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Biomedical subjects

T Robertson

Publications and source records attributed to T Robertson.

At least 37 records · Page 2Linked to original sources
PubMed1994

Dying in palliative care units and in hospital: a comparison of the quality of life of terminal cancer patients.

A comparison of the quality of life of terminal cancer patients in two palliative care units with that of those in a general hospital is reported here. Quality of life was considered as a multidimensional concept. It was assessed for the 182 patients by applying content analysis scales to transcripts of their responses to part of a standardized interview. A personal construct model of dying provided the specific hypotheses about differences in quality of life. Patients in specialized palliative care units were, as predicted, found to differ from those dying in hospital, showing less indirectly expressed anger but more positive feelings. They also reported more anxiety about death but less anxiety about isolation and general anxiety, and fewer influential and nonspecified shared relationships. Against prediction, the patients in the two specialized units were also found to differ from each other, those in the smaller unit showing more directly expressed anger and helplessness than those in the larger unit.

Attitude to Death↗
PubMed1994

Detection and possible functions of a cysteine protease involved in digestion of rod outer segments by retinal pigment epithelial cells.

PURPOSE: To investigate the presence and role of a recently cloned cysteine protease (cathepsin S) in the digestion of rod outer segments (ROS) by cultured retinal pigment epithelial (RPE) cells. METHODS: RPE cell cultures were established from eye bank donor eyes. Total RNA was extracted from freshly harvested cultures, and after reverse transcription, the cDNA was subjected to polymerase chain reaction (PCR). Cathepsin S (Cat S) mRNA translation was inhibited by antisense oligonucleotides, and the effect of inhibition on the accumulation of fluorescent debris was examined. The activity of cysteine and aspartic proteases in ROS-challenged RPE cell cultures was inhibited by leupeptin and pepstatin, respectively. The accumulation of autofluorescent debris within RPE cells was measured by a fluorophotometric flow cytometer. The presence of phagosomes in antisense DNA-inhibited and control cultures was demonstrated by electron microscopy. RESULTS: The expression of Cat S in RPE cells was demonstrated by RNA-PCR. Using antisense oligonucleotide-mediated-specific inhibition of Cat S, a significant ROS-derived increase in autofluorescence was detected within the RPE cells when they were compared with the unchallenged control cultures and cultures in the presence of ROS and sense oligonucleotides. Electron microscopy demonstrated the presence of a large number of phagosomes that enveloped structures similar to ROS. The accumulation of autofluorescent debris was also demonstrated in cysteine protease-inhibited, ROS-challenged RPE cultures, but it was not detected with aspartic protease inhibition. CONCLUSIONS: The expression of Cat S in RPE cells and the accumulation of an autofluorescent debris in cultures in which cysteine proteases or Cat S activity is inhibited suggest a key role for this enzyme, either in the ROS digestion process or in the activation of cathepsin D, the major lysosomal enzyme present in RPE cells.

Animals↗
PubMed1994

Gene expression of transforming growth factor-beta 1 and its type II receptor in giant cell tumors of bone. Possible involvement in osteoclast-like cell migration.

Giant cell tumor of bone (GCT) is a relatively rare skeletal neoplasm characterized by multinuclear giant cells (osteoclast-like cells) scattered in a mass of mononuclear cells. The currently favored hypothesis for the origin of cells within GCT is that the multinuclear giant cells are reactive osteoclasts, whereas the truly neoplastic cells are the major component of the mononuclear population. However, the pathological significance and the precise relationship of tumor cells and osteoclast-like cells in GCT have not been fully established. In this study, we evaluated two GCTs for the presence of transforming growth factor-beta 1 (TGF-beta 1) and TGF-beta type II receptor gene transcripts and attempted to establish a possible role for TGF-beta 1 in the interaction between tumor cells and osteoclast-like cells. By using in situ hybridization and Northern blot analysis, we have demonstrated that TGF-beta 1 mRNA transcript is consistently detected in both tumor mononuclear cells and osteoclast-like cells, whereas TGF-beta type II receptor gene transcript is only present in osteoclast-like cells. Moreover, isolated rat osteoclasts were tested for their ability to migrate in response to GCT-conditioned medium (GCTCM) in an in vitro chemotactic assay. Our results showed that GCTCM stimulates the migration of osteoclasts in a dose-dependent manner. Interestingly, only osteoclasts containing less than three nuclei can migrate through 12-mu pore filters. Addition of monoclonal antibody against TGF-beta significantly reduced but did not abolish the chemotactic activity of GCTCM. Moreover, TGF-beta type II receptor mRNA has been demonstrated in the normal rat osteoclasts and may be involved in the chemotactic action of TGF-beta 1. We concluded that TGF-beta 1, possibly in concert with other cytokines, is involved in the recruitment of osteoclast-like cells in GCT by acting in an autocrine or paracrine fashion.

