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Biomedical subjects

M Gallagher

Publications and source records attributed to M Gallagher.

At least 163 records · Page 9Linked to original sources
PubMed1989

Elevated dynorphin in the hippocampal formation of aged rats: relation to cognitive impairment on a spatial learning task.

Radioimmunoassay revealed increased dynorphin A(1-8)-like immunoreactivity [dynA(1-8)LI] in the aged rat brain. Among a number of brain regions examined, an age-related dynA(1-8)LI elevation was found only in the hippocampal formation and frontal cortex. Moreover, the increase in dynA(1-8)LI in the aged hippocampus was associated with a decline in spatial learning ability: dynA(1-8)LI distinguished aged rats that were behaviorally impaired from aged cohorts that learned the spatial task as rapidly as younger animals. Northern blot hybridization using a 32P-labeled complementary RNA probe encoding rat prodynorphin indicated that the abundance of prodynorphin mRNA was also significantly increased in the hippocampal formation of aged rats with identified spatial learning impairments.

Aging↗
PubMed1989

Prevention in practice: obstacles and opportunities.

General Practitioners are excellently placed within the community to provide health education and advice in relation to HIV infection and AIDS. This paper will report on some of the findings from the first national study of HIV infection and general practice in England and Wales. The findings cast light on the preparedness of practitioners to undertake health education on HIV infection. Findings that relate to the extent of contact that practitioners have with people with HIV infection, people with AIDS and people with worries about HIV infection or AIDS will be discussed in the light of opportunities that are created for HIV-related health education and prevention. Findings that relate to practitioners' opinions about providing health education and counselling, about working with people who are gay, bisexual and injecting drugs, and about confidentiality and consent, will be discussed in the light of obstacles that exist to the effective provision of HIV-related health education and prevention. The paper will conclude by discussing the implications of these findings for primary health care responses to HIV infection in Britain.

Attitude of Health Personnel↗
PubMed1989

Long-term strength assessment of postoperative diskectomy patients.

A test battery was used to measure abdominal and back muscle strength and endurance in 20 patients at least 1 year after surgical diskectomy. There were ten men and ten women. Data on isometric and isokinetic performance were compared with previously reported normal values. The data showed that every strength parameter tested except male isokinetic flexion strength showed at least a 30% decrease when compared with normal values. Compared with strength data on these same patients immediately after surgery, a 2-tailed Student t test demonstrated a significant difference only in male isokinetic strength (P less than 0.10) and in female isokinetic strength (P less than 0.05). No other difference was found in isometric strength or endurance compared with data obtained from these patients 4 to 6 weeks postoperatively. From these data, it is obvious that more intensive physical therapy is necessary to improve postoperative strength in patients undergoing surgical diskectomy. These data allow for the design of specific isometric, isokinetic, and endurance rehabilitation programs for the postoperative diskectomy patient.

Adult↗
PubMed1989

HIV infection and Scottish general practice: workload and current practice.

To estimate the effect of human immunodeficiency virus (HIV) infection on general practice, a postal survey was undertaken of one in three of all principals in Scotland. Of the 834 general practitioners who responded (78% response rate), 31% were working in practices with patients known to be infected with HIV. The estimated prevalence of known HIV infection in general practice was 19 per 100,000 population, and the estimated annual consultation rate for HIV related problems (including consultations by the 'worried well') was seven per 1000 population. Both statistics showed considerable variation between health boards, with peaks in Lothian and Tayside. Few practices had drawn up policies relevant to HIV infection, and the use of procedures for controlling infection was variable. Policies about HIV and for infection control tended to be more common in areas where the prevalence of HIV infection was higher. Most respondents were offering both opportunistic health education and counselling about HIV infection, especially to patients at high risk. Although general practitioners are responding positively to the increasing demands of HIV infection, there is an urgent need for policies, both national and local, to guide specific aspects of practice.

Acquired Immunodeficiency Syndrome↗
PubMed1989

HIV infection and Scottish general practice: knowledge and attitudes.

To assess the knowledge and attitudes of general practitioners about HIV infection, a postal survey was undertaken of one in three of all principals in Scotland; 834 (77.6%) responded. Respondents' knowledge about HIV was often limited, and they found the discussion of sexual behaviour difficult. Most were in favour of routine HIV testing being offered to patients, but against testing without consent. Most general practitioners considered consent unnecessary for the passing of information about HIV status between medical colleagues, but necessary for informing others, in particular the patient's family and sexual partners. Most general practitioners would accept high-risk and HIV-positive patients onto their lists but less than half would accept intravenous drug users. Most respondents did not feel at significant personal risk of HIV infection, but expressed reservations about many other aspects of HIV infection in general practice. If practitioners are to fulfil their potential for tackling the problems of HIV infection, they need increased resources and a policy for education and training that is responsive to local needs.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Effects of opioid microinjections into the medial septal area on spatial memory in rats.

