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Biomedical subjects

L Schoenfeld

Publications and source records attributed to L Schoenfeld.

9 recordsLinked to original sources
PubMed1991

A technique for evaluating cast foam positioning and immobilization devices used in breast cancer radiotherapy.

Patient setup reproducibility when Alpha Cradles* are used is not well documented. A simple technique is described that localizes longitudinal and transverse planes in breast setups utilizing 4 mm lead-sphere markers embedded in a modified HS-2 Alpha Cradle. The markers are positioned in the cradle coincident with the projected simulator central axis crosshair when the x-ray beam is directed vertically down through a setup point on the patient. A reference film recording patient position relative to the Alpha Cradle is taken through the setup point at the end of the simulation procedure. On the treatment machine, the images of the lead markers on the portal film, taken through the same setup point, indicate longitudinal and transverse planes. These planes are then used to correlate and quantitate the reproducibility of the original reference planes. This technique is easily initiated, and when used in conjunction with a careful analysis of conventional treatment portal films, is very useful in determining the accuracy of patient repositioning in the Alpha Cradle, and precise field placement. Results of a study utilizing a modified HS-2 Alpha Cradle will be presented.

Breast Neoplasms↗
PubMed1990

Intravenous regional sympatholysis: a double-blind comparison of guanethidine, reserpine, and normal saline.

This double-blind, randomized study was designed to compare the effectiveness of intravenous regional sympatholysis using guanethidine, reserpine and normal saline. Twenty-one patients with reflex sympathetic dystrophy of an upper or lower extremity were enrolled and received intravenous regional blockade (IVRB) with one of the three medications. There was significant pain relief in all three groups at 30 min. There were no significant differences among the three groups in the degree of pain relief, the number of patients obtaining pain relief in the 30 min after the block, or the number of patients reporting more than 50% pain relief for more than 24 hr. The saline group's high rate of pain relief could be partially due to a mechanism of tourniquet-induced analgesia.

Adult↗
PubMed1989

Normative model for cold pressor test.

The cold pressor test elicits an emotional/motivational pain experience from the immersion of a limb in cold water. It has been widely used to evaluate (experimental and chronic) pain. However, normative models for quantification and comparison for pain tolerance have not previously been established. This study developed a normative mathematical model for pain tolerance using the cold pressor test with over 600 subjects. Norms for age, sex, and ethnic group were calculated. In addition, chronic pain patients were compared with pain-free patients to determine normative differences in response. The results indicate that at any given age Anglo-Saxon males have the longest tolerance time followed by non-Anglo-Saxon males, Anglo-Saxon females, and finally non-Anglo-Saxon females. There is a consistent decrease in tolerance time as the male age increases and minimal change in tolerance time as the female age increases. Chronic pain patients exhibited the same type of pain response pattern as healthy volunteers when corrected for age, sex, and ethnocultural subgroup.

Adolescent↗
PubMed1986

Analgesic effectiveness of D-phenylalanine in chronic pain patients.

Enkephalins are a biochemical pathway for endogenous analgesia. A number of compounds inhibit degradation of enkephalins within the body. One of these compounds, D-phenylalanine (DPA), has been shown to increase the pain threshold in animals. It is hypothesized that this naloxone reversible analgesia is induced by DPA blockage of enkephalin degradation by the enzyme carboxypeptidase A. Preliminary studies of chronic pain patients have shown a response rate to DPA from 32% to 75%. This study was a double-blind crossover evaluation of a randomized parallel design to determine the efficacy of DPA in 30 subjects with chronic pain from varied etiology which was unrelieved by multiple therapeutic interventions. Each patient received a stabilized therapeutic regimen during this study consisting of four weeks of either DPA 250 mg or lactose (placebo) orally four times a day. After four weeks the DPA and placebo groups were crossed over for an additional four weeks of treatment. Pain was quantified using a visual analog pain scale and a cold pressor test. Data from the pain questionnaires revealed more pain relief on DPA reported by 25% of the patients, more pain relief on placebo reported by 22% of the patients, and no difference in pain relief reported by 53% of the patients. Lowest pain level of the visual analog scale was reported by 47% of the patients on DPA and 53% on placebo. There appears to be no significant analgesic effect from D-phenylalanine in chronic pain patients when compared to placebo.

Animals↗
PubMed1978

Anterior urethral valves.

A case of anterior urethral valves is presented. A diagnosis of anterior urethral valves can be suspected clinically by watching the patient void. Dribbling and a diminished force of the patient's urinary stream are present in this condition. Confirmation is made with a voiding cystourethrogram and panendoscopy. Various modes of therapy are discussed.

Diagnosis, Differential↗