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Biomedical subjects

G Taylor

Publications and source records attributed to G Taylor.

At least 415 records · Page 23Linked to original sources

In vitro activation of the alternative pathway of complement by settled grain dust.

Settled grain dust was collected from several active grain elevators in the Superior-Duluth areas of the United States. Particle size distribution (47% less than 5 micrometer) and endotoxin contamination (429 ng/gm) of the dust were similar to those reported for the airborne parent dust. Human complement uas activated in vitro in a dose-response manner which could be quantified. This hemolytic consumption was via the alternative pathway as defined by ethylenediaminetertraacetic acid/ethylene-glycol-bis-(beta-amino-ethyl ether) N,N'-tetraacetic acid (EDTA/EGTA) differential serum chelation, factor B conversion, and complement reductions in serum from guinea pigs deficient in C4. It is proposed that continuous low-dose exposure to aerosolized, biologically active rafter dust could contribute to the respiratory insult of grain workers.

Complement Activation↗

A 1:2 crystalline complex of ApA:proflavine: a model for binding to single-stranded regions in RNA.

The structure of a 1"2 complex of adenylyl-(3',5')-adenosine phosphate and proflavine hemisulfate has been determined using the methods of x-ray crystallography. Since the ApA does not form a mini double helix, it may serve as a model for the interaction of planar molecules with single stranded nucleic acids. The dinucleotide adopts an extended conformation with the adenines in adjacent molecules forming base pairs. A most unusual feature of the molecule is that it does not obey the "rigid nucleotide" concept although none of the torsion angles occur in energetically unfavourable regions. This is most probably due to the strong interactions between the proflavine and the oligonucleotide.

Acridines↗

The effect of pneumonia induced in mice with Mycoplasma pulmonis on resistance to subsequent bacterial infection and the effect of a respiratory infection with Sendai virus on the resistance of mice to Mycoplasma pulmonis.

The effect of pneumonia induced by Mycoplasma pulmonis in mice on the resistance of the lung to additional bacterial infection was examined. The effect of pneumonia induced by Sendai virus on the resistance of mice to M. pulmonis was also investigated and compared with the effect of Sendai virus on resistance to Staphylococcus aureus. Sendai virus infection decreased subsequent resistance to M. pulmonis in proportion to the virus dose. Decreased resistance to subsequent S. aureus and M. pulmonis infection was greatest at about the same time after inoculation of virus and was related to virus-induced lesions. Besides affecting the resistance of mice to subsequent mycoplasma infection, Sendai virus could enhance an existing mycoplasma infection. Pneumonia induced by M. pulmonis did not decrease resistance to subsequent bacterial infection. The mechanism whereby Sendai virus decreases host resistance is therefore similar for bacteria and mycoplasmas, but pneumonia induced by mycoplasmas does not have the same effect.

Animals↗

Demoniacal possession and psychoanalytic theory.

Psychodynamic explanations of demoniacal possession have been based mainly on Freud's retrospective interpretation of the illness of Christoph Haitzman. Freud applied libido theory to his analysis of the case and subsequently influenced the psychoanalytic theory of paranoid symptom formation and the psychoanalytic approach to the psychoses. Fairbairn, and later Guntrip, applied an object relations theory to the case and conceptualized demoniacal possession in terms of bad internalized objects. They used the example of Haitzman to illustrate an object relations approach to the understanding and treatment of severely disturbed patients. In this paper the psychoanalytic treatment of a case of demoniacal possession is described to indicate the multiple dynamic meanings which possession may have and to demonstrate the necessity for integrating and applying aspects of libido and object relations theories. Current trends in psychoanalysis are towards recognizing the psychotic core which is frequently masked by an apparently psychoneurotic illness so that analysis must reach beyond oedipal conflicts to the primitive internalized object relations. A psychoanalytic study of demoniacal possession contributes much to the understanding of such patients but particularly to the conceptualization of borderline and psychotic states. It is in the treatment of these patients that the role of the psychotherapist is more akin to that of the exorcist.

Adult↗

Effects of lymecycline on Mycoplasma pulmonis-induced arthritis in mice.