Adult↗
PubMed1993

Baseline characteristics and therapeutic goals in the New Approaches to Coronary Intervention (NACI) registry.

BACKGROUND: The New Approaches to Coronary Intervention (NACI) voluntary registry was designed to study the use, safety, and efficacy of new percutaneous transluminal interventional devices including directional coronary atherectomy, the transluminal extraction catheter, the rotablator, the Palmaz-Schatz stent, the Gianturco-Roubin stent, the Advanced Interventional Systems (AIS) laser, and the spectranetics laser. METHODS: To date, more than 3800 consecutive patients treated for the first time with a new device at 41 centers have been entered into the registry. Complete detailed information about the patient, lesions, device characteristics, reasons for device selection, and procedural data, such as adjunctive use of conventional balloon angioplasty (PTCA), was available for the first 2835 patients. RESULTS: The registry shows that 88% of the 3233 attempts with a new device were intended as a definitive treatment of target lesions, frequently in combination with adjunctive PTCA. The remaining 12% of attempts with a new device were unplanned, prompted by unexpected complications, unsuccessful attempts, or suboptimal results with PTCA. Although there was some overlap in the indications for selecting a given interventional device, the variation from device to device was sufficiently large to caution users against any direct comparison of either safety or efficacy between devices without careful attention to the differences in baseline patient and lesion characteristics, treatment plans, and the circumstances of device use. CONCLUSION: This report provides the first comprehensive overview of how new interventional devices are currently being used in the treatment of coronary artery lesions at the 41 centers participating in the NACI registry.

Angina Pectoris↗
PubMed1992

Evidence for a viral aetiology of Jembrana disease in Bali cattle.

Jembrana disease is an acute infectious disease of Bali cattle (Bos javanicus) in Indonesia. High titres of the infectious agent are present in plasma during the febrile phase of the disease. The size of the agent determined by membrane filtration was between 50 and 100 nm, indicating it is a virus and not a rickettsia as previously proposed. Spherical virus-like particles of 75 to 130 nm diameter with a smooth membrane and frequently with an eccentric nucleoid were detected by electron microscopy in plasma from infected animals. The virus replicated in mononuclear cell cultures of peripheral blood origin but not in other cell cultures. The virus and the associated disease have characteristics consistent with viruses in the family Retroviridae.

Animals↗
PubMed1992

One-year results of the Thrombolysis in Myocardial Infarction investigation (TIMI) Phase II Trial.

BACKGROUND: The Thrombolysis in Myocardial Infarction (TIMI) Phase II Trial randomized 3,339 patients to either an invasive (INV, n = 1,681) or a conservative (CON, n = 1,658) strategy after intravenous recombinant tissue-type plasminogen activator (rt-PA) for acute myocardial infarction. METHODS AND RESULTS: The patients assigned to the INV strategy routinely underwent cardiac catheterization, and when anatomically appropriate, percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting 18-48 hours after infarction. CON patients had these procedures only in response to the occurrence of spontaneous or provoked ischemia. One-year follow-up data are available in 3,316 patients (99.3%). The primary trial end point, death and nonfatal reinfarction, occurred in 14.7% of INV patients and in 15.2% of CON patients (p = NS). When analyzed individually, there was no difference (p = NS) in death (INV, 6.9%; CON, 7.4%) or recurrent infarction (INV, 9.4%; CON, 9.8%) between the two groups. Anginal status at 1 year was also similar. Cardiac catheterization and PTCA were performed more often in INV (98.0% and 61.2%, respectively) compared with CON (45.2% and 20.5%, respectively) patients. At 1 year, the cumulative number of patients who underwent coronary bypass surgery (INV, 17.5%; CON, 17.3%) was similar in the two groups. CONCLUSIONS: The INV and CON strategies resulted in similar favorable outcomes at 1 year of follow-up. In particular, the rates of mortality and reinfarction were not different and were impressively low in both groups. One possible advantage of the INV strategy was detected in subgroup analyses. In patients with a history of myocardial infarction, the data are suggestive that 1-year mortality was lower in INV patients (10.3%) than in CON patients (17.0%) (p = 0.03).

