Search PubMed⌕ Search

Biomedical subjects

J M Moran

Publications and source records attributed to J M Moran.

At least 37 records · Page 2Linked to original sources
PubMed1995

A comparative study of stain removal with two electric toothbrushes and a manual brush.

Recent studies have suggested that a sonic electric toothbrush is more effective than a manual brush at removing extrinsic dental stain. There have been few studies of the comparative stain removal properties of different electric brushes. The study reported here was conducted to compare the efficacy of the sonic toothbrush (Sonicare) with an oscillating/rotating brush (Braun Oral-B Plaque Remover) and a conventional manual brush (Crest Complete). The study was a single-blind, randomized, cross-over design, balanced for residual effects and employing 24 subjects. Stain was enhanced over a 21-day period by twice-daily rinses with chlorhexidine and frequent intakes of tea and/or coffee. At the end of each period, tooth stain intensity and area, tongue stain intensity and area, lower lingual calculus and subjective tooth sensitivity were recorded together with preference for the brushes determined at the study's completion. Similar levels of tongue staining were recorded for the three periods, with no significant differences between the three groups. Tooth stain intensity, for most sites, was not significantly different between the three groups. For mean total stain area and for lingual and lingual interproximal sites, a significant reduction in stain was seen following use of the oscillating/rotating brush compared to the manual brush. The reductions in stain with the sonic brush were not significantly different from the manual brush. With the exception of maximum stain intensity, there were no significant differences between the oscillating/rotating and sonic brushes. Significantly less tooth sensitivity was found following use of the oscillating/rotating brush compared to both the manual and sonic brushes. All three brushes were found to be safe, but volunteer preference significantly and predominantly favored the oscillating/rotating brush. The results suggest that the oscillating/rotating brush is superior to a manual brush for stain removal.

Adult↗
PubMed1994

Postoperative intramyocardial abscess caused by mucormycosis.

We report the case of an intramyocardial abscess caused by mucormycosis that arose after cardiac operation. Several causes of immunosuppression in a 71-year-old woman were exacerbated after she underwent coronary revascularization. Before she died of multiple organ system dysfunction, a variety of supraventricular and ventricular arrhythmias, as well as complete heart block, developed, but the cause was not clear until autopsy revealed a large septal myocardial abscess due to mucormycosis.

Abscess↗
PubMed1992

Predictors of surgical mortality and long-term results of endocardial resection for drug-refractory ventricular tachycardia.

The results of surgical therapy performed in 51 consecutive patients with ventricular tachycardia were reviewed to determine short- and long-term predictors of success of such therapy in preventing recurrences of life-threatening ventricular arrhythmias. Of 41 patients (80%) who survived surgery, 40 had postoperative programmed stimulation and, of these patients, 78% (n = 31) had no inducible ventricular tachycardia on no antiarrhythmic therapy. This group had a very low incidence of arrhythmia recurrence, with only one nonfatal episode of ventricular tachycardia after a mean follow-up of 41 +/- 30 months. In contrast, two of the nine patients (22%) who had inducible arrhythmias postoperatively had cardiac arrest (p = 0.12). Multivariate analysis identified two significant predictors of perioperative mortality in our patients: increased duration of cardiopulmonary bypass time and increased baseline pulmonary capillary wedge pressure. It is concluded that (1) patients who do not have inducible ventricular tachycardia after arrhythmia surgery have a very low incidence of recurrent arrhythmia and (2) prolonged time of cardiopulmonary bypass and increased pulmonary capillary wedge pressure are predictive of perioperative mortality.

Adult↗
PubMed1991

Spontaneous healing of a traumatic thoracic aortic tear: case report.

A patient with deceleration trauma of the thoracic aorta causing significant intimal disruption is described in whom complete angiographic resolution was documented during a period of medical management. Review of the literature, along with our experience, suggests that traumatic aortic disruption constitutes a spectrum of injury rather than an all-or-none phenomenon. Immediate surgery, especially in multiply injured patients, may be delayed or even postponed indefinitely if the injury is relatively limited.

Accidents, Traffic↗
PubMed1990

Surgery for ventricular arrhythmia.

Years of frustration of cardiac surgeons attempting to control intractable ventricular arrhythmia finally ended when the team of Harken, Josephson, and Horowitz performed electrophysiologically directed left ventricular endocardial resection and reported their early results 10 years ago. The scientific background for this breakthrough is reviewed and some subsequent modifications of their procedure are described. The current status of arrhythmia surgery since the advent of the automatic internal cardioverter-defibrillator is described: the two methodologies are complementary, not competitive.

