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Biomedical subjects

P Cooper

Publications and source records attributed to P Cooper.

At least 91 records · Page 5Linked to original sources
PubMed1994

Protein C, antithrombin III and plasminogen: effect of age, sex and blood group.

We conducted a cross-sectional study of antithrombin III (ATIII), protein C (PC) and plasminogen (Plg) concentrations in a population of healthy plasma donors in the Trent Region. The distribution of values for protein C was log normal whereas for ATIII and Plg the distributions were positively skewed and differed significantly from normal and log normal. Males had higher antithrombin III concentrations (mean 1.10 iu/ml, range 0.72-1.65) than females (mean 1.07 iu/ml, range 0.75-1.69) (P = 0.001) and levels increased with age in women. Younger women aged 25-34 had significantly lower plasma concentrations of ATIII compared to males of similar age. For protein C, concentrations were higher in males (mean 1.07 u/ml, range 0.37-2.11) than in females (mean 1.01 u/ml, range 0.59-1.61) (P < 0.001) and levels increased with age in both sexes P < 0.001). In women, a novel difference in protein C concentration between ABO blood groups was noted. There was no significant difference in plasminogen concentration between males and females, and in women plasminogen decreased with age (r = -0.205, P < 0.001). We conclude that these variations in ATIII and protein C with age and sex are important considerations in the determination of reference ranges for these proteins.

ABO Blood-Group System↗
PubMed1994

Long-term stability studies on the WHO IRP for thromboplastin (human plain BCT/253).

Long-term stability studies on the WHO second primary International Reference Preparation (IRP) for thromboplastin (human plain BCT/253) stored at -20 degrees C have been conducted for ten years. Three centres took part in the exercise using frozen normal and coumarinised plasma samples which were tested throughout. There has been no measurable change in the prothrombin time performance of the human plain IRP over the ten-year period. It can therefore be concluded that new IRP may continue to be calibrated against this preparation in accord with WHO recommendations.

Analysis of Variance↗
PubMed1993

Appearance of granulocyte-macrophage colony-stimulating factor activity at allergen-challenged cutaneous late-phase reaction sites.

The cytokines IL-3 and granulocyte-macrophage CSF (GM-CSF) activate and/or prime monocytes, basophils, and eosinophils for a number of proinflammatory events in vitro. It was hypothesized that IL-3 and GM-CSF might also participate in the local inflammatory cascades that occur at cutaneous blister sites after Ag challenge in vivo. The M-07e megakaryocytic leukemia cell line, which proliferates in response to IL-3 or GM-CSF, was used to determine whether these cytokines were present in fluids derived after Ag challenge in the cutaneous blister chamber model. Fluids from blister chambers after either Ag (timothy grass, orchard grass, or ragweed) or vehicle control challenge were collected hourly for 12 h from nine patients with allergic rhinitis. Cytokine (IL-3/GM-CSF) activity was modestly elevated at 4 h after Ag challenge compared to control with the median of maximal proliferation 4% (range, 2 to 22%) vs 2% (range, 1 to 14%), respectively (Ag vs control, p < 0.03). Activity peaked at 7 h (Ag = 10%, range 1 to 12%, vs control = 1%, range 1 to 9%, p < 0.02) and then steadily declined. No increase in cytokine activity over control was seen in Ag-challenged nonatopics (n = 5, p = NS), indicating that release did not result from a nonspecific effect of the Ag solution. Neutralization of cytokine bioactivity in pooled late phase reaction (LPR) fluids from h 4 to 12 (n = 5) with anti-IL-3, anti-GM-CSF, or both antisera revealed that the majority of the activity was GM-CSF. To better quantify cytokine levels, pooled LPR fluids prepared from an additional 11 subjects were concentration-dialyzed (10x) and tested for cytokine activity. Pooled fluids from Ag-challenged sites contained a median of 625 pg/ml (range, 30 to 1250 pg/ml) GM-CSF equivalents, whereas those from the vehicle control-challenged sites contained a median 30 pg/ml (range, 30 to 300 pg/ml) GM-CSF equivalents (p < 0.004 Ag vs control groups, n = 11). Concentrated fluid from Ag- and control-challenged sites in two nonatopic subjects contained < 10 pg/ml cytokine activity. To evaluate the IL-3 and GM-CSF activity with a separate technique, ELISA were performed on separately pooled blister fluids from six atopic subjects. Although no IL-3 activity was detected after Ag challenge in these six subjects, all of them demonstrated levels of GM-CSF at Ag-challenged sites comparable to that found in the bioassay.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1993

Physical mapping of 2000 kb of the mouse X chromosome in the vicinity of the Xist locus.

