Picloram stability in a sample of forest soil during handling and storage.
Explore the source record for details and available documents.
Drug Stability↗
Biomedical subjects
C E Evans
Publications and source records attributed to C E Evans.
Hypertension control in two Canadian communities: evidence for better treatment and overlabelling.
We evaluated the prevalence and control of hypertension in two Canadian cities without university medical centre facilities. A stratified multistage probability sample was selected, and we interviewed 6258 adults between the ages of 30 and 69 inclusive. Blood pressure measurements were obtained during home interviews. Up to two further visits were made to people with untreated blood pressure elevation. By a diagnostic criterion of 90 mmHg, the hypertension prevalence was 114/1000. Six per cent of the hypertensives were undetected, 6% detected but untreated, 17% treated but uncontrolled and 70% were being treated and controlled. Control was better in females and older subjects. These findings show no disadvantages to hypertensives living away from university medical centres. We found a hypertension prevalence of 143/1000 among people who reported being diagnosed as hypertensive but who had normal blood pressure while not on medication. These results suggest a problem with over-labelling of hypertensives.
Adult↗
Educational package on hypertension for primary care physicians.
The usefulness of an educational package on hypertension that provides clinically important, up-to-date medical information and office "aids" to primary care physicians was tested in a randomized controlled trial. Fifty-six physicians completed a pretest multiple-choice questionnaire and were allocated at random either to a group that received the educational package (the "study group") or to a control group. There was a highly significant correlation between the pretest scores and the number of years since graduation (r = -0.55, p less than 0.0001), which indicated that younger physicians are more likely than older physicians to have an up-to-date knowledge of the management of hypertension. The increase in knowledge in the study group (17.5%) was significantly greater than that in the control group (2.7%). Furthermore, although the post-test scores in the control group were still significantly correlated with the number of years since graduation, those in the study group were not. It was concluded that although the older physicians knew less than their younger colleagues about hypertension, the use of the educational package significantly increased knowledge, and the increase was not limited by the physician's age.
Age Factors↗
Prostacyclin production by confluent and non-confluent human endothelial cells in culture.
Prostacyclin (PGI2) production by cultured human umbilical vein endothelial cells was examined by platelet bioassay and by radioimmunoassay of its stable metabolite 6-oxo-prostaglandin F1 alpha (6-oxo-PGF1 alpha). Confluent cultures produced PGI2 in a burst of activity approx. 20 min after changing the growth medium. This occurred in either normal, serum-supplemented growth medium or in balanced salt solution. The mechanical action of changing the growth medium did not appear to be responsible for this burst of PGI2 production. PGI2 production by non-confluent cultures decreased as cell density increased towards confluence. Supplementing the growth medium with arachidonic acid did afford some protection against decreased PGI2 production, whilst the use of conditioned media potentiated this effect. Reduction of cell density by passaging confluent cultures further demonstrated the inverse relationship between PGI2 production and cell density. These results are discussed in relation to the control of PGI2 production in cultured endothelial cells.
6-Ketoprostaglandin F1 alpha↗
6-Keto prostaglandin F1 alpha production in endothelial-cell cultures in response to normal and diabetic human serum.
Prostacyclin, being a potent vasodilator and platelet aggregation inhibitor, is of interest because of its possible relationship to microangiopathy associated with diabetes and other vascular diseases. Using a radioimmunoassay for the stable product of prostacyclin breakdown (6-keto PGF1 alpha) we have examined the ability of serum from diabetic patients to stimulate prostacyclin production in human endothelial cells. Results in the study of the effects of human serum on prostacyclin production by endothelial cells showed that there was a highly significant difference between diabetics and controls, with diabetic serum causing much lower prostacyclin production from cultured cells. The effect of serum in this study was not dependent on the age or sex of the donor.
6-Ketoprostaglandin F1 alpha↗
Maternal and infant characteristics in abuse: a case control study.
Eighty-six abused children identified by two Children's Aid Societies in Hamilton-Wentworth County, Ontario, were compared with 86 controls born in the same hospital. Three factors were significantly more common in the abused group: (1) low socioeconomic status of the mother, (2) younger age at time of delivery, and (3) indication of a psychosocial problem recorded in the medical chart. The failure to find significant differences between abused children and controls in birthweight, Apgar score, and prematurity contrasts with earlier investigations of infant characteristics and child abuse.
Adult↗
Predicting compliance with a regimen of digoxin therapy in family practice.
The ability of family physicians to predict patients' compliance with a regimen of digoxin therapy was studied by an analytic survey. Compliance was assessed by a pill count at a home visit and measurement of the serum digoxin level in a blood sample obtained at that visit. Of 74 patients 70% were found to be taking more than 80% of their pills and 86% had a therapeutic serum digoxin level. The 10 physicians were unable to predict compliance better than chance, even for the 58 patients they had known for 5 or more years. Physicians should be cautious in predicting compliance, and when they prescribe oral digoxin therapy they should monitor the patient's compliance by means of the serum digoxin levels.
Adult↗
Effects of bile salts on the plasma membranes of isolated rat hepatocytes.
