat. However, reliable dose x time interactions for risk assessment measures suggest ethanol effects similar to those of diazepam but most pronounced in initial stages in the test session.

Animals↗
PubMed1990

The characterization and modelling of antipredator defensive behavior.

The mammalian behavioral antipredator defense systems have been characterized in terms of reactions to present, localizable, threat stimuli: Analysis of the relationship between features of the predator and the environment, and specific defensive behaviors indicates that the latter can be predicted with a high degree of accuracy. A different set of defensive behaviors are seen when rats living in burrow systems are confronted by a predator outside the burrow. Flight to the burrow and immobility inside the burrow are followed by active investigation of the surface where the cat was seen (risk assessment), with all of these accompanied by inhibition of nondefensive behaviors such as eating, drinking, sexual behavior and aggression. Two additional behaviors are described in this context, ultrasonic cries made at a high initial rate (50% time) by animals inside the burrow systems, and declining over 1-2 hours following predator exposure, and, a specific modification of eating patterns when the subjects return to the surface and begin to eat. Eating bouts are shortened, with fewer episodes of continuous eating, interspersed with intervals of scanning of the environment, a vigilance activity previously reported in field research. This analysis of a broad spectrum of defensive behaviors is being used to develop test batteries providing simplified models of these phenomena.

Aggression↗
PubMed1988

Combined modality treatment of localized unresectable adenocarcinoma of the pancreas.

Since 1978, 86 patients with unresectable localized adenocarcinoma of the pancreas have been treated with a combined modality program using radioactive iodine 125-Implantation, external beam radiation, and systemic chemotherapy. Three treatment approaches were used with sequential modifications of the technique based on the course of disease and patterns of failure. Group 1 was comprised of 13 patients treated with a combination of implantation followed by a planned external radiation dose of 5000 to 6000 cGy delivered in 6 weeks. Group 2 included patients treated as in Group 1 followed by adjuvant chemotherapy. The most recent group of 54 patients, Group 3, has been treated since 1981 with implantation into the tumor of radioactive Iodine 125 seeds (12000 cGy minimal peripheral dose), perioperative chemotherapy (5-FU, Mito-C), and external beam irradiation (5000-5500 cGy) followed by further chemotherapy. Incidence of perioperative mortality has been reduced from 31% (10/32) in Groups 1 & 2 to 7% (4/54) in Group 3. Clinical local control of tumor has been excellent in all three groups (84%). Analysis of the Group 3 results indicate that the problem of distant metastasis, in spite of adjuvant chemotherapy, still remains overwhelming (64%)--especially to the liver--and requires development of more effective regimens. Median survival in the three groups of patients is 5.5, 11.3, and 12.5 months. The 2-year survival is 0, 15, and 22%, retrospectively in the three groups.

Adenocarcinoma↗
PubMed1988

Postdoctoral education and training for clinical service providers in health psychology.

It was recommended by the 1983 National Working Conference on Education and Training in Health Psychology (Stone, 1983) that 2 years of postdoctoral education and training be mandated for future licensed health service providers in health psychology. The background for requiring this postdoctoral training, a model for education, criteria for developing programs, issues of funding, and a rationale for accepting this mandate are presented. Highlighted are the stable and consistent growth of health psychology, the need to expand the period of clinical training to meet the many advances in the field, and the challenges that exist for the fully trained clinical health service provider.

Behavior Therapy↗
PubMed1987

Nutritional aspects of preoperative management.

The preoperative evaluation of the surgical patient should include a careful evaluation of the patient's nutritional status. A careful history and physical examination are appropriate and reliable means for evaluation of nutritional status. Patients with certain diagnoses, such as Crohn's disease or visceral malignancies, are likely to become malnourished even if they are not malnourished at the time of hospital admission. Preoperative and postoperative nutritional support, continued until the patient is able to take adequate nutrients by mouth, is an important part of the management of these patients and can improve the care and decrease the likelihood of complications.

Costs and Cost Analysis↗
PubMed1987

Mass screening for colorectal cancer--the Philadelphia experience.

