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Biomedical subjects

R Foley

Publications and source records attributed to R Foley.

At least 19 recordsLinked to original sources
PubMed1991

Capacity, duration, and position effects in visual memory following a successive field procedure.

This study considered the efficacy of a Successive Field procedure in revealing properties of iconic memory. 8 subjects were required to identify differences between sequentially presented stimulus and target arrays of letters. While results were broadly in line with previous estimates of the capacity and duration of iconic storage, there was also evidence that identification of target letters depended on their position in the array.

Adult↗
PubMed1989

Granulomatous interstitial nephritis after a jejunoileal bypass: an ultrastructural and histochemical study.

We present a case of granulomatous interstitial nephritis and renal failure after a jejunoileal bypass for obesity. Improvement of the renal function occurred after reversal of the intestinal bypass. The renal biopsy showed an interstitial nephritis, oxalate crystal deposition and several aggregates of multinucleated giant cells related to the crystal material (granulomatous reaction). By ultrastructural and histochemical studies we demonstrated mitochondrial alterations in the tubular epithelial cells, and we suggested the proximal tubule origin of the giant cells. The association of the oxalate crystals with damaged tubules and giant cells suggests that the oxalate crystals are responsible for these alterations. The possibility of an associated immunological process as the cause of the interstitial nephritis cannot be excluded.

Acute Kidney Injury↗
PubMed1987

Spectrum of gas within the kidney. Emphysematous pyelonephritis and emphysematous pyelitis.

Renal emphysema is an important clinical entity that is not addressed frequently in the medical literature. The affected patients may have gas within the renal parenchyma, emphysematous pyelonephritis, or confined to the collecting system, emphysematous pyelitis. Two patients that illustrate the spectrum of this entity are described. The literature has been reviewed to determine the clinical features of each disorder and to provide a schema for diagnosis and management. Emphysematous pyelonephritis is seen primarily in diabetic patients, whereas emphysematous pyelitis is recognized most often in association with urinary tract obstruction. The diagnosis is made radiographically by demonstrating renal gas on plain abdominal roentgenography or intravenous pyelography. Location and extent of renal gas are best evaluated by computed tomographic scanning. Intraparenchymal gas usually requires nephrectomy, whereas successful therapy of gas limited to the collecting system involves medical management, with a drainage procedure when obstruction coexists.

Adult↗
PubMed1987

Renal adenocarcinoma and end stage kidney disease.

The association of end stage kidney disease with cystic degeneration and renal adenocarcinoma was first recognized in 1977. Since then a number of reports have confirmed this relationship. Duration of dialysis has been the most strongly associated risk factor. We report 8 cases of end stage kidney disease and renal adenocarcinoma. Median duration of hemodialysis was approximately 1 year, and 3 patients never had hemodialysis. Factors other than duration of dialysis, such as toxic metabolites, toxins from dialysis tubing, polyamines or other carcinogens, may be as or more important.

Aged↗
PubMed1985

Treatment of acute cyanide intoxication with hemodialysis.

A dramatic response was noted in a patient at our hospital who received hemodialysis therapy for severe acidosis secondary to an unknown toxin, subsequently identified as cyanide. We were unable to find any information concerning the hemodialysis clearance and extraction ratio of cyanide; thus, we studied the effect of hemodialysis in dogs receiving a constant infusion of cyanide with and without a simultaneous infusion of thiosulfate. The hemodialysis clearance of cyanide in the presence of thiosulfate was 38.3 +/- 5.4 ml/min with an extraction ratio of 0.43 +/- 0.06 (n = 4). Hemodialysis was found to increase the lethal dose of cyanide without thiosulfate infusion, and a further increase was noted with the thiosulfate infusion. Thiosulfate promotes mitochondrial metabolism of cyanide to thiocyanate. The end product, thiocyanate, is quickly removed by hemodialysis. We believe that the demonstrated effectiveness of hemodialysis in the treatment of acute cyanide intoxication is related not only to the hemodialysis clearance of cyanide, but also to the removal of its metabolic end product, thiocyanate. Based on our observations, we feel that hemodialysis is an effective adjunct in the treatment of acute cyanide intoxication.

