Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FLASH”

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 1,009 records · Page 56Linked to original sources
PubMed1980

[Electron spin resonance of electron transport in photosynthetic systems. IX. Temperature dependence of the kinetics of P700 redox transients in bean chloroplasts induced by flashes of different duration].

The temperature dependence of the kinetics of P700 redox transients in bean chloroplasts was studied. The flashes of white light with different duration (7 microseconds, 0.5 and 0.75 ms) were fired simultaneously with the background continuous far red light (lambda max = 707 nm). It was shown that the rate of P700+ reduction was temperature dependent and increased with the rise of the concentration of the reductants in the electron transport chain between photosystems. Photosystem 2 donates electrons to P700+ at temperatures from -5 to 45 degrees C under various modes of flash illumination. Experiments with spin labels showed that there were correlation between the physical state of lipids in the chloroplasts membrane and the rates of different steps of electron transport from photosystem 2 to photosystem 1--plastoquinone reduction by photosystem 2 and plastoquinol oxidation by photosystem 1. We assume that the rates of electron transport reaction of the plastoquinone shuttle are controlled by diffusion of plastoquinone and plastoquinole in the hydrophobic part of the thylakoid membrane. Additional evidence in support of that proposal was obtained from the temperature dependence of light induced spin label reduction which occurred due to its interaction with the plastoquinol of plastosemiquinone.

Chlorophyll↗
PubMed1983

Flash and pattern VEPs: examples of cases of hysterical amblyopia and provoked visual impairment (Uhthoff's sign).

The diagnostic application of averaged visual evoked potentials (VEPs) is illustrated in the investigation of hysterical amblyopia and multiple sclerosis. Averaged VEPs elicited either by a flash of light or a presentation of a grating lasting 100 ms were recorded from the occiput of patients. All the VEPs in hysterical amblyopia were normal. In multiple sclerosis the flash VEPs looked normal for both eyes, whereas the VEPs elicited by grating (2 and 5 c/deg) showed an increase in the latency of the first positive wave, again for both eyes. After physical exercise the VEPs from the right eye were dramatically reduced in amplitude (Uhthoff's sign).

Adolescent↗
PubMed1994

Duchenne muscular dystrophy: negative scotopic bright-flash electroretinogram but not congenital stationary night blindness.

Patients with Duchenne muscular dystrophy (DMD) have recently been reported to have an abnormal scotopic electroretinogram (ERG) showing weak rod-related responses along with a negative configuration of the bright-flash response, which has been described as being similar to the one in congenital stationary night blindness (CSNB). We compared qualitatively and quantitatively the ERGs of 6 subjects with DMD, 10 subjects with the complete form of CSNB (cCSNB), 13 subjects with the incomplete form of CSNB (iCSNB) and 1 subject with complex glycerol kinase deficiency (CGKD). The rod-related activity and the bright-flash responses were abnormal and similar in all four groups. The cone-related activity, however, was within normal limits only in the DMD group; the b-wave was subnormal in CGKD, truncated in cCSNB and nearly absent in iCSNB. The electrophysiologic signature in DMD clearly distinguishes the retinal function of these patients from any other retinal condition so far described.

Adolescent↗
PubMed1994

Duchenne muscular dystrophy: negative scotopic bright-flash electroretinogram and normal dark adaptation.

Recent reports indicate that most subjects with Duchenne muscular dystrophy (DMD) have a negative scotopic bright-flash electroretinogram (ERG). We performed dark adaptometry in seven patients with the DMD phenotype. Three patients had the negative bright-flash response combined with severely reduced rod-related activity; their mean psychophysical dark-adapted threshold was -5.5 +/- 0.3 (normally -5.4 +/- 0.3) cd.m-2. Two of the three patients were able to sit through the complete test: the profile of their dark adaptation curve was normal. The four other patients had a normal scotopic ERG, and their mean psychophysical dark-adapted threshold was -5.3 +/- 0.3 cd.m-2. One of the four was able to complete the entire procedure, and a normal profile was found. In patients with DMD the dark adaptation measurements are normal despite abnormalities in rod-related ERG activity.

Adolescent↗
PubMed1994

Hot flashes--physiology, hormonal therapy, and alternative therapies.

Hormone replacement therapy should be discussed with every postmenopausal woman and should be the first therapy offered to treat hot flashes owing to its high efficacy and other beneficial properties. Women who are ineligible for or uncomfortable with estrogen replacement therapy and who suffer from hot flashes that interfere with the quality of life should be offered other regimens as discussed in this article.

Adrenergic alpha-Agonists↗
PubMed1993

[The clinical use of steady-state flash visual evoked potentials].

