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Biomedical subjects

J M Hall

Publications and source records attributed to J M Hall.

At least 55 records · Page 3Linked to original sources
PubMed1997

Relaxation of the ovine isolated iris sphincter by adenosine receptor agonists: lack of effect of adenosine A1 and A2 receptor antagonists.

The effects of adenosine receptor ligands on the tone of the ovine isolated iris sphincter were investigated, and adenosine analogues were found to relax the carbachol-contracted tissue in a concentration-dependent manner with an order of potency of 5'-N-ethylcarboxamidoadenosine > or = 2-(p-(2-carboxyethyl)phenylethylamino)-5'-N-ethylcarboxamidoadenos ine (CGS 21680) > or = N6-cyclopentyladenosine > adenosine, consistent with activation of an adenosine A2A receptor. However, these responses were not inhibited by the non-selective adenosine A1/A2 receptor antagonist 8-p-sulphophenyltheophylline (50 microM), the selective adenosine A2A/A1 receptor antagonist N-[2-(dimethylamino)ethyl]-N-methyl-4-(2,3,6,7-tetrahydro-2,6-dioxo-1,3- dipropyl-1H-purin-8-yl)benzenesulphonamide (PD 115,199) (0.1 microM) or the non-xanthine adenosine A2A receptor antagonist (4-(2-[7-amino-2-(2-furyl) [1,2,4]-triazolo[2,3-a][1,3,5]triazin-5-yl-amino]ethyl)phenol) (ZM 241385) (0.1 microM). The relaxations cannot therefore be mediated by activation of adenosine A1, A2A or A2B receptors.

Adenosine↗
PubMed1997

Bradykinin receptors.

1. The last decade has witnessed a phenomenal increase in our understanding of the pharmacology of bradykinin receptors, and has led to an appreciation of a key role for the peptide kinins as proinflammatory mediators. This short review summarises the major changes that have taken place in the expanding area of bradykinin receptor pharmacology, and highlights important advances that we hope to anticipate in the future. 2. Bradykinin receptors are cell surface, G-protein coupled receptors of the seven-transmembrane domained family. The existence of two subtypes of bradykinin receptor, B1 and B2, has been confirmed through the use of high affinity peptide and nonpeptide receptor antagonists, radioligand binding studies and, recently, receptor cloning and expression studies. 3. Differences in the affinities of B2 receptor antagonists, including those of the [D-Phe7]-bradykinin series, D-Arg-[Hyp3, Thi5, D-Tic7, Oic8]-bradykinin (Hoe140, Icatibant) and the non-peptide, WIN64338, have led to proposals of the possible existence of further subtypes of bradykinin receptor (including a tracheal B3 receptor), and/or of species homologues of the B2 receptor. 4. Molecular cloning techniques have identified the gene encoding B1 receptors in the rabbit, human and mouse, and B2 receptors in the rat, human and mouse. B1 and B2 receptor show little (36%) overall sequence homology. Cloning studies reveal the potential for the existence of species homologues of receptors. 5. The use of bradykinin receptor antagonists in vivo has led to an appreciation of the involvement of bradykinin receptors in inflammation. Evidence suggests a role for B2 receptors in more classical acute inflammatory events, such as oedema and inflammatory pain, whereas B1 receptors appear to be involved in chronic inflammatory responses, including certain forms of persistent hyperalgesia. 6. The continuing advances in our knowledge of the characteristics of bradykinin receptors through the further development of selective receptor antagonists and molecular biology techniques will aid in the rational design of drugs effective in the therapeutic manipulation of inflammatory processes and in the control of inflammatory disease.

Animals↗
PubMed1997

Beyond "true" and "false" memories: remembering and recovery in the survival of childhood sexual abuse.

As survivors of childhood sexual abuse (CSA) struggle to grasp and reclaim their selves, their stories, and their futures from the grip of aftereffects of trauma, the processes of recovery and rehabilitation are interwoven with remembering. Questions about women's delayed memories of CSA have stirred a controversy that places clients' credibility at stake. Nurses need to understand the historical and political roots of this controversy and to be familiar with the empirical knowledgebase that exists about traumatic memory. This article is a critical feminist analysis of the topic. Its purposes are to provide a historical context for the current debate about "true" and "false" CSA memories; to discuss selected literature about conventional understandings of memory and their relevance to this debate; to present an integrative, phenomenological approach to memory in the recovery and rehabilitation of women CSA survivors; and to use the insights gained to draw conclusions from a nursing perspective about the authenticity of delayed CSA memories. Phenomenological concepts of reminding, reminiscing, recognition, body memory, place memory, and commemoration are discussed as they illuminate the complexity of traumatic memories and the recovery and rehabilitation needs of survivors of childhood sexual abuse.

Adult↗
PubMed1997

Dirty protests: a phenomenological assessment.