A physical map encompassing approximately 2.0 megabases (Mb) in the region of the mouse X-inactivation center has been constructed. The map extends from the Gjb-1 locus to the Xist locus and demonstrates the order of probes inseparable by genetic analysis. The deduced locus order is as follows: Gjb-1, Ccg-1, DXCrc171, Rps4, Phka, DXCrc177, DXCrc318, Xist. Detailed physical mapping in the region between the Phka and Xist loci indicates the position of CpG-rich islands associated with the 5' end of genes. The DXCrc177 and DXCrc318 loci, both defined by probes derived from linking clones, are associated with CpG-rich islands. The map provides a framework for the isolation of underlying sequences in the mouse X-inactivation center region.

Animals↗
PubMed1993

Modulation of secretory processes of phagocytes by IX 207-887.

In chronic inflammation, the mediators released by phagocytes are in part responsible for the initiation and perpetuation of the disease. IX 207-887, which is a novel antiarthritic drug, inhibits the release of cytokines from mononuclear cells at concentrations which are achieved therapeutically in human rheumatoid arthritis and in animal models of arthritis. Furthermore, the production of superoxide and release of azurophil and specific granules by N-formyl-Met-Leu-Phe-stimulated neutrophils are significantly reduced. As a consequence, IX 207-887 may break the vicious circle which is manifest in chronic inflammation. In a recent double-blind placebo controlled study IX 207-887 has been shown to be an effective slow-acting drug for use in rheumatoid arthritis.

Animals↗
PubMed1993

Vaginal squamous cells in follicular aspirates following transvaginal puncture.

Squamous cells are common findings on cytological examination of fluid obtained following transvaginal aspiration of simple ovarian cysts. This prospective study confirms the hypothesis that these cells are commonly introduced as contaminants during puncture of the vaginal wall. The occasional finding of bacteria also suggests a possible mechanism for post-operative pelvic infection.

Adult↗
PubMed1993

Cutaneous IgE-mediated inflammatory lesion size is inhibited by an H1 antagonist (terfenadine) while mediator release is unaffected in vivo and in vitro.

We are interested in understanding the pathogenesis of the cutaneous IgE-mediated late phase reaction. A double-blind, placebo-controlled, randomized cross-over study with 10 subjects of the effect of the non-sedating antihistamine, terfenadine (Selddane), on the cutaneous reaction to antigen (ragweed or mixed grass) administered intradermally and over denuded blister bases was performed. The activity of terfenadine on anti-IgE-induced mediator release from the skin mast cell, lung mast cell and basophil was also examined in vitro. Terfenadine significantly inhibited the size of the cutaneous reaction at every hour between hours 1 and 9 (hr 9, control 2250 +/- 500 mm2 vs drug 1250 +/- 250 mm2, P < 0.01, n = 10) and showed some inhibitory effect at hours 10-12. While terfenadine blocks histamine release after nasal antigen challenge the release of mediators at skin blister sites was unaffected. The infiltration of leucocytes into the blister supernatant was unaffected by terfenadine although previous studies have shown significant inhibition with another antihistamine, cetirizine. In vitro, terfenadine, like other antihistamines, was found to have inhibitory activity on anti-IgE-induced mediator release at concentrations of 10(-4)-10(-5) M in lung and skin mast cells and basophils. We conclude that the effects of the newer antihistamines on cellular movement into the skin may be diverse, that terfenadine may show organ specificity in vivo and that terfenadine significantly decreases both the early and late gross inflammatory response of the skin to antigen. We cannot, as yet, explain the mechanism(s) by which this occurs.