Animals↗
PubMed1990

Long-term amiodarone administration protects against global myocardial ischemia.

Reports on the effects of amiodarone on cardiac function have been variable. This study addresses the effect of long-term amiodarone administration on recovery of cardiac function after a period of global ischemia. Normotensive and spontaneously hypertensive rats were used. Normotensive rats (n = 6) received 240 mg/kg amiodarone for 4 weeks, for a total of 72 +/- 3 mg. Hypertensive rats (n = 6) received 500 mg/kg amiodarone for 4 weeks, for a total of 116 +/- 5 mg. Final myocardial concentrations of amiodarone and desethylamiodarone were 1.85 +/- 1.75 and 0.50 +/- 0.61 micrograms/g wet weight for the normotensive rats and 1.30 +/- 0.58 and 0.31 +/- 0.17 micrograms/g for the hypertensive rats (p = nonsignificant). Equal numbers of controls received sterile saline solution for 4 weeks. The hearts were excised and perfused in a Langendorff apparatus. The results indicate that, after 15 minutes of normothermic ischemia, hearts treated with this relatively low dose of amiodarone recovered a greater percentage of preischemic work (97% +/- 13%) as compared with the controls (76% +/- 17%) (p less than 0.005).

Amiodarone↗
PubMed1989

Transpedicular screw fixation.

Spinal fixation employing transpedicular screws has recently been the focus of increased attention at various institutions throughout the world, but concerns about the safety and efficacy of transpedicular screws linger. This study was undertaken to address some of these concerns. The study included evaluation of the internal and external morphology of the vertebral pedicles, which revealed that adequate bone stock is generally available at T2, T7, T12, and L1-L5 spinal levels to accept screws in the 4-7-mm diameter range. The pedicle was observed to be composed of abundant cancellous bone internally with relatively thick cortical walls. The method of pilot hole preparation for pedicle screws was also examined. Screws inserted in pilot holes prepared with a 3.4-mm blunt probe (ganglion knife) resulted in higher pullout forces in eight of 10 trials as compared with those with pilot holes prepared using a 3.2-mm drill. Furthermore, the probes afford greater control of hole depth and alignment. Fatigue studies on three screw designs revealed a graduation of strength between a 7.0-mm pedicle screw, a 5.5-mm pedicle screw, and a modified 6.5-mm cancellous lag screw. The modified cancellous lag screw has an inherent stress riser that affected fatigue life. It was noted that extreme care must be exercised to prevent bending of the pedicle screws during implantation. If bending occurs one can expect a 50% reduction in the number of cycles to failure.

Bone Screws↗
PubMed1989

Hypertonic saline attenuates the hormonal response to injury.

We reported previously in a randomized double-blinded study in 20 postoperative coronary bypass patients that hypertonic saline (1.8% NaCl, HS) provides early hemodynamic benefits, increased osmolality and net negative fluid balance compared to 0.9% NaCl (NS). To investigate the effects of HS on the hormonal response to injury, we measured ACTH, cortisol, angiotensin II (AII), aldosterone, vasopressin (AVP), and atrial natriuretic factor (ANF) in these patients. ACTH and cortisol concentrations increased in the NS group but were suppressed in the HS group (p less than 0.05). Aldosterone increased in NS patients, but was suppressed in HS patients (HS: delta Aldosterone 13.0 +/- 3.0 vs. NS: delta Aldosterone 26.0 +/- 7.0 ng/dl, p less than 0.05). The AII response was suppressed at six and eight hours (p less than 0.05) in patients receiving HS but did not change in patients receiving NS. ANF did not change significantly for either group. The significant increases in AVP were similar in both groups (p less than 0.05), but correlated with increases in osmolality only in the NS group (r = 0.8, p less than 0.009). Other than AVP, HS suppressed the responses of some of the hormones that normally increase in response to injury, relative to NS. Attenuation of the neuroendocrine response and other previously reported effects of HS suggest that HS may be an efficacious solution for resuscitation in the postoperative and postinjury period.

Adrenocorticotropic Hormone↗
PubMed1989

Hypertonic saline fluid therapy following surgery: a prospective study.

