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Biomedical subjects

J Hanson

Publications and source records attributed to J Hanson.

At least 217 records · Page 12Linked to original sources
PubMed1984

Bilateral breast cancer in northern Alberta: risk factors and survival patterns.

Of 2231 women with stage I, II or III breast cancer who were registered and seen between 1971 and 1979 and followed to the end of 1981, 48 (2.2%) had synchronous and 58 (2.6%) asynchronous bilateral breast cancer. The unadjusted incidence rate for a second breast cancer was 6.4/1000 breast-years at risk, compared with a rate of 0.70 for the risk of a first breast cancer in women. When calculated from the date of diagnosis of the first breast cancer the survival rate was better for the group with asynchronous disease than for the group with synchronous disease or for a group with unilateral disease, but when calculated from the date of diagnosis of the second cancer the rate was the same in all three groups. Comparison of known risk factors showed a significant association between the development of bilateral cancer and a later age at the birth of the first child and a longer interval between menarche and that birth. There was a trend towards greater age and more stage III cancer in the group with synchronous disease. There was no correlation between receiving radiotherapy for the first breast cancer and development of the second cancer. Annual mammography and clinical examination of asymptomatic women at a cancer centre resulted in the detection of a significantly higher proportion of minimal breast cancers in the second breast compared with the first. Such screening practices should be even more valuable in the earlier detection of unilateral breast cancer in asymptomatic women who have not had breast cancer.

Actuarial Analysis↗
PubMed1984

Drug testing using a soft agar stem cell assay on patient and xenograft tumor material.

Since 1981 we have received 50 tumor samples from 10 different sites; over half were breast or ovary. Of the 27 that were considered suitable for cloning, 11 produced colony formation and 6 of these were drug tested. One ovarian granulosa cell tumor and its xenograft (V7) were tested against several cytotoxic agents. During a period of 16 months, sensitivity to cisplatin was relatively stable but sensitivity to vinblastine was markedly changed when the original tumor cells and original cells stored in liquid nitrogen were compared with xenograft cells. These changes may be related to patient treatments prior to tumor sample collection. This xenograft V7 exhibited chromosome karyotype and iso-enzyme Glucose-6-phosphate dehydrogenase consistent with it being of human origin. Gross histology of original tumor and xenograft were similar. Chemosensitization in vivo of a breast xenograft (Hx99) to melphalan by misonidazole was investigated. Misonidazole at a total dose of 0.5 g/kg given prior to melphalan (14 mg/kg) was an effective chemosensitizer.

Animals↗
PubMed1983

Evaluation of histological grading (Gleason) in carcinoma of the prostate: adverse influence of highest grade.

The value of the Gleason system of histological grading in carcinoma of the prostate is a subject of considerable controversy. The value of this system is demonstrated in a group of 488 patients treated radically with radiation therapy. Analysis, utilizing the Gleason system in these patients, indicates that the worst histological grade identified is most important in determining the prognosis. Since nearly 18% of our patients have more than two grades identified, simple identification of primary and secondary grades, ie, the two predominating grades, is inadequate and may underestimate the aggressiveness of the tumor. This finding has implications in the analysis of the results of treatment and in determining the method of treatment in individual patients.

Adenocarcinoma↗
PubMed1983

Computed tomography of the craniocervical junction in rheumatoid arthritis.

Thirty-three patients with rheumatoid arthritis had computed tomographic examination of the craniocervical junction. This demonstrated soft tissue features which have not previously been described in published reports. A low attenuation lesion between the odontoid and the transverse ligament shown in 11 patients was considered a premonitory sign of rupture of the transverse ligament or a manifestation of active disease. Computed tomography revealed spinal cord compression in 3 patients and ligamentous changes in the transverse ligament and the alar and spinal ligaments in 26 patients. Erosion of the odontoid was shown in 19 patients and subluxation in 20 patients. No relationship could be found between the clinical signs and symptoms and the radiological abnormalities except in the case of cord compression.

Adolescent↗
PubMed1983

Matching and maximizing with concurrent ratio-interval schedules.

Animals exposed to standard concurrent variable-ratio variable-interval schedules could maximize overall reinforcement rate if, in responding, they showed a strong response bias toward the variable-ratio schedule. Tests with the standard schedules have failed to find such a bias and have been widely cited as evidence against maximization as an explanation of animal choice behavior. However, those experiments were confounded in that the value of leisure (behavior other than the instrumental response) partially offsets the value of reinforcement. The present experiment provides another such test using a concurrent procedure in which the confounding effects of leisure were mostly eliminated while the critical aspects of the concurrent variable-ratio variable-interval contingency were maintained: Responding in one component advanced only its ratio schedule while responding in the other component advanced both ratio schedules. The bias toward the latter component predicted by maximization theory was found.

Animals↗
PubMed1983

[Scanning electron microscopy studies of the mucous membrane in precancerous conditions of the larynx].