Basophils↗
PubMed1993

The management of acute bronchiolitis. Thoracic Society of Australia and New Zealand.

The management of acute bronchiolitis is mainly supportive, but infants require minimal handling. Of those who are hospitalized, less than 3% require intensive care and ventilation but in these children the condition is life threatening. Oxygen, fluid replacement and careful observation remain the cornerstones of management. Bronchodilators should be avoided in young infants and antiviral therapy should only be considered in critically ill infants who have an underlying cardiopulmonary condition.

Acute Disease↗
PubMed1993

Reduced tissue type plasminogen activator activity of the gastroduodenal mucosa in peptic ulcer disease.

The gastroduodenal mucosa has a rich blood supply. An active fibrinolytic system is presumably required to maintain vascular patency, and impairment may result in reduced blood flow, focal tissue necrosis, and peptic ulcerogenesis. Tissue type and urokinase type plasminogen activator activity (expressed as mIU/mg protein) and plasminogen activator inhibitor type-1 antigen were assayed in homogenates of gastric and duodenal biopsy specimens taken from patients with: normal endoscopy (controls) (n = 14); active duodenal ulcer (n = 21); healed duodenal ulcer (n = 12); and active benign gastric ulcer (n = 15). In controls mean duodenal tissue type plasminogen activator activity was 4110 and urokinase type plasminogen activator activity 150; gastric tissue type plasminogen activator was 2760 and urokinase type plasminogen activator 170; plasminogen activator inhibitor type-1 was generally undetectable. At the edge of active duodenal ulcers tissue type plasminogen activator was considerably reduced, 2220 (p < 0.001) whereas urokinase type plasminogen activator was raised, 290 (p < 0.01). At the edge of active benign gastric ulcers tissue type plasminogen activator was substantially reduced, 1160 (p < 0.001) but urokinase type plasminogen activator was unchanged. At the scar of healed duodenal ulcers tissue type plasminogen activator was slightly reduced, 3290, but urokinase type plasminogen activator was increased, 308 (p < 0.05). H2 receptor antagonist treatment had little effect on tissue type or urokinase type plasminogen activator activity. Plasminogen activator inhibitor type-1 was increased at the edge of active ulcers (p < 0.05) especially when tissue type plasminogen activity was low (r = -0.61, p < 0.05). These findings are consistent with the hypothesis that impaired fibrinolytic activity may be implicated in peptic ulcerogenesis.

Duodenal Ulcer↗
PubMed1993

Occipitocervical fusion with a five-millimeter malleable rod and segmental fixation.

Although occipitocervical fusion is frequently used for instability of the upper cervical spine and the occipitocervical articulation, most currently used techniques have one or more of the following disadvantages: the necessity for sublaminar wires, the use of occipital screws, a fixed angle of instrumentation, or the necessity for routine postoperative halo immobilization. Moreover, many reported techniques are associated with a high rate of nonunion or instrumentation failure. We present our experience with a technically simple method of obtaining rigid occipitocervical arthrodesis using a 5-mm malleable rod that is fixed to the skull by a pair of wires passed through four suboccipital burr holes. Segmental spinal fixation is achieved with Wisconsin interspinous wires and is occasionally supplemented with sublaminar wires. Supplemental autogenous bone graft is used in all cases. A cervical collar is routinely used for postoperative immobilization. The results of treatment were retrospectively reviewed in 16 patients with an average age of 49.4 years (range, 9-69). Mean follow-up was 24 months (range, 12-36 mo). The indication for fusion was instability of the occiput-C1-C2 complex as a result of Chiari malformation, rheumatoid disease, skull base tumor resection, basilar invagination, ankylosing spondylitis, Down's syndrome, cervical laminectomy, and trauma. The average number of levels fused was 5.4 (range, O-C3 to O-T3). Successful occipitocervical arthrodesis was achieved in all but one of the surviving patients. The single patient with a pseudarthrosis was successfully managed with supplemental bone grafting and halo immobilization. There were two deaths from medical complications in chronically ill patients. Other complications included one postoperative instrumentation loosening, one myocardial infarction, and one superficial occipital decubitus. In conclusion, rodding and segmental interspinous wiring is an effective, technically simple method of obtaining rigid occipitocervical fixation, which obviates the need for bulky orthoses.

