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Biomedical subjects

K Ellis

Publications and source records attributed to K Ellis.

At least 37 records · Page 2Linked to original sources
PubMed1996

Pulmonary sarcoidosis: could mycoplasma-like organisms be a cause?

The etiology of sarcoidosis is unknown but an unusual bacterial agent is possible. Mycoplasma-Like Organisms [MLO] are obligate intracellular cell wall deficient bacteria with a distinctive ultrastructural appearance. MLO are a common cause of various transmissible plant diseases. Despite over 25 years of effort MLO remain uncultivated. Molecular biologic studies indicate MLO are only distantly related to extracellular cultivable mycoplasma. Diagnosis of MLO diseases is based chiefly on detection of the organisms in infected cells by electron microscopy. Recently MLO have been detected by electron microscopy within leucocytes in sterile inflamed aqueous and vitreous humor from patients with idiopathic chronic uveitis including sarcoidosis uveitis. Preliminary molecular biologic studies suggest that human MLO are quite closely related phylogenetically to plant MLO. Inoculation of human uveitis MLO into mouse eyelids produced chronic uveitis and lethal systemic granulomatous disease with MLO within leucocytes and endothelial cells in the disease sites. The MLO induced animal pulmonary disease resembled sarcoidosis. This report describes abnormal intracellular bodies consistent with MLO within leucocytes and endothelial cells adjacent to the granulomas in transbronchial biopsies from 9 corticosteroid untreated sarcoidosis patients versus none in 4 control lungs.

Adult↗
PubMed1995

Early intervention for alcohol use: family physicians' motivations and perceived barriers.

OBJECTIVE: To elucidate family physicians' motivations concerning early intervention for alcohol use and their perceived barriers to such intervention. DESIGN: Qualitative study with the use of focus groups and semistructured interviews. SETTING: Community-based, fee-for-service family-medicine practices in London, Ont. PARTICIPANTS: Twelve focus-group participants recruited through telephone contact by two family physicians on the project team. Participants were required to be physicians in family practice in London. Twelve interview participants recruited through a grand-rounds presentation at two local hospitals. Participants were required to be physicians in a community-based family practice in which primary care was not delivered by residents and to have agreed to participate in all phases (e.g., needs assessment, training and evaluation) of a training program on interventions to help patients reduce alcohol consumption or quit smoking. MAIN OUTCOME MEASURES: Motivations concerning early intervention for alcohol use and perceived barriers to such intervention, as identified by physicians. RESULTS: Physicians in the focus groups and those interviewed endorsed their role in helping patients to reduce alcohol consumption and cited several reasons for the importance of that role. There was strong support for viewing alcohol use as a lifestyle issue to be dealt with in the context of a holistic approach to patient care. Participants cited many barriers to fulfilling their role and were particularly concerned about the appropriateness of asking all adolescent and adult patients about alcohol use, even at visits intended to discuss other issues and concerns. Physicians gave several motivations for improving their work in reduction of alcohol consumption, including their current frustration with the lack of a systematic strategy or tangible materials to help them identify and manage patients. CONCLUSIONS: Interventions with patients who use alcohol should be framed in the context of a holistic approach to family medicine. Qualitative knowledge of the motivations and barriers affecting physicians can inform future research and educational strategies in this area.

Adult↗
PubMed1994

A red cell membrane abnormality in a subgroup of schizophrenic patients: evidence for two diseases.

There are several reports of abnormalities in fatty acids in brain and blood phospholipids in schizophrenic patients. In order to see if the broad categories of negative and positive schizophrenia were linked to specific changes in fatty acids, an initial study was made of patients showing severe symptoms of these two types. Thirteen patients had persistent chronic negative symptoms of apathy and withdrawal while 12 patients had persistent positive symptoms of either thought disorder or hallucinations and delusions. The positive and negative groups were matched for length of history and drug exposure. Negative symptoms were associated with high levels of saturated fatty acids and low levels of long-chain unsaturates in red blood cell (RBC) membranes, while the positive symptom patients showed the opposite picture. In order to see if this bimodal distribution would be found in patients diagnosed as schizophrenic but without classification of symptoms, we examined frequency distribution curves for fatty acids in plasma and in RBC membranes in 68 individuals classified as schizophrenics and 259 normal individuals. A bimodal distribution was found for 20- and 22-carbon unsaturated fatty acids in RBC membranes from the schizophrenics; the same fatty acids in normal RBC membranes showed an unimodal distribution.

Adult↗
PubMed1994

A more reliable PCR for detection of Mycobacterium tuberculosis in clinical samples.

