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L Dawson

Publications and source records attributed to L Dawson.

49 records · Page 3Linked to original sources

Lack of association of the development of anti-sperm antibodies and other autoantibodies as a consequence of vasectomy.

The possibility of autoantibodies--other than sperm antibodies--developing as a consequence of vasectomy has been investigated in 255 volunteers. During the first year after vasectomy no obvious increase was observed in the occurrence of any of these antibodies (rheumatoid factor, antinuclear antibodies and antibodies against smooth muscle, mitochondria, gastric parietal cell, thyroid microsomes and thyroglobulin). Ninety-nine of the patients were also examined for agglutinating and immunofluorescent antibodies to sperm to see if there was any relationship between the occurrence of anti-sperm antibodies and other autoantibodies. However, the prevalence of non-sperm autoantibodies did not differ in two nearly equal groups of patients with and without indications of autoimmune reactions to spermatozoa, respectively. Consequently the present results lend no support to the hypothesis that vasectomy could induce autoimmunity to other autoantigens than sperm-specific antigens.

Agglutinins↗

Autoimmune implications of vasectomy in man.

The frequent development of sperm antibodies following vasectomy does not appear to be related to the formation of other autoantibodies. We have examined serum taken from 346 men before and 6 months after vasectomy for seven different autoantibodies. The occurrence of positive results is comparable to any normal population.

Antibody Formation↗

Levels of C-type viral p30 antigens in lymphoma-resistant mice.

Until relatively recently, interest has largely centered upon the causal role of oncogenic viruses especially with respect to the development of murine lymphomas. Host factors have recently come to the fore and are considered to be effective here, where we note that, in spite of relatively high levels of C-type viral antigen in the AKR X CBA F1 mouse, this hybrid remains relatively lymphoma resistant. Evidence points to an overriding host factor in this situation that is dominant with respect to tumor resistance and furthermore independent of the viral load at least as judged by levels of p30 viral antigen, an assumption confirmed by xc plaque assay.

Animals↗

Murine leukaemia virus expression in the AKR following thymectomy.

Thymectomy effectively prevents the development of spontaneous lymphoma in the AKR but how this effect is achieved remains to be determined. One possible mechanism, namely suppression of genomic expression of the oncogenic murine leukaemia virus now seems unlikely since levels of the group specific MuLV antigen were in comparision with their sham operated controls unaltered in both neonatally and adult thymectomized AKR.

Age Factors↗

Efficacy of two minor tranquilizers in relieveing symptoms of functional gastrointestinal distress.

Two minor tranquilizers, diazepam and lorazepam were significantly better than a placebo preparation in relieving symptoms of functional gastrointestinal distress in 28 patients who took part in a double-blind cross-over trial. The beneficial therapeutic effect may be group- rather than preparation-specific. Both agents were also of significant benefit to the sub-group of patients with aerophagy as a major symptom.

Adult↗

Investigation of NZB mice born to BALB/c immunized against NZB allotype.

Allotype suppression is held to be an example of T-cell suppressor function. Failure of generalized suppressor T-cell function is considered to be responsible for the chronic and progressive disease of the NZB. The possible association of allotype suppression and autoimmune disease has been investigated here in a group of NZB mice, transplanted and born from BALB/c recipients whilst producing anti-NZB allotype. In this situation it was anticipated that if allotype suppression should fail this would coincide with the development of autoimmune disease; both processes reflecting failure of T-cell suppressor function. However, in spite of the fact that allotype suppression was not achieved, certain observations seem important. The fact that NZB born the BALB/c were in no way different from normally derived NZB confirms that the cause of the NZB disease is established prior to the stage of implantation. Maternal influence at or beyond this stage appears of little consequence in terms of effecting the development or progression of the NZB disease. The failure to induce allotype suppression in the NZB is important. In this context this strain appears to be no different from the majority of other strains that have been tested as homozygotes. The suppression obtained with (BALB/c X SJL/J)F1 hybrids in which chronic suppression has been achieved therefore seems to represent an exceptional situation and this suggests that it is perhaps unwise to base general assumptions as to the universal adaptability of T-cell control mechanisms upon unusual findings. It must be remembered that only homozygotes were examined here. Earlier attempts to induce allotype suppression in homozygotes also failed, even in the SJL/J. Since allotype suppression has only been demonstrated in heterozygote mice there is a distinct possibility that this phenomenon never occurs in the homozygote situation. The significance of this possibility is discussed.

Age Factors↗

Comfort zone.

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Adaptation, Psychological↗

Significance of pathological parameters of endomyocardial biopsy in clinical outcome of patients of dilated cardiomyopathy--II. Value of cardiac immune complexes and heart reactive antibodies.

We have evaluated the status of cardiac immune complexes and heart reactive antibodies in endomyocardial biopsies (EMB) and patients' sera from cases of dilated cardiomyopathy (DCM) using immunofluorescence. This was done with an aim to test whether this parameter can be of diagnostic and/or prognostic value in cases of DCM in its inflammatory and non inflammatory stages. Deposition of IgG was consistently observed in all cases of DCM regardless of the presence or absence of inflammation. Complement was detected in only a few while IgG and C3 together was seen to be deposited in only 4 cases. IgA and IgM were noted in an occasional case only. Heart reactive antibodies were seen in 13 of the 23 cases of DCM. Light microscopically, in 7 of the 23 biopsies mild focal lymphocytic myocarditis was detected. Presence of IgG in EMB and a low left ventricular ejection fraction (LVEF 35%) in almost all the cases, highlight the prognostic significance of IgG (in EMB) as an independent parameter. Based on this small study, it is difficult to attach significance to these observations as regards predicting the outcome of these patients. Nevertheless, the present study initiates evaluation of one of the parameters which is accessible and can be easily carried out in most routine laboratories for diagnosis, prognosis, and eventually monitoring of therapy in patients of DCM. Importance of immunofluorescence technique can be further strengthened by evaluating a larger number of cases with varying duration of symptoms and a follow up study of cases of DCM.

Adolescent↗

Women's health as a multidisciplinary specialty: an exploratory proposal.

The purpose of this paper is to encourage the development of women's health as a multidisciplinary specialty. The idea for such a specialty arose from the grass roots women's health movement of the 1960s, whose tenets were rapidly embraced by physicians sympathetic to its ideals, especially members of the American Medical Women's Association. Women's health would be a multidisciplinary specialty offering service to a specific patient population, analogous to geriatric medicine. It would blend primary care, ambulatory obstetrics-gynecology, and psychiatry with additional training in endocrinology, nutrition, sports medicine, and orthopaedics. Suggestions for residency training and specialty certification are included.

Education, Medical↗