Adolescent↗
PubMed1993

Health service development for physician/medical records: a 1980s model, a 1990s application and refinement.

A new service to dictate hospital discharge summaries for attending physicians was developed using the Bushman-Cooper health care service development procedural model. The development of this service by the application of this model provided evidence of the model's general usefulness and specific areas where the model could be refined. Recommendations are made to improve the model's practical applicability.

Attitude of Health Personnel↗
PubMed1992

An EPR investigation of spin-labelled erythrocytes as a diagnostic technique for malignant hyperthermia.

Spin labelled (7-, 12- and 16- doxylsteric (DS) acid) erythrocyte (red blood cell) membranes isolated from six malignant hyperthermia susceptible (MHS) and six malignant hyperthermia normal (MHN) volunteer donors were characterized using the order parameter (S) and rotational correlation time (tau r) determined from 37 degrees C, 9 GHz electron paramagnetic resonance spectra. These parameters were found to decrease due to the increasing fluidization of the membrane as the halothane and benzyl alcohol sample concentration is increased and that significant differences exist in the values of S and tau r between the MHS and MHN sample groups, but that the differences in these parameters between the presence and absence of an external fluidizing agent are not significant for both sample groups. In the absence of these fluidizing agents, the mean values and standard errors of S at 37 degrees C for MHS and MHN are 0.643(2) and 0.652(3) for 7-DS, 0.554(2) and 0.563(3) for 12-DS, respectively, and of tau r are 2.139(12) and 2.223(13) ns for 16-DS, respectively. The values of S and tau r are significantly smaller for the MHS group than for the MHN group contrary to some previous reports. These observations revise and extend previous reports and show that the observed values of S and tau r in the absence of a fluidizing agent depend on the erythrocyte membrane structure in MHS and MHN subjects. They also suggest that the potential to use spin-labelled red blood cells as a screening protocol for MH deserves further investigation.

Benzyl Alcohol↗
PubMed1992

Pullout strength comparison of two methods of orienting screw insertion in the lateral masses of the bovine cervical spine.

We undertook a biomechanical study to compare the pullout strength of 3.5-mm AO screws placed in two different orientations within the bovine cervical spine. The first set of screws were oriented obliquely and passed through the lateral mass, as recommended by the AO group. The orientation of the second set was anterior to posterior through the lateral mass, as recommended by Roy-Camille. All screw holes were drilled and tapped by a spinal surgeon experienced with both techniques. Pullout force was measured on an Instron materials testing machine using a self-centering screw-holding chuck and loading rate of 0.833 mm/sec. Although the bone strength in the Roy-Camille orientation was greater (46.7 N/mm versus 36.1 N/mm, p < 0.05), the overall mean pullout force for the AO orientation was greater (607 N versus 471 N, p < 0.025) due to the longer length of bone available for screw purchase (17.0 mm versus 10.3 mm).

Animals↗
PubMed1992

Management of women with a cervical smear showing a mild degree of dyskaryosis: a review of policy.

Three hundred and thirty-seven women who presented for the first time with a cervical smear showing a mild degree of dyskaryosis were followed for a minimum period of 3 years and 9 months. Of the 305 women with complete cytological and histological records, 178 were biopsied and 127 remained on cytological follow up. In the biopsied group one case of microinvasive squamous cell carcinoma was diagnosed within 1 year of the patient's first abnormal smear. A further 24% showed cervical intraepithelial neoplasia (CIN) I, 17% showed CIN II and 29% showed CIN III. The overall regression rate for the group of 305 women was 34%. Our results indicate that cytological surveillance is acceptable provided that biopsy is advised when dyskaryosis persists. No major modifications to laboratory policy are indicated and in approximately 34% of cases an unnecessary hospital referral would be avoided.

Adult↗