On May 18, 1985, the Philadelphia Division of the American Cancer Society and WCAU-TV entered into a jointly-sponsored colorectal health day to do mass screening throughout the greater Philadelphia area. This was preceded by a week-long series of television awareness programs, and an organization based on having individual hospital coordinators for those hospitals participating. A total of 46 hospitals in Pennsylvania alone participated in this project, and over 16,000 people were screened in a single day. 410 patients had positive stools for occult blood on site, and 359 were positive on take-home 3-packs. Rectal pathology was diagnosed initially in 502 patients. 13 colorectal cancers and 38 polyps have been diagnosed directly as a result of this screen. Total cost to the Cancer Society was $13,300, meaning each diagnosed cancer cost $1,023 and each cancer or polyp cost $266 in actual funds expended for the screen. This overwhelming response by the public to such a mass screening effort indicates the potential for such programs for colorectal cancer, and the techniques employed in planning, implementing, and following up on data retrieval are discussed. This mass screening effort should serve as a model for future projects, and emphasize the importance not only of interrelationships with the media, but also liaison efforts with a network of area hospitals and individual hospital coordinators.

Colorectal Neoplasms↗
PubMed1985

Rapid intra-abdominal spread of pancreatic cancer. Influence of multiple operative biopsy procedures.

Intra-abdominal spread of tumor is a common cause of treatment failure in patients with pancreatic cancer. We have reviewed 62 patients with pancreatic cancer undergoing repeat laparotomy in order to learn what factors are associated with the high risk of intra-abdominal metastases. Patients who underwent two or more operative biopsy procedures were at a markedly increased risk of developing intra-abdominal tumor seeding. These metastases were not detectable by preoperative computed tomography scan or ultrasound. This information affirms that multiple biopsies of pancreatic tumors increase the risk of local disease failure, and regimens based on nonoperative staging are likely to incorrectly minimize the extent of tumor involvement.

Adult↗
PubMed1985

Impact of radiotherapy on palliative gastroenterostomy in pancreatic cancer.

The previously unaddressed impact of radiotherapy and vagotomy on palliative gastroenterostomy (GE) in patients with unresectable pancreatic cancer was studied. Sixty-eight patients were retrospectively evaluated. A higher overall incidence of complications was found in the group (N = 44) undergoing irradiation as well as gastroenterostomy compared to a group undergoing gastroenterostomy alone. The increased complications were due to 16 episodes of bleeding among the irradiated patients. Rates of obstructive complications were similar for both groups (20%). Rates of bleeding were highest among patients undergoing prophylactic GE and irradiation compared to those receiving GE alone. Vagotomy in 12 patients who were irradiated did not appear to protect against bleeding. We found the irradiated prophylactic GE to provide poor palliation in patients with unresectable pancreatic cancer and recommend it not be performed if radiotherapy is to be used for attempt in local control of unresectable pancreatic cancer.

Adult↗
PubMed1985

Energy expenditure after spinal cord injury: an evaluation of stable rehabilitating patients.

Caloric requirements for spinal cord patients are not well understood. Energy expenditure was measured by indirect calorimetry and compared with predicted expenditure by manipulations of the Harris-Benedict (Long and Rutten), Quebbeman, and Spanier and Shizgal equations, using actual and ideal body weight: 45 measurements were made on 22 spinally injured patients, who were medically stable in their early rehabilitation phase of treatment, and included quadriplegics, paraplegics, and patients with Brown-Sequard syndrome. Other nutritional parameters were also followed. Equations based on normal patients consistently overestimated energy requirements of spinally injured patients. From the time of injury, spinally injured patients appear to have a reduction in their energy needs proportional to the amount of muscle which has been denervated. This decrease in caloric requirements continues throughout the rehabilitation and plateau phases. We have demonstrated that stable, rehabilitating spinally injured patients require 23.4 kcal/kg/day. As a group, quadriplegics required 22.7 kcal/kg/day, and paraplegics 27.9 kcal/kg/day. This represents only 45 to 90% of the recommended calories for maintenance as calculated by any of these recognized formulae, based on normal heights, weights, age, and sex, when using either current weight or ideal body weight. Spinally injured patients as a group are subjected to fluctuations in weight during treatment. Our own patients tended to become obese approximately 12 months after spinal cord injury on uncontrolled diets. All patients underwent an initial weight loss which was greater in the quadriplegics as a group, compared with paraplegics. On uncontrolled diets, our patients gained an average of 1.7 kg/wk and this was also greater in the quadriplegic group.