Recent work has demonstrated that posttraining systemic opioid antagonist administration facilitates the acquisition of a radial arm maze task in new spatial environments. In this study, we examined the effect of posttraining naloxone and beta-endorphin microinjections into the medial septal area on the acquisition of a radial maze task in new spatial environments. The results of these experiments demonstrated that posttraining intraseptal naloxone administration facilitated, whereas posttraining intraseptal beta-endorphin administration impaired, the acquisition of criterion performance on a maze task performed in new spatial environments. Further, intraventricular beta-endorphin administration did not produce effects that were comparable to those observed following intraseptal beta-endorphin administration, which indicates that the septal region is a brain site that is sensitive to the effects of opioids on spatial memory in new environments. Further, posttraining intraseptal beta-endorphin administration had no effect on working memory in a familiar spatial environment, whereas pretraining intraseptal beta-endorphin administration had no effect on the performance of a previously acquired spatial task.

Animals↗
PubMed1988

AIDS and HIV infection: ethical problems for general practitioners.

AIDS and HIV infection raise a number of important ethical issues and problems for general practitioners. The ethical issues which impinge most directly on the personal relationship between patient and practitioner are duty to care, consent and confidentiality. These issues, and some practical problems which are likely to be encountered by practitioners, are discussed with the help of case studies and by applying fundamental ethical principles.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Effects of training on a spatial memory task on high affinity choline uptake in hippocampus and cortex in young adult and aged rats.

The relation of forebrain cholinergic function to learning and memory was explored by identification and characterization of a training-induced change in high-affinity choline uptake (HACU), an index of cholinergic activity. Young adult rats were trained to find an invisible escape platform in a water tank using environmental cues. After 4 d of this place-training (16 trials), hippocampal HACU was significantly reduced relative to that observed in rats trained to find a visible platform (cue-training), even when cue- and place-trained rats were yoked for swim time. These place- but not cue-trained rats showed significantly lower hippocampal HACU than did naive rats, and no effect of training was noted after only 1 d of training. Similar results were obtained in parietal cortex. These differential training effects on HACU correspond to previous reports that muscarinic blockade impairs place, but not cue, learning. A further experiment revealed that the decrease in HACU in hippocampus, but not in parietal cortex, occurred only during the acquisition phase of learning and was related to the rate of acquisition for individual animals. Hippocampal HACU in naive young and aged (24-27 months) rats did not differ, but the response of the septohippocampal cholinergic system to training was diminished in the aged rats. Old rats displayed impaired place learning and a corresponding dampening of the training-induced change in HACU. These results suggest that there is a task-specific engagement of cholinergic function in young animals that does not occur in behaviorally impaired aged animals, a finding that is consistent with a role for cholinergic dysfunction in memory impairments associated with aging.

Aging↗
PubMed1987

Alterations in [3H]desmethylimipramine binding in the aged rat brain: an in vitro autoradiographic demonstration.

Using in vitro autoradiographic receptor binding, the present report provides a descriptive analysis of [3H]desmethylimipramine ([3H]DMI) binding in the aged rat brain. Small circular patches of intense [3H]DMI binding were present within the caudate nucleus in every aged brain examined. Occasionally, similar patches of label were present in restricted cortical regions of aged brains. Comparable patches of [3H]DMI binding were never observed in young brains used in these investigations. Additional evidence suggests that these age-dependent changes in [3H]DMI binding are anatomically restricted to the loci indicated above.

Aging↗
PubMed1987

Scopolamine-disruption of radial arm maze performance: modification by noradrenergic depletion.

Administration of muscarinic cholinergic antagonists impairs performance on a variety of memory tasks. We examined the hypothesis that denervation of norepinephrine input to the forebrain would augment this effect of cholinergic antagonists. Administration of 6-hydroxydopamine into the dorsal noradrenergic bundle did not by itself alter the performance of rats on a radial maze working memory task. In Experiment 1, scopolamine, a muscarinic antagonist, impaired the performance of the NE-depleted animals more than that of animals in an operated control group. This result was again observed in Experiment 2; but here a lesion by order of dose administration interaction provided evidence for recovery from the effects of NE-depletion. In Experiment 3, it was found that NE denervation did not alter the functional status of basal forebrain cholinergic neurons as reflected in in vitro determination of sodium-dependent, high affinity choline uptake in hippocampus and cortex. These results suggest that an age-related decline in brain NE neurons, as well as further deterioration in this system in some cases of Alzheimer's disease, may contribute to the cognitive and memory deficits more typically ascribed to cholinergic dysfunction.