The use of faecal material as a means to effect a personal protest appears to be a behaviour restricted to prison establishments. Over the last decade, this form of protest appears to be diminishing. Dirty protests are described, and possible aetiologies explored.

Behavior↗
PubMed1997

Safe closure of therapeutic relationships with abuse survivors.

1 Safe closure of a therapeutic relationship is needed because neither healer nor client can be a "stranger" again. 2 A "failed termination" may overshadow the therapeutic gains that were made during the working phase, constituting a "retraumatization." 3 Closure, as opposed to termination, involves a unique, individualized mutual transformation of the therapeutic relationship into a "real relationship."

Adult↗
PubMed1996

A new approach for creating double-stranded DNA biosensors.

The principle of 'sandwich'-type biosensors based on liquid-crystalline dispersions formed from [DNA-polycation] complexes is outlined. These biosensors will find application in the determination of a range of compounds and physical factors that affect the ability of a given polycationic molecule to maintain intermolecular crosslinks between neighbouring DNA molecules. In the case of liquid-crystalline dispersions formed from [DNA-protamine] complexes, the lowest concentration of hydrolytic enzyme (trypsin) detectable was approximately 10-(14) M.

Animals↗
PubMed1996

Delayed recall of childhood sexual abuse: psychiatric nursing's responsibilities to clients.

In no other area of psychiatric care is such suspicion being cast on clients as in the area of delayed recall of childhood sexual abuse. Adult survivors of childhood abuse are encountered in nursing contexts of all kinds. Psychiatric nurses should be the ones that other nurses and members of the public can look to for guidance and clinical wisdom about dissociative amnesia for childhood abuse. It is incumbent on psychiatric nurses, especially those who publish about clinical issues, to provide the most accurate and complete available knowledge, to prioritize clients' needs, and to recommend care that meets the highest standards.

Adult↗
PubMed1996

Geography of childhood sexual abuse: women's narratives of their childhood environments.

This article explores the geography of childhood sexual abuse by describing characteristics of the home, school, and community environments in which abused girls grew up. Results of this focused life story research involving 20 women survivors who narrated their childhood experiences suggest a topography of 20 distinct characteristics integral to the milieux of these abusive childhood homes. Dynamics of the home environment were reinforced in school and community environments. Implications for prevention and early, environmentally based interventions for girls at risk of abuse and retraumatization are discussed.

Adolescent↗
PubMed1996

An occupational transmission of HIV: collision of ethical worlds in nursing practice.

This article proposes a new theoretical frame for ethical practice in nursing by locating ethical questions within the worlds of everyday nursing experience. The authors advocate a process of ethical thought and action that is not so much a weighing of dichotomized alternatives as a continual journey in which nurses delve deeper into their examination of clinical contexts, structural contingencies, and the meanings of experience for themselves and their clients. This theoretical vision is illustrated with a case study about a nurse who was infected with HIV on the job. The purposes in presenting the case study are to give testament to this brave woman's story, illustrate the dynamics of a contextualized ethics, and challenge nurses to make changes in practice, policy, and structure to foster truly ethical work and relations with others.

Attitude of Health Personnel↗
PubMed1996

Voices of impoverished Brazilian women: health implications of roles and resources.

This qualitative study was based on individual interviews with 75 Brazilian women in an impoverished peri-urban squatter community (favela) in southeastern Brazil. The purposes of the study were to describe women's role involvement in domestic and employment contexts; identify stresses and satisfactions of maternal, spousal, and employment roles; and assess personal and environmental role constraints and resources from the perspective of women's health. The analytic approach to the interview data was qualitative content analysis, through which thematic categories of maternal, spousal, and employment role satisfactions and stresses were identified by the researchers. Women's unrelenting work in the face of harsh social and economic environments was a broad theme woven throughout the women's descriptions of their lives. The confluence of role constraints affecting the participants' lives included poverty, marginalization, abuse, and lack of support and recognition by partners and society. In order to overcome great adversity and meet heavy role demands, these women relied on self, faith in God, family, and health resources. Implications for women's health promotion are discussed.

Adult↗
PubMed1996

Pervasive effects of childhood sexual abuse in lesbians' recovery from alcohol problems.

In narratives of 35 lesbians in alcohol recovery, 46% unexpectedly disclosed having survived childhood sexual abuse (CSA), linking it with addiction and recovery experiences. This subgroup described unbounded difficulties that pervaded their lives well into recovery. They reported multiple addictions, self-harm, isolation, sexual problems, depression, self-loathing, physical illness, and inability to work more often than did other participants. Those not reporting CSA were more socially and occupationally stable, self-satisfied, and physically well in recovery; their alcohol problems seemed circumscribed and responsive to conventional intervention. Conclusions indicate that CSA history may foster health risks that complicate alcohol recovery, necessitating more comprehensive clinical attention.

