Search PubMed⌕ Search

Biomedical subjects

M Norton

Publications and source records attributed to M Norton.

At least 37 records · Page 2Linked to original sources
PubMed1998

Comparison between planar and tomographic radionuclide ventriculography for detecting inferior wall motion abnormalities.

Gated planar radionuclide ventriculography is routinely used for the detection of regional wall motion abnormalities of the left ventricle. However, for inferior wall motion abnormalities, sensitivity is known to be low in the left anterior oblique 'best septal' projection, although improved if a left posterior oblique (LPO) view is also acquired. Gated tomography of the cardiac blood pool is now available. This study compared the sensitivity of planar 'best septal' projection, LPO and tomographic radionuclide ventriculography in the detection of inferior wall motion abnormalities. Thirty-two patients consisting of 18 with previous inferior myocardial infarction and 14 normal controls were studied. All patients underwent equilibrium planar 'best septal', planar LPO and then tomographic radionuclide ventriculography. Inferior wall motion abnormality was detected in 'best septal' in eight (44%) patients, LPO in 12 (67%) and tomography in 17 (94%) patients, respectively. Tomographic radionuclide ventriculography was best at detecting inferior wall motion abnormality while planar LPO projection is better than 'best septal' projection.

Aged↗
PubMed1998

Detection of response to chemotherapy using positron emission tomography in patients with oesophageal and gastric cancer.

BACKGROUND: The aim of the study was to determine whether 2-[18F]-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) could detect response to chemotherapy in patients with oesophageal and gastric cancer. METHODS: Fourteen patients underwent imaging before and after chemotherapy using FDG-PET. Computed tomography (CT), dysphagia scores and weight changes were used for comparison of evidence of response. Tumour to liver ratios (TLRs) and influx constants for FDG (K) were used for quantification purposes. RESULTS: Thirteen of 14 lesions were successfully imaged before therapy. Changes were seen in all follow-up scans, ranging from a complete response to a 15 per cent increase in tumour FDG uptake. Response was demonstrated by CT in four patients; all four had large reductions in FDG uptake after chemotherapy. Two patients with an increase in FDG uptake reported no improvement in dysphagia and continued to lose weight during therapy. CONCLUSION: Changes in tumour FDG uptake were seen in all tumours after chemotherapy. FDG-PET may have a role to play in the assessment of patients with upper gastrointestinal malignancy receiving chemotherapy.

Adenocarcinoma↗
PubMed1998

The persistence of hibernating myocardium after acute myocardial infarction.

OBJECTIVE: To establish the persistence of hibernating myocardium initially detected after myocardial infarction treated with thrombolysis. METHODS AND RESULTS: Fourteen patients underwent gated positron emission tomography with 18-fluoro-deoxyglucose and N13-ammonia at a median of 8 days after first myocardial infarction. Repeat scans were performed at a median of 13 weeks post-infarction. A total of 148 (30.9%) myocardial segments showed reduced N13-ammonia uptake at the time of the first scan compared with 154.5 (32.2%) segments at the time of repeat imaging. The median change in the number of segments with reduced perfusion was -1.0. Initially 13 subjects had hibernating myocardium, seven patients had large areas and six had smaller regions. Six (46.2%) subjects had repeat scans showing unchanged areas of hibernating tissue and seven had second scans demonstrating changes in the size of the region of hibernating myocardium. One patient had no hibernating myocardium on either scan. CONCLUSIONS: Positron emission tomography performed several months after myocardial infarction demonstrates significant changes in myocardial perfusion. However, a reduction in the number of segments with reduced perfusion does not always result in an improvement in myocardial metabolism and contraction. Whilst most regions of hibernating myocardium were still present several months after infarction, in only approximately half was the size of the mismatched region unchanged. Therefore it is not possible to predict the fate of hibernating myocardium which is present after infarction.

Aged↗
PubMed1998

Efficiency of MicroSort flow cytometry for producing sperm populations enriched in X- or Y-chromosome haplotypes: a blind trial assessed by double and triple colour fluorescent in-situ hybridization.

Using fluorescent in-situ hybridization (FISH) we have evaluated, on a blind basis, the efficiency of flow cytometry to separate human X- and Y-chromosome bearing spermatozoa. Our data demonstrate that human spermatozoa can be sorted to a purity of 80-90% for X spermatozoa and of 60-70% for Y spermatozoa. Our results using triple FISH fully agree with the sorting treatment used in each case and corroborate the efficiency of the flow sorting technique for sperm sex selection. In these limited samples (200-500 sperm/donor), the frequencies of disomic or diploid spermatozoa were not increased when comparing the sorted samples with unselected samples or with our control series.

