Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “R:FR”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources
PubMed1992

[Muscarinic receptor subtypes in respiratory center and their functions].

Radioreceptor binding assays using [3H]quinuclidinyl benzilate and [3H]pirenzepine were performed on the pons and medulla oblongata (MeOb) of rat brain. The M1 cholinergic receptor (M1-R) was found to account for approximately 30-40% of the total muscarinic receptors (M-R) in the pons and MeOb, and the M2 accounted for about 60-70%. The receptor binding capacities of scopolamine and atropine were compared with those of pirenzepine (Pir) and AF-DX 116 on the 2 parts of the brain. The affinity values (pKi) suggest that the selectivity of scopolamine for M1-R is greater than for M2-R, and that of atropine for M2 is greater than for M1. In conscious rabbits, the respiratory frequency (FR), tidal volume (TV), and minute ventilation volume (MVV) were determined. Arterial blood samples were taken intermittently and analyzed for pO2, pCO2, and pH. When pilocarpine (a M1-R subtype selective agonist) was given, excitatory effects on respiration were seen through FR, TV, MVV, and the pO2, pCO2, and pH. When 6 beta-acetoxy nortropane (6 beta-AN, a novel M2-R subtype selective agonist) was given, the effects were inhibitory. These results were reversed after administration of Pir, scopolamine, AF-DX 116, and atropine. Thus, it shows that Pir and scopolamine inhibit respiration by blocking the M1-R subtype of the respiratory center, while the excitatory effects of AF-DX 116 and atropine are brought about by blocking the M2-R subtype of the respiratory center.

Animals↗
PubMed2000

Physiological interactions of phytochromes A, B1 and B2 in the control of development in tomato.

The role of phytochrome B2 (phyB2) in the control of photomorphogenesis in tomato (Solanum lycopersicum L.) has been investigated using recently isolated mutants carrying lesions in the PHYB2 gene. The physiological interactions of phytochrome A (phyA), phytochrome B1 (phyB1) and phyB2 have also been explored, using an isogenic series of all possible mutant combinations and several different phenotypic characteristics. The loss of phyB2 had a negligible effect on the development of white-light-grown wild-type or phyA-deficient plants, but substantially enhanced the elongated pale phenotype of the phyB1 mutant. This redundancy was also seen in the control of de-etiolation under continuous red light (R), where the loss of phyB2 had no detectable effect in the presence of phyB1. Under continuous R, phyA action was largely independent of phyB1 and phyB2 in terms of the control of hypocotyl elongation, but antagonized the effects of phyB1 in the control of anthocyanin synthesis, indicating that photoreceptors may interact differently to control different traits. Irradiance response curves for anthocyanin synthesis revealed that phyB1 and phyB2 together mediate all the detectable response to high-irradiance R, and, surprisingly, that the phyA-dependent low-irradiance component is also strongly reduced in the phyB1 phyB2 double mutant. This is not associated with a reduction in phyA protein content or responsiveness to continuous far-red light (FR), suggesting that phyB1 and phyB2 specifically influence phyA activity under low-irradiance R. Finally, the phyA phyB1 phyB2 triple mutant showed strong residual responsiveness to supplementary daytime FR, indicating that at least one of the two remaining phytochromes plays a significant role in tomato photomorphogenesis.

Base Sequence↗
PubMed1989

Rapid effects of red light on the isopentenyladenosine content in scots pine seeds.

Red light (R) stimulates germination in Scots pine seed (Pinus sylvestris L.). The response is far red (FR) reversible. The dynamics of cytokinin changes following light treatment was investigated. Extracts were purified by immunoaffinity and high performance liquid chromatography. N(6)-(Delta(2)-Isopentenyl) adenosine (iPA) and trans-zeatin riboside (ZR) were quantified by both UV-absorbance of high performance liquid chromatography peaks and by enzyme-linked immunosorbent assay. Identification of iPA was accomplished by gas chromatography-mass spectrometry. Levels of cytokinins were low in seeds imbibed in the dark. Exposure of seeds imbibed in the dark for 5 hours to R for 15 minutes induced a strong, immediate but transitory increase in iPA content. This increase was not observed when the R treatment was followed by 10 minutes of FR or by storage in darkness before extraction. No ZR was detected during the first 8 hours of imbibition in any treatment. Addition of iPA via acetone enhanced seed germination in the dark. The results suggest that iPA may be involved in the R-mediated release of dormancy of Scots pine seed.

Journal Article↗
PubMed2003

Cognitive impairment in patients suffering from relapsing-remitting multiple sclerosis with EDSS < or = 3.5.

