Search PubMed⌕ Search

Biomedical subjects

R J Morris

Publications and source records attributed to R J Morris.

At least 73 records · Page 4Linked to original sources
PubMed1998

Postpartum coronary artery dissection: emergency coronary artery bypass with ventricular assist device support.

Acute myocardial infarction during pregnancy and in the puerperium is a rare event: the incidence ranges from 1 per 10,000 to 1 per 30,000 deliveries. Although the etiology is unknown, the pathology may involve thrombosis, spasm, or dissection of the coronary artery. We present the case of a 34-year-old white woman who presented to our institution in cardiogenic shock after an acute myocardial infarction 2 weeks postpartum. This case reinforces the concept that postpartum coronary artery dissection is a fatal disorder. We were able to successfully support the myocardium and the end-organs with a ventricular assist device. We performed concomitant coronary artery bypass grafting in an attempt to salvage the remaining myocardium. Management with emergency coronary revascularization and ventricular assist device support is described.

Adult↗
PubMed1997

Evidence that cutaneous carcinogen-initiated epithelial cells from mice are quiescent rather than actively cycling.

The basal layer of the epidermis and hair follicles is composed of actively cycling, transit-amplifying cells and quiescent cells including stem cells. To determine which population is the target of carcinogenic chemicals, we treated CD-1 female mice topically with 5-fluorouracil (5-FU), an agent known to kill cycling but not quiescent cells, to probe the origin of the neoplastic lesions. We first determined that 5-FU kills cycling cells in the epidermis. Treatment of mice at 59 days of age (when in anagen 1) with topical 5-FU delayed hair regrowth by 10 days compared to vehicle-treated controls, suggesting that 5-FU killed the cells in anagen. Moreover, 5-FU suppressed the usual hyperplastic response of the epidermal cells to treatment with 12-O-tetradecanoylphorbol-13-acetate. 5-FU reduced the number of epidermal basal cells counted in cross-sections of skin and suppressed DNA synthesis. Approximately 50% of mice treated with 5-FU developed, within 1 week of treatment, a sloughing of the epidermis persisting for 3 weeks, followed by complete healing. Despite the evidence of cell killing in the epidermis and lower hair follicles, in a carcinogenesis experiment where 5-FU or vehicle was applied following tumor initiation with 7,12-dimethylbenz[a]anthracene, the papilloma and carcinoma responses were virtually identical whether or not the mice were treated with 5-FU, suggesting that the tumors arose from quiescent, rather than actively cycling, epidermal cells. When 5-FU was applied before initiation, the papilloma but not the carcinoma responses were slightly but significantly reduced relative to controls. These results are consistent with the hypothesis that the quiescent rather than the rapidly proliferating cells are the targets of tumor initiation.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1997

Ornithine decarboxylase overexpression leads to increased epithelial tumor invasiveness.

Ornithine decarboxylase (ODC) overexpression cooperates with genetic lesions such as an activated c-rasHa to enhance epithelial tumorigenesis. To assess the invasiveness of ODC-overexpressing cells, two noninvasive epidermal cell lines, nontumorigenic BK-1 cells, and the papilloma-derived cell line SP-1 were infected with a replication-defective retrovirus that overexpresses ODC, inoculated into deepithelialized rat tracheas, and transplanted into athymic nude mice. After 5 weeks, ODC-overexpressing BK-1 cells remained localized on the luminal surface of the tracheal xenotransplants, whereas the ODC-overexpressing SP-1 cells were extremely invasive, with the whole tracheal wall penetrated. This invasiveness of ODC-overexpressing SP-1 cells was accompanied by elevated proteinase expression, including increased urokinase plasminogen activator activity in ODC-overexpressing cells and elevated stromelysin-1 mRNA expression in the stromal cells of invaded tracheal transplants.

Animals↗
PubMed1997

Absent pericardium during coronary bypass.

The importance of recognizing congenitally absent left pericardium in the setting of acquired cardiovascular disease was recently appreciated during a case of coronary artery bypass grafting. An associated defect in the left hemidiaphragm and an abnormal location of the left phrenic nerve were found. Careful dissection of the phrenic nerve from the surface of the heart and closure of the diaphragmatic defect were necessary to avoid injury to the former and prevent hernia through the latter structure. Absent left pericardium discovered during cardiac surgery requires attention to the location of the left phrenic nerve and recognition of associated defects in the diaphragm.

Abnormalities, Multiple↗
PubMed1997

Management of infected implantable cardiac defibrillators.