Cell Separation↗
PubMed1998

Staging of the axilla in breast cancer: accurate in vivo assessment using positron emission tomography with 2-(fluorine-18)-fluoro-2-deoxy-D-glucose.

OBJECTIVE: To evaluate the ability of positron emission tomography (PET) with 18F-fluoro-2-deoxy-D-glucose (18F-FDG) to determine noninvasively axillary lymph node status in patients with breast cancer. BACKGROUND: The presence of axillary lymph node metastasis is the most important prognostic factor in women with breast cancer. It signifies the presence of occult metastatic disease and indicates the need for adjuvant therapy. The only reliable way in which this important prognostic information may be obtained is by performing axillary dissection, which may be associated with significant complications and delay in discharge from the hospital. PET with 18F-FDG can visualize primary cancers in the breast and metastatic tumor deposits. METHODS: Fifty patients with untreated breast cancer had clinical examination of their axilla performed (graded as positive or negative), followed by PET of the axilla and midthorax. PET data were analyzed blindly and graded as positive or negative, depending on the presence or absence of axillary nodal metastases. Cytopathologic assessment of the axillary nodes was carried out within 1 week of PET, by fine-needle aspiration cytology in 5 patients and axillary dissection in 45; the excised specimens were examined by a single pathologist. RESULTS: The overall sensitivity of PET in 50 patients was 90% and the specificity was 97%. Clinical examination of the same patients had an overall sensitivity of 57% and a specificity of 90%. In the 24 patients with locally advanced breast cancer (T3, T4, TxN2), PET had a sensitivity of 93% and a specificity of 100%. In T1 tumors (seven patients), the sensitivity and specificity were 100%. PET had a high predictive value (>90%) and accuracy (94%) in staging the axilla. CONCLUSIONS: PET is a sensitive and specific method of staging the axilla in patients with breast cancer. It may obviate the need for axillary surgery in women with small primary tumors, define the women likely to benefit from axillary dissection, or allow radiotherapy to be substituted for surgery, particularly in post-menopausal women.

Adult↗
PubMed1997

Behavioral assessment of relaxation: the validity of a Behavioral Rating Scale.

Poppen (Behavior Relaxation Training and Assessment, 1988) has developed an observational method of assessing the degree to which individuals show a relaxation response. Although promising, this method, the Behavioral Rating Scale (BRS), has yet to be thoroughly investigated. Subjects in this study were randomly assigned to a progressive relaxation training group or an attention-control group. Following a training period, subjects participated in a laboratory session in which self-report measures of relaxation were obtained, physiological measures were monitored, and behavioral observations were made using the BRS. Results supported the use of the BRS as a valid, observable measure of an individual's relaxation response. Discriminant validity was demonstrated by between-group differences on the BRS and construct validity was shown by significant correlations between changes on the BRS and changes on self-report and physiological measures. It is argued that, though alternative explanations are feasible, this study's results support the use of the BRS as an effective assessment tool when measuring an individual's response to progressive muscle relaxation.

Adolescent↗
PubMed1996

Incidence of hibernating myocardium after acute myocardial infarction treated with thrombolysis.

OBJECTIVE: To establish the incidence of hibernating myocardium after myocardial infarction treated with thrombolysis and to observe differences in the clinical outcome between patients with and without hibernating tissue. METHODS: 41 patients underwent gated positron emission tomography with 18-fluorodeoxyglucose and 13N-ammonia at a median of eight days after first myocardial infarction. RESULTS: All 41 subjects had a matched perfusion-metabolism deficit in the region of myocardium indicated as the site of infarction by an electrocardiograph; 32 patients (78%) had scans which also showed at least one area of reduced blood flow and contraction with a concomitant increase in glucose uptake, representing hibernating myocardium. Patients were followed up at a median of six months: all 41 were alive and none had sustained a further infarct or cardiac arrhythmia; 17 subjects with hibernating tissue (53.1%) and two without (25%) reported chest pain after myocardial infarction. CONCLUSIONS: Hibernating myocardium is relatively common shortly after myocardial infarction treated with thrombolysis. It does not influence mortality or the incidence of postinfarction chest pain.

Aged↗
PubMed1993

Right ventricular infarction vs. left ventricular infarction: review of pathophysiology, medical treatment, and nursing care.

Myocardial infarction is a significant health problem causing tremendous morbidity and mortality in the United States. Differences exist between right and left ventricular wall myocardial infarction which influence the treatment and nursing care rendered. Knowledge of the pathophysiology and management of right versus left ventricular infarction is important in providing proper patient care.

