Search PubMed⌕ Search

Biomedical subjects

P Rogers

Publications and source records attributed to P Rogers.

At least 109 records · Page 6Linked to original sources
PubMed1990

Oxitropium bromide: an acute dose response study of a new anticholinergic drug in combination with fenoterol in asthma and chronic bronchitis.

The aim of this study was to compare the bronchodilator response of patients with either stable asthma or stable chronic bronchitis to the acute administration of oxitropium bromide and a beta agonist (fenoterol) when given both separately and together in order to determine the responses of these two groups of patients and the optimal doses of these agents when given in combination. The responses of 23 patients with asthma and 25 patients with chronic bronchitis to 400 micrograms of fenoterol, and 200 micrograms of oxitropium given either alone or together with 100, 200 or 400 micrograms of fenoterol was studied. The peak bronchodilator response to oxitropium bromide of the patients with chronic bronchitis was equivalent to the fenoterol response while, in the patients with asthma, the response to oxitropium bromide was approximately 30% of the response to fenoterol. In both groups of subjects the addition of oxitropium bromide to fenoterol significantly increased both the magnitude and the duration of the bronchodilator response without a significant increase in side effects. In both groups of subjects 200 micrograms of oxitropium bromide and 200 micrograms or more of fenoterol gave the optimal response.

Adult↗
PubMed1990

A factorial study of fat and fibre changes and sodium restriction on blood pressure of human hypertensive subjects.

1. Diets used to reduce sodium intake often involve changes in fats and fibre which might themselves affect blood pressure and/or lipid metabolism. To evaluate the relative importance of these dietary changes for the management of hypertension we have studied the independent and additive effects of sodium restriction (less than 60 mmol/day) and a low fat (30% energy), high P/S ratio (1.0), high fibre (30-50 g/day) 'cholesterol lowering' diet. 2. Ninety-five hypertensives entered a four group parallel study with a factorial design. Following 5 weeks familiarization subjects [BP range 109/66-168/105 mmHg] were randomly assigned to either a 'low sodium, cholesterol lowering' diet or a 'low sodium, cholesterol maintaining' diet. Half the subjects in each group were then assigned to 100 mmol/day NaCl supplement and the remainder to placebo. These diets were continued for 8 weeks. Seventy-nine of the 91 hypertensives who completed the study were on antihypertensive therapy throughout. 3. Mean urinary sodium excretion decreased from 137 (54 mmol/day (n = 43) at baseline (B) to 52 (32) mmol/day (n = 45, P = 0.0001) during intervention (I) in the low sodium groups and remained unchanged in the groups which received slow sodium (B = 129 [46], n = 43; I = 134 [29], n = 42). Diet record and plasma fatty acid analysis confirmed that the dietary aims of the study were achieved. 4. Sodium restriction reduced supine and standing systolic BP by a mean (+/- s.e.m.) of 6 +/- 2 and 6 +/- 4 mmHg, respectively (P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1990

Cloning of a lactate dehydrogenase gene from Clostridium acetobutylicum B643 and expression in Escherichia coli.

A lactate dehydrogenase (LDH) gene of Clostridium acetobutylicum B643 was cloned on two recombinant plasmids, pPC37 and pPC58, that were selected by complementation of Escherichia coli PRC436 (acd), a fermentation-defective mutant that does not grow anaerobically on glucose. E. coli PRC436(pPC37) and PRC436(pPC58) grew anaerobically and fermented glucose to mostly lactate. When pPC37 and pPC58 were transformed into E. coli FMJ39 (ldh pfl), an LDH-deficient strain, the resulting strains grew anaerobically on glucose and produced lactate. Crude extracts of E. coli FMJ39(pPC37) and FMJ39(pP58) contained high LDH activity only when assayed for pyruvate reduction to lactate, and the LDH activity was activated 15- to 30-fold by the addition of fructose 1,6-diphosphate (FDP). E. coli FMJ39 had no detectable LDH activity, and E. coli LDH from a wild-type strain was not activated by FDP. Maxicell analysis showed that both plasmids pPC37 and pPC58 expressed a protein with an apparent Mr of 38,000 in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Restriction endonuclease mapping of pPC37 and pPC58 and DNA hybridization studies indicated that a 2.1-kb region of these two clones of C. acetobutylicum DNA encodes the FDP-activated LDH.

Cloning, Molecular↗
PubMed1990

Decline in head growth and cognitive impairment in survivors of acute lymphoblastic leukaemia.