BACKGROUND: The implantable cardiac defibrillator (ICD) was introduced clinically in 1980 for the management of ventricular arrhythmias. METHODS: From January 31, 1989, through May 29, 1996, 329 ICD devices were implanted at Allegheny University Hospital, Hahnemann Division, Philadelphia, Pennsylvania. All device-related infections were examined. RESULTS: Fifteen patients (5%) experienced infection of the generator component of the ICD. There were 14 male and 1 female patients with a mean age of 62 years (range, 38 to 79 years). All infections involved the generator with or without other component involvement. Complete removal of the system was performed in 7 patients, partial removal in 5, and the entire system was left intact in 3. In 4 patients (27%), further procedures were performed to remove additional infection. Three patients (20%) died during the hospital stay. CONCLUSIONS: Infection of ICD devices is a devastating event. We favor complete removal of the ICD generator and all the components when possible. Partial removal of the ICD unit (ie, generator only) is reserved for patients in whom the risk of complete removal is too high and infection is confined to the generator only.

Adult↗
PubMed1997

The Fasting Hyperglycaemia Study: I. Subject identification and recruitment for a non-insulin-dependent diabetes prevention trial.

Subjects at increased risk for developing non-insulin-dependent diabetes mellitus (NIDDM) were encouraged via a public awareness campaign, general practitioners, or a direct approach (in the case of women with previous gestational diabetes) to attend one of three English and two French centers for fasting plasma glucose (FPG) measurement. Of 1,580 subjects (mean +/- SD age, 47 +/- 10 years), 29% were male, 56% had a diabetic relative, 20% had a history of elevated blood glucose or glycosuria, and 9% previously had gestational diabetes. Thirty-one percent (493) had an initial increased fasting glucose ([IFG] 5.5 to 7.7 mmol.L-1), 3% (41) a diabetic fasting glucose ([DFG] > or = 7.8 mmol.L-1), and 66% (1,046) a normal fasting glucose ([NFG] < 5.5 mmol.L-1). Four hundred forty-one of the 493 returned for a second FPG measurement, and 67% (293) of these had a similar value on repeat testing 2 weeks later. A 75-g, 2-hour oral glucose tolerance test (OGTT) in 223 of these subjects showed that 37% (83) had impaired glucose tolerance (IGT), 26% (58) diabetes mellitus (DM), and 37% (82) normal glucose tolerance (NGT). Seven percent of self-referred patients had NIDDM by World Health Organization (WHO) criteria. Eighty-eight percent of those with an initial DFG had an increased glycated hemoglobin (> 6.2%), and 75% an increased fructosamine (> 282 mumol.L-1). While these two glycemic measures provided good discrimination for diabetes, neither were reliable in detecting those with increased but not diabetic FPG values. In conclusion, 293 (19%) of 1,580 self-referred subjects were identified as having persistently increased FPG, and 227 have been entered into a randomized NIDDM prevention trial evaluating healthy-living advice and sulfonylurea therapy.

Adult↗
PubMed1997

The Fasting Hyperglycaemia Study: II. Randomized controlled trial of reinforced healthy-living advice in subjects with increased but not diabetic fasting plasma glucose.

Self-referred subjects (N = 227) thought to be at risk of developing non-insulin-dependent diabetes mellitus (NIDDM) and with fasting plasma glucose (FPG) in the range of 5.5 to 7.7 mmol.L-1 on two consecutive tests 2 weeks apart were randomized to reinforced or basic healthy-living advice. They were simultaneously allocated either to a sulfonylurea group or a control group in a two-by-two factorial design. A total of 201 subjects in three English and two French centers completed 1 year's follow-up study. Reinforced advice recommending dietary modification and increased exercise was given every 3 months, and basic advice was given once at the initial visit. Glycemia was monitored by FPG, dietary compliance by body weight and food diaries, and fitness compliance by bicycle ergometer assessment and exercise diaries. Both reinforced and basic advice groups had a significant mean reduction in body weight (1.5 kg) at 3 months, although the weight subsequently returned to baseline. After 1 year, subjects allocated to reinforced advice versus basic advice (1) reported a lower fat intake (34.1% v 35.8%, P = .04) with no difference in lipid profiles, (2) had improved fitness as shown by increased calculated maximal oxygen uptake ([Vo2max] 2.39 v 2.18 L.min-1, P = .007) with no change in insulin sensitivity, (3) showed no change in FPG, glucose tolerance, or hemoglobin A1c (HbA1c), and (4) showed a greater tendency to withdraw from the study (16% v 7%, P = .03). In conclusion, reinforced healthy-living advice given to self-referred subjects with increased FPG did not encourage sufficiently pronounced life-style changes for significantly greater effects on body weight and glycemia in a 1-year study than basic healthy-living advice.

