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Biomedical subjects

A Ackerman

Publications and source records attributed to A Ackerman.

At least 19 recordsLinked to original sources
PubMed2002

An aesthetic component of the IOTN for black subjects.

A study was undertaken among black evaluators to determine their perceptions about anterior dental aesthetics in Negroid subjects with bimaxillary protrusion. One hundred evaluators assessed photographs of the anterior occlusion of 24 patients with varying complexity of bimaxillary protrusion. These adjudicators were requested to select the 5 best and the 5 worst among the 24 photographs. The 10 selected photographs were then shown to 343 Grade nine, 219 Grade twelve and 260 university students, who were required to select the most attractive, second most attractive, most unattractive, second most unattractive and an average photograph. The average ages of the groups of Grade nine, Grade twelve and university students were 15, 19 and 24 years respectively. Results were analysed statistically to determine the 5 most selected photographs in these categories. These photographs are presented and it is hoped to add them to the aesthetic component of the Index of Orthodontic Treatment Need (IOTN) so as to extend the use of this valuable index to include subjects with bimaxillary protrusion common to South Africa and Africa in general.

Adolescent↗
PubMed2000

Chromium (VI) increases endothelial cell expression of ICAM-1 and decreases nitric oxide activity.

Occupational, airborne pollutants, such as heavy metals, are recognized for inducing injury and cytotoxicity. Chromium(VI) is a redox cycling heavy metal that has been strongly implicated in the initiation of cancer. Its proinflammatory effects, however, have not been systematically examined. In our study, we found that potassium dichromate [Cr(VI)] treatment of human umbilical vein endothelial cells (HUVEC) increased intracellular adhesion molecule (ICAM) expression at the message level. ICAM message levels remained elevated for 12-24 hours after exposure and increased with time and concentration. Cr(VI) increased the release of superoxide anion without affecting the ability of endothelial cultures to produce nitric oxide. However, Cr(VI) decreased cGMP in HUVEC, suggesting that the nitric oxide produced was scavenged intracellularly. Cr(VI) also increased nitrotyrosine in HUVEC cultures. These data are consistent with the idea that exposure to Cr(VI) increases the production of superoxide anion, which scavenges nitric oxide to increase the formation of peroxynitrite. The loss in nitric oxide activity and increased formation of peroxynitrite likely enhance endothelial cell expression of ICAM-1. Cr(VI)-induced increases in the adhesive properties of the endothelium may play a critical role in the initiation and progression of tissue injury through increased recruitment of proinflammatory white blood cells.

Cells, Cultured↗
PubMed1998

The treatment need of a group of senior dental students as assessed by the IOTN and PAR indices.

Recently the Index of Orthodontic Treatment Need (IOTN) and Peer Assessment Rating (PAR) were introduced in the United Kingdom as a standard for future epidemiological research in orthodontics. The purpose of this study was to assess the suitability of these indices for South African epidemiological studies and to evaluate the treatment need of a group of senior dental students. Examinations in accordance with the IOTN and PAR were performed on 206 dental students by three postgraduate orthodontic students. According to the Dental Health Component of the IOTN 54.9 per cent of the sample had no treatment need, 26.7 per cent had a moderate treatment need and 18.4 per cent had an urgent treatment need. 74.2 per cent of the students were at the no-treatment-needed end of the aesthetic scale, which compared poorly with the 88.5 per cent recorded by student self assessment. The majority of dental students in this study were not in need of orthodontic treatment. Certain occlusal traits common to negroids, such as bimaxillary protrusion, are not represented in these assessment instruments and minor adjustments may be needed to make the systems more applicable in these population groups.

Adult↗
PubMed1994

The occlusal status of disabled children.

The occlusal status of children in 6 schools for the handicapped was determined using the Occlusal Index (O.I.) of Summers (1966). Two dentists examined 381 children who had not previously received orthodontic treatment. An additional questionnaire investigating treatment interests and habits was also completed for each child. The study showed that 74,5 per cent required treatment, 10,5 per cent had good occlusions and 15 per cent had slight malocclusions where treatment was not considered essential. The mean O.I. was 7,92 +/- 4,33. Schools with mainly cerebral and mentally disabled children had a slightly higher O.I. but the difference in values was not statistically significant. The analysis also showed that 40,6 per cent of children were interested in receiving orthodontic treatment, but only 0,5 per cent were planning to seek it. There is a need for orthodontic treatment amongst disabled children and this should be taken into account in future oral health care planning.

Adolescent↗
PubMed1991

Current trends in pediatric residency training.

A spreading gap has developed between available pediatric level 1 positions and those filled through the National Resident Matching Program. To define which variables enhance a program's ability to match, we surveyed program directors of all categorical pediatric training programs. An 82% response rate showed that ability to match was positively associated with larger program size and offering of shared residency positions. A negative association was found between many benefits and ability to match. The call schedule and number of call-free elective months had no measurable effect. Factors that we were unable to investigate, such as geographic location and academic reputation, may also play a role. Our results emphasize the irrelevance of enhancing benefits as a way of making programs competitive. Our energies need to be directed at attracting junior medical students to a career in pediatrics rather than competing for fourth-year students applying to pediatric programs.

Career Choice↗
PubMed1989

Lead based remedies for empacho: patterns and consequences.

This paper discusses research designed to investigate the patterns and consequences of the use of lead based folk remedies in the treatment of some gastrointestinal problems in Mexico. Use of lead is seen in 35% of the population sampled in Guadalajara who treated the folk illness empacho, and 5% of a similar population in Oaxaca. Lead use seems to be associated with mestizo ethnic background, and with lower levels of parental education and income.

