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Biomedical subjects

J Robertson

Publications and source records attributed to J Robertson.

At least 181 records · Page 10Linked to original sources
PubMed1990

Issues in the evaluation of a community psychogeriatric service.

The need for evaluation of community psychogeriatric programs is stressed. The results of the evaluation of an outpatient service, with a liaison component, based in a community general hospital are presented. The use of treatment outcome scales, user satisfaction surveys, and a study of cost effectiveness are discussed. The issues of needs assessment, service models, staffing, target population, and the role of the family physician are addressed. It is recommended that evaluation processes be initiated by psychogeriatric services and that program data collection be developed in a manner that allows for service comparability, the assessment of ongoing community needs and the determining of program effectiveness.

Aged↗
PubMed1990

The body-worn alarm in the treatment of childhood enuresis.

Two studies examined the effectiveness of the body-worn alarm in out-patient treatment of childhood nocturnal enuresis. The first involved 40 children, previously untreated by conditioning methods, treated with either the body-worn alarm or the traditional pad and bell alarm. The second study compared the body-worn alarm with modified dry-bed training with 48 children previously resistant to treatment. Results of both studies indicated the body-worn alarm was as effective as other methods in terms of the proportion of children successfully treated and was superior with respect to rapidity of response and consumer appeal. Such findings indicate that the body-worn alarm could become the treatment of choice for nocturnal enuresis.

Adolescent↗
PubMed1990

Persisting inapparent chlamydial infection in a trachoma endemic community in The Gambia.

In a Gambian village with endemic trachoma, C. trachomatis was isolated from some 50% of children with active trachoma but from only 1% of adults with scarring sequelae. One possibility is that individuals with progressive scarring disease have clinically inapparent, non-productive infection which cannot be detected by cell culture. In whole village survey, 12% of 808 people carried ocular chlamydial antigen detected by EIA. Around 70% of antigen positive children were clinically active. By contrast, for adults age greater than 25 years, only 10% of antigen positives were clinically active. Antigen positive adults were twice as likely to develop scarring disease and longitudinal studies suggest that they are intermittently infectious. Implications for the pathology and prevention of trachoma are discussed.

Adolescent↗
PubMed1989

Slowing of cell cycle traverse for cells in exponential monolayer cultures placed into plateau-fed and starved medium.

MCa-11 tumor cells in exponential monolayer cultures were pulse/chase-labeled with [3H]thymidine and then regrown in fresh, plateau-fed, or starved medium. We measured the DNA content and autoradiographic labeling of these cells by absorption cytophotometry at intervals of 0, 2, 4, 8, 12, and 24 h to follow the progress through the cell cycle of those cells which had incorporated isotope. We found that for the cells grown in plateau-fed and starved medium the G0/G1, S, and G2 phases of the cell cycle were prolonged when compared to those for cells grown in fresh medium. These results show that, under adverse microenvironmental conditions, the growth of tumor cells can be regulated in all phases of the cell cycle, and that this regulation can include lengthening and even cessation of replicative DNA synthesis.

Cell Cycle↗
PubMed1989

A multimedia medical communication link between a radiology department and an emergency department.

The most critical aspect of a radiologist's work is communicating his findings to the attending physician responsible for the patient's care. This is also the part of the process that is least well organized and the most subject to failure. At the University of Ottawa Medical Communications Research Centre we are investigating technical means to improving communications between radiologists and attending physicians. We first introduce the radiology communication service problem and show why it is essentially a multimedia communication problem. We then briefly describe a multimedia communication system designed and implemented by our research team. The multimedia system consists of several work stations linked by the Hospital's local area network (LAN). Each physician work station comprises a Compaq 386/20-Mhz microcomputer with 16 Mbytes of RAM, a 500-Mbyte image disk, and an image memory that drives a 1,000-line monochrome monitor. The images are digitized using a Konica laser-based film digitizer (2430 by 2000 10-bit pixels for a standard chest radiograph). The multimedia file server manager station is built around a PC-AT compatible with a Northern Telecom Meridian SL-1ST digital PBX and a Meridian Mail digital voice messaging system. This last device is used to store voice data and is linked via the PBX to the workstations' digital telephones. A Sytek 6,000 LAN links all work stations to the file server. All data, image, and graphic information is transmitted via this network, while the twisted pair connections linking the digital PBX to the telephone sets are used for transmitting voice data.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer Communication Networks↗
PubMed1989

Context-dependent enhancements for radiological images.