OBJECTIVES: Previous papers have mainly demonstrated the presence and the frequency of cognitive impairment in patients suffering from relapsing-remitting multiple sclerosis. The purpose of this study was to investigate subjects with the relapsing-remitting form of the disease and mild clinical disability (EDSS < or = 3.5), so as to quantify this deficit when the illness does not yet interfere with daily living and the ability to work. METHODS: Fifty patients and 50 healthy controls were submitted to a wide neuropsychological battery, including Wechsler Memory Scale I- (WMS), Benton Visual Retention Test D- (BVRT), Raven Coloured Progressive Matrices (RCPM), Kohs' test (KT), Judgement of Lines Orientation H- (JLO), Facial Recognition (FR) and Aachner Aphasie Test (AAT). They also underwent Clinical Depression Scale (CDQ) and State-Trait Anxiety Inventory (STAI). RESULTS: The results show the presence of significant memory impairment on both WMS (P = 0.000) and BVRT (P = 0.000) in patients compared with controls. Patients were also impaired in abstract reasoning and problem-solving deficit (KT P = 0.003; RCPM P = 0.000) and in FR (P = 0.019). Cognitive decline correlated with illness duration (r = 0.761), but was independent of EDSS (r = 0.085). CONCLUSION: Cognitive decline was present even when physical disability was not yet severe, but it was mild and did not limit patients' ability to work. The cognitive impairment outlined was of the subcortical type and correlated with illness duration. This study emphasizes the importance of cognitive examination in clinical practice. It is suggested that a complete neurological examination include tests on memory and abstract reasoning.

Adult↗
PubMed1973

Anatomy and innervation ratios in motor units of cat gastrocnemius.

1. Muscle fibres belonging to single motor units of identified type were studied in frozen sections of cat medial and lateral gastrocnemius muscles. Reconstruction of the distribution of fibres in individual units showed that the territories of all three physiological types present in the cat medial gastrocnemius were quite extensive. Within its territory, fibres belonging to the studied unit were distributed more or less uniformly without localized collections. The density of unit fibres suggests that, in cat medial gastrocnemius, a given region of the muscle may be shared by as many as fifty different muscle units.2. Direct determination of innervation ratios in identified muscle units required complete reconstruction of the three-dimensional distribution of unit fibres within the whole medial gastrocnemius. Satisfactory results were obtained with two type FF units and one type FR unit.3. Indirect estimates of the average innervation ratios expected for muscle units of different physiological type were obtained using counts of muscle fibres with characteristic histochemical profiles and data on relative frequencies of motor units of known type in the medial gastrocnemius unit pool. Such indirect estimates of innervation ratios agreed with the results of direct fibre counts in identified units for types FF and FR muscle units. Taken in sum, the available evidence suggests that an average muscle unit in the cat medial gastrocnemius contains between 400 and 800 muscle fibres, irrespective of physiological type.4. Tension production by single muscle units depends on a number of factors, including innervation ratio, the cross-sectional areas of unit fibres and the specific tension outputs of the unit fibres. The present results suggest that the specific tension output of gastrocnemius type S unit muscle fibres is considerably smaller (about 0.6 kg/cm(2)) than in either FF units (about 1.5-2.0 kg/cm(2)) or type FR units (2.6-2.9 kg/cm(2)).

Adenosine Triphosphatases↗
PubMedDate not supplied

Evaluation of the local effects of vitamin E (E-Mousse) on free radicals in diabetic microangiopathy: a randomized, controlled trial.

The aims of the study were to evaluate the short-term effects of a new thermosensitive, vitamin E (V-E) mousse on local free radicals (FR) and skin flux in diabetic microangiopathy. A group of 40 patients with diabetic microangiopathy was included. The variation in measurements of skin FR was evaluated by the D-Rom test. Subjects were between 45 and 65 years with type II diabetes and good metabolic control. E-mousse, a thermoactive preparation of acetate vitamin E (20%), was applied twice daily on the whole surface of the leg (below knee) and foot for 3 weeks. The contralateral leg was untreated acting as control. Subjects with age between 45 and 65 years with type II diabetes (diagnosed at least 5 years before) and good metabolic control (blood sugar < 180 mg/dL) were included after informed consent. Patients with uncontrolled diabetes, peripheral vascular disease, and severe lower limbs infections were excluded. Local free radicals (FR) and laser Doppler flux including the venoarteriolar response (VAR) were evaluated. The tolerability was evaluated by a semiquantitative score. Of the 40 included patients 34 completed the study. The 2 groups were comparable. At 3 weeks there was no decrease in FR in controls; the decrease in the treatment group was 45.3% (p < 0.05). Also in the treatment group RF decreased (p < 0.05) and the VARveno improved from an average of 21% to an average of 38% (p < 0.05). No significant variations were observed in the control group. The variation in symptomatic score was from a total value of 8 to 5 in the control group and from 8 to 1 in the treatment group (p < 0.02). Their tolerability was good. In conclusion local treatment with E-mousse for 3 weeks in diabetic microangiopathy improves skin microcirculation and the metabolic condition as shown by the decrease in FR.