In 21 cases of laryngeal cancer precursors (diffuse laryngitis chronica; so-called "plain", "verrucous" or "papillary" keratosis circumscripta) a microlaryngoscopy was performed, followed by microsurgical removal of the dysplasia. One part of each tissue specimen was studied histologically, the corresponding other part was observed in the SEM. In comparison of the microlaryngoscopic findings and histologic diagnoses on the one hand to the submicroscopic findings got by SEM on the other hand we may describe interesting characteristic structures of the laryngeal mucous membrane. Chronic laryngitis is represented in two different types: 1. plain parakeratotic type, 2. irregularly elevated hyperkeratotic type. Obviously last of them seems to have a greater tendency of malignant degeneration. The so-called "keratoses" represent specific SEM patterns according to their microlaryngoscopic pictures: - Homogeneous structure including sporadic parakeratotic keratinisation in cases of "plain" keratosis (mostly "leukoplakia"). - Irregularity of cell and tissue surface including cell walls, but also roughness and keratinisation of microvilli in cases of "verrucous" or "papillary" keratoses (mostly "pachydermia" or adult papilloma). - Characteristic SEM picture of cancer (echelon phenomenon) in cases of precancerous lesions, in which signs of atypia were proved histologically. Our SEM results confirm the value of an exact review of the laryngeal mucosa surface for laryngologists. Precancer diagnostics can be completed furthermore by intravital staining for instance. Nevertheless there is no doubt, that also a most careful surface diagnostics cannot replace histologic tissue examination in cases of early cancer detection. Obviously there are the limits of scanning electron microscopy in laryngeal cancer research.

Chronic Disease↗
PubMed1982

Factors influencing the survival of patients with cancer of the prostate.

During the period 1969 through 1973, 777 new cases of cancer of the prostate in northern Alberta men were registered with the Alberta Cancer Registry. The overall survival rate after 5 years was 41.2%. As expected, the rates were higher for those aged less than 65 years than for those who were older at the time of diagnosis and higher for those without metastases than for those with metastases at that time. Urban residents had a higher survival rate than rural residents (45.3% v. 38.0%), and the survival ratio of the former, 1.31, was significant. Information on occupation, smoking and the interval between appearance of the first symptom and diagnosis was not always available. However, the differentials observed suggest that those in a professional occupation and nonsmokers live longer after the diagnosis of cancer of the prostate but that the interval before diagnosis does not affect the length of survival.

Aged↗
PubMed1982

Brain metastases in breast cancer patients receiving adjuvant chemotherapy.

A retrospective analysis was performed comparing the incidence of brain metastases as a site of first recurrence in patients receiving adjuvant chemotherapy during the period from 1973--1979 for node-positive operable carcinoma of the breast, compared to a matched control group of patients presenting during the same period treated by local measures only. Five of 115 patients (4.3%) receiving adjuvant chemotherapy have had brain metastases as first site of distant recurrence compared to zero of 115 (0%) in the control group. This comprised 12.8% of first distant recurrences in the adjuvant group. The authors suggest that this increased incidence of brain metastases, as site of first recurrence, reflects prolonged suppression of systemic disease by adjuvant chemotherapy with less effect in controlling metastases in the brain.

Adult↗
PubMed1981

Effect of chemotherapy on survival in metastatic breast cancer.

In order to assess the impact of modern combination chemotherapy on overall survival of metastatic breast cancer patients, we retrospectively analysed survival data of those patients who presented with breast cancer and developed metastases at our clinic from 1971-78 inclusive. Our results indicate a trend towards improved survival from onset of first distant metastasis after 1975. Assessment of survival by treatment modality revealed significantly longer survival from first metastasis for those patients receiving predominantly endocrine treatment compared to chemotherapy, median survival being 32.5 versus 23 months for endocrine therapy and chemotherapy respectively. Patients receiving adriamycin in combination with other drugs, had longer survival from first metastasis than those patients receiving chemotherapy without adriamycin (median survival being 25 versus 18.5 months respectively). These differences are most probably due to patient selection. On the basis of these results it would appear that chemotherapy may be improving short-term survival in some patients, but is making no major impact on long-term survival.

Antineoplastic Agents↗
PubMed1981

Possible fenthion toxicity in magpies (Pica pica).

Unusual mortality in magpies (Pica pica) is described. Dead or sick birds were discovered in proximity to cattle in Alberta feedlots. Subsequent examinations indicated magpies were being exposed to fenthion, an organophosphate used on cattle for control of warble larvae and lice. The possibility of toxicity with fenthion is suggested.

Animals↗
PubMed1980

Discriminant analysis of ribosomal protein synthesis findings in carrier detection of Duchenne muscular dystrophy.

Previous studies have shown that in vitro muscle ribosomal protein synthesis (RPS) by monomeric ribosomes (MR) and total polyribosomes (TPR) and collagen synthesis (CS) are significantly increased (P less than 0.01) in 47 known carriers of Duchenne muscular dystrophy as compared to 60 age-matched controls. However, there was considerable overlap of the distribution of controls and carriers, particularly for monomeric ribosomal protein synthesis and collagen synthesis. To improve detection of carriers we used discriminant analysis utilizing logs of each measurement as superior to a univariate or bivariate scheme. This study considered four groups: proven carriers (30) (group 1), presumptive carriers (female relatives of Duchenne patients with high serum creatine kinase (CK) levels) (32) (group 2), controls greater than or equal to 20 years old (42) (group 3) and controls less than 20 years (36) (group 4). Comparison of groups, Misclassification (%), (see chart). These results suggest that discriminant analysis reduces the misclassification rates as compared with univariate or bivariate analysis and confirm the superiority of RPS measurements as a carrier test for Duchenne muscular dystrophy.

Adult↗