The conjugated trihydroxy bile salts glycocholate and taurocholate removed approx. 20--30% of the plasma-membrane enzymes 5'-nucleotidase, alkaline phosphatase and alkaline phosphodiesterase I from isolated hepatocytes before the onset of lysis, as judged by release of the cytosolic enzyme lactate dehydrogenase. The conjugated dihydroxy bile salt glycodeoxycholate similarly removed 10--20% of the 5'-nucleotidase and alkaline phosphatase activities, but not alkaline phosphodiesterase activity; this bile salt caused lysis of hepatocytes at approx. 10-fold lower concentrations (1.5--2.0mM) than either glycocholate or taurocholate (12--16mM). At low concentrations (7 mM), glycocholate released these enzymes in a predominantly particulate form, whereas at higher concentrations (15 mM) glycocholate further released these components in a predominantly 'soluble' form. Inclusion of 1% (w/v) bovine serum albumin in the incubations had a small protective effect on the release of enzymes from hepatocytes by glycodeoxycholate, but not by glycocholate. These observations are discussed in relation to the possible role of bile salts in the origin of some biliary proteins.
Animals↗
Rubella antibody titres and immunization status in a family practice.
Rubella vaccination status and immunity to rubella were studied in 230 "active patients" aged 8 to 22 years in a teaching family practice by means of a chart review and measurement of the rubella antibody titre in a blood sample. Of the 200 patients who submitted a blood sample 161 (80%) were found to be immune, having a rubella hemagglutination-inhibiting antibody titre of 1:16 or greater. Log linear analysis showed that immunity to rubella was independent of a history of rubella, and that 94% of the vaccinated patients versus 74% of the unvaccinated patients (a significant difference; P = 0.007) were immune. In retrospect we estimated that 80% of the study group were protected at the start of the study. After surveillance and follow-up, with vaccination of 27 of the 39 patients identified as susceptible to rubella, this estimated proportion increased to 90%. The study showed that there is nothing to be gained by asking about a history of rubella but that vaccination against this disease is increasing among children aged 5 to 9 years.
Adolescent↗
Teachers in general practice: a comparative study.
Thirty-nine randomly selected general practitioners in the Cambridgeshire Health Area were surveyed in an attempt to determine whether there were prior differences between those practitioners who choose to become involved with undergraduate medical students and those who choose not to. Teachers were found to have graduated more recently, subscribe to more journals and were more likely to use medical libraries than non-teachers. All the solo practitioners in the study and two of the four practitioners in two-man groups belonged to a subgroup of non-teachers who had never had students and did not want students in the future. This subfroup also subscribed to fewer journals than the other groups, bought fewer textbooks and used medical libraries less. The only prior differences between teachers and non-teacher that have been demonstrated are year of graduation and type of practice. Other differences could well be attributed to the influence of the students themselves. Studies are needed to clarify this issue, especially as it realates to continuing medical education.
Education, Medical, Continuing↗
Giant-cell arteritis of the uterus and adnexa.
The case history and pathological findings in an excisional biopsy are described of a sixth example of giant-cell arteritis affecting the female internal genitalia. Histologically, giant-cell arteritis in this location tends to focus on the outer layers of the blood vessel, and it is thought that this is due to the "senile" elastosis of the adventitia which occurs so commonly in blood vessels in this situation.
Aged↗
Effects of bile salts on the plasma membranes of isolated hepatocytes [proceedings].
Explore the source record for details and available documents.
Animals↗
A study of inter observer error in reading 70 mm roentgenograms.
Explore the source record for details and available documents.
Diagnosis↗
Internal carotid artery aneurysm: a singular anomaly.
A 9-year-old Indian boy was found to have an aneurysm of the left internal carotid artery. The vessel was heavily atherosclerosed, and the distal segment of the artery was tortuous and dilated. Serum lipid estimations showed the presence of type IIB hyperlipoproteinemia, with evidence of the disease in the patient's identical twin sibling and 37-year-old father. There was also a marginal increase in serum triglycerides in a 4-year-old younger brother. The patient's 29-year-old mother was unaffected. The patient had suffered hemolytic disease as a newborn, which resulted in kernicterus and subsequent mental retardation. This incident is considered to have been the result of a proven glucose-6-phosphate dehydrogenase deficiency. The aneurysm was resected and arterial continuity was ensured by using an end-to-end anastomosis. Post-operative blood flow studies showed normal flow patterns in the reconstituted artery. Postoperatively, the patient's mental performance increased dramatically; it is hypothesized that such progress is the consequence of an improvement in the blood supply to the limbic system, following the operative procedure.
Adult↗
A three-rooted mandibular second premolar.
If an endodontic problem is diagnosed in a mandibular premolar, and root canal therapy is provided, it must be considered that second and third canals might exist. Although the existence of a third canal would be rare, a thorough evaluation may help to prevent future complications. In the case presented here, failure to recognize a third canal might have resulted in incomplete instrumentation and canal obturation, and endodontic failure. Variations in root canal morphology and the number of canals might not have been detected even during close inspection of the pulp chamber floor. Therefore, the dentist must have a thorough knowledge of root canal morphology and its variations.
Adult↗
Does a mailed continuing education program improve physician performance? Results of a randomized trial in antihypertensive care.
Evidence is sparse concerning the value of the "educational" materials that physicians receive in the mail. We conducted a randomized trial of a mailed continuing education program on hypertension for primary care physicians. Although formal pretesting documented that the program led to significant improvements in physician knowledge over the short term, the current study showed no lasting effect on physician knowledge (mean scores on an end-of-study questionnaire were 50% and 52% for study and control physicians, respectively) and no influence on performance in lowering the blood pressures of patients referred from screening (mean blood pressure drop for study patients, 12.2/10.4 mm Hg vs 13.0/10.6 mm Hg for control patients). The chance that we missed a difference in diastolic blood pressure as great as 3 mm Hg is less than 5%. Resources spent on instructional materials mailed to physicians may be wasted.
Adult↗