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Biomedical subjects

D B Ferguson

Publications and source records attributed to D B Ferguson.

At least 19 recordsLinked to original sources
PubMed2001

Effects of chlorhexidine gluconate as an endodontic irrigant on the apical seal: short-term results.

The aim of this study was to ascertain whether chlorhexidine gluconate (0.12%), used as an endodontic irrigating solution would affect the apical seal obtained when using three different root canal cements. One hundred extracted human single-canal teeth were divided into 9 experimental groups of 10 teeth each and a positive and negative group of 5 teeth each. The teeth were decoronated at the level of the cementoenamel junction, then accessed, instrumented to a Master Apical File #50, irrigated with either sterile saline, 5.25% NaOCl or 0.12% chlorhexidine gluconate, and dried using paper points. Obturation was accomplished using lateral condensation and 1 of 3 endodontic sealers: Roth's 811, AH26, or Sealapex. At 90 and 180 days after obturation apical leakage was measured using the fluid filtration method. Using the ANOVA test the results showed no significant difference in seal related to the irrigant at both the 90- and 180-day observation periods.

Analysis of Variance↗
PubMed2000

The value of a questionnaire in assessing the acquisition and retention of basic science knowledge by dental students.

This cross-sectional study aimed to assess and compare, by performances in a questionnaire, the level of knowledge of basic medical sciences in 6th-form school pupils studying science subjects as entrance requirements to University and in 2nd, 3rd and 4th-year undergraduate dental students. A 40-part multiple response, true/false questionnaire, testing recall of factual knowledge in anatomy, biochemistry, physiology and oral biology, was used as the method of assessment. The results suggested that this simple format was an acceptable and useful method of assessment of the knowledge level of the study groups. The difference in scores of knowledge, expected to be higher in 2nd-year students compared to 6th form groups, was greatest in anatomy and oral biology, less in biochemistry and, unexpectedly, was not apparent in physiology. A difference in performance on the knowledge questionnaire was observed between 4th and 2nd year dental students, attributable primarily to decreased scores for 4th year dental students in biochemistry and, to a lesser extent, anatomy. The results obtained with this standardised test of factual knowledge recall may be of value to teachers compiling medical sciences courses for dental undergraduates and to those planning and evaluating new curricula with a less didactic approach.

Cross-Sectional Studies↗
PubMed1999

The flow rate and composition of human labial gland saliva.

Since the flow rate of saliva from human labial salivary glands has usually been measured as the secretion from an area of labial mucosa as 0.05-4.8 microl/cm2/min. The only data for single glands gives a comparable figure of 0.1 microl/min/gland. There is no consensus on the effects of gustatory stimulation, gender or ageing, although most reports suggest that flow rate is not related to gender and ageing up to age 60. The main differences in composition between labial gland saliva and that from the major glands are the higher and variable sodium concentration, the very low phosphate and hydrogen carbonate concentrations, and the higher protein concentration despite low concentrations of amylase. The concentrations of IgA and blood group substances are notably higher in labial gland saliva. In Sjogren's syndrome and cystic fibrosis flow rates are decreased. Low rates of flow have been associated with a higher incidence of dental caries.

Adult↗
PubMed1997

A problem-based preclinical course for dental students.

In September 1994 the Turner Dental School, University of Manchester, introduced a new curriculum in which the first 2 years were problem-oriented. The 82 dental students share the first year and part of the second with 252 medical students, making this the largest cohort of students in a problem-based learning course in the world. It is one of two or three dental courses of its kind. In addition to the problem-oriented work, the course includes a substantial informatics component involving computer skills. The number of lectures has been reduced to a maximum of four per week in the first year and seven per week in the second. Most of the students' learning is achieved by group work in which they study clinical cases and search out the basic biological background to them. At the same time the students consider the social and psychological implications of the cases and develop their own communication skills. Thus far the course has resulted in students having a much broader but less detailed subject knowledge. Students are able to integrate their knowledge more effectively. In the new kinds of examination developed for the course the dental students achieve marks around 5% lower than their medical colleagues, as in more traditional combined courses. The first year of the course was designed for medical students and may not therefore be optimal for dental students but the second year has more specifically dental components.