Adult↗
PubMed1988

Toxic Mexican folk remedies for the treatment of empacho: the case of azarcon, greta, and albayalde.

This article discusses the availability of three lead-based salts which are being used as folk remedies in Mexico. Distribution systems and geographic availability were determined, and purchased samples were found to be very high in lead content. The findings suggest the need for further research to understand the reasons why such remedies are chosen, and the development of an educational program to discourage their use.

Drug Utilization↗
PubMed1983

Increasing productivity rates in adult mentally retarded clients: the failure of self-monitoring.

A series of three studies investigating procedures to increase productivity rates of mentally retarded adults in a sheltered workshop are reported. In the first study, the use of a behavioral intervention program implemented in a small classroom consisting of prompting, social praise, and performance feedback was found to significantly increase the productivity rates of five mentally retarded adults. Study 2 showed that simply the change in environment from the large, open space workshop setting to the smaller classroom did not contribute significantly to improve production. Despite the gains evident in the first study, production rates were found to decrease to pretreatment levels once the intervention was terminated. Study 3 examined the use of self-monitoring to increase productivity and achieve generalization across settings. Results of that study found self-monitoring to be ineffective. Implications for future research are discussed in light of the failure of self-monitoring with the mentally retarded.

Adult↗
PubMed1982

[Various aspects of the regulation of aldosterone secretion].

Angiotensin was regarded as the major stimulus of aldosterone secretion until the late sixties, when the discussion about the regulation of aldosterone release has been renewed. The present study demonstrates the response of plasma renin activity, aldosterone in serum and electrolytes in serum and urine to ACTH (0.25 mg Synacthen i.v.), pretreatment with dexamethasone (2 mg Millicorten p.o.) and to combined administrations of furosemide (40 mg Lasix i.v.) + potassium (80 mmol Kalinor p.o.) and furosemide + propranolol (5 mg Dociton i.v.) in eight healthy volunteers. Plasma renin activity and aldosterone were measured by radioimmunoassay, electrolytes in serum and urine according to routine methods. ACTH increases aldosterone without influencing plasma renin activity. Pretreatment with dexamethasone decreases aldosterone and stimulates renin response to upright posture. Potassium delays the increase of plasma renin activity after furosemide and propranolol inhibits the furosemide-induced renin release, both without impairing aldosterone secretion. We conclude that the regulatory system of aldosterone production is far more complex than suggested by the concept of the renin-angiotensin-aldosterone-system.

Adrenocorticotropic Hormone↗
PubMed1977

The death of Frank.

Explore the source record for details and available documents.

Attitude to Death↗
PubMed1977

Life adjustment postmyocardial infarction: determining predictive variables.

Sixty-eight patients with diagnosed myocardial infarctions were followed up for one year postinfarct onset to determine psychosocial adjustment. A previous pilot had differentiated between two groups of patients--depressive and deniers-who had poor vs good rehabilitation results, respectively. Results from this study substantiated previous findings in that 70% of those who were depressed postinfarct remained so throughout follow-up. These patients failed to remain at work and/or to function sexually and had a higher hospital readmission rate. The denial group, although still functioning with minimal psychosocial distress, was not distinguished from the remainder of the study population who generally also functioned well. Women postinfarct seemed to have the most difficult time, accounting for 80% of the deaths and 50% of the depressed group. Their noticeable type A behavior may account for this finding.

Adaptation, Psychological↗
PubMed1971

A cellular deficit in the reconstitutive capacity of immune populations of lymphoid cells demonstrable in studies of delayed hypersensitivity in mice. Evidence for thymus-bone marrow cell synergism.

A cell-transfer system was employed in the present work to investigate several characteristics of the capacity of immune and normal lymphoid cells to transfer the delayed response to methylated human serum albumin in lethally irradiated syngeneic recipients. Spleen cells derived from donor mice immunized with goose erythrocytes were far less effective in transferring responsiveness when compared with equal numbers of normal cells. Statistical analyses indicated a frequency of 1 reactive cell or cell unit in 1.3 x 10(7) normal cells and in 6.2 x 10(7) immune cells. These findings provided confirmatory evidence that antigen-induced suppression (antigenic competition) employing sequential administration of two non-cross-reacting antigens is due to relative deficits of immunocompetent cells generated by lymphoproliferation in lymphoid tissues secondary to immunization with the initial antigen. The cellular deficit in the immune population was shown to be resident in a thymus cell population, which restored the number of responders to a level equivalent to the normal population. The thymic cell was akin to the antigen-reactive cell. The cell limiting the degree of response, that is the effector cell for both normal and immune cell populations, was of bone marrow origin. Both populations of cells were shown to act in synergy to reconstitute the delayed response to the antigen.

Animals↗
PubMed1970

Fate of surviving low-birth-weight infants with coagulation deficiencies on the first day of life.

Fifty-two surviving low-birth-weight infants who had low Thrombotest (Owren) results on the first day, together with the same number of matched controls with higher Thrombotest results, were examined for the integrity of their central nervous system. Gross abnormalities were found in 13.5% of the low Thrombotest group compared with 1.9% in the higher group. Minor brain damage syndromes were more common in the low Thrombotest group. The combined brain damage syndromes were 23.1% in the low Thrombotest group compared with 3.8% in the higher group.It is suggested that the causes of the brain damage in the low Thrombotest group are either non-fatal cerebral haemorrhage or intravascular fibrin deposition associated with disseminated intravascular coagulation.

Birth Weight↗