Twenty five children in remission, who were asymptomatic and who had last been treated at least two years before for acute lymphoblastic leukaemia, were examined neurologically and neuropsychologically. Their treatment included early cranial irradiation (24 Gy or 18 Gy), intrathecal methotrexate, and systemic chemotherapy. One half of the children demonstrated a decline in head circumference centile, which occurred in all patients treated with 24 Gy and in those patients treated with 18 Gy under the age of 3 years. In those children whose head growth was reduced, performance was significantly impaired in neuropsychological tests designed to assess concentration and short term memory. These children also developed clinically important learning difficulties in the classroom. Minor neurological dysfunction was present in almost half of the entire group. These data suggest that the treatment employed to prevent central nervous system leukaemia (primarily cranial irradiation) has a deleterious effect on head and brain growth and intellectual function.

Adolescent↗
PubMed1989

Neutral selection of transfected mammalian cells using tissue plasminogen activator gene expression.

The gene that produces the proteolytic enzyme, tissue plasminogen activator (tPA), was used as a selectable marker for transfection. Cells that were successfully transfected with plasmids containing a gene for tPA (tpa) produce plaques in the caseinolysis assay. Two tpa-containing plasmids were constructed and used to transfect a variety of cell types. One plasmid contained the promoter region of simian virus 40 and the other contained the Moloney murine leukemia virus promoter. No significant difference in transfection frequencies was found for the two plasmids. However, 80% of the cell types tested produced plaques. This system allows for the identification and isolation of transfected cells under conditions that are not lethal to nontransfected cells.

Animals↗
PubMed1989

Crystallization and preliminary X-ray studies of pyridoxal kinase from sheep brain.

Crystals of pyridoxal kinase from sheep brain have been grown from solutions of ammonium sulfate or Na+/K+ phosphate. The crystals are trigonal, space group P3(1)21 with axes a = b = 102.2 A and c = 58.5 A. The crystals are quite stable to x-rays and diffract at 2.2-A resolution. This macromolecule is a 80,000-kDa dimer and utilizes the 2-fold symmetry of the space group, resulting in one subunit/asymmetric unit.

Ammonium Sulfate↗
PubMed1989

Pregnancy results following embryo transfer in women receiving low-dosage variable-length estrogen replacement therapy for premature ovarian failure.

This study was undertaken to evaluate the effectiveness of a new, constant low-dose, variable-length estrogen replacement therapy in preparing the endometrium of women suffering premature ovarian failure for embryo implantation. Five of 10 patients receiving the new regime became pregnant following a total of 14 embryo transfers. This study proves the efficacy of low-dosage variable-length estrogen replacement therapy for preparing the endometrium for embryo implantation in patients suffering premature ovarian failure. These studies confirm earlier observations that sequentially increasing doses of estrogen during the follicular phase are unnecessary for implantation and that the length of the follicular phase within certain undefined limits is not critical. A second important observation arising from this study concerns the relative effectiveness of the route of administration of progesterone. Five of seven patients became pregnant after receiving vaginal pessaries, compared to none of seven following intramuscular injections.

Adult↗
PubMed1989

Cloning of Plasmodium yoelii genes expressing three different sporozoite-specific antigens.

Genomic DNA isolated from Plasmodium yoelii (strain #17XNL) was prepared by partial digestion and cloned in Escherichia coli TB-1 with pUC18 plasmid. Antigen-producing recombinants were detected by a battery of monoclonal antibodies against antigens of the sporozoite stages. Four clones producing stage-specific sporozoite antigens were identified. One produced P. yoelii circumsporozoite protein, and three produced other P. yoelii sporozoite antigens.

Animals↗
PubMed1989

A preliminary analysis of the ameliorative effects of time-out from speaking on stuttering.

Relatively few attempts have been made to systematically examine the processes responsible for the ameliorative effects of response-contingent stimulation (RCS) on stuttering. It was hypothesized that the reductions in stuttering that frequently accompany RCS are the result of the stutterer being encouraged to access extant fluent speech that may not be fully evident during "contingency-free" (CF) conditions. A preliminary analysis of the hypothesis was conducted by monitoring RCS and CF stuttering frequency and speaking rate in 20 adult stutterers before, during, and after a program of fluency training. Subjects were divided into "high" and "low" responders on the basis of their baseline response to the RCS procedure of time-out from speaking, after which they participated in a 32-hour program of fluency training aimed at minimizing stuttering. After showing a degree of relapse during a subsequent 6-mon follow-up, high and low responders were found to be equally affected by time-out. This result contrasted the differential response shown by the two groups during the baseline phase, and is consistent with the hypothesis that improvements in fluency during RCS may occur when stutterers access extant fluent speech that is not otherwise being fully utilized.