Biology↗
PubMed1996

The flow rate of unstimulated human labial gland saliva.

Although the minor salivary glands contribute an important fraction of the resting flow of saliva, which may be particularly relevant in xerostomia, there is currently no precise method of measuring the flow from individual glands or recording the number of active glands in a given area. These experiments were devised to test a photographic method of assaying labial gland saliva and to see whether subjects of different ages had differing flow rates and/or numbers of glands. Unstimulated saliva secretion from labial salivary glands was measured in healthy non-medicated subjects aged 20 to 55 years by a photographic method. The number of glands in a unit area, the individual gland flow rates, and the flow rates per unit area were assessed. There was a high correlation between flow rate per unit area as measured by this method and measurements from weighing filter paper before and after absorption of the saliva droplets when the latter method could be used. The mean flow rate for 22 subjects was 2.35 +/- 1.65 microL/min over the whole area photographed. Subjects with higher flow rates had both more active glands and a higher rate of secretion from individual glands. There was no correlation between either number of active glands in a unit area or of flow rate and age in the age range represented by these subjects.

Adult↗
PubMed1992

Acute hydralazine overdose: marked ECG abnormalities in a young adult.

Although hydralazine is a commonly prescribed antihypertensive agent, reports of acute human poisoning are uncommon. Most of the literature focuses on chronic toxicity, most notably, the drug-induced systemic lupus erythematosus syndrome. A case of acute hydralazine overdose associated with marked ECG ST segment depression in a young adult is presented. Although the patient also had mild hypotension, acidemia, and ethanol intoxication, the ECG abnormality was alarming and suggestive of myocardial ischemia. The patient was managed conservatively in an ICU setting, and the metabolic and ECG abnormalities resolved. No reports of such marked ECG changes associated with acute hydralazine poisoning in a young adult could be found. Clinical and experimental data on acute hydralazine exposure suggest that the possibility of direct drug effects, including positive inotropic and chronotropic effects and myocardial cell injury, should be considered.

Adult↗
PubMed1991

Disposition of spontaneous pneumomediastinum.

In the evaluation of spontaneous pneumomediastinum, it is important to exclude pathological causes of pneumomediastinum, including Boerhaave's syndrome, which carries a high mortality rate. The literature varies greatly as to the care of patients with presumed spontaneous pneumomediastinum. The authors present an illustrative case of spontaneous pneumomediastinum treated with intravenous antibiotics and intensive care unit (ICU) admission despite a normal esophagram. Spontaneous pneumomediastinum is a benign entity that may not require observation in an ICU, and patients may do as well with close outpatient follow-up. For those patients in which the etiology of the pneumomediastinum is unclear, a contrast esophagram is recommended to assess for esophageal disruption. The signs, symptoms, pathophysiology, and disposition of spontaneous pneumomediastinum are discussed.

Adult↗
PubMed1989

Dorsal dislocation of four metacarpophalangeal joints.

We report the case of a 23-year-old man who fell from a third-floor window and injured his left hand. Physical examination and radiographic evaluation revealed open dorsal metacarpophalangeal dislocation of four fingers. The index finger dislocation was reduced in the emergency department, and the other three fingers responded to closed reduction during surgery. The patient made an uneventful recovery without complications. Metacarpophalangeal dislocations are unusual, with multiple dislocations rarely described.

Accidental Falls↗
PubMed1987

Current diagnostic uses of saliva.

Most of the information which has been collected on salivary composition in different disease states (with the notable exception of that in digitalis intoxication) has proved of little practical diagnostic value. Diagnostic use of saliva has become more extensive in recent years, particularly in relation to estimation of systemic levels of lipid-soluble drugs and hormones. Thiocyanate levels have been used to validate self-reported frequency of tobacco-smoking, and nitrate levels have been assayed to estimate dietary nitrate intakes. The estimation of steroid hormone concentrations in saliva is now generally recognized as a means of determining systemic steroid levels which offers many advantages over estimation in serum or urine samples. Immunoassay methods now permit measurement of very small concentrations of biologically active substances in saliva.

Diagnosis↗