Acidosis↗
PubMed1985

Urinary pCO2 as an index of collecting duct hydrogen ion secretion during chronic hypercapnia.

The rise in urinary pCO2 above blood pCO2 which occurs in response to bicarbonate loading (i.e. the urine to blood (U-B) pCO2 gradient), is used with increasing frequency as an index of collecting duct hydrogen ion secretion. We recently proposed, however, that the U-B pCO2 gradient is not an appropriate index of collecting duct hydrogen ion secretion when blood pCO2 is altered acutely. This issue was further investigated by examining the effect of chronic hypercapnia on urinary pCO2 generation. In rats exposed to chronic hypercapnia induced by breathing 10% CO2 for 3 days in an environmental chamber, acute sodium bicarbonate infusion resulted in a U-B pCO2 lower than that of normocapnic control rats (11 +/- 4.6 and 30 +/- 1.8 mm Hg, p less than 0.001). This finding could be interpreted to indicate that collecting duct hydrogen ion secretion is depressed in rats with chronic hypercapnia. The urinary pCO2 of rats with chronic hypercapnia was lower than that of the blood (54 +/- 6.0 and 86 +/- 1.2 mm Hg, p less than 0.005, respectively). In these rats, NaHCO3 infusion, while blood pCO2 was kept constant, elicited a marked rise in urine pCO2 (from 54 +/- 6.0 to 104 +/- 6.0 mm Hg, p less than 0.005) which was not significantly different from that observed in normocapnic control rats. The infusion of carbonic anhydrase resulted in a comparable fall in urine pCO2 in hypercapnic and normocapnic rats (-27 +/- 5 and -30 +/- 3 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)

Amiloride↗
PubMed1983

Suppression of distal urinary acidification after recovery from chronic hypocapnia.

This study examined urinary acidification shortly after recovery from chronic hypocapnia induced by hypoxemia. Distal acidification was evaluated by measuring the urinary PCO2 and urine-blood PCO2 difference (U-B PCO2) when blood PCO2 had returned to normal. In posthypocapnic rats, maximal alkalinization of the urine by acute sodium bicarbonate loading failed to increase urine PCO2 and U-B PCO2 to the level of posthypoxemic control rats and normal control rats with comparable blood pH and urine bicarbonate concentration. To test the hypothesis that decreased distal hydrogen ion secretion in posthypocapnic rats resulted from intracellular alkalosis secondary to protracted hypocarbia, posthypocapnic rats were exposed to hypercapnia of brief duration (30 min) and prolonged duration (120 min) in an attempt to restore distal acidification to normal. In posthypocapnic rats, hypercapnia of brief duration was associated with a significant increase in urine PCO2 and a fall in urine pH. Prolonged hypercapnia resulted in a marked increase in urine PCO2 and a further fall in urine pH. At any urinary bicarbonate concentration, however, the urine PCO2 and U-B PCO2 posthypocapnic rats exposed to hypercapnia were still significantly lower than in normal control rats identically subjected to prolonged hypercapnia and with comparable blood PCO2 and blood pH. Our findings indicate that distal acidification after abrupt recovery from chronic hypocapnia is decreased as if the kidneys were still under the influence of sustained hypocapnia. These findings could not be ascribed to extracellular alkalemia but could be explained by postulating that decreased urinary acidification resulted from persistence of cell alkalinity secondary to the accumulation of non-CO2 buffers generated during protracted hypocarbia. Alternatively, factors other than cell pH could mediate the adaptive decrease in distal hydrogen ion secretion of posthypocapnic rats.

Alkalosis, Respiratory↗
PubMed1979

Teacher-student interaction in a medical clerkship.

Seventeen randomly selected clinical teaching sessions in a medical school clerkship were videotaped during a one-month period, including teaching rounds, working rounds, morning report sessions, lectures, patient management conferences, grand rounds, and journal clubs. Using a verbal behavior classification schedule, the investigators analyzed the videotapes in terms of the proportion of talking done by clerkship instructors, medical students, residents, and others. The nature of the verbal interaction was examined by assessing the proportion of time devoted to giving information versus asking questions. The proportions on these dimensions were further analyzed according to the cognitive level of the verbal interaction. The data suggest that the teaching observed was not optimal for promoting problem-solving ability, since students were placed in a very passive role in which they received a preponderance of low-level, factual information.