Adult↗
PubMed1997

The Fasting Hyperglycaemia Study: III. Randomized controlled trial of sulfonylurea therapy in subjects with increased but not diabetic fasting plasma glucose.

Self-referred subjects (N = 227) thought to be at increased risk of developing diabetes who had fasting plasma glucose (FPG) values in the range of 5.5 to 7.7 mmol.L-1 on two consecutive occasions 2 weeks apart were randomized to sulfonylurea therapy (gliclazide, < or = 160 mg.d-1) or to a control group allocated either to double-blind placebo or to no tablets. Subjects were randomly allocated also to reinforced or basic healthy-living advice in a factorial design. A total of 201 subjects have been evaluated for 1 year in three English and two French hospital outpatient centers. Those allocated to sulfonylurea had a significant (P < .001) reduction in median FPG compared with the control group (6.0 mmol.L-1 to 5.6 mmol.L-1, P < .001, v 6.0 mmol.L-1 to 6.0 mmol.L-1, NS). Median hemoglobin A1c (HbA1c) also improved (P < .0002; 5.8% to 5.6%, P < .001, v 5.7% to 5.6%, NS), as did mean beta-cell function (62% to 70%, P < .01, v 62% to 61%, NS). Mean body weight was unchanged in subjects allocated to sulfonylurea (81.7 kg to 82.4 kg, NS), but decreased in the control group (81.6 kg to 80.4 kg, P < .01). More subjects in the sulfonylurea group versus the control group reported one or more minor symptoms of hypoglycemia over 1 year (50% v 24%, P < .0001). Only two subjects reported major hypoglycemic episodes requiring assistance, both of whom were taking sulfonylurea. Insulin sensitivity did not change between groups. Sulfonylurea therapy with gliclazide improved glycemic control and beta-cell function significantly in subjects with increased but not diabetic FPG levels. The study is being extended to determine whether sulfonylurea therapy prevents progression to non-insulin-dependent diabetes mellitus (NIDDM).

Adult↗
PubMed1997

Post-operative iris prolapse following phacoemulsification and extracapsular cataract surgery.

PURPOSE: This study retrospectively compared and contrasted iris prolapse occurring following extracapsular cataract extraction and phacoemulsification. METHODS: The clinical notes of all patients who had undergone iris prolapse repair in the last 5 years at Southampton Eye Unit were recalled. Sixty-five patients (mean age 73 years; 41.6% male, 58.4% female) were identified out of a total of 7252 cataract operations performed (5983 extracapsular, 1269 phacoemulsification). RESULTS: Fifty-nine (93.3%) iris prolapses occurred following extracapsular surgery (83% had corneal incisions, 17% limbal). We identified 3 cases of phaco-related prolapse each of which occurred where the scleral tunnel had been extended to enable insertion of a 7.0 mm optic intraocular lens but had not been sutured. Overall, the average best corrected visual acuity achieved was 6/9. CONCLUSION: The authors conclude that although iris prolapse is much less common following phacoemulsification, all scleral sections that are extended should be sutured.

Aged↗
PubMed1997

Detached superior rectus following scleral buckling: anatomy and surgical management.

We describe two patients who developed vertical diplopia following circumferential scleral buckling for retinal detachments. Both were found to have hypodeviation and impaired elevation of the operated eye. In each case this was initially ascribed to the presence of the buckle itself, but there was no clinical improvement when this was subsequently removed, and the insertion of the superior rectus was therefore explored. In both patients this muscle was found to be detached from its normal insertion, and was identified in a retracted position overlying the insertion of the superior oblique. Following surgical re-attachment of the superior rectus, ocular elevation was restored, with resolution of symptoms.

Aged↗
PubMed1997

Inferior rectus recession--an effective procedure?

AIMS: To examine the postoperative stability of inferior rectus recession, with particular reference to the incidence of progressive overcorrection. METHODS: The results of consecutive patients undergoing inferior rectus recession over a 3 year period were reviewed. RESULTS: 21 patients underwent inferior rectus recession, using an adjustable suture technique in all but three cases. In 16 patients additional vertical muscle surgery was performed at the time of the inferior rectus recession. All patients were followed for a minimum of 3 months postoperatively, with a mean follow up of 9.3 months. At the final postoperative visit 11 patients were well aligned, eight were undercorrected, and two were overcorrected. In five of the eight undercorrected cases, the residual deviation was the result of postoperative drift in the direction of the preoperative deviation, following an initially good alignment. Review of the results failed to reveal any factor predictive for this postoperative drift. CONCLUSION: The risk of postoperative overcorrection following inferior rectus recession should be considered, but in this study, undercorrection occurred more frequently than overcorrection. The possible reasons for overcorrection and undercorrection are discussed.