Administration, Topical↗
PubMed1997

Corticosteroids significantly delay the onset of docetaxel-induced fluid retention: final results of a randomized study of the European Organization for Research and Treatment of Cancer Investigational Drug Branch for Breast Cancer.

PURPOSE: To confirm the efficacy of docetaxel in patients with breast cancer previously treated with one chemotherapy regimen for advanced or metastatic disease and to compare the incidence of fluid retention (FR) and skin toxicity when docetaxel is administered with and without prophylactic corticosteroids. PATIENTS AND METHODS: Eighty-three patients, pretreated with one chemotherapy regimen for metastatic breast cancer (MBC) with bidimensionally measurable and progressive disease, were eligible for this randomized trial. Docetaxel with prophylactic oral antihistamine was administered at a dose of 50 mg/m2 as a 1-hour infusion on days 1 and 8 every 21 days and patients were randomized to receive methylprednisolone (40 mg days -1, 0, 1, 7, 8, and 9 of each cycle) (arm A) or no methylprednisolone (arm B). RESULTS: Twenty-eight patients (34%, 95% confidence interval [CI], 23% to 45%) achieved on objective response. The median time to disease progression and median overall survival time were 5 and 13.5 months, respectively. In total, 415 cycles of docetaxel were administered (arm A: N = 219, median = six; arm B: N = 196, median = five). The most common toxicity observed was grade 3 or 4 neutropenia, which occurred in 79% of patients. Clinically significant nonhematologic side effects included skin reactions and asthenia. In an intent-to-treat analysis, patients who received methylprednisolone premedication had a delayed onset of FR (median time to onset of FR: arm A, 84 days; arm B, 62 days; P = .01) and received a higher median cumulative dose of docetaxel before the onset of FR (arm A, 333 mg/m2; arm B, 215 mg/m2; P = .001). There was no statistically significant difference in the incidence of skin toxicity between the two arms. CONCLUSION: Docetaxel, at this dose and schedule, has definite antitumor activity in pretreated MBC patients. Moreover, this is the first randomized trial to show that corticosteroids have a favorable impact on docetaxel-induced FR.

Adult↗
PubMed1975

Influence on adipocyte plasma membrane bound protein kinase by feedback regulator.

Protein kinase, phosphodiesterase and adenylate cyclase of plasma membrane of adipocytes and the effect of the feedback regulator (FR) on these three enzymes was measured and compared. The basal level ratio of adenylate cyclase to phosphodiesterase to protein kinase was 1:1.9:3.0. Epinephrine and/or FR alters this ratio. FR stimulated protein kinase activity up to 3 fold in the presence of a wide range of enzyme concentrations, 5-50 mug membrane protein/tube. The concentration of FR effective for stimulation of membrane protein kinase was much greater than that needed for inhibition of adenylate cyclase and phosphodiesterases. The inhibition by FR on adenylate cyclase was the most potent effect among the 3 enzymes. 1 U (or 2 U/ml) of FR inhibited 50% of the adenylate cyclase activity in a defined system. The maximum effective concentration of FR for stimulation of membrane protein kinase was greater than 10 U/ml. Histone type 11A was the best substrate for protein phosphorylation so far observed. The FR stimulatory effect was observed at all substrate concentrations used ranging from 1-5 mg/ml. A NaF concentration curve shows that 15 mM NaF gave maximum phosphorylation. The stimulatory effect of FR was observed both in the presence and absence of NaF. Protein kinase of adipocyte plasma membrane was mainly cAMP-independent. The effect of FR (20 U/ml) in stimulation of protein phosphorylation was much greater than that of cAMP (1 X 10(-6) M). The cAMP and FR effects seemed to be additive. Preincubation of plasma membrane with FR in the absence of ATP resulted in no decrease but slight increase in protein kinase activity. A shift in protein kinase, phosphodiesterase and adenylate cyclase ratios by FR suggests the regulatory role of FR in cAMP metabolism in adipocytes.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1984

[Echocardiographic study of the left ventricular mass-dilatation ratio in hypertensive disease].