Humans↗
PubMed1991

Relating patient characteristics at the time of admission to outcomes of hospitalization.

In clinical practice, physicians informally address patient characteristics such as illness severity, comorbidity, functional status and stability when considering prognosis and diagnostic or therapeutic interventions. These same attributes, more formally measured, have been used as measures of casemix in clinical research to classify patients into similar risk strata. To determine whether physician estimates of illness severity, function status and stability were predictive of morbidity, mortality, length of stay and average daily ancillary charges, a cohort of 604 patients was studied. The predictive ability of the patient characteristics were found to be outcome specific. Illness severity was a significant predictor of in-hospital morbidity and mortality, length of stay and charges (p less than 0.001). Functional status was predictive of in-hospital morbidity and mortality, 1 year mortality, length of stay and charges (p less than 0.01). Physician estimates of stability were predictive only of morbidity (p less than 0.01) and comorbidity was only a preditor of 1 year mortality (p less than 0.001). Stratifying patients on the basis of specific clinical characteristics determined at the time of admission will be useful in studies of patient outcomes and resource utilization.

Aged↗
PubMed1988

Trade-offs between hospital charges and patient outcomes.

The increasing cost of health care has focused attention on the trade-offs between health care expenditures and patient outcomes. In this study, hospital charges were contrasted with the health status at 1 year of follow-up of 549 patients admitted to a university hospital medical service. The findings related to short-term outcomes were consistent with those of other investigators: large expenditures were associated with patients who died in the hospital, especially those whose death was unexpected. Both 1-year survival and hospital charges were found to correlate with physician estimates of illness severity and prognosis at the time of admission. Patients considered not ill with a favorable prognosis had a mortality rate at 1 year of 3%, comprised 7% of the cohort and generated 2% of total charges. In contrast, patients considered severely ill with an unfavorable prognosis had a mortality rate of 65%, comprised 19% of the cohort and generated 30% of total charges. Nevertheless, 46% of the survivors in this latter group were considered to be functional and only mildly ill at 1 year of follow-up. The imprecision of clinical judgements at the time of admission in predicting long-term outcome argues for aggressive management of acutely hospitalized patients when there is any doubt about their prognosis.

Fees and Charges↗
PubMed1984

Maternal and neonatal effects of epidural morphine for labor and delivery.

To determine the efficacy of epidural morphine during labor and delivery, 40 healthy parturients who requested epidural analgesia were randomly given either a single injection of morphine sulfate (2 mg, n = 9; 5 mg, n = 10; or 7.5 mg, n = 11) or 0.5% bupivacaine (n = 10). Bupivacaine provided excellent analgesia in all patients. Morphine (2 or 5 mg) did not produce adequate analgesia and needed to be supplemented by local anesthesia. Morphine (7.5 mg) gave satisfactory analgesia in 7 of 11 patients until the end of the first stage of labor, and, in an additional patient, for almost 13 hr, at which time cephalopelvic disproportion was diagnosed. In all patients given epidural morphine, local anesthesia was needed for the second stage of labor if instrumentation or episiotomy was required. The only side effect was pruritus, which occurred in three patients. Epidural morphine did not produce neonatal depression, as evidenced by Apgar scores and neurologic and adaptive capacity scores. We conclude that 7.5 mg of epidural morphine can give satisfactory pain relief during labor but not delivery, and that 2 or 5 mg of morphine is ineffective. Although 0.5% bupivacaine provided better anesthesia, epidural morphine might prove useful for selected patients.

Acid-Base Equilibrium↗
PubMed1983

Palliation of airway obstruction from tracheobronchial malignancy: use of the CO2 laser bronchoscope.

A CO2 laser rigid bronchoscope system has been used to palliate symptoms of a malignancy obstructing the tracheobronchial airway. Fifty-nine endoscopic laser operations (34 patients) were done between 1975 and 1981. Severe dyspnea and obstructive atelectasis were the most common indications for treatment. Contraindications for treatment included extrinsic tracheobronchial compression, widespread distant metastases, rapidly progressing tumors, and highly vascular neoplasms. There were nine primary tracheal malignancies, five metastases from distant sites, and 20 primary lung cancers with tracheobronchial obstructions. Most patients were previously treated with one or more standard modalities (radiation therapy, surgery, and chemotherapy). Removal of airway obstruction was occasionally indicated prior to radiation therapy to facilitate treatment. There were seven instances of complications in this group of patients and one mortality. Most patients (23 of 34) have died from their malignancy. The best palliation was achieved in proximal (tracheal and main stem bronchial), slower growing tumors.

Aged↗