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Biomedical subjects

P Nolan

Publications and source records attributed to P Nolan.

At least 91 records · Page 5Linked to original sources
PubMed1990

The effect of immunosuppressive agents on the induction of nuclear factors that bind to sites on the interleukin 2 promoter.

Cyclosporin A (CSA), FK506, and glucocorticosteroids all inhibit the production of lymphokines by decreasing lymphokine gene expression. Previous experiments have defined six different sites that may contribute to the transcriptional control of the interleukin 2 (IL-2) promoter, and for each, active nuclear binding factors are induced upon mitogenic stimulation. While dexamethasone markedly blocks the increase in IL-2 mRNA in stimulated human blood T cells, we found that the drug does not block the appearance of factors that bind to the transcriptional control sites termed AP-1, AP-3, NF-kB, OCT-1, B site, and NF-AT. In contrast, both CSA and FK506 have similar effects: the drugs cause modest decreases in AP-3 and NF-kB, and markedly decreases in the activity of AP-1 and NF-AT. Therefore, CSA and FK506, while chemically different, seem to act upon a similar pathway that leads to IL-2 gene expression, whereas glucocorticoids do not affect this pathway.

Anti-Bacterial Agents↗
PubMed1990

The responses of superior laryngeal nerve afferent fibres to laryngeal airway CO2 concentration in the anaesthetized cat.

In anaesthetized cats, the isolated, in situ, larynx was subjected to a simulated respiratory cycle and the responses of fifty-six superior laryngeal nerve (SLN) afferent fibres to respiration-related stimuli were examined during changes in the fractional CO2 concentration of the laryngeal airway (Faw, CO2). Sensory SLN fibres which displayed low rates of discharge when the larynx was unventilated (quiescent fibres) and which responded to negative laryngeal airway pressure were excited by elevations in Faw, CO2 whereas quiescent fibres responsive to positive laryngeal pressure were inhibited by the same procedure. We propose that changes in airway CO2 levels may play a role in maintaining upper airway patency, especially during sleep.

Anesthesia↗
PubMed1990

The effects of changes in laryngeal airway CO2 concentration on genioglossus muscle activity in the anaesthetized cat.

In the anaesthetized cat the larynx was isolated in situ, artificially ventilated and used to assess reflex effects exerted by respiration-related laryngeal stimuli on genioglossus electromyographic activity (Gg EMG) and respiratory frequency (RF). Phasic Gg EMG was not observed when the larynx was unventilated but was evoked, with a concurrent decrease in RF, when negative pressures or oscillatory pressures similar to those of normal ventilation were applied to the larynx. Increases in laryngeal airway CO2 concentration also enhanced Gg EMG and reduced RF. All reflex effects were abolished by bilateral section of the superior laryngeal nerves. We propose that negative intralaryngeal pressure and CO2 may act together to restore pharyngeal patency during obstructive apnoea.

Anesthesia↗
PubMed1987

Folylpolyglutamates in Leishmania major.

The intracellular folates of the protozoan parasite Leishmania major have been examined. About 95% of the exogenous [3H]folate accumulated by the protozoan is metabolized to polyglutamate conjugates within 65 hr, and the intracellular folates are about forty-fold concentrated over the folate in the medium. The predominant metabolite of folic acid is the pentaglutamate conjugate (85%), with lessor amounts of the tetraglutamate (approximately 9%) and hexaglutamate (approximately 3%), and trace (less than 2.5%) amounts of di-, tri- and hepta-glutamate conjugates. Chromatographic properties of the products indicate that the conjugates are linked through the gamma-carboxyl groups. The folylpolyglutamate distribution in Leishmania is similar to that found in mammalian tissues.

Animals↗
PubMed1985

Alterations of capillary flow during sepsis.

Normal red cells are flexible and can thus negotiate small capillaries with ease. Impaired red cell deformability (RCD) has been found in patients with uremia, peripheral vascular disease, and diabetes. This study was performed in order to determine if impaired RCD is present during sepsis. The RCD of citrated whole blood (WB) and citrated buffy coat-poor whole blood (BCP) from ten septic patients was compared to ten age-, sex-, and race-matched control patients. The samples were passed through polycarbonate 5 micron pore filters at -10 cm H2O pressure according to the technique of Reid. A red cell deformability index was calculated for each patient by multiplying the volume of blood flowing through the apparatus in a 1-minute period by the hematocrit. The results show very highly significant decreases of flow in both the WB and BCP blood in the septic group. Alterations in flow in the WB can be explained on the basis of changes in the buffy coat fraction and/or the red cell deformability. A decrease in flow in the BCP blood can be explained in terms of a diminished deformability of the red cells themselves. This increased rigidity of the red cells could, in part, explain the AV shunting and decreased microcirculatory flow seen in the septic state.

Capillaries↗
PubMedDate not supplied

A survey of patients placed on the supervision register in one mental health trust.

Mental health nurses, in common with other health care groups, are charged with monitoring the quality of care for severely mentally ill clients. It is now apparent that improving the social functioning of these clients is far more complex than was previously thought and demands better coordinated services. To improve services is especially challenging at a time when resources are diminishing and existing generic mental health services find themselves under severe pressure. The introduction of the Supervision Register (1994) was one response to a number of high profile incidents in the U.K. which suggested that greater collaboration between health services, social services and voluntary agencies needed to be sought. This study aimed to ascertain the characteristics of clients placed on the Register and the reaction of the mental health professionals who have to implement it. Although the majority of staff interviewed in the course of the study acknowledged that the Register served to highlight and perhaps potentiate the constituents of good practice, a number were concerned that in the absence of appropriate and sufficient community-based resources, procedural mechanisms such as the Supervision Register were merely a cosmetic purpose.

Attitude of Health Personnel↗
PubMedDate not supplied

Intraarticular iliotibial band reconstruction for anterior cruciate ligament insufficiency.

Intraarticular reconstruction of the anterior cruciate ligament by transferring the distal aspect and insertion of the iliotibial band has been clinically successful. Our surgical technique theoretically retains normal neurovascular supply, and thus, the potential for dynamic repair exists. Thirty-five patients, 28 men and 7 women, underwent this reconstruction. The average age was 24 years, with a range from 18 to 46. There were 27 chronic and 8 acute injuries. Pathological findings included an absent anterior cruciate (14 knees), severe stretching (13), failed reconstruction or repair (4), midportion tears (3), and avulsion (1). Postoperative patients were evaluated according to the Kennedy criteria. An anterior drawer of 2+ was not observed in any patient. There were no cases of 2+ rotary instability, and no pivot shifts. The possibility of a dynamic or proprioceptive repair was assessed by electromyography. While no evidence of electrical activity was recorded on the gluteus maximus on 60 normal knee examinations, all 10 tested postoperative iliotibial band patients had electrical activity. The failed results of the series showed no evidence of activity.

Adolescent↗