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Biomedical subjects

N Grant

Publications and source records attributed to N Grant.

At least 19 recordsLinked to original sources

A consensus development approach to define national research priorities in bone metastases: proceedings from NCIC CTG workshop.

AIMS: A 1-day workshop was conducted to gather interested Canadian radiation oncologists to identify priority research questions that could be answered through clinical trials under the auspices of the National Cancer Institute of Canada--Clinical Trials Group (NCIC-CTG) Symptom Control committee. MATERIALS AND METHODS: In preparation for the workshop, a survey of Canadian radiation oncologists resulted in four research areas in symptom control, including radiation-induced mucosal reactions, fatigue, radiotherapy for brain metastases and radiotherapy for bone metastases. The first half of the workshop consisted of plenary sessions where the research setting and perspective was defined for each area. This was followed by deliberations by a subgroup of researchers with special interest in the topic area. The bone-metastases subgroup deliberated the clinical context, the scientific merits and the required methodology of research questions related to the role of radiotherapy in early treatment of bone metastases, the role of re-irradiation, the role of systemic radiotherapy and patient selection for different fractionation schedules. A list of prioritised clinical studies was proposed. RESULTS: The question of single vs multi-fraction re-irradiation for symptomatic bone metastases was identified as most pertinent to the Canadian radiation oncologists present. A multi-centre, international intergroup study is undergoing protocol development. Other study concepts, such as an alternative dose-schedule of 17 Gy/2 fractions/1 week for intermediate-prognosis patients, and early referral for radiation oncologist assessment of early or mildly symptomatic bone metastases for good-prognosis patients, require further methodological development before a clinical trial can be proposed. CONCLUSION: An NCIC-CTG workshop provided an update on current evidence-based knowledge in palliative radiotherapy for bone metastases. New trial concepts were discussed among practitioners and clinical investigators to promote dialogue and collaboration. The proposal of an international intergroup randomised trial of single vs multiple fraction re-irradiation for painful bone metastases received the most support among participants.

Bone Neoplasms↗

Pyridines and pyrazolines from salicylic acid derivatives with propenone residue and their antimicrobial properties.

Reaction of the propenones 1c, d with chlorosulfonyl isocyanate followed by hydrolysis gave the corresponding carbamoyloxybenzoates 2a, b. While their reaction with ethyl isocyanate afforded the 1,3-benzoxazine-2,4-diones 3a, b. Reaction of 1a, b with aryl hydrazines gave the pyrazolines 4a, d, whereas, with hydrazine hydrate in acetic acid, the acetyl derivatives 4e, f were produced. 1c, d reacted with malononitrile and ethyl cyanoacetate affording the cyanopyridines 5 and cyanopyridones 6 respectively. The products show antimicrobial activities.

Anti-Bacterial Agents↗

Asian, American, and deaf: a framework for professionals.

The authors present a multicultural framework for thinking about, assessing, and working with Deaf people from Asian and Asian Deaf backgrounds. Emphasis is placed on cultural awareness and cultural competence for professionals and on building bridges across cultural networks.

Asian↗

Program characteristics of home-delivered meals programs for persons with HIV and AIDS.

The nutritional status of persons with HIV and AIDS [PWAs] is constantly challenged throughout the progression of the illness. Home-delivered meals programs for PWAs are rapidly developing across the country to address this problem among the growing population of people with HIV infection and AIDS. This study examined client socio-demographic characteristics (sex, age, ethnicity), types of services offered by these programs, organizational and financial criteria, and characteristics of survey respondents. Data for this study was obtained from 15 of the 17 known home-delivered meals programs for PWAs in the United States through an original, cross-sectional survey instrument conducted by telephone interview between March 1994 and May 1994. Results from this study show an increase in the number of minority populations who participate in these programs (36% African-American and 12% Hispanic vs. 51% Caucasian), as well as women (17.2%) and children (7%). Geographic location was an important determinant for program eligibility. The number of meals served weekly varied greatly (from 510 to 12,600 per week). Other significant services included nutrition counselling, newsletters, and holiday-basket programs. Enhancing service-delivery systems was one of the more prevalent "high-priority" concerns cited, especially with regard to food quality and safety. These results show that these programs are catering increasingly to minority populations, women and children, and that they are expanding their services to meet the growing needs of their client populations. These findings suggest that there is a greater need for meals and other home-based services for persons living with HIV and AIDS.

Acquired Immunodeficiency Syndrome↗

Synthesis of indole-N-propionitrile, N-propionic acid and N-propionamide derivatives of potential biological activity.

Cyanoethylation of a selected group from indole derivatives 1a-i using acrylonitrile in pyridine and potassium hydroxide afforded the corresponding indole-1-propionitrile 2a-h derivatives which readily hydrolysed in basic medium to the corresponding indole-1-propionic acid derivatives 4a-c. A several attempts to cyclize the above products-to the corresponding dihydropyrroloquinolin-4-one derivatives. The indole-1-propionamide derivatives reacted with diethyl carbonate and ethyl acetate under Claisen condensation also, with diazonium salts and nitric acid.

