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Biomedical subjects

R A Knight

Publications and source records attributed to R A Knight.

206 records · Page 12Linked to original sources

Allescheria boydii and Aspergillus fumigatus skin test antigens.

May, Lewis K. (Woman's Medical College of Pennsylvania, Philadelphia), Ralph A. Knight, and H. William Harris. Allescheria boydii and Aspergillus fumigatus skin test antigens. J. Bacteriol. 91:2155-2157. 1966.-Protein and polysaccharide fractions were extracted from culture filtrates of Allescheria boydii and Aspergillus fumigatus by the methods of Seibert and of Heidelberger, and injected intradermally into guinea pigs previously infected with these fungi. The diameter of erythema and induration was determined at 8, 24, and 48 hr. The protein and polysaccharide antigens yielded specific skin reactions in homologously infected guinea pigs. Erythema appeared at 8 hr with both the protein and polysaccharide antigens. At this time, the polysaccharide skin tests showed erythema and a central blanched wheal. A similar wheal was not observed with the protein. The erythema of the polysaccharide reaction began fading at 24 hr, whereas the protein reaction remained unchanged through 48 hr with both antigens. In guinea pigs, the area of erythema was more constant and thus easier to measure than was induration.

Animals↗

Adoptive T cell immunotherapy of MSV-induced tumours in nude mice. Part I. Biology of tumour regression and recurrence.

The induction of immunity to progressively growing murine sarcoma virus (MSV) tumours in nude (nu/nu) mice by reconstitution with immune T cells from syngeneic (+/+) donors has been studied. Whole spleen cell preparations served as the source of immune T cells. Transfer of immune, but not of normal, spleen cells resulted in partial or apparently complete regression of primary tumours and a related moderate to considerable extension of survival time. The dose, the time in days between immunization and transfer, as well as timing of the spleen cells in relation to tumour cell challenge, were all factors which influenced the effectiveness of the protective inocula. An unexpected consequence of even the very effective primary immunotherapy regimens, was secondary tumour development after varying tumour-free intervals. This was most frequently manifest as tumour recurrences at the original injection site either on their own or in combination with distant metastases. Such a relatively high frequency of tumour reappearance and metastatic spread contrasts markedly with the rare instances of secondary regrowth in normal immunocompetent mice. The present reconstitution system may therefore provide a new model for studying the inhibitory or stimulatory properties of T cells with respect to tumour regression and dissemination.

Animals↗

Adoptive T cell immunotherapy of MSV-induced tumours in nude mice. Part II. Sequential analysis of serum immune complexes and blocking activity in reconstituted mice in relation to tumour biology.

In seven separate experiments, nude (nu/nu) mice carrying established murine sarcoma virus (MSV) tumours were reconstituted with syngeneic (+/+) immune splenic T cells. These immune protected mice were randomly divided to provide smaller groups for serial exsanguination. At various time points mice were individually bled and CIC concentration and blocking activity of each individual serum was determined. Control sera were obtained from nu/nu and adult +/+ mice inoculated with tumour cells only, and from nu/nu mice protected with normal +/+ spleen cells. In all the mice studied, CIC and blocking appeared to be mutually independent parameters throughout the MSV tumour course. On the other hand, in immune protected mice considered alone or together with the control groups, CIC and time after tumour cell inoculation, but not tumour size, were significantly correlated. A significant relationship between blocking and tumour size was also established, although this only applied to immune protected mice. However, analysis of the combined data from sequentially bled immune protected mice in relation to different phases of tumour behaviour, did not support the notion that blocking, and more particularly the persistence of CIC, contribute to tumour regrowth and dissemination.

Animals↗

Genetics of cystic fibrosis.

The cystic fibrosis gene specifies a membrane transport protein and over 100 disease-causing mutations have now been identified. Although at least some of these determine the incidence of pancreatic disease, there is no association between a particular mutation and the severity of lung and liver disease.

Cystic Fibrosis↗

An inducible cell line (Natasha), from a neuroblastoma patient with circulating HSR-positive blasts, expressing neurohormones.

A cell line, established from a neuroblastoma patient, expresses NCAM and L1 cell adhesion molecules. Two chromosomal abnormalities were present in bone marrow (10%) and cell line (82%) metaphases: (i) a homogeneously staining region (HSR) at the distal part of chromosome 14, and (ii) an insertion of unidentified dark G-banding material in 1 p36. The identification in the patient of chr 14-HSR-positive tumour cells, before the in vitro adaptation, suggests a direct HSR formation without preceding double minutes (dms; or a very early in vivo dms----HSR transformation). N-myc was amplified in the HSR. Cells expressed proopiomelanocortin and corticotropin releasing factor mRNAs. Untreated cells were relatively differentiated; nevertheless they dramatically responded to retinoic acid, forming extensive neurites, growth-cones, cell-cell and cell-neurite junctions. Neurofilaments and synaptic figures containing many dense core granules were identified. This differentiation was irreversible. This cell line is therefore useful for the study of differentiation and in particular for the involvement of neurohormones in the differentiation process.

Antigens, Neoplasm↗

Interleukin-1 beta and interleukin-6 mRNA are expressed in human glioblastoma and neuroblastoma cells respectively.

We report the expression of different interleukins (IL) in four human glioblastoma and neuroblastoma cell lines. The glioblastoma cell line LI, expresses IL-1 beta and IL-6 mRNA, though not IL-2 and IL-4. The expression of the former gene is modulated by retinoic acid. Two cell clones [BE(2)-C and BE(2)-M17] as well as the neuroblastoma cell line SK-N-BE(2), from which both clones were derived, express IL-6 mRNA, but not IL-1 beta, IL-2 or IL-4. Both IL-1 beta and IL-6 cytokines are known to increase hypothalamic CRH mRNA, a gene reported to be expressed in all these cell lines. The production of both cytokines and neuropeptides indicates a complex dialogue between tumour cells and anti-tumour immunity.

Blotting, Northern↗