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Biomedical subjects

D A Lieberman

Publications and source records attributed to D A Lieberman.

At least 73 records · Page 4Linked to original sources
PubMed1984

Severe and prolonged oral contraceptive jaundice.

Oral contraceptives frequently produce mild hepatocellular dysfunction, but only rarely cause jaundice. The syndrome of oral contraceptive jaundice is usually mild, with rapid resolution upon withdrawal of the drug. We describe a patient who had a severe illness with marked jaundice after one cycle of oral contraceptives. Her symptoms progressively worsened and serum bilirubin increased for almost 3 months after discontinuation of oral contraceptives. Full recovery ultimately occurred. Her severe and prolonged course demonstrates the wide spectrum of oral contraceptive jaundice.

Adult↗
PubMed1984

Common anorectal disorders.

Anorectal disorders include a diverse group of pathologic processes that are frequently encountered in general medical practice but are poorly understood. The optimal management of anal pain, itching, bleeding, and incontinence is based on sound anatomic and pathophysiologic principles. Advances have been made in understanding the pathogenesis and management of four anorectal disorders frequently encountered by internists: hemorrhoids, fissures, pruritus, and incontinence.

Anal Canal↗
PubMed1984

Arterial embolization for massive upper gastrointestinal tract bleeding in poor surgical candidates.

Therapeutic vascular occlusion was used in 32 patients to control massive upper gastrointestinal tract bleeding. All patients were poor surgical candidates and received an average of 12 U of red cells before embolization. Control of bleeding (for greater than 24 h) was attained in 23 of 32 patients (72%). Six of these 23 patients (26%) subsequently died within a 6-mo follow-up period, 5 due to underlying diseases, and only 1 due to rebleeding. Nine patients were not controlled initially with embolization, although 6 had marked reduction in bleeding. Eight of these 9 patients died (89%), 6 from hemorrhage or emergent gastric surgery, and 2 from underlying diseases. All patients with Mallory-Weiss tears (5) and with hemobilia (3) were successfully treated with embolization. Serious complications included gastric infarction in 2 patients with prior compromise of gastric arterial supply. Embolization offers an efficacious alternative to emergent surgery for control of massive upper gastrointestinal arterial hemorrhage in the poor risk surgical candidate.

Adolescent↗
PubMed1984

Ergonovine-provoked esophageal spasm during coronary angiography.

In many patients with chest pain of esophageal origin, findings are normal on routine esophageal manometry and dysmotility develops only upon provocation with ergonovine maleate. Unfortunately, ergonovine may induce myocardial ischemia in patients in whom coronary artery spasm did not occur during previous provocative testing in a cardiac laboratory-limiting its clinical usefulness. We have recorded esophageal pressure simultaneously with ergonovine infusion during angiography in ten patients without significant arterial stenoses. In two patients their usual chest pain developed associated with esophageal spasm and without changes in coronary vessels. Simultaneous performance of angiography and manometry enhanced the diagnostic yield of provocative testing by showing esophageal motility changes. This method may detect significant changes in the esophageal motility, is easy to carry out and does not interfere with angiography. It maximizes the information gained from a single provocative test and avoids the risk of ergonovine infusion outside of a cardiac laboratory.

Adult↗
PubMed1983

Colonic varices due to intestinal cavernous hemangiomas.

Colonic varices are an unusual cause of rectal bleeding. Occurring most often in the setting of portal hypertension, colonic varices have also been linked to congenital vascular lesions. One such vascular lesion, the cavernous hemangioma, is rarely found in the bowel. We report a patient with cavernous hemangiomas involving skin, lower extremities, and gastrointestinal tract, who presented with chronic rectal bleeding from colonic varices. The progression of his hemangiomatous lesions over an 18-year course is documented. The association of colonic varices and hemangiomas of the bowel is discussed.

Adult↗
PubMed1983

The role of marking when reward is delayed.