Amides↗

Endogenous antibodies that interfere with thyroxine fluorescence polarization assay but not with radioimmunoassay or EMIT.

We have identified an individual whose thyroxine (T4) concentration was undetectable with Abbott's fluorescence polarization immunoassay (FPIA) but within the reference range by radioimmunoassay or EMIT (Syva). The patient's thyrotropin, triiodothyronine, and T-uptake values were within the normal range. The T4 concentration measured by FPIA increased to normal when the immunoglobulin fraction was selectively removed from the serum. When the patient's immunoglobulin fraction was added to normal serum, the T4 content of the normal serum measured by FPIA became falsely low. The patient's antibody interfered with the T4 FPIA by binding to the fluorescein-T4 conjugate. The T-uptake was less affected by the patient's serum because of the low affinity of the patient's antibody to fluorescein-T4 (K = 3.5 x 10(8) L/mol). The patient's immunoglobulin bound preferentially to fluorescein-T4, in comparison with binding to fluorescein or T4 alone. We conclude that the patient's immunoglobulin bound to an epitope unique to the fluorescein-conjugated T4.

Adult↗

The role of calcium, polyamines and centrosomes in the formation and organization of cleavage furrows in amphibian eggs.

Cleavage furrows of amphibian eggs exhibit characteristic morphological features: the presence of finger-like microvilli (MV) along their outer edges, the formation of furrow walls from new plasma membrane lacking MV, and the subsequent retrieval of this membrane during the infolding of the furrow. A similar structure can be induced, specifically, by certain cytoplasmic components such as centrosomes, polyamines and calcium. Their respective roles in the events associated with the furrowing process have been investigated by injecting these agents into nucleated and enucleated Pleurodeles eggs and evaluating their effects using cytochemical labelling of the egg surface with a biotin-streptavidin system. The injection of polyamines (spermine or spermidine) and in some cases, calcium into enucleated eggs provoked MV elongation and the appearance of newly formed, smooth plasma membrane. In these eggs, this membrane was not incorporated into the furrows, and as a consequence, the blastomeres did not actually separate. In contrast, the injection of centrosomes into enucleated eggs induced both the incorporation and internalization of new membrane, resulting in the formation of furrows and a true cellularization of the eggs, identical to the cleavage process observed in fertilized eggs. The present results provide further evidence that the establishment of the furrow depends on two complementary interacting systems: the contractile elements of the egg cortex which regulate the insertion of new membrane and the mitotic center which is essential for the invagination of the furrow.

Animals↗

Effect of Duchenne muscular dystrophy on enzymes of energy metabolism in individual muscle fibers.

Individual muscle fibers from patients with Duchenne muscular dystrophy at an early stage in their disease, and from apparently normal boys of similar age, were analyzed for 13 enzymes of energy metabolism. This approach avoided the serious problems with muscle homogenate assays from increases in nonparenchymal components and permitted assessment of disease changes in different fiber types. Some enzymes of glycogenolysis (phosphorylase, phosphoglucomutase, and pyruvate kinase) were decreased in dystrophic fibers of all types. Phosphofructokinase was decreased in presumptive type II fibers. Lactate dehydrogenase was increased in type I fibers and essentially unchanged in type II. Phosphoglucoisomerase was near normal. Two enzymes of glucose metabolism not involved in glycogenolysis, hexokinase and glycogen synthase, were near normal, but a third, fructose bisphosphatase, was sharply reduced. Two enzymes of oxidative metabolism, citrate synthase, and beta-hydroxyacyl CoA dehydrogenase, were unchanged or increased. Two enzymes of high energy phosphate transfer, creatine kinase and adenylokinase, were only marginally affected. The net result is to leave the type II fibers, which normally exert the greatest force, with a severe deficit in the glycogenolytic enzyme machinery to maintain that force.

Adenylate Kinase↗

Cyclic regulation of cytokinesis in amphibian eggs.

The effects of amphibian egg cytoplasm extracted at different times after activation and during the first four cleavages on cytokinesis were examined. Extracts of artificially activated or fertilized Xenopus or Pleurodeles eggs taken at the time of activation (T = 0) provoked precocious cleavage furrows in Pleurodeles eggs. Between T = 0.25 and T = 0.75 of the first cell cycle, the period corresponding to interphase, an inhibitory effect was found, and the division of injected eggs was delayed up to 30%. After T = 0.75, that is during mitosis, the cleavage induction effect was observed again. These enhancing and inhibitory effects were also found in the two fractions obtained following gel filtration of the cytoplasmic extracts. These experiments support the hypothesis that two antagonistic factors control cytokinesis. The inhibitory factor is active only during interphase, while the positive factor is present during mitosis and appears to regulate cytokinesis.

Animals↗

Intracerebral neuroblastoma. Report of a case with neuronal maturation and long survival.

A case of primary intracerebral neuroblastoma with long survival is reported. The initial biopsy at the age of 3 years showed a primitive, poorly differentiated tumour. Nine years later, the recurrent tumour examined by light and electron microscopy had the appearances of a cerebral neuroblastoma with many mature neurons and occasional abnormal astrocytic elements.

Brain Neoplasms↗