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Biomedical subjects

G A Miller

Publications and source records attributed to G A Miller.

At least 127 records · Page 7Linked to original sources
PubMed1986

Isolated coronary ostial stenosis.

We have examined 5 patients with typical angina pectoris and found them to have left coronary ostial stenosis without evidence of any other coronary arterial disease and without evidence of aortic disease (Takayasu aortitis, syphilitic aortitis, or familial hypercholesterolaemia). All five patients were female aged between 38 and 53 years, a striking difference from the normal 7:1 male:female ratio for atherosclerotic coronary artery disease. It may be that these patients represent a rare but distinct syndrome. The angiographic diagnosis can be difficult but a pressure drop as the catheter tip engages the ostium and lack of spill-over of contrast into the sinus of Valsalva are findings that should lead the angiographer to suspect ostial stenosis.

Adult↗
PubMed1986

Information processing deficits in anhedonia and perceptual aberration: a psychophysiological analysis.

Building on recent reports of psychophysiological deviance in two groups believed to be at risk for psychosis, the present study sought to identify corresponding cognitive deviance in these groups. Subjects defined according to Chapman's questionnaires on physical anhedonia (n = 16) and perceptual aberration (n = 16) were tested in an auditory discrimination task while brain wave and autonomic activity was monitored. Although the discrimination performance of at-risk subjects equaled that of controls (n = 16), significant group differences occurred in event-related brain potential and heart rate responses. Interpreted within an information processing model of the discrimination task, these results suggest a deficit in the use of memory templates by anhedonics, for which they can compensate if given adequate stimulus input.

Adolescent↗
PubMed1986

Production of monoclonal antibodies to salinomycin.

Protein conjugates of salinomycin were prepared and utilized to produce murine monoclonal antibodies (MAbs) in the BALB/c-P3X63.Ag 8.653 fusion system. Several antibodies were cloned, stabilized, and evaluated for cross-reactivity to other ionophorous antibiotics. Selected antibodies were used to develop quantitative assays for salinomycin by means of an enzyme-linked immunosorbent assay (ELISA). These assays were sensitive to 50 ng of salinomycin.

Animals↗
PubMed1985

Technique to facilitate percutaneous nephrostomy in non-obstructed kidneys.

A technique for performing antegrade pyelography during nephrotomy is described--puncture with a 21-gauge, 20-cm Cope needle, placement of a 0.018-inch SMG mandril "coat-hanger"-shaped guidewire, with the needle exchanged for a 3-French multi-sidehole dilator. Use of the 3-French dilator provides more security and less trauma to the renal pelvis; nephrotomy time is also curtailed. In 25 patients the technique was used successfully with 2 minor complications.

Humans↗
PubMed1985

The psychophysiological process of therapy in a case of injury-scene-elicited fainting.

In a single case study, the psychophysiological process of change was studied during treatment of fainting with exposure to blood/injury stimuli. Therapy involved two procedures: a muscle-tensing maneuver and a cognitive coping strategy, each applied in A-B-A format. During therapy, bradycardia was associated with reports of greater fear. Muscle tensing brought higher heart rate and lower fear ratings. In contrast, the cognitive strategy produced lower fear ratings without affecting heart rate. At termination and at 6- and 30-month follow-up, the patient reported problem-free exposure to injury stimuli. Results supported the efficacy of the treatment approach, differentiated the effects of separate components of the intervention, and clarified its physiological basis.

Adult↗
PubMed1985

Atrial septal defect in patients over the age of 50.

Clinical, haemodynamic and follow-up data are presented for a group of 49 patients with atrial septal defect who first presented between the ages of 50 and 79. The incidence of supraventricular arrhythmias, pulmonary vascular disease and "heart failure" all increased with increasing age. Those who had the defect closed tended to be the more symptomatic and surgery resulted in symptomatic improvement in almost all. The combined early and late surgical mortality was 6.6%. Surgery appears to be of benefit in symptomatic patients below the age of 70. Above this age our small experience would suggest caution in recommending closure of the defect.

Aged↗
PubMed1985

Characterization of a renal cell carcinoma cell line suitable as a target for immunological studies in vitro and in the nu/nu mouse.