The effect of lymecycline treatment on arthritis in C3H mice produced 5 months previously by i.v. inoculation of Mycoplasma pulmonis was examined. Treatment had little effect on the severity of the clinical disease. However, there was a marked reduction the severity of the histopathological inflammatory reaction in joints from lymecycline-treated mice when compared with untreated controls. This reduction was associated with eradication of viable mycoplasmas from the joints. The findings suggest that persistent arthritis in C3H mice is due to the continued presence of viable M. pulmonis organisms in the joint tissues.

Animals↗

Nucleic acid binding drugs. Part IV. The crystal structure of the anti-cancer agent daunomycin.

The crystal structure has been determined of the anti-cancer drug daunomycin, as the hydrochloride monohydrate pyridine salt. The overall structure, previously determined by X-ray analysis of an N-bromoacetyl derivative (Anguili, R., Foresti, E., Riva Di Sanserverino, L., Isaacs, N.W., Kennard, O., Motherwell, W.D.S., Wampler, D.L. and Arcamone, F. (1971) Nat. New Biol. 234, 78-80) has been confirmed, although substantial conformational differences are observed. The conformation described here is very similar to that found for the related drug carminomycin I (Wani, M.C., Taylor, H.L., Wall, M.E., McPhaill, A.T. and Onan, K.D. (1975) J. Am. Chem. Soc. 97, 5955-5956; Pettit, G.R., Einck, J.J., Herald, C.L., Ode, R.H. Von Dreele, R.B., Brown, P., Brazhnikova, M.G. and Gause, G.F. (1975) J. Am. Chem. Soc. 97, 7387-7388); it is suggested that this represents a significantly stable molecular conformation; an intramolecular C(7)...O(9) hydrogen bond is invoked to account for this. This conformation is likely to be at least close to that of daunomycin when bound to DNA.

Computers↗

Tumour-specific antibodies reactive with cell-surface antigens in children with Wilms' tumour.

Tumour-specific antibodies directed against membrane antigens were demonstrated by immunofluorescence in three of 45 patients with Wilms' tomour. Antibody capable of collaborating with K cells to kill Wilms' tumour was present in two additional patients. No patient exhibited both membrane immunofluorescence and K-cell collaborating antibody. Of 27 patients with non-renal solid tumours and 52 age-matched controls, none possessed tumour-specific antibody.

Adolescent↗

Bilateral intracranial arterial aneurysms with a persistent trigeminal artery.

A 62-year-old hypertensive woman had bilateral intracranial arterial aneurysms associated with persistent trigeminal artery. The presenting symptom of this patient was painless ophthalmoplegia. We review embryologic development of the circle of Willis as an explanation for the occurence of the trigeminal artery. We also discuss the high incidence of associated vascular malformations with these vessels.

Cerebral Arteries↗

Respiratory allergy and month of birth.

A total of 476 patients with respiratory allergy were interviewed to establish whether the season of birth influenced the type of allergy experienced. Patients with perennial symptoms did not differ from the general population of the U.K. in the distribution of their months of birth. Patients with summer seasonal symptoms attributable to grass pollen sensitivity were more likely to have been born in December to February than in August to November. This trend was most significant in female patients who did not have associated perennial symptoms and who developed symptoms early in life. Other significant differences were also noted between groups of patients complaining of the same symptoms. More males than females had summer seasonal symptoms whereas more females than males had perennial symptoms. Patients who had both perennial symptoms and summer seasonal exacerbations had a higher incidence of a positive family history of atopy and developed symptoms earlier in life than those patients who had summer seasonal or perennial symptoms only.

Adolescent↗

Protective effect of vaccines on Mycoplasma pulmonis-induced respiratory disease of mice.