Diagnostic techniques based on PCR have two major problems: false-positive reactions due to contamination with DNA fragments from previous PCRs (amplicons) and false-negative reactions caused by inhibitors that interfere with the PCR. We have improved our previously reported PCR based on the amplification of a fragment of the Mycobacterium tuberculosis complex-specific insertion element IS6110 with respect to both problems. False-positive reactions caused by amplicon contamination were prevented by the use of uracil-N-glycosylase and dUTP instead of dTTP. We selected a new set of primers outside the region spanned by the formerly used primers to avoid false-positive reactions caused by dTTP-containing amplicons still present in the laboratory. With this new primer set, 16 copies of the IS6110 insertion element, the equivalent of two bacteria, could be amplified 10(10) times in 40 cycles, resulting in a mean efficiency of 77% per cycle. To detect the presence of inhibitors of the Taq polymerase, which may cause false-negative reactions, part of each sample was spiked with M. tuberculosis DNA. The DNA purification method using guanidinium thiocyanate and diatoms effectively removed most or all inhibitors of the PCR. However, this was not suitable for blood samples, for which we developed a proteinase K treatment followed by phenol-chloroform extraction. This method permitted detection of 20 M. tuberculosis bacteria per ml of whole blood. Various laboratory procedures were introduced to reduce failure or inhibition of PCR and avoid DNA cross contamination. We have tested 218 different clinical specimens obtained from patients suspected of having tuberculosis. The samples included sputum (n=145), tissue biopsy samples (n=25), cerebrospinal fluid (n=15), blood (n=14), pleural fluid (n=9), feces, (n=7), fluid from fistulae (n=2), and pus from a wound (n=1). The results obtained by PCR were consistent with those obtained with culture, which is the "gold standard." We demonstrate that PCR is a useful technique for the rapid diagnosis of tuberculosis at various sites.

Bacteriological Techniques↗
PubMed1994

How general practitioners view alcohol use. Clearing up the confusion.

This paper reviews the findings of qualitative and quantitative research into family physicians' attitudes, beliefs, and experience with patients with alcohol problems. The implications of the findings are discussed in the context of the need for educational programs to improve physicians' work with these patients.

Alcohol Drinking↗
PubMed1993

Cryotherapy precision. Clinician's estimate of cryosurgical iceball lateral spread of freeze.

OBJECTIVE: To examine physicians' ability to estimate the lateral spread of freeze (LSF) of a cryosurgical iceball using three techniques. DESIGN: A nonrandomized control trial of in vitro nitrous oxide cryosurgical procedures. SETTING: Primary care residency training programs. PARTICIPANTS: A convenience sample of 80 resident and faculty physicians from four family practice residency programs and one obstetrics and gynecology residency program. INTERVENTIONS: After performing cryosurgery with standard naked-eye and colposcopic-assisted techniques, subjects used a new experimental cryosurgical iceball gauge (CIG) to estimate the LSF during cryotherapy. MAIN OUTCOME MEASURES: LSF estimations reported physicians were compared simultaneously with those measured by an observer. RESULTS: The mean (+/- SD) LSF estimation errors at the termination of freeze were as follows: 2.62 +/- 2.42 mm for the colposcopy technique, 2.00 +/- 2.16 mm for the naked-eye method, and 1.28 +/- 0.87 mm for the CIG technique. The range of maximum error was 6.5 to 11 mm for the colposcopic technique, 5.5 to 12.5 mm for the naked-eye method, and 3.0 to 4.0 mm for the CIG technique. CONCLUSIONS: Overestimation of the LSF, which increases the risk of undertreatment and residual disease, was more common than underestimation. The CIG minimized perceptual error and provided the best cryosurgical precision.

Calibration↗
PubMed1992

Surgical management of the infant with coarctation of the aorta and ventricular septal defect.

Clinical and cardiac catheterization data were collected from 39 infants with coarctation of the aorta and ventricular septal defect, 31 of whom were initially managed only by surgical repair of coarctation. Data were analyzed to determine mortality, morbidity, outcome and factors that might predict survival or the need for septal defect closure. Of the eight patients who did not require surgical treatment before 3 months of age, seven underwent coarctation repair alone at a mean age of 2.3 years. Of the 23 infants managed with coarctation repair alone, before age 3 months, 9 needed no additional surgical treatment and 6 required early and 8 required late repair of the ventricular septal defect. Seven infants underwent coarctation repair and simultaneous pulmonary artery banding and one eventually required debanding after spontaneous closure of the septal defect. The overall mortality rate in this series was 10.3% (mean follow-up time 5.7 years). Of 39 infants, 16 (41%) never required a second operation for ventricular septal defect closure. For patients who had only coarctation or coarctation repair with pulmonary artery banding at less than 3 months of age, ventricular septal defect size was categorized as small (less than 0.5 cm/m2), moderate (less than 1 cm/m2) or large (greater than 1 cm/m2) on the basis of defect size at operative repair or echocardiographic or angiographic assessment. Defect size did not necessarily correlate with the need for operative repair.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Coarctation↗
PubMed1991

Delayed pneumothorax after subclavian vein catheterization and positive pressure ventilation.