A continuous human renal carcinoma cell line designated RPMI-SE was established from a patient with a poorly to moderately differentiated renal cell carcinoma. The cells are anchorage dependent, have a well defined globular shape with pseudopod-like structures, a doubling time in vitro of 24 hr. and are able to grow subcutaneously in female ICR Swiss nu/nu mice. RPMI-SE cells obtained from tissue culture and the nude mouse had the chromosome number of near-tetraploidy. Common morphologic rearrangements were present in both the cell line and nu/nu mouse tumor. RPMI-SE was evaluated as a target cell line in an in vitro Indium-111 release assay. Three patterns of cytotoxicity were observed at an effector to target cell ratio of 100:1. The highest degree of cytotoxicity (75 per cent) was obtained with autologous lymphocytes. An intermediate level of cytotoxicity (50 per cent) was obtained with allogeneic lymphocytes. The lowest level of cytotoxicity (27 per cent) was obtained with normal lymphocytes and was comparable to the level of cytotoxicity observed with the NK sensitive K562 target cell line. Morphologic data and chromosomal analysis indicate that the RPMI-SE cell line has maintained characteristics of the original tumor. This cell line will be useful for immunological studies as a target cell line in vitro as well as in vivo in the nude mouse.

Animals↗
PubMed1985

Balloon valvuloplasty and angioplasty in congenital heart disease.

Balloon dilatation valvuloplasty was performed in 16 patients with pulmonary valve stenosis aged 10 days to 17 years. Gradients were reduced in all but two patients and were less than or equal to 20 mm Hg after the procedure in all but these two and one other. Unsatisfactory initial results in these three patients were attributed to the use of too small a balloon in one patient (gradient subsequently abolished at repeat valvuloplasty), to a dysplastic valve in a neonate, and to the fact that there had been a previous surgical valvotomy with scar tissue formation in one patient. The good result was retained in six of seven patients followed up at three to six months. In one the gradient, having been reduced from 60 to 18 mm Hg, had risen to 35 mm Hg. Repeat valvuloplasty was technically impossible in this patient, but in two others residual gradients of 24 and 22 mm Hg were reduced to 4 and 8 mm Hg respectively by repeat valvuloplasty. Balloon dilatation angioplasty was successful in dilating a severe stenosis at the lower limb of an atrial baffle (previous correction of complete transposition) and in dilating supravalvar stenosis of the pulmonary artery resulting from previous banding and debanding. Thus balloon pulmonary valvuloplasty, though still a new technique, appears to be the treatment of choice in patients with typical pulmonary stenosis and thin mobile valves. Patients with dysplastic valves may be less suitable candidates for the procedure. Balloon angioplasty is likely to have other applications, including the treatment of postoperative stenotic lesions.

Adolescent↗
PubMed1985

Tenckhoff peritoneal dialysis catheters: the use of fluoroscopy in management.

Manipulation of the Tenckhoff catheter under fluoroscopic guidance is a useful procedure in patients who undergo chronic ambulatory peritoneal dialysis (CAPD). We reviewed 50 manipulations in 28 patients. There were no significant complications attributable to the procedure. Ten per cent of the manipulations were performed for visceral pain, 40% for malfunction within the first two weeks of catheter placement, and the remaining 50% for malfunction after two weeks of adequate dialysate flow. Overall, an initial success rate of 88% was recorded, and, after long term study, a durable success rate of 58% was demonstrated. Early malfunction (i.e., within the first two weeks) is a more ominous prognostic indicator than previously realized, with only 30% of these manipulations ultimately succeeding vs. 60% of manipulations in late onset catheter failure. Nevertheless, at least one attempt is warranted in manipulation of a malfunctioning Tenckhoff catheter.

Catheterization↗
PubMed1985

Complications of percutaneous nephrostolithotomy.

In 224 patients, renal stones were removed from the urinary tract using either direct extraction with a basket or forceps (59 patients), ultrasonic lithotripsy (164 patients), or infusion chemotherapy (one patient). Residual stone fragments were present more frequently in patients treated with ultrasonic lithotripsy (27%) than with direct extraction (5%). Other complications included hemorrhage (eight patients), catheter dislodgement (four patients), large amounts of urine extravasation (three patients), glycine ascites (three patients), infection (two patients), pneumothorax (one patient), and a prolonged ileus (one patient). More complications occurred among the first 50 patients than the last 50 patients, even though more difficult cases, including patients with staghorn calculi, were accepted during the latter period. Although a learning curve exists, complications can be minimized by attempting to treat more favorable cases during the initial experience.

Extravasation of Diagnostic and Therapeutic Materi↗