Adolescent↗
PubMed1984

Multimodality therapy of localized unresectable pancreatic adenocarcinoma.

Eighty-eight patients with localized unresectable carcinoma of the pancreas were treated at Thomas Jefferson University Hospital between 1974 and 1981. Four treatment regimens were used which were sequential modifications of the technique based on the experience in the preceding group of patients. Each treatment changed the course of the disease, and as patterns of failure were identified, the treatment was altered to deal with them. Initially, all patients were treated with external beam radiation. Subsequently, Iodine-125 implantation was added to improve local control; low-dose preoperative radiotherapy to reduce the risk of peritoneal seeding; and adjuvant chemotherapy to reduce the risks of distant metastases. The addition of 125I implantation increased the local control from 22% to 81%, but did not increase the median survival, which was unchanged from 7 months. The addition of adjuvant chemotherapy increased the median survival from 7 months to 14 months, but had no impact on the control of the pancreatic tumor. Adjunctive chemotherapy and low-dose preoperative radiotherapy appear synergistic in reducing the risk of peritoneal seeding. The combination of 125I implantation, external beam radiation, and adjunctive chemotherapy is safe and effective. This regimen produces excellent local control with acceptable morbidity. This regimen produced a 30% survival at 18 months. The patterns of failure among these patients suggest future modifications of the technique.

Adenocarcinoma↗
PubMed1984

Bowel obstruction in cancer patients: performance status as a predictor of survival.

Ninety-five patients with known cancer who developed bowel obstruction were reviewed in an effort to evaluate the reliability of preadmission performance status as a predictor of outcome of therapy. Based on the review, a number of conclusions can be reached. Performance status, which is more easily measured than stage of disease at admission, is correlated with successful resolution of obstruction and survival. Many patients with known cancer who develop bowel obstruction have a nonmalignant cause of obstruction. Prolonged nonoperative treatment of cancer patients with bowel obstruction is unlikely to be successful and is fraught with complications.

Enteritis↗
PubMed1984

An expert consultation system for frontline health workers in primary eye care.

In developing countries, blindness is a major health problem whose control depends on the application of simple measures by frontline workers because, in many of these countries, specialist medical care is not readily available. To assist primary health workers in the management of common and potentially blinding eye disorders, we have developed a prototype computer program for a hand-held computer that incorporates a set of guidelines for diagnosis and treatment. This eye treatment program will help evaluate the potential of such devices for improving health care delivery in developing countries. This approach is now feasible because of recent advances in expert system and portable computer technology.

Blindness↗
PubMed1984

Therapy selection in an expert medical consultation system for ocular herpes simplex.

This paper describes a general scheme for selecting therapies which can be used in expert medical consultation systems. The scheme consists of a topological sorting procedure within a general production rule representation. The procedure is used to choose among competing therapies on the basis of precedence rules. This approach provides a natural way in which therapy choices can be automatically explained. The precedence rule has the capability to summarize a great many facts elegantly and to insure that the conclusions reached will be mutually exclusive. Precedence rules are computationally more efficient in both storage and time than an equivalent set of production rules. As the number of competing therapies increases this computational advantage increases. An expert consultation system for diagnosis and therapy planning of ocular herpes simplex has been implemented using this approach and examples of the system's output on actual cases of this disease are given.

Antiviral Agents↗
PubMed1984

Intraoperative sonographic identification of nonpalpable pancreatic masses.

Intraoperative ultrasonography has been used for diagnosis and guidance during surgical exploration in a variety of organ systems. Use of the technique in four patients who underwent surgical exploration of the pancreas is described. Two of the patients had bile duct dilatation suggesting pancreatic carcinoma, but had otherwise unremarkable conventional imaging studies and normal palpation of the surgically exposed organ. Both proved to have small cancers, identified by sonography. Two other subjects with known pancreatic pseudocysts had additional cysts imaged during the intraoperative examination.

Adenocarcinoma↗