Delayed pneumothorax may occur after subclavian vein catheterization and results from slow accumulation of air in the pleural space. Thus initial postinsertion chest x-rays may not detect this complication. The addition of positive pressure ventilation for general anaesthesia may make this complication life threatening. We report three cases and the literature is surveyed.

Aged↗
PubMed1991

Fleischner lecture. Developmental abnormalities in the systemic blood supply to the lungs.

Developmental abnormalities in the systemic blood supply to the lungs occur in association with congenital heart disease, congenital lung disease, and rarely with apparently normal heart and lungs. Although most of these anomalies are rare, in the aggregate they are relatively common and of special interest to students of chest and heart disease.

Bronchopulmonary Sequestration↗
PubMed1990

Prediction of cardiac and pulmonary complications related to elective abdominal and noncardiac thoracic surgery in geriatric patients.

PURPOSE: Major cardiac and pulmonary complications associated with abdominal and noncardiac thoracic surgery are a common cause of mortality and serious morbidity in elderly patients. We postulated that a simple, inexpensive bicycle exercise test could provide objective documentation of cardiopulmonary reserve and, therefore, predict perioperative pulmonary as well as cardiac complications. PATIENTS AND METHODS: Prior to elective surgery, 177 patients aged 65 years or older had assessment of the clinical history, results of physical examination, electrocardiogram, chest radiograph, blood chemistries, pulmonary function test findings, supine exercise test results, Dripps classification, and Goldman cardiac risk factors. Observations in patients with and without major perioperative cardiac and/or pulmonary complications were compared using univariate analysis followed by a multivariate logistic regression procedure. RESULTS: Major perioperative complications were pulmonary in 24 patients, cardiac in 25 patients, and either cardiac or pulmonary in 39 patients. By multivariate analysis, inability to perform two minutes of supine bicycle exercise raising the heart rate above 99 beats/minute was the best predictor of perioperative pulmonary, cardiac, and combined cardiopulmonary complication (p less than 0.0005). Among 108 patients who were able to achieve these exercise criteria, cardiac or pulmonary complications occurred in 10 patients (9.3%), with one death (0.9%). Among 69 patients unable to exercise satisfactorily, cardiac or pulmonary complications occurred in 29 patients (42%), with five total deaths (7.2%). CONCLUSION: Objective measurement of exercise capacity by supine bicycle ergometry appears to be of clinical value for preoperative risk stratification for both pulmonary and cardiac complications prior to major elective abdominal or noncardiac thoracic surgery in elderly patients.

Abdomen↗
PubMed1989

Parathyroid hormone and calcitriol changes in normal and insulin-dependent diabetic pregnancies.

In pregnancy, an increase in serum calcitriol and parathyroid hormone concentrations has been reported in several studies, though the increase in parathyroid hormone remains controversial. In magnesium deficiency states, parathyroid hormone and calcitriol secretion may be decreased. Because magnesium deficiency may occur in insulin-dependent diabetic patients, mainly because of urinary magnesium losses, we hypothesized that serum parathyroid hormone and calcitriol do not increase in the diabetic pregnancy. We studied, in a prospective longitudinal manner, 35 nondiabetic and 199 insulin-dependent diabetic pregnancies. In diabetic women, the goals of glycemic control were fasting blood glucose below 100 mg/dL and postprandial blood glucose less than 140 mg/dL. Serum magnesium, calcium, parathyroid hormone (whole molecule; ie, 1-84 fragment), and calcitriol were measured three times: 1) 8-12 weeks, 2) 22-28 weeks, and 3) 32-38 weeks' gestation. In normal women, serum parathyroid hormone did not change significantly over pregnancy, and a wide scatter of values was observed. Serum calcitriol increased significantly with advancing gestation. In diabetic women, serum parathyroid hormone had a narrow scatter, but values were within the low-normal range. During the third trimester there was no increase, and even a decrease, in serum calcitriol concentrations. Diabetics had, throughout pregnancy, significantly reduced serum magnesium concentrations when compared with controls. Their serum calcium and ionized calcium concentrations were similar to those of controls, except in the third trimester, when diabetic women had significantly lower serum calcium and ionized calcium concentrations than controls. We speculate that mineral metabolism abnormalities in diabetic pregnancies might be due to relative magnesium and/or insulin deficiency.