Many techniques have been proposed to enhance radiographic images and each of them may be optimal depending upon the circumstances. However, the problem confronting the radiologist or the physician is which enhancement to use and how to select the parameters when a specific feature is to be emphasized. At the University of Ottawa, our research work is oriented towards automatic context-dependent enhancements. Our approach attempts to match the three phases involved in viewing a radiograph: getting a global impression, analyzing the objects and the local features, and focusing on the image perturbations. In this article, we report on enhancements to support the first two phases in the case of chest radiographs and on the applicability of gray level reversal transformations.

Emergency Service, Hospital↗
PubMed1989

Clinicopathologic and cytogenic features of CD34 (My 10)-positive acute nonlymphocytic leukemia.

The authors performed membrane antigen phenotyping on 75 patients with acute nonlymphocytic leukemia with a panel of myeloid-associated monoclonal antibodies. The 34 patients (45%) with CD34-positive leukemia were not significantly different from the 41 with CD34-negative leukemia with respect to age, hemoglobin, white blood cell count, or platelet count at presentation, but their blasts were more likely to lack the CD15 or CD33 antigens and to have FAB M1 or M2 morphologic characteristics. CD34-positive leukemia was more likely to arise after chemotherapy. Patients with CD34-positive leukemia were less likely to enter a complete remission even when analysis was limited to those patients receiving a high-dose induction-type chemotherapy regimen. Giemsa-banding karyotyping studies were obtained in 55 of the cases. In 30 of these cases (56%) clonal karyotypic abnormalities were demonstrated. Although the karyotypic abnormalities and phenotypes were varied, there was a high degree of association between the karyotypic abnormalities monosomy 7/del (7q) and the CD34-positive phenotype; this antigen was expressed on blasts from eight of the nine patients displaying this abnormality. Monoclonal antibody phenotyping of myeloid leukemia with reagents such as anti-CD34 may help to define biologically interesting subsets of ANLL with distinct clinicopathologic expression.

Antigens, Differentiation↗
PubMed1989

Residential instability in adolescent inpatients.

The case records of 225 randomly selected adolescent psychiatric inpatients were reviewed to determine prevalence of residential instability. The study also examined the demographic, family composition, life event, and behavior characteristics associated with residential instability. Approximately 30% of the sample had experienced a high rate of residential instability (i.e., from 5 to 20 domicile moves). Analyses indicated that residential instability was associated with a set of characteristics that included caregiver neglect, caregiver abuse, parental separation, multiple hospitalizations, lower IQ, indices of poor impulse control, and antisocial behavior. The possible contribution of residential instability to treatment resistance and the development of antisocial behaviors in some adolescents is discussed.

Adolescent↗
PubMed1989

Demonstration of the cell cycle positions of taxol-induced "asters" and "bundles" by sequential measurements of tubulin immunofluorescence, DNA content, and autoradiographic labeling of taxol-sensitive and -resistant cells.

We used reliable and relatively inexpensive equipment to make sequential sets of measurements of antitubulin immunofluorescence, Feulgen staining, and autoradiography on the same cells. This was done to evaluate tubulin conformations, DNA content, and [3H]-thymidine incorporation in cell lines sensitive (HL60) and resistant (K562) to the novel anti-tubulin chemotherapeutic agent taxol. Numbers of cells with microtubule bundles have been found to correlate with sensitivity to taxol by clonogenic assay for several leukemic cell lines. We have found that cells with "asters" produced by taxol exposure are in mitosis and that cells with taxol-induced "bundles" are in G0/G1, S, and G2 phases. We further found that S-phase cells with microtubule bundles in both sensitive (HL60) and resistant (K562) cell lines were able to incorporate [3H]-thymidine after 4-hr exposure to taxol. As microtubule bundles and asters occur in cells of the same cell cycle phases in both lines, we conclude that the greater frequency of cells with microtubule bundles reported for sensitive cells after taxol treatment cannot result from drug exclusion nor from different effects of the drug on cell microtubules in these two leukemic lines.