Adolescent↗
PubMed1997

Bimedial rectus recession using the anchored hang-back technique.

Hang-back recession of a rectus muscle offers several advantages over conventional techniques: a reduced risk of scleral perforation, easy intraoperative adjustment, and a convenient site for suturing to the sclera. There are also disadvantages: the muscle tends to collapse, thereby increasing the effective recession and making the result less predictable. In addition, the insertion cannot accurately be displaced upward or downward, as may be required to correct A- and V-patterns, or vertical deviations. The authors describe a modified technique, an anchored hang-back recession, and discuss the results in 60 consecutive cases of bimedial rectus recession.

Amblyopia↗
PubMed1996

Normal spatial learning despite regional inhibition of LTP in mice lacking Thy-1.

The process of learning involves stable changes in synaptic efficacy for which long-term potentiation (LTP) provides a widely adopted mammalian model. Synaptic modification induced by learning or LTP may involve the action of cell adhesion molecules. One such candidate is the ubiquitous neuronal glycoprotein Thy-1. In mice in which the gene encoding Thy-1 has been inactivated, we find a regionally selective impairment of LTP in vivo in the hippocampal formation: LTP is normal in area CA1 but strongly inhibited in the dentate gyrus. Spatial learning by Thy-1-deficient mice, as assessed in the watermaze, is unimpaired. Thus LTP in the cortical input to the dentate gyrus seems not to be required for spatial learning.

Animals↗
PubMed1996

Mycobacterium fortuitum infection of the sternum. Review of the literature and case illustration.

Sternal wound infection with atypical mycobacteria following open heart surgery is a rare occurrence. Previous reports have described infection by Mycobacterium fortuitum, an acid-fast bacillus and member of a larger family of rapidly growing mycobacteria. The source and mode of transmission have not been identified. Surgical debridement and the combination of aminoglycosides and quinolones have been shown to be effective methods of treatment. More recently, clarithromycin has been shown to be the drug of choice against rapidly growing mycobacteria. We describe a 49-year-old woman who underwent infundibular stenosis repair and in whom M fortuitum sternal osteomyelitis developed. Total sternectomy, muscle flap reconstruction, and antibiotic treatment successfully eradicated the infection.

Female↗
PubMed1996

Internal thoracic artery for coronary artery grafting in octogenarians.

BACKGROUND: Use of the left internal thoracic artery as a bypass graft has been shown to result in better long-term patency and improved survival. In elderly patients, the internal thoracic artery has been used less often for coronary artery bypass grafts because of the belief that greater morbidity and mortality are associated with this procedure. This study was undertaken to test this premise in the octogenarian population. METHODS: Over an 8-year period, 474 consecutive patients 80 years of age and greater had coronary artery bypass grafting. The left internal thoracic artery was used in 188 patients (39.7%) (group 1) and saphenous vein grafts only (group 2), in 286 (60.3%). The mean age was 82.6 years (range, 80 to 95 years). There were 312 men (65.8%) and 162 women (34.2%). RESULTS: Use of the internal thoracic artery as a graft has risen steadily each year, as has the number of patients who are octogenarians. The hospital mortality rate was 7.8%. Patients in group 1 had a mortality rate of 9.0% and patients in group 2, a mortality rate of 7.0%. The mortality rate among survivors at 1 year was 6.7%. Long-term survival was significantly greater in group 1. CONCLUSIONS: On the basis of this study, we conclude that the internal thoracic artery is the bypass graft of choice, especially in regard to long-term mortality, and should not be denied to this high-risk group.

Age Distribution↗
PubMed1996

Comfortable effort level revisited.

The purpose of this study was to measure the variability of frequency and intensity of speech, using multiple voice samples obtained over a period of time at a speaker's "comfortable effort level." Variability in vocal output within and across several experimental sessions was assessed from measures of speaking fundamental frequency (SFF) and vocal intensity for utterances repeated three times a day over a 3-day period. Three distinct age groups of men and women-young, middle-aged and elderly-repeated the vowel /a/, read a standard passage, and spoke extemporaneously during each experimental session. Results indicated that variability in SFF and intensity were present across experimental sessions, age groups, gender, and speaking samples. Generally, group means indicated that approximately +/- 1 semitone of variability for SFF and approximately 2 db sound pressure level (SPL) variation in vocal intensity from any one experimental session to the next could be expected; individual variations within any group may reach two semitones and 6 db SPL.

Adult↗