Mice inoculated intranasally with either a virulent or an avirulent strain of live Mycoplasma pulmonis were resistant to respiratory disease induced by a subsequent intranasal challenge with virulent organisms. Similarly, mice inoculated intravenously with the virulent strain were resistant to intranasal challenge with the same strain. In contrast, mice inoculated intravenously with avirulent M. pulmonis were not resistant to intranasal challenge with the virulent mycoplasma strain. Studies on mice inoculated intravenously with the two strains of M. pulmonis indicated that persistance of mycoplasmas in the respiratory tract may be important in inducing resistance to intranasal challenge with M. pulmonis. These observations, together with the lack of correlation between the level of serum antibodies and resistance to M. pulmonis-induced respiratory disease, suggested that local immune mechanisms were important in resistance. It is proposed that an effective vaccination schedule to protect mice against M. pulmonis-induced respiratory disease may be one that stimulates both systemic and local immune defenses. This suggestion is supported by the observation that systemic followed by local administration of inactivated M. pulmonis was more effective in inducing resistance in mice to intranasal challenge with live organisms than was systemic administration alone. In addition, mice inoculated solely by the intranasal route with inactivated mycoplasmas were resistant to M. pulmonis-induced respiratory disease. These studies indicate the importance of local defense mechanisms in the induction of resistance to M. pulmonis-induced respiratory disease in mice.

Administration, Intranasal↗

Factors in resistance to and recovery from M. pulmonis-induced arthritis in mice.

A previous infection of C3H mice with viable Mycoplasma pulmonis organisms protected them from arthritis induced by intravenous inoculation of these organisms, whether or not their initial arthritis had resolved at the time of challenge. Although spleen cells obtained from such animals conferred resistance to acute arthritis in syngeneic recipient mice, convalescent-phase serum was much more effective in this respect. In addition, the transfer of 'immune' spleen cells to M. pulmonis-infected mice treated with cyclophosphamide did not prevent them from dying, whereas the transfer of convalescent-phase serum to such animals reduced the incidence of mortality. Since M. pulmonis organisms are rapidly inactivated in mice treated with convalescent-phase serum it is suggested that the transferred serum may act by promoting phagocytosis of the mycoplasmas. Although the reason for some mice developing a prolonged arthritis is not clear, the results show that humoral immune mechanisms are more important than cell-mediated ones in preventing acute arthritis and that the humoral mechanisms are of greater importance than the cell-mediated in resistance to and recovery from a generalized mycoplasma infection.

Animals↗

The influence of IgE-mediated reactions on the expression of delayed hypersensitivity in the rat.

The effect of IgE-mediated reactions on the expression of delayed hypersensitivity skin reactions was examined in the rat. It was found that the elicitation of an IgE-mediated reaction at the time of skin test could either potentiate or inhibit the development of delayed reactions. At a fixed level of IgE sensitivity, large delayed reactions were potentiated and small delayed reactions suppressed. These interactions were not dependent on the two types of sensitivity being direct against the same antigen but were dependent on the reaction of IgE with its appropriate antigen.

Animals↗

Augmented local anaphylaxis at sites of delayed hypersensitivity skin reactions.

The magnitude of passive anti-ovalbumin IgE-mediated reactions was quantified at normal skin sites and sites of tuberculin reactions in rats by measurement of induration. It was found that significantly greater immediate reactions occurred at sites of positive tuberculin reactions than at normal skin sites. The augmentation of IgE-mediated reactions was maximal in tuberculin reactions elicited 1 week after active immunization but was still significant in reactions elicited 6 weeks after immunization. The magnitude of the delayed reaction influenced the degree of augmentation of the IgE-mediated reaction observed, greater tuberculin reactions producing greater augmentation. Similar degrees of augmentation by the tuberculin reaction were observed in IgE-mediated reactions elicited 24, 48, and 72 hs after elicitation of the delayed skin test.

Animals↗

Unexpected cardiac arrest during anesthesia and surgery. An environmental study.

Medical and legal records of 41 cases of cardiac arrest that occurred during surgery were supplied by a professional liability insurance company and a review was undertaken in an attempt to identify recurring or common factors. The majority of patients in this study were healthy and required relatively routine elective surgical procedures. Only three of the patients survived the cardiac arrest and returned to normal activities. The remaining patients either died in the hospital or had a major central nervous system deficit. Hypoxia from hypoventilation and low levels of inspired oxygen appeared to be the chief cause of cardiac arrest in this study. Because of the unknown frequency of cardiac arrest during surgery, we recommend the establishment of a national registry of cardiac arrest cases that occur in surgical patients, in order to monitor incidence, causes, and outcome. Only in this way will it be possible to lessen the frequency of this disastrous event.

Anesthesia↗