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Biomedical subjects

L Porter

Publications and source records attributed to L Porter.

At least 55 records · Page 3Linked to original sources
PubMed1989

Ligand-independent tyrosine phosphorylation of EGF receptor and the erbB-2/neu proto-oncogene product is induced by hyperosmotic shock.

Treatment of intact cells with media containing high concentrations of ionic and non-ionic solutes induced increased tyrosine phosphorylation of the epidermal growth factor (EGF) receptor and the protein product of the erbB-2/neu proto-oncogene. This self phosphorylation occurred in the absence of EGF or other growth factors. High concentrations of solutes did not activate phosphorylation of either isolated EGF receptor or EGF receptor solubilized by non-ionic detergents. No evidence for receptor dimerization was found in response to hyperosmotic shock. Since receptor dimers have been implicated in the EGF-induced activation of EGF receptor, hyperosmotic shock may activate EGF receptor by a different mechanism.

Cell Line↗
PubMed1988

Conditioned circling in rats: bilateral involvement of the mesotelencephalic dopamine system demonstrated following unilateral 6-hydroxydopamine lesions.

High rates of conditioned circling have previously been associated with a bilateral augmentation of striatal dopamine metabolism. These results suggest that both striata subserve this response. The present experiment further assessed this possibility by determining the effects of unilateral 6-hydroxydopamine lesions of the mesotelencephalic dopamine system on conditioned circling. Rats were initially trained to circle in their preferred direction for water reinforcement. Upon establishment of this response, they received unilateral lesions at the level of the lateral hypothalamus either contralateral or ipsilateral to the reinforced direction of circling. Reinforced responding was virtually abolished in rats with contralateral lesions. In contrast, rats lesioned ipsilateral to the direction of reinforced circling exhibited only a 50% decrease in rate of reinforced responding. Non-reinforced responding was increased only in rats with contralaterally placed lesions. Following 5 postoperative test sessions, the experimental contingencies were reversed. 'Ipsilaterally lesioned' rats were now required to circle away from their lesion whereas 'contralaterally lesioned' rats had to turn towards their lesion. The 'Contralateral' group acquired the reversal, such that reinforced responding occurred more frequently than non-reinforced responding. However, reinforced rates of responding did not reach preoperative rates. Conversely, 'ipsilaterally lesioned' rats could not learn to turn contraversively and now made more non-reinforced than reinforced responses. These findings suggest that conditioned circling is mediated by a bilateral involvement of the mesotelencephalic dopaminergic systems. However, the specific role of each side appears to be dependent upon its relationship with the direction of circling emitted.

Animals↗
PubMed1986

The development of an observation schedule for measuring nurse-patient touch, using an ergonomic approach.

An observation schedule for recording nurse-patient touch was developed, using an ergonomic approach to design. A preliminary study using video-tape analysis and a ward survey indicated that 'instrumental touch' was more frequently employed by nursing staff than 'expressive touch'. Three levels of relevant information relating to touch were recorded: General circumstances (the type of hospital, etc.); Demographic variables (relating to participants in the touch episode); Events specifically relating to the touch episode. The third section of the schedule was tested in an acute geriatric ward, using inter-observer reliability techniques. Reliability was found to be acceptable for those where the criteria for categorization were reasonably objective. It was concluded that an instrument for recording nurse-patient touch has useful applications for both ergonomic and nursing research.

Adult↗
PubMed1985

Sonography of arcuate uterine blood vessels.

Five sonographic cases are presented with images that demonstrate normal arcuate arteries and peripheral uterine blood vessels. These vascular structures are shown in both the longitudinal and transverse sections, and should not be confused with pathology such as Nabothian cysts, hydrosalpinx, pelvic inflammatory disease, hydatid cysts of Morgagni, endometriosis, or abnormal pelvic varices.

Adult↗
PubMed1976

Mental health centers and the criminal justice system.

Through questionnaires, interviews, and site visits, the authors undertook to ascertain to what extent the 26 community mental health centers in Kansas were contributing to the resolution of problems that concern the criminal justice system. They found that in all large communities some reciprocal programs have developed between the two systems, but meaningful collaboration is rare in small communities. Juvenile courts, urban law enforcement agencies, and county probation officers are most receptive to collaborative programs. An evaluation of several effective programs revealed three basic conditions that attribute to their success: an urban community setting, individual initiative by staff from each system, and location of the program within the criminal justice system.

Adolescent↗
PubMed1976

Cell-mediated destruction of human leukemic cells by MHC identical lymphocytes: requirement for a proliferative trigger in vitro.

These experiments have investigated cellular mechanisms involved in the generation of cellular immune responses to human acute leukemic blasts. Because normal human lymphocytes are not able to recognize immunologically, in vitro, lymphocytes from MHC identical siblings, the present studies have examined the in vitro proliferative and cytotoxic responses of normal lymphocytes to MHC identical AML and ALL blasts. In those cases where acute leukemic cells were unable to induce a proliferative response by MHC identical lymphocytes, the generation of effective anti-leukemic cytotoxicity required the addition of unrelated stimulating cells to the sensitization culture. In contrast, leukemic blasts that induced a proliferative response by MHC identical lymphocytes were also able to stimulate anti-leukemic cytotoxicity. This could be augmented by the addition of unrelated stimulating cells to the sensitization culture. The specificity of anti-leukemic cell cytotoxicity was demonstrated in all instances by simultaneous testing of putative killer cells on 51Cr leukemic blasts as well as 51Cr-labeled MHC identical phytohemagglutinin blasts or normal lymphocytes. Simultaneous sensitization to MHC identical leukemic blasts and unrelated stimulating lymphocytes did not invariably generate anti-leukemic cytotoxicity even when allogeneic cytotoxicity was observed; the absence of demonstrable suppressor activity in these nonreactive combinations suggested that some individuals may be specifically immunoincompetent, and thereby unable to generate effective anti-leukemic CML.

Cell Transformation, Neoplastic↗
PubMedDate not supplied

Effect of chronic stress associated with unemployment on salivary cortisol: overall cortisol levels, diurnal rhythm, and acute stress reactivity.

This study examined the effect of chronic stress associated with unemployment on the magnitude of salivary cortisol excretion, on the diurnal rhythm of cortisol, and on cortisol reactivity to acute naturalistic stressors using Experience Sampling Methodology (ESM). Employed (N = 60) and unemployed (N = 60) subjects were studied for 2 days. Subjects were beeped 6 times per day by a preprogrammed wristwatch to assess acute stressors; 25 minutes after each ESM-beep, subjects were beeped a second time for saliva samples. The groups did not differ in their overall cortisol excretion or in cortisol reactivity to acute daily stressors. Compared to employed subjects, unemployed subjects had a diurnal pattern of cortisol excretion with relatively higher morning and lower evening levels. Subjects' daily activities and their locations were associated with diurnal rhythm differences.

Adult↗