Adult↗
PubMed1995

Detection of maternal cells in human umbilical cord blood using fluorescence in situ hybridization.

Cord blood is a potential source of hematopoietic stem cells for transplantation and is being used on a growing number of patients. However, there are concerns that cord blood might be contaminated with maternal cells that could lead to graft-versus-host disease. To ascertain the extent to which maternal cell contamination of cord blood occurs, we examined 49 cord blood samples from male babies for maternal cells by fluorescence in situ hybridization using probes to the X and Y chromosomes. A minimum of 1,000 nuclei were scored from each sample, and maternal cells were found in 7 of the 49 cord bloods, at levels ranging from 0.04% to 1.0%. In addition, in 39 and 27 of the cord blood samples, respectively, we examined the CD8+ and CD34+ cell populations for maternal cells. Maternal cells were found in 5 of the 39 CD8 fractions and in 1 of the 27 CD34 fractions, at levels similar to that found in the unfractionated cord blood. In sum, maternal cells were found in either the unseparated mononuclear fraction or the CD8 or CD34 fractions in 10 of the 49 cord blood samples (20%). These results show that maternal cells are present in a substantial number of cord bloods, and that some of these maternal cells are T cells.

Antigens, CD↗
PubMed1995

Amperometric detection of histamine at a quinoprotein dehydrogenase enzyme electrode.

Methylamine dehydrogenase, a tryptophan tryptophyl quinone (TTQ) containing quinoprotein, catalyzes the oxidation of a variety of primary aliphatic monomaines and diamines to their respective aldehydes and ammonia. This paper reports the construction and characterization of an enzyme electrode capable of detecting histamine and methylamine at +200 mV versus a saturated calomel reference electrode. The methylamine dehydrogenase isolated from Paracoccus denitrificans was used in conjunction with the insoluble mediator tetracyanoquinodimethane (TCNQ) to construct enzyme electrodes which will potentially provide simple rapid analysis of histamine without the need for the extensive sample pretreatments currently required in HPLC and GLC analysis. The linear response of this amperometric sensor, between 0 and 200 microM, correlates well with elevated histamine levels predominant in patients with chronic myelogenous leukaemia, whilst the observed limit of detection, 4.8 microM, compares favourably with the lower limits of detection reported for a potentiometric histamine sensitive enzyme electrode.

Biosensing Techniques↗
PubMed1995

Inhibition of bradykinin-evoked trigeminal nerve stimulation by the non-peptide bradykinin B2 receptor antagonist WIN 64338 in vivo and in vitro.

1. This study investigated the effect of the recently described non-peptide bradykinin B2 receptor antagonist, WIN 64338 ([[4-[[2- [[bis(cyclohexylamino)methylene]amino]-3-(2-naphthalenyl)-1-oxopropyl] amino]phenyl]methyl]tributylphosphoniumchloride monohydrochloride), in experimental models of bradykinin-evoked sensory nerve stimulation. 2. In the rabbit isolated iris sphincter in vitro, bradykinin-evoked contractile responses are mediated via tachykinins released from peripheral endings of the trigeminal sensory nerve. WIN 64338 (1-10 microM) competitively antagonised contractile responses to bradykinin with a pKB estimate of 6.6 +/- 0.1 (n = 11). The antagonism was selective since WIN 64338 (10 microM) did not significantly inhibit submaximal contractile responses to the direct-acting spasmogens substance P (10 nM), neurokinin A (3 nM), substance P methyl ester (10 nM) or senktide (100 nM); nor by sensory non-adrenergic non-cholinergic nerve stimulation evoked by capsaicin (10 microM), or electrical field-stimulation (3, 10, 30 Hz) (P > 0.05; n = 3-11). 3. Topical application of bradykinin to the conjunctiva and to the nasal mucosa of the guinea-pig in vivo causes plasma extravasation predominantly via the release of tachykinins from peripheral endings of the trigeminal nerve. The increases in plasma extravasation (measured by extravasation of Evans blue dye) induced by bradykinin in the guinea-pig conjunctiva (20 nmol) and nasal mucosa (50 nmol) were markedly reduced (by 81 +/- 3% and 69 +/- 5%, respectively) following pretreatment with WIN 64338 (30 nmol kg-1, i.v.) (n = 5-6; P < 0.05), with almost complete inhibition at a higher dose of WIN 64338 (300 nmol kg-1, i.v.; n = 5-6). This inhibition was selective since at 300 nmol kg-1, WIN 64338 did not inhibit plasma extravasation evoked by substance P in the conjunctiva (5 nmol; P > 0.05; n = 6) or in the nasal mucosa (50 nmol; P > 0.05; n = 5). 4. This study demonstrates that WIN 64338 is a selective and competitive bradykinin B2 receptor antagonist and can be useful for analysing bradykinin-evoked trigeminal nerve stimulation both in vitro and in vivo.

Animals↗