Alkaloids↗
PubMed1988

Immunocytochemical localization of estrogen receptor in human breast tissue.

An immunocytochemical assay for the measurement of estrogen receptor (ER-ICA; Abbott Diagnostics) has been evaluated in 163 human breast carcinomas. Specific binding was observed in the nuclei of 111 of 163 (68%) tumors. An excellent correlation was observed between the ER-ICA and the estrogen receptor enzyme immunoassay. A significant relationship was observed between ER-ICA status and percentage of ER-ICA negative cells, histological grade of malignancy, and mitotic activity of the tumors. A significant correlation was also observed between ER-ICA status and age at mastectomy with 50% of patients with ER-ICA positive breast tumors presenting with their disease over 60 years of age. No association was observed with either tumor size or patient nodal status. Examination of the proportion of negative cells within tumors revealed a trend for the acquisition of poor prognostic features to be associated with an increase in the negative cell population. Data on the recurrence free interval of these patients showed a significant recurrence free advantage in ER-ICA positive patients, particularly those whose tumors contained low numbers of negative cells.

Adult↗
PubMed1988

Captopril and the response to stress in the spontaneously hypertensive rat.

The purpose of this study was to determine the effect of chronic blockade of the brain renin-angiotensin system on the hormonal response to stress in spontaneously hypertensive rats (SHR). To this end, we measured changes in plasma corticosterone, vasopressin, plasma renin activity, aldosterone, norepinephrine, and epinephrine in SHR treated with a 4-week intracerebroventricular infusion of captopril (osmotic minipump, 1.25 micrograms/hr) or vehicle in response to cold stress (4 degrees C x 4 hours) or ether stress (5 minutes). Within the fourth week of treatment, the average systolic blood pressure of captopril-treated SHR was significantly lower than that of vehicle-treated rats. Basal plasma levels of corticosterone, but not vasopressin, were significantly lower in SHR treated with captopril. In response to cold stress, captopril-treated SHR showed significantly lesser increases in both corticosterone and vasopressin than did vehicle-treated SHR. There were no differences in basal plasma levels of norepinephrine, epinephrine, plasma renin activity, or aldosterone between captopril-treated and vehicle-treated SHR, and both groups showed elevations of a similar magnitude after exposure to cold. In response to ether stress, captopril-treated SHR also showed significantly smaller increases in corticosterone and vasopressin than did vehicle-treated SHR. These results suggest that chronic intracerebroventricular administration of captopril, through blockade of the brain renin-angiotensin system, alters the hormonal response of SHR to stress.

Adrenocorticotropic Hormone↗
PubMed1987

Radioprotective action of carbimazole in radioiodine therapy for thyrotoxicosis--influence of the drug on iodine kinetics.

Pretreatment with carbimazole of patients given radioiodine (131I) therapy for thyrotoxicosis reduces the incidence of early hypothyroidism. The possibility that this radioprotective effect might be a consequence of drug induced alteration in thyroidal iodide turnover, leading to a reduction in thyroid irradiation, was investigated in a prospective study of 24 thyrotoxic patients. Subjects were randomly assigned to receive 131I alone or to be treated with carbimazole for a minimum of three months before 131I. Thyroxine supplements were given in the latter group to prevent iatrogenic hypothyroidism. The effective half-life of therapeutic 131I in the thyroid was measured using a gamma camera/computer system after oral administration of the dose, allowing the biological half life of the anion and estimated radiation dose to the thyroid to be derived. Effective half life of 131I, biological half life of 131I and estimated radiation dose to the thyroid were similar in the two groups of subjects. It is concluded that the radioprotective action of carbimazole is not a consequence of altered thyroidal iodide kinetics.

Carbimazole↗
PubMed1987

t(3;5)(q21;q31) in a myelodysplastic syndrome.

Cytogenetic analysis from the bone marrow of a patient with a myelodysplastic syndrome revealed the balanced translocation t(3;5)(q21;q31). Although this translocation has recently been described in six cases of AML, this is the first such observation in a preleukaemic syndrome. Subsequent evolution into RAEB and AML(M2) was noted without the acquisition of additional cytogenetic changes and complete remission achieved with conventional cytotoxic chemotherapy. The relationships with other acquired abnormalities of chromosomes 3 and 5 in MDS/AML are discussed.

Adult↗