Successful resuscitation of the injured may be achieved more rapidly and with less fluid using hypertonic crystalloid solutions than with isotonic solutions. This randomized, double-blind study compared 0.9% normal saline (NS) to 1.8% hypertonic saline (HS) in 20 postoperative coronary artery bypass patients suffering uniform injury. Study solutions were administered to maintain physiologic endpoints: heart rate, blood pressure, and pulmonary capillary wedge pressure. The groups were similar with respect to age, body surface area, operative procedure, intraoperative fluid status, and intraoperative and postoperative red cell transfusion requirements. HS patients required 30% less fluid than NS patients and were in negative fluid balance during the study (-1,715 +/- 732 ml/24 hr, HS, vs. +266 +/- 825 ml/24 hr, NS; p less than 0.01). In contrast, NS patients were in positive fluid balance after 8 hours. Moreover, HS patients experienced less chest tube drainage than NS patients (981 +/- 88 ml, HS, vs. 1,700 +/- 285 ml, NS; p less than 0.01). Systemic and pulmonary hemodynamic measurements, oxygen delivery, oxygen consumption, and shunt fraction did not differ between the two groups. Serum sodium and osmolality increased in the HS group and peaked at 12 hours (145.4 +/- 1.4 mEq/L and 308.7 +/- 2.0 mOsm/kg, respectively) and correlated with the volume of HS infused (correlation coefficient = 0.81). No deaths occurred and no complication was attributed the hypertonicity of the solution. We conclude that 1.8% hypertonic saline is a safe alternative to isotonic crystalloid therapy in the fluid management of postoperative patients. Decreased third-space losses may occur with HS as suggested by the lower thoracic losses in the HS group; 1.8% NaCl may be the preferred solution in situations where excess free water administration is not desired, and where interstitial edema is detrimental to function and/or survival.

Clinical Trials as Topic↗
PubMed1988

Evaluation of Dacron-covered and plain bovine xenografts as replacements for the anterior cruciate ligament.

Surgical repair of the anterior cruciate ligament often involves the use of a suitable autograft. As alternatives to sacrificing these normal structures, various allografts, xenografts, and synthetic materials have been investigated as ligament replacement materials. This study investigates Dacron fabric-covered and plain bovine xenograft tendon as such materials in the canine knee. The implants were tested to failure in an MTS machine following 13 weeks of implantation in a canine knee. Dacron woven fabric-covered implants became more firmly attached than those covered by Dacron mesh fabric or plain xenografts. The implants were also analyzed according to their method of attachment (fixation staples or sutures). Overall, the sutured implants failed at slightly higher forces than did the stapled ones. Histologically, limited vascular invasion of the xenograft was observed. No host fibrous or osseous tissue could be identified within the graft. Fibrous tissues did form between the bone and xenograft. The implants exhibited extreme intraarticular wear, which suggests a low potential for intraarticular ligament replacement.

Animals↗
PubMed1987

A morphometric study of human lumbar and selected thoracic vertebrae.

The results of a morphometric study of selected human vertebrae undertaken to provide data for implant design are presented in this report. Twenty-seven dimensions were measured from thoracic (T2, T7, T12) and lumbar (L1-L5) vertebrae using prepared spinal columns from 30 skeletons belonging to the Hamann-Todd Osteological Collection. Maximum and minimum pedicle dimensions indicated that the pedicles are less symmetric cephalad than they are caudal. Vertebral body height increases caudally except posteriorly where, after an initial increase, it decreases in the lower lumbar region. Major and minor body diameters and the major spinal canal diameter slightly increase caudally, whereas minor spinal canal diameter exhibits little or no change.

Female↗
PubMed1986

Use of tricalcium phosphate or electrical stimulation to enhance the bone-porous implant interface.

Implant stabilization by biologic ingrowth into a porous surface offers a durable method of prosthetic fixation. These systems, however, lack the immediate stability offered by the use of acrylic bone cement. The interface strength of porous coated Co--Cr--Mo in a canine model does not approach that of acrylic bone cement until two weeks postoperatively. It is expected that this would be a minimum time period in clinical applications. Both chemical and electrical means have been advocated as methods to affect tissue ingrowth. A study using a canine model was undertaken to determine tissue ingrowth rates utilizing examples of these two methods: (1) impregnation of the porous structures with tricalcium phosphate powder (TCP); or (2) the application of an electrical stimulator to the implant with the implant itself serving as the cathode. Ten implants were coated with TCP, two each at weekly intervals from 1 to 5 weeks. Plain porous rods were likewise implanted, serving as the controls. While histology did reveal a slightly more dense bony structure, the interface bond strength was not affected by TCP. Electrical stimulation of the implant was similarly investigated with an additional time period of 10 weeks. Compared to the controls, the electrically stimulated implants reveal no statistically demonstratable difference in interface strength. Histologic specimens indicate larger areas of calcification than are observed in the controls.

Animals↗