Angioplasty, Balloon, Coronary↗
PubMed1991

The NACI Registry: an instrument for the evaluation of new approaches to coronary intervention. The NACI Investigators.

The New Approaches to Coronary Intervention (NACI) Registry was developed to collect in-depth data about patients whose coronary artery lesions are being treated with new interventional techniques such as atherectomy, stents, and laser devices. The NACI Registry database distinguishes among several possible "modes" for device use, such as preparatory, planned definitive, and bailout use. Common definitions are used for data collection across all devices, and device-specific forms are used to record procedural details. NACI's unique modular form design facilitates thorough data collection, even for the most complex treatment scenarios. The database structure allows for data analysis at the patient, procedure, lesion, and device levels, as required to perform in-depth analyses of the immediate and long-term success of new devices. Once adequate knowledge of basic device performance has been collected, the Registry structure can also allow expeditious planning and performance of randomized trials comparing a new device to conventional PTCA.

Angioplasty, Balloon, Coronary↗
PubMed1990

Analysis of possible triggers of acute myocardial infarction (the MILIS study).

Recent documentation of a circadian variation in acute myocardial infarction (AMI) suggests that AMI is not a random event, but may frequently result from identifiable triggering activities. The possible triggers reported by 849 patients enrolled in the Multicenter Investigation of Limitation of Infarct Size were analyzed. Possible triggers were identified by 48.5% of the population; the most common were emotional upset (18.4%) and moderate physical activity (14.1%). Multiple possible triggers were reported by 13% of the population. Younger patients, men and those without diabetes mellitus were more likely to report a possible trigger than were older patients, women and those with diabetes. The likelihood of reporting a trigger was not affected by infarct size. This study suggests that potentially identifiable triggers may play an important role in AMI. Because potential triggering activities are common in persons with coronary artery disease, yet infrequently result in AMI, further studies are needed to identify (1) the circumstances in which a potential trigger may cause an event, (2) the specific nature of potential triggering activites, (3) the frequency of such activities in individuals who do not develop AMI and (4) the presence or absence of identifiable triggers in various subgroups of patients with infarction.

Aged↗
PubMed1989

Pericarditis in acute myocardial infarction: characterization and clinical significance.

To determine the significance of pericarditis following acute myocardial infarction, the hospital course and 12-month follow-up were analyzed in 703 patients enrolled in the Multicenter Investigation of the Limitation of Infarct Size (MILIS). Pericarditis, defined by the detection of a pericardial rub, occurred in 20% of the patients (n = 141) and was more likely to follow Q wave than non-Q wave infarction (25% vs 9%, p less than 0.001). Patients with pericarditis experienced more serious myocardial damage compared to those without pericarditis, as evidenced by a larger infarct size (25 +/- 1 vs 17 +/- 1 MB-CK gm-Eq/m2, p less than 0.001), a lower admission left ventricular ejection fraction (42 +/- 1% vs 48 +/- 1%, p less than 0.001), and a higher incidence of congestive heart failure (47% vs 26%, p less than 0.001) and atrial tachyarrhythmias (16% vs 10%, p less than 0.05). When patients were classified by the presence of Q or non-Q wave infarction, these differences persisted although statistical significance was not always achieved due to smaller sample size. Mortality at 12-month follow-up for patients with pericarditis was 18% compared with 12% for patients without pericarditis (p = 0.055). This mortality difference could be accounted for in part by the lower ventricular ejection fraction in patients with pericarditis (p = 0.20 after adjustment).

Electrocardiography↗
PubMed1989

The effect of diabetes mellitus on prognosis and serial left ventricular function after acute myocardial infarction: contribution of both coronary disease and diastolic left ventricular dysfunction to the adverse prognosis. The MILIS Study Group.