Adult↗
PubMed1989

When exercise can kill: how to spot IHSS.

For the patient who has idiopathic hypertrophic subaortic stenosis vigorous activity can be deadly. Identifying this condition and teaching the patient how to compensate may keep him alive.

Adult↗
PubMed1988

Calcitriol in the treatment of postmenopausal osteoporosis.

Calcitriol was compared with placebo in the treatment of postmenopausal osteoporosis in a double-blind, randomized, parallel clinical trial of 24 months' duration. Adjustment was made in dietary calcium to maximize the dose of calcitriol. The study was completed by 15 patients who received placebo and 12 patients who received calcitriol. The calcitriol group had positive slopes (compared with negative slopes for the placebo group) for total body calcium, bone mineral content of the radius, bone mineral density of the lumbar spine, and radiographic absorptiometry of the middle phalanges. The difference between the two groups was statistically significant for each of these measurements. The fracture rate in the treatment group was 250 per 1,000 patient-years as compared with 333 for the placebo group. The mean dose of calcitriol was 0.8 micrograms per day. Hypercalcemia, hypercalciuria, and perhaps nephrolithiasis were observed as complications of treatment. Calcitriol increased bone mineral density by decreasing bone resorption, but not by increasing bone formation. Future studies should concentrate on treatment with oral calcitriol in lower doses. It would also be of interest to examine parenteral administration of calcitriol. It is possible that bone formation can be increased by achieving higher serum levels of the drug, whereas complications may be avoided by using a non-oral route of administration.

Aged↗
PubMed1988

Evaluation of electrophoretic methods for typing methicillin-resistant Staphylococcus aureus.

Three electrophoretic methods of typing methicillin-resistant Staphylococcus aureus (MRSA) strains--plasmid profiles (PP), whole-cell protein profiles (WCPP) and immunoblotting profiles (IP)--were evaluated and compared with phage typing. The results obtained with isolates from 12 outbreaks were compared both within the outbreaks, to determine the consistency of results, and between outbreaks. There was generally good agreement between the typing methods but in only six outbreaks did all four methods indicate the same relationship between isolates. WCPP comprised more than 50 bands; when differences occurred, they were seen in only a few bands. In contrast, IP comprised only one or two major bands and the differences were much easier to interpret. The PPs of many of the isolates were similar; many isolates contained a plasmid of mol. wt (18-25) x 10(6). In several outbreaks both WCPP and IP showed minor differences between isolates that were not apparent with phage typing. When comparisons were made between the 12 index strains and an isolate representing the London epidemic MRSA strain, phage typing and WCPP were the most discriminatory methods; both gave nine distinct patterns, whereas there were eight IPs and only six PPs amongst the 13 strains. It was concluded that both WCPP and IP could provide valuable epidemiological data on MRSA and that IP was the easiest of the three methods to interpret.

Bacterial Proteins↗
PubMed1988

Radiologic detection of thymoma in patients with myasthenia gravis.

From 1973 through 1986, 154 consecutive patients who had a transsternal thymectomy for myasthenia gravis had preoperative radiologic evaluation for a possible thymoma. Examinations included posteroanterior and lateral (n = 154) and shallow oblique (n = 126) chest radiography, linear tomography (n = 80), and chest CT (n = 96). At surgery, a thymoma was found in 26 patients (17%). Plain film findings, which often were subtle, correctly predicted a thymoma in 15 (58%) of 26 patients. CT findings correctly predicted a thymoma in 17 of 20 patients (sensitivity, 85.0%; specificity, 98.7%; and accuracy, 95.8%). CT findings failed to detect a thymoma in three patients because a small tumor was indistinguishable from adjacent thymus (n = 2) and respirator motion artifacts (n = 1). Four (15%) of the tumors were invasive, and three (12%) were calcified. The likelihood of a thymoma increased with increasing age (3% for 20 years old and under, 12% for 21-45 years old, and 35% for 46 years old and older). In the youngest group, the thymus is densely cellular and normally relatively large, and therefore a small thymoma may be hidden. In patients 21-45 years old, partial fatty involution leaves parenchymal islands that can mimic a thymoma or obscure a small tumor. In patients over 45 years old, fatty involution enhances recognition of even small thymic tumors. For all patients with myasthenia gravis, we recommend that the initial chest radiographic examination include posteroanterior, lateral, and shallow (20 degrees) oblique views. For those patients under 21 years old, we recommend chest CT only when local symptoms, signs, or radiographic findings suggest the presence of thymic abnormality. For those patients 21 years old and older, we recommend routine chest CT.

Adolescent↗