Adult↗
PubMed1989

Uterine receptivity in women receiving steroid replacement therapy for premature ovarian failure: ultrastructural and endocrinological parameters.

Endometrial biopsies and plasma oestradiol (E2) and progesterone (P4) levels in 23 patients were evaluated during 26 replacement therapy cycles for premature ovarian failure. Plasma E2 and P4 levels showed wide patient to patient variability, despite each patient being given the same hormone replacement therapy. Biopsies were studied by conventional histological dating and scanning electron microscopy (SEM). Eight morphological features of the surface epithelium that have previously been linked to uterine receptivity for implantation were identified and quantified. No correlation was found between endometrial surface morphology by SEM and circulating E2 and P4 levels. The results of this study do not support the hypothesis that there is an obligatory link between any of the eight morphological features measured in this study and uterine receptivity for implantation. To date, three ongoing pregnancies have been achieved following 18 embryo transfers to a total of 10 of the women in the study group.

Adult↗
PubMed1989

Multiple lymphomatous polyposis of the gastrointestinal tract. A clinicopathologically distinctive form of non-Hodgkin's lymphoma of B-cell centrocytic type.

Multiple lymphomatous polyposis of the gastrointestinal tract was initially described as mucosal lymphomatous involvement by any of a variety of Hodgkin's or non-Hodgkin's lymphomas that produced a polypoid appearance over long segments of the gastrointestinal tract. We studied four patients in whom histology revealed diffuse small cleaved cell lymphoma (one case), or intermediate lymphocytic lymphoma of diffuse type (one case), or mantle zone pattern (two cases). All four cases are classifiable as centrocytic lymphoma. Cell suspension and immunocytochemical studies demonstrated B-cells of IgMD or M type with light chain restriction (two kappa, two lambda) showing a B1+ HLA Dr+ LN2+ CD5+ CD10+. Although all four patients had a partial response to combination chemotherapy, three of them died within 3 years. Analysis of 24 cases reported since 1971 (including the present cases) suggests that MLP is a distinct clinicopathological entity that results from gastrointestinal involvement by a B-cell centrocytic lymphoma. It is distinct from the recently described clinicopathological forms of centrocytic lymphoma and intermediate lymphocytic lymphoma, which both show extensive peripheral lymphadenopathy and splenomegaly, but it is probably closely related to them. The differences are probably attributable to distinct cell tropism or homing properties rather than to cellular histogenesis or degree of maturation.

Aged↗
PubMed1989

Relative efficacy of intensive and spaced behavioral treatment of stuttering.

Twenty adult and adolescent stutterers were randomly assigned to two treatment formats consisting of either 16 two-hour sessions of fluency training administered within a concentrated period of four consecutive days (intensive treatment), or two two-hour sessions per week for eight weeks (spaced treatment). Frequency of stuttering and rate of speaking were repeatedly assessed from speech samples obtained in six different clinic and extra-clinic speech settings. The efficiency of treatment, subject compliance, and communication "attitudes" were also measured. Fluency training produced significant reductions in stuttering frequency, and significant improvements in speaking rate and communication attitudes for both treatment formats. Both formats were found equivalent on all measures. In addition, generalization of treatment effects was observed in all settings. However, maintenance of generalization effects was uneven across settings, suggesting the possible need for differential levels of training for different speaking situations.

Adult↗
PubMed1989

A randomised double blind comparison of enalapril versus hydrochlorothiazide in elderly hypertensives.

To assess the suitability of therapy with an angiotensin-converting enzyme inhibitor for older hypertensives, a randomised double blind two group comparison of enalapril (10 to 40 mg daily) with hydrochlorothiazide (25 to 100 mg daily) was carried out in 32 untreated and independently living subjects aged 63 to 82 years with pressures on screening greater than 100 mmHg diastolic or greater than 180 mmHg systolic and after two weeks on placebo greater than 90 mmHg diastolic or greater than 160 mmHg systolic. Twenty-five subjects completed the ten weeks of active treatment with the majority in both groups reaching target blood pressures. Four subjects on enalapril and three on hydrochlorothiazide withdrew because of side effects. Eighteen of the 32 patients volunteered troublesome symptoms they attributed to therapy, which in some instances were alleviated by reductions in drug dosage. Small but significant falls in plasma potassium and sodium and increases in plasma urea and uric acid were seen on hydrochlorothiazide only. It was concluded that although in most cases good blood pressure control can be achieved by enalapril with some advantages over other drugs in the elderly, the potential for adverse effects remains significant. Halving usual starting doses of this and other antihypertensives may help to minimise problems in older subjects.