Patients with diabetes mellitus experience a more adverse outcome after acute myocardial infarction compared with nondiabetic patients, although the mechanisms responsible for these findings are not clear. From the Multicenter Investigation of the Limitation of Infarct Size (MILIS) study, the course of acute infarction in 85 diabetic patients was compared with that in 415 nondiabetic patients, all of whom had serial assessments of left ventricular function. The diabetic patients experienced a more complicated in-hospital and postdischarge course than did the nondiabetic patients, including a higher incidence of postinfarction angina, infarct extension, heart failure and death, despite the development of a smaller infarct size and similar levels of left ventricular ejection fraction. Although diabetic patients had a worse profile of cardiovascular risk factors at the time of the index infarction, the increased incidence of adverse outcomes among them persisted despite adjustment for these baseline imbalances. Diabetic women had a poor baseline risk profile compared with the other groups categorized by gender and diabetic status, and experienced an almost twofold increase in cardiac mortality despite development of the smallest infarct size during the index event. The duration of diabetes and the use of insulin at the time of the index infarction were associated with a better in-hospital mortality rate, but the duration of diabetes did not exert a major influence on the outcome of the diabetic patients. The factors responsible for the increased incidence of adverse outcomes among diabetic patients may be related to an acceleration of the atherosclerotic process, diastolic left ventricular dysfunction associated with diabetic cardiomyopathy or other unidentified unfavorable processes.

Cardiovascular Diseases↗
PubMed1989

Research collaboration.

The complexity and cost of cardiovascular medical care dictate research to deliver high quality and cost-conscious cardiovascular care. This goal is aided by modeling medical decision making. To be useful, the modeling must be based on real data so that the results can serve as a guide to actual practice. It is suggested that a registry of randomized clinical trials and larger data bases in cardiovascular disease and health care delivery be established. The registry would be a resource for those desiring to model decision making. The registry would contain key words allowing retrieval by modelers accessing the registry and would contain contact information for consideration of possible collaborative work. The initiation of such a registry should contain plans for its evaluation to determine whether the registry itself is a cost-effective tool to encourage the needed research.

Clinical Trials as Topic↗
PubMed1989

Long-term follow-up of coronary angioplasty: the 1977-1981 National Heart, Lung, and Blood Institute registry.

Between September 1977 and September 1981, 1587 consecutive patients underwent a first coronary angioplasty (PTCA) at 16 clinical centres. After excluding patients with prior coronary bypass surgery (CABG) and left main or minimal vessel disease, 1390 were available for in-hospital and long-term follow-up. Mean duration of follow-up was 5.9 years (range 0-9.0 years). PTCA was successful (all attempted lesions reduced greater than or equal to 20%) in 882 patients (63.4%) and, overall, 624 patients (44.9%) had complete (COREV) and 766 (55.1%) incomplete (INCOREV) revascularization or a failed PtCA. In-hospital events included death in 0.7%, myocardial infarction (MI) in 5.0% and CABG in 24.0% of patients. Patients with COREV had significantly lower rates of these events than the INCOREV group. At 6 years, mortality in all registry patients was 6.5% and MI rate 15.0%; CABG was performed after the initial hospitalization in 15.5% of patients and repeat PTCA in 19.1%. All events, except repeated PTCA, were less frequent in the COREV than the INCOREV group. Among patients with a successful first PTCA, cumulative 6-year mortality was 5.8% and incidence of MI 10.8%; 16.9% underwent CABG and 24.7% repeat PTCA during follow-up. CABG was slightly more frequent in INCOREV than COREV patients with successful PTCA, but all other events were similar in the two groups, suggesting that INCOREV 'by intent' has a good prognosis. In patients with INCOREV, mortality and incidence of MI were higher during follow-up for patients with multivessel rather than single vessel disease. However, the incidence of CABG and repeat PTCA was similar in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Morning increase in onset of ischemic stroke.

The time of onset of ischemic stroke was determined for 1,167 of 1,273 patients during the collection of data by four academic hospital centers between June 30, 1983, and June 30, 1986. More strokes occurred in awake patients from 10:00 AM to noon than during any other 2-hour interval. The incidence of stroke onset declined steadily during the remainder of the day and early evening. The onset of stroke is least likely to occur in the late evening, before midnight.

Acute Disease↗
PubMed1987

The neurotoxicity of high-dose cytosine arabinoside is age-related.

Fifteen patients with acute myeloid leukaemia were given a total of 17 courses of high-dose cytosine arabinoside (Ara-C). The median age of the patients was 37 years. Four patients developed severe irreversible neurotoxicity, three developed mild to moderate, reversible neurotoxicity, whereas eight patients had no toxicity. Of five patients over the age of 55 years given high dose Ara-C, four developed severe, irreversible neurotoxicity, but there were no severe episodes in nine patients aged 55 years or less. (P less than 0.01). At a dose of 3 g/m2 given intravenously every 12 hours for 3 days, three cases of severe irreversible neurotoxicity were noted in elderly patients. Neurotoxicity at this total dose has previously been considered unusual. Administration of high dose Ara-C at total doses of 18 g/m2 and over carries a risk of severe irreversible cerebellar toxicity that increases with age.