Two-choice spatial discrimination by rats is enhanced if a salient stimulus marker occurs immediately after every choice response and again after a delay interval (Lieberman, McIntosh & Thomas, 1979). Three experiments further explore this effect. Experiment 1 found that the second marker is unnecessary. Experiment 2 found that a marker presented before a response is as effective as one presented after. Both effects could be explained in terms of markers focusing attention on subsequent cues. Experiment 3, however, found that markers after choice enhance learning even when no discriminative cues are present following the marker. Markers thus appear to initiate both a backward search through memory and attention to subsequent events; both processes help to identify events that might be related to the unexpected marking stimulus.

Animals↗
PubMed1982

Glucagonoma and its angiographic diagnosis.

Four patients with metastatic glucagonoma are described. Angiography demonstrated a small avascular primary tumor of the tail of the pancreas in one patient and large hypervascular tumors of the pancreatic head in the other three. Liver metastases, were hypervascular in all four. Including our 4 with 21 cases from the literature, glucagonomas show a 92% incidence of increased tumor vascularity--thus increasing the likelihood of successful angiographic diagnosis. The awareness of clinically subtle or atypical glucagonomas and use of plasma glucagon determination are important factors leading to early diagnosis of these neoplasms. Since angiography can localize the tumor, assess its extent, and detect hepatic metastases, it is essential to the detailed evaluation of glucagonomas.

Adenoma, Islet Cell↗
PubMed1979

Learning when reward is delayed: a marking hypothesis.

Rats were trained on spatial discriminations in which reward was delayed for 1 min. Experiment 1 tested Lett's hypothesis that responses made in the home cage during the delay interval are less likely to interfere with learning than responses made in the maze. Experimental subjects were transferred to their home cages during the delay interval, and control subjects were picked up but then immediately replaced in the maze. Contrary to Lett's hypothesis, both groups learned. Further experiments suggested that handling following a choice response was the crucial variable in producing learning: No learning occurred when handling was delayed (Experiment 2) or omitted (Experiment 3). One possible explanation for the fact that handling facilitated learning is that it served to mark the preceding choice response in memory so that subjects were then more likely to recall it when subsequently reinforced. In accordance with this interpretation, learning was found to be just as strong when the choice response was followed by an intense light or noise as by handling (Experiment 4). The implication of marking for other phenomena such as avoidance, quasi-reinforcement, and the paradoxical effects of punishment is also discussed.

Animals↗
PubMedDate not supplied

Community-based research--a framework for problem formulation: the case of upper endoscopy for gastroesophageal reflux disease.

OBJECTIVE: To identify clinical hypotheses and information gaps underlying disagreement about the use of upper gastrointestinal endoscopy (EGD) for the diagnosis of gastroesophageal reflux disease (GERD), and to design a registry study to test these hypotheses. DESIGN AND SETTING: Structured group discussions with community-based practicing gastroenterologists. RESULTS: Thirty-three gastroenterologists from 17 sites discussed a set of clinical scenarios concerning the use of EGD in GERD patients with different clinical histories. Clinicians identified patient characteristics and outcome variables missing from the original problem formulation. Using decision tables, the combinations of patient characteristics that provoked disagreement among clinicians were determined. The resulting decision tables specified which characteristics and outcome variables should be measured to test competing clinical theories of when to use EGD in patients with GERD. Subsequently, the clinicians conducted a practice-based study measuring uncertain variables associated with disagreement about the need for EGD in specific clinical situations. CONCLUSION: A structured, but flexible, approach to group discussion may help identify factors that are important in decision making and the hypotheses that should be addressed in resolving variations in practice styles. Technology assessors can use these methods to identify variables underlying clinicians' concerns about the clinical validity of recommendations about practice. This experience with eliciting patient characteristics and uncertain variables underscores the importance of involving practicing clinicians in the process and could be a useful model for problem formulation in guideline development and in community-based research.

Adult↗