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Biomedical subjects

E L Robinson

Publications and source records attributed to E L Robinson.

25 records · Page 2Linked to original sources
PubMed1983

External pituitary irradiation as a cause of TRH deficiency in patients with pituitary adenomas.

The influence of external pituitary irradiation (XRT) on thyrotroph function and PRL secretion was studied in twenty-five patients with pituitary adenomas, of whom eight had acromegaly. Twenty-one patients had undergone subtotal operative removal of their adenomas 8-190 weeks (median 12 weeks) before XRT. Following irradiation there was a significant reduction in peak serum TSH levels in response to i.v. TRH (P less than 0.05, compared with before XRT). Peak TSH levels returned to normal at 3 months. Similarly a transient reduction in TRH-stimulated beta-TSH release was observed. Serum T3 and T4 concentrations also fell after XRT, the levels at 3 months being significantly lower than control values (P less than 0.02), though no difference was seen at 6 and 12 months. A delayed (hypothalamic) serum TSH response to TRH (60 greater than 20-min level) developed at 6 months. In contrast, PRL concentrations (basal and TRH stimulated) were not altered during the 12 months following XRT. These findings demonstrate that thyrotroph function can be transiently impaired following external pituitary irradiation. None of the patients studied required T4 replacement therapy. The development of a delayed TSH response to i.v. TRH may indicate endogenous TRH deficiency. It was not associated with supra-sellar tumour enlargement in our patients and may be due to hypothalamic damage by irradiation.

Adenoma↗
PubMed1983

Spontaneously hypertensive rats exhibit an enhanced mydriatic response to clonidine. Evidence for enhanced sensitivity of central alpha 2-adrenoceptors.

Comparisons among spontaneously hypertensive (SHR), Kyoto Wistar (KW), and Wistar (W) rats were made of the functional states of central nervous system (CNS) alpha 2-adrenoceptors (clonidine-induced mydriasis) and nonvascular peripheral presynaptic alpha 2-adrenoceptors (clonidine-induced inhibition of the neurogenic twitch of the isolated vas deferens). While there were no differences among the strains of rats in the concentration of clonidine required to produce a 50% inhibition of the electrically evoked contractile response of the vas deferens, there was a significant reduction in the mean effective concentration (ED50) of clonidine to induce mydriasis in SHR as compared with KW and W rats. These observations indicate that CNS alpha 2-adrenoceptors may be functionally more sensitive in SHR. The data also suggest that the sensitivity of nonvascular presynaptic alpha 2-adrenoceptors, at least in the vas deferens, is not altered in hypertensive animals.

Animals↗
PubMedDate not supplied

The perceived racism scale: a multidimensional assessment of the experience of white racism among African Americans.

The experience of racism is a complex, multidimensional phenomenon. At present, there are few instruments that attempt to capture the experience of racism in all of its complexity. For this study, a new instrument, the Perceived Racism Scale, has been constructed to assess the experience of racism in African Americans in a multidimensional manner. The scale not only provides a measure of the frequency of exposure to many manifestations of racism (including individual and institutional, overt and covert, attitudinal, behavioral, and cultural), but takes a step forward in more comprehensively measuring the experience of racism by assessing emotional and behavioral coping responses to racism. These responses are measured with respect to exposure to racism in three situational domains: on the job, in academic settings, and in the public realm. Measurement of responses to a fourth domain, that of exposure to racist statements, is also included. It is hoped that the Perceived Racism Scale will facilitate a more comprehensive understanding of the experience of racism among African Americans and, through its use in research and clinical settings, will ultimately move us closer to reducing the prevalence and potentially untoward effects of racism.

Adaptation, Psychological↗