Communication↗
PubMed1978

Interaction of glucocorticoids with macrophages. Identification of glucocorticoid receptors in monocytes and macrophages.

Glucocorticoid binding was measured in resident and thioglycollate-elicited mouse peritoneal macrophages, rabbit alveolar macrophages, and human monocytes. Two assays of binding were used--an assay with intact cells in suspension or monolayers, and an assay of cytosol and nuclear forms of glucocorticoid receptors. The mononuclear phagocytes contained approximately equal to 4--10 X 10(3) high affinity receptor sites per cell, with dissociation constants of approximately equal to 2--8 nM dexamethasone. The binding to the saturable sites was specific for steroids with glucocorticoid or antiglucocorticoid activity. Cortisol, corticosterone, and progesterone competed with dexamethasone for binding, whereas estradiol, dihydrotestosterone, and 11-epicortisol competed very little. Binding of dexamethasone to cytosol and nuclear forms of the receptor complex and temperature-sensitive translocation of cytosol forms to nuclear forms were shown. At 37 degrees C the predominant form of the hormone-receptor complex was nuclear. These results demonstrate that corticosteroids interact with macrophages at physiological concentrations.

Animals↗
PubMed1978

Glucocorticoid receptors and glucocorticoid-sensitive secretion of neutral proteinases in a macrophage line.

A continuous line of mouse macrophages (P388D1) has been shown to secrete elastase, collagenase, and plasminogen activator at activities comparable to those of macrophages elicited by an inflammatory stimulus in vivo. At physiologic concentrations anti-inflammatory glucocorticoids selectively and reversibly inhibited secretion of the three proteinases but did not inhibit secretion of lysozyme, a constitutive enzyme produced by the P388D1 cells. The secretion of the neutral proteinases was inhibited 50% by 2 to 10 nM dexamethasone. Proliferation of the macrophages was also glucocorticoid sensitive. The P388D1 macrophages contained about 4000 saturable glucocorticoid-binding sites per cell. Concentrations of hormone saturating the high affinity receptor site (for dexamethasone the dissociation constant for steroid-receptor binding, Kd, was 4 nM) correlated well with concentrations inhibiting secretion of the proteinases. Only glucocorticoids and progesterone competed for binding to the specific receptors. Temperature-sensitive translocation of hormone-receptor complexes from "cytoplasm" to nucleus similar to that found with rat thymocytes was demonstrated. Thus, the interaction between glucocorticoids and the P388D1 cell line provides a model for the regulation of macrophage secretion of neutral proteinases under normal and stress conditions.

Cell Line↗
PubMed1978

Instructor plays patient: an alternative to the case presentation method.

This article describes a teaching technique which provides an alternative to the usual case presentation for teaching small groups. In this method the instructor plays a patient, an intern, and a laboratory technician, while a group of students play the role of physicians. Students have the opportunity to deal with a combination of medical and psychosocial problems, demonstrate their ability to interact with patients, and discover that in the total clinical process a correct diagnosis is only one step toward solving the patient's problem. This technique allows the instructor to teach material not found in standard texts, assess students' problem solving efforts, and observe student interaction. Other advantages of this method are that it involves a group of students in "live" interaction with a patient and various members of the healthcare team. The instructor can also observe the thought processes of students during their interaction around a case paralleling what one typically faces in a clinical setting.

Clinical Competence↗
PubMed1976

A departmental approach for improving lecture skills of medical teachers.

The programme described here concentrated on improving the lecture skills of medical teaching staff in a single department. The training format for this programme included videotaping faculty lectures, providing written feedback, and formal training sessions. As a result of participating in this programme members of teaching staff felt that their lecture skills had improved and wanted additional training in other areas of education. The significance of the programme rests not only with its impact on the staff of this specific department but in its being a pilot of an approach to teacher development utilizing an exclusively self-instructional format.

Education, Medical↗