The object of this work is the exhaustive interpretation of 52 echocardiograms of hypertensive African subjects. The following parameters were measured on the echocardiogram: Dd (left ventricular end diastolic dimension), Ds (left ventricular end systolic dimension), DSd (interventricular end diastolic dimension), DEd (left ventricular posterior wall end diastolic thickness). Left ventricular performance was evaluated with the calculated Vcf, FR (fractional shortening) and EF (ejection fraction). A ratio "R" was estimated as he ratio of the left ventricular mass (MVG) measured with Bennett's formula: [(Dsd + DEd + Dd)3-Dd3] x 1,05] to the left ventricular end diastolic dimension. A carotid pulse and phonocardiogram were simultaneously recorded and systolic time intervals were measured and corrected for heart rate, using regression equations corresponding to African subjects. The analysis of the "R" ratio has led us to put forward a new concept of the progression of the hypertensive cardiomyopathy. It has been shown, in this study, that the hypertensive heart becomes hypertrophic, even under treatment and after return of blood pressure to normal. It appears that hypertrophy is a reaction tending to keep normal or almost normal the telediastolic left ventricular dimension and consequently to prevent left ventricular dilatation. This can be explained by the tendency of myocardial hypertrophy to reduce wall stress and oxygen consumption. The analysis of the correlation between MVG and Dd (good), TAM (mean arterial blood pressure) and Dd (poor) and TAM and MVG (nil) has les us to the conclusion that the stimulus to hypertrophy lies in the left ventricular dilatation.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomegaly↗
PubMed1999

Determinants of hip and knee flexion range: results from the San Antonio Longitudinal Study of Aging.

OBJECTIVE: We analyzed data from the San Antonio Longitudinal Study of Aging, a neighborhood-based study of community-dwelling elderly people, to identify factors that determine the flexion range (FR) of hips and knees. METHODS: The FR of hips and knees was measured in a cohort of 687 subjects aged 65 to 79 years. We used multivariate models to examine the associations among the FR of hips and knees, and between these and age, gender, ethnicity, body mass index (BMI), pain and its location, self-reported arthritis, and diabetes mellitus. The functional relevance of hip and knee FR was tested by measuring its association with 50-foot walking velocity. RESULTS: More than 90 degrees of flexion in both hips and both knees was observed in 619 subjects (90.1%). Correlations among the FR of hips and knees ranged from 0.54 to 0.80 (P < 0.001 for Spearman r values). Multivariate analysis revealed a pattern of significant associations between each of the joints and its contralateral mate and ipsilateral partner joints that was consistent for both hips and both knees. Using each individual joint as the unit of analysis, the following variables were independently associated with hip or knee FR in multivariate models: rising BMI and female sex with reduced FR of both hips and knees, a Mexican American ethnic background with decreased hip FR, and knee pain with decreased knee FR. The functional importance of the FR of these two important joints was supported by its significant association with walking velocity in a model that adjusted for age, gender, ethnic background, BMI, and hip or knee pain. CONCLUSIONS: Most community-dwelling elderly people have a FR of hips and knees that can be considered functional. The ipsilateral and contralateral hip or knee are significant independent determinants of the FR of each of these joints. Obesity, a health problem potentially amenable to preventive and therapeutic interventions, is a factor significantly associated with decreased FR of hips and knees.

Aged↗
PubMed1994

Two distinct non-T helper type 2 interleukin-4+ cell subsets in mice as revealed by single-cell cytokine analysis.

We have previously defined four murine CD4+ peripheral T cell subsets, fractions (Fr.) I-IV, based on expression of the 6C10 and 3G11 determinants (Hayakawa, K. and Hardy, R. R., J. Exp. Med. 1988. 168: 1825). These subsets also show distinctive levels of other cell surface markers: the two minor subsets, Fr. III and Fr. IV, are both CD45RBlow/-, L-selectin (Mel-14)- and CD44hi, characteristic of secondary T cells. The patterns and levels of cytokine production by individual cells in each subset were determined by bioassay for interleukin (IL)-2/IL-4 or IL-4/interferon (IFN)-gamma production after anti-CD3 stimulation. Our data revealed that these four phenotypically defined subsets largely coincide with clusters of cells showing uniform distinctive cytokine profiles, i.e. IL-2+/IFN-gamma-/IL-4- (Fr. I and Fr. II, L-selectin+), IL2+/IFN-gamma +/IL-4+ (Fr. III, L-selectin-), and IL-2-/IFN-gamma low/-/IL-4+ (Fr. IV, L-selectin-). Besides these subsets, an L-selectin-negative cell subfraction within Fr. II appears to represent a transitional population between the IL-2+/IFN-gamma-/IL-4- stage and the IL-2+/IFN-gamma +/IL-4+ stage. Taken together, these results demonstrate the presence of two IL-4+ secondary T cell subsets with distinct cytokine production patterns, and show that the majority of IL-4+ cells found in healthy adult laboratory mice co-produce IFN-gamma, and thus are not typical T helper type 2 cells.

Animals↗