Activities of Daily Living↗
PubMed1987

Prognosis after cardiac arrest due to ventricular tachycardia or ventricular fibrillation associated with acute myocardial infarction (the MILIS Study). Multicenter Investigation of the Limitation of Infarct Size.

Previous studies have reached conflicting conclusions about whether cardiac arrest due to ventricular tachycardia (VT) or ventricular fibrillation (VF) in acute myocardial infarction (AMI) is of long-term prognostic significance. The mortality rate in 849 patients with confirmed AMI was analyzed. The mortality rate during the initial hospitalization was higher for patients in whom VT/VF occurred (27% vs 7%, p less than 0.001). The in-hospital mortality rate for patients with primary VT/VF, that is, VT/VF occurring in the absence of hypotension or heart failure, was similar to that of patients who did not have VT/VF (8% vs 7%, difference not significant), whereas the rate for patients with secondary VT/VF was significantly greater than that for patients with no VT/VF (51% vs 7%, p less than 0.001). The timing of occurrence of VT/VF also influenced mortality: Patients in whom VT/VF occurred more than 72 hours after admission had a higher in-hospital mortality rate than did patients in whom it occurred within 72 hours (57% vs 20%, p less than 0.05). All cases of primary VT/VF occurred within the first 72 hours of admission. The long-term mortality rate for hospital survivors was not significantly different for patients who had had VT/VF during acute infarction compared with those who had not (19% vs 21%) (mean follow-up 32 months). Thus, cardiac arrest due to ventricular tachyarrhythmia was associated with a higher in-hospital mortality rate but was not a prognostic factor among hospital survivors. Patients resuscitated from primary VT/VF, which characteristically occurs early after AMI, do not have an adverse prognosis.

Aged↗
PubMed1987

High-risk subgroups of patients with non-Q wave myocardial infarction based on direction and severity of ST segment deviation.

To determine the significance of the direction of ST segment deviation on admission of patients who evolved non-Q wave myocardial infarction (MI), 97 patients with initial ST segment depression were compared to 207 patients with initial ST segment elevation. Patients with ST segment depression developed smaller infarcts than those with ST segment elevation (creatine kinase MB isoenzyme 8.2 vs 13.3 gmEq/m2, p less than 0.002), but had a lower left ventricular ejection fraction on admission (44% vs 51%, p less than 0.001), more in-hospital complications, and a higher cumulative 1-year mortality (29% vs 11%, p less than 0.001) that could be accounted for by an excess of adverse baseline characteristics. Although a severity index (combining magnitude and extent of the initial ST segment deviation) was not useful for discriminating prognosis of patients with non-Q wave MI who presented with ST segment depression, it was useful in identifying a subgroup of patients with ST segment elevation with an adverse prognosis. The poor outcome of patients with non-Q wave MI presenting with either ST segment depression or severe ST segment elevation on admission suggests that patients in these subgroups should receive close surveillance and should possibly be considered for aggressive therapy.

Electrocardiography↗
PubMed1987

Effects of gender and race on prognosis after myocardial infarction: adverse prognosis for women, particularly black women.

Controversy has arisen concerning whether gender influences the prognosis after myocardial infarction. Although some studies have shown there to be no difference between the sexes, most have indicated a worse prognosis for women, attributing this to differences in baseline characteristics. It has been further suggested that black women have a particularly poor prognosis after infarction. To determine the contribution of gender and race to the course of infarction, 816 patients with confirmed myocardial infarction who were enrolled in the Multicenter Investigation of the Limitation of Infarct Size (MILIS) were analyzed. Of those patients, 226 were women and 590 were men, 142 were black and 674 were white. The cumulative mortality rate at 48 months was 36% for women versus 21% for men (p less than 0.001, mean follow-up 32 months). The cumulative mortality rate by race was 34% for blacks versus 24% for whites (p less than 0.005). Both women and blacks exhibited more baseline characteristics predictive of mortality than did their male or white counterparts. It was possible to account for the greater mortality rate of blacks by identifiable baseline variables; however, even after adjustment, the mortality rate for women remained significantly higher (p less than 0.002). The poorer prognosis for women was influenced by a particularly high mortality rate among black women (48%); the mortality rate for white women was 32%, for black men 23% and for white men 21%. The mortality for black women was significantly greater than that of the other subgroups. Thus, findings in the MILIS population indicate that the prognosis after myocardial infarction is worse for women, particularly black women.

Black People↗