Aged↗
PubMed1988

Nonspecific interstitial pneumonitis without evidence of Pneumocystis carinii in asymptomatic patients infected with human immunodeficiency virus (HIV).

STUDY OBJECTIVE: To assess how often Pneumocystis carinii organisms, P. carinii pneumonia, or other pulmonary pathologic processes were present in persons infected with human immunodeficiency virus (HIV) without pulmonary symptoms or previous history of P. carinii, and with a normal chest roentgenogram. DESIGN: Serial, prospective assessment of eligible HIV-seropositive patients over 21 months. PATIENTS: Twenty-four HIV-seropositive patients with either a nonpulmonary manifestation of the acquired immunodeficiency syndrome (AIDS) (n = 12) or an absolute CD4 lymphocyte count of 0.200 X 10(9) cells/L or less (n = 12), no pulmonary symptoms, a normal chest roentgenogram, no history of P. carinii pneumonia, and no history of treatment with antipneumocystis prophylaxis. INTERVENTIONS: Pulmonary assessment with arterial blood gases, pulmonary function tests, gallium-67 citrate scans, and bronchoscopy with bronchoalveolar lavage and transbronchial biopsies. MEASUREMENTS AND MAIN RESULTS: Mean alveolar-arterial gradient was 11.1 mm Hg +/- 8.5 and mean diffusion capacity was 73.0% +/- 20.0% of predicted. None of the 24 patients showed P. carinii or other pathogens on stains of bronchoalveolar lavage fluid. No patient had histologic evidence of P. carinii pneumonia. Transbronchial biopsy specimens showed chronic, nonspecific interstitial pneumonitis (11 of 23) and no pathologic abnormality (12 of 23). Six patients have developed P. carinii pneumonia during 2 to 18 months of follow-up. CONCLUSIONS: HIV-infected patients without pulmonary symptoms did not have detectable Pneumocystis organisms in bronchoalveolar lavage fluid or transbronchial biopsy specimens; but 11 of 23 had evidence of chronic, nonspecific interstitial pneumonitis. Pneumocystis organisms in a pulmonary specimen from a symptomatic patient probably indicate the cause of the pulmonary dysfunction even if only a few are detected.

Adult↗
PubMed1988

Signal transduction of gamma/delta T cell antigen receptor with a novel mitogenic anti-delta antibody.

Human T lymphocytes express either alpha/beta- or gamma/delta-TCR in association with the CD3 complex. We have isolated a mAb, delta TCS1, that immunoprecipitated the gamma/delta-TCR heterodimer from cell lysates of Peer and Molt-13 leukemia cell lines. After dissociation of the gamma- and delta-chains of TCR by treatment with SDS, delta TCS1 specifically immunoprecipitated the delta-chain. This antibody bound to the surface of other gamma/delta-positive T cell lines and clones and was able to stimulate the proliferation of a minor cell population (0.9 to 4.0%) of resting human PBL. Upon binding to gamma/delta-TCR-bearing Molt-13 cells and PBL, delta TCS1 elicited a fura-2 Caa+ signal indicating that the gamma/delta-receptor is functionally similar to the alpha/beta-heterodimer. These data indicate that the delta TCS1 antibody recognizes an epitope on TCR delta-chain and its mitogenic activity should be useful in characterizing the functional properties of human gamma/delta-positive T lymphocytes.

Animals↗
PubMed1988

Monoamine oxidase inhibitors and anaesthesia. A review.

There has been a recent renewal of interest in the use of monoamine oxidase inhibitors in psychiatry. The concurrent administration of anaesthetic agents, particularly narcotic analgesics, is often a cause for concern. Although many monoamine oxidase inhibitor-drug interactions have been reported, in practice it is only the interaction with pethidine which has led to fatalities. What is not appreciated is that the monoamine oxidase inhibitor-pethidine interaction has two distinct forms-"excitatory" and "depressive". It is this lack of appreciation that has led to much confusion when dealing with patients taking monoamine oxidase inhibitors.

Anesthesia↗