Adrenergic Fibers↗
PubMed1987

Augmentation of normal and malignant B cell proliferation by monoclonal antibody to the B cell-specific antigen BP50 (CDW40).

We recently described a 50,000 dalton polypeptide Bp50 (CDw40) that is expressed on human B cells and plays a role in regulating B cell proliferation. Here we additionally characterize the functional signal given by antibody binding to Bp50 on both normal and malignant B cells. A monoclonal anti-Bp50 antibody could augment the proliferation of B cells activated by anti-IgM, anti-CD20, or 12-O-tetradecanoyl phorbol-13-acetate (TPA) stimulation, but was not co-stimulatory with B cell growth factor (BCGF), interleukin 1, or interleukin 2. The signal did not depend on the Fc portion of the antibody, because F(ab')2 fragments of anti-Bp50 were still functionally active. Both anti-Bp50 and a low m.w. BCGF preparation were similar in that both were co-stimulatory with the same agents and both anti-Bp50 and BCGF affected activated B cells but not resting B cells. However, a panel of B cell malignancies differed in their responsiveness to anti-Bp50 vs BCGF: some tumors proliferated in response to anti-Bp50 but not BCGF, whereas other tumors had the opposite pattern. Bp50 was found to have several properties in common with HLA class II molecules: both Bp50 and class II were expressed at lower levels on blood B cells than on tonsillar B cells; the expression of both Bp50 and class II was increased after activation of blood B cells with TPA or anti-IgM; and the expression of both Bp50 and class II was increased after activation of non T, non-B acute leukemias with BCGF. Thus class II and Bp50 expression may be under common regulatory control. The fact that BCGF modulated the expression of Bp50 on leukemic cells suggests that BCGF and Bp50-mediated signals may be coordinately regulated.

Animals↗
PubMed1987

An evaluation of spatial information processing in aged rats.

The spatial learning abilities of young, middle-age, and senescent rats were investigated in two experiments using several versions of the Morris water maze task. In Experiment 1, Long-Evans hooded rats were trained to find a submerged escape platform hidden within the water maze. During this phase of testing, aged rats exhibited acquisition deficits compared with either young or middle-age subjects. With continued training, however, all age groups eventually achieved comparable asymptotic levels of performance. Subsequent testing in Experiment 1 revealed that following original training, aged rats were not impaired in learning a novel escape location or in their ability to locate a visible, cued escape platform. In an attempt to identify the basis of the age-related impairments observed in Experiment 1, naive young and aged rats in Experiment 2 were initially tested for their ability to locate a cued escape platform in the water maze. During this phase of testing, the escape latencies of both young and aged rats rapidly decreased to equivalent asymptotic levels. Subsequent analyses revealed that following cue training, young subjects exhibit a significant spatial bias for the region of the testing apparatus where the platform was positioned during training. In contrast, aged rats showed no spatial bias. Training was continued in Experiment 2 using a novel submerged platform location for each subject. During these place training trials, the escape latencies of senescent rats were longer than those of young subjects. These impairments were also accompanied by a lack of spatial bias among aged rats relative to young control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1987

Effects of opiate manipulations on latent inhibition in rabbits: sensitivity of the medial septal region to intracranial treatments.

The effects of opiate manipulations were examined on latent inhibition of classically conditioned heart rate in rabbits. Animals were exposed to an auditory stimulus that was later used as a conditioned stimulus (CS). Administration of the agonist levorphanol into the medial septal region either preceding or immediately following CS preexposure sessions attenuated latent inhibition of the conditioned response. This effect was observed in animals that showed no change in long-term retention of habituation. Administration of levorphanol into the central nucleus of the amygdala, a sensitive site for opiate manipulations on aversive conditioning tasks, was ineffective. Further analysis of the effect obtained within the septal region revealed pharmacological specificity. The effect of posttraining levorphanol was also time dependent and exhibited neuroanatomical specificity. Posttraining opiate antagonist administration into the medial septum produced a modest augmentation of latent inhibition. The medial septal region appears to provide a site where opiate manipulations alter some aspect of retention for events that occur in the absence of reinforcement.

Acoustic Stimulation↗