The authors applied 30Hz flash stimuli to record steady-state flash visual evoked potentials (FVEP) and extracted the amplitudes and phases of the first and second harmonics as the characteristic value by discrete Fourier transform (DFT). 46 normal controls (89 eyes) and 78 patients (109 eyes) were detected and analysed by this method. The result showed that the characteristic values of the normal controls are significantly different in three age groups and showed the positive in 35 eyes with the optic never diseases (82.9%), 25 eyes with age-related macular degeneration (92%), and 9 eyes with retinal detachment involved macular (100%). It indicates the method is a sensitive index to evaluate the macular visual function. After preliminary observation, the visual acuities of postoperation were found above 0.4 in cataracts (28 eyes) or opacities (12 eyes) if preoperative FVEP were normal and non-complicated, or less than 0.4 if preoperative FVEP were abnormal. This suggests the method is one of the effective index to detect the postoperative vision of the media opacities. The advantages, disadvantages and the clinical applications were discussed.

Adolescent↗
PubMed1993

[The assessment of blue mechanism by measuring the threshold versus intensity curve under flashed background].

The threshold versus intensity curve with brief blue stimuli with a flashing background of the same wavelength was measured in normal subjects and subjects with several kinds of optic nerve and retinal diseases. In young normal subjects the threshold curve rose sharply away from the line measured under the same conditions but without flashing blue background, as has been reported in measurements with light of long wavelengths. In the convalescent stage of optic neuritis, diabetic retinopathy, and central serous chorioretinopathy, the threshold curves presented two patterns; one pattern was shifted upward and the other shifted upward and to the right. We suggest that this method with short wavelength light is useful in differentiating retinal diseases from the change of optic media, and for layer-by-layer diagnosis of retinal diseases.

Adult↗
PubMed1996

[Hot flashes and hormonal treatment of prostate cancer].

Androgen suppression in the context of the treatment of prostatic cancer is responsible for hot flashes in 75% of patients, which alter the quality of life to varying degrees depending on the patient. They constitute a source of major discomfort in 30 to 40% of patients. The pathophysiology of this effect is now known and involves: sex steroids, central opiates and intrahypothalamic catecholamines. The incidence of hot flashes appears to vary according to the type of hormonal treatment administered. The various treatments available are not equally effective. Non-hormonal treatments are of little value. Hormonal treatments: oestrogens and steroidal antiandrogens are the most effective. Progestogens also appear to be just as effective or even more effective than these other agents, with negligible adverse effects at the doses used in this indication.

Androgen Antagonists↗
PubMed1996

[Lateralization in dissociated vertical deviation with flash visual evoked potentials].

Lateralization, suggesting misrouting of optic nerve fibers in albinism, was examined by the flash visual evoked potentials (flash VEP) test in dissociated vertical deviation (DVD). Eighteen cases of DVD were studied and compared with 5 cases of X-recessive ocular albinism and 4 normal controls. Full-field monocular and binocular stimulation was employed with electroencepharograph electrodes on O1 and O2 (10/20 system), and the latency of P100 was statistically analysed with two-way analysis of variance. The difference in the P100 latency between contralateral and ipsilateral stimulation was significant (p < 0.05) in albinism, but not in DVD and normal controls. Therefore, DVD is probably not associated with misrouting of optic nerve fibers.

Adolescent↗
PubMedDate not supplied

Alternatives to estrogen for the treatment of hot flashes.

Postmenopausal women experiencing hot flashes in whom estrogen replacement is contraindicated have alternatives available to them; however, there is no clearly defined treatment modality. The literature addressing many of these alternatives has serious limitations, which include the small number of women enrolled and lack of comparative studies between agents. Each patient needs to be assessed in terms of her current medical status, concomitant medications, and the degree to which vasomotor instability interferes with everyday activities. The literature suggests that megestrol acetate 20 mg bid may provide significant relief. Women who opt to use megestrol acetate must be told in advance that the effects will not be felt immediately particularly if tamoxifen is used concomitantly. Clonidine and medroxyprogesterone may constitute potential alternatives, but patients may not be able to tolerate the adverse effects. Because of the lack of literature supporting their clinical use, options such as vitamin E and ginseng need to be approached cautiously. Exercise has a role in alleviating some of the complications associated with menopause, such as heart disease and osteoporosis, but its effect on neurotransmitters and hormone concentrations, and how this relates to the treatment of hot flashes have not been characterized. Patients should be told that regular physical activity, a balanced diet, avoidance of alcohol and caffeine, and stress reduction may be of additional help in decreasing vasomotor flushing.

Adrenergic alpha-Antagonists↗
PubMed1996

Follow-up studies on the usefulness of the flash visual evoked potential.

Thirty patients with possible demyelinating disease or visual system disorder were referred for Visual Evoked Potentials (VEP) and had abnormal flash (FL) but normal pattern reversal (PR) responses. Patients with confirmed organic brain disorders had significantly longer latencies to P100 from FL than in the unconfirmed group, but the subgroup, later proven to have demyelinating disease had the most significantly abnormal latencies to FL. Even the PR responses, although within normal limits, showed significantly longer latencies in the organic brain disorder group, compared to the unconfirmed group. For patients who could be followed-up, 45% of them proved to have demyelinating disease. A visual disorder was confirmed in 53% and an organic brain disorder in an additional 13%, so that 2/3 of all patients had one of the latter two conditions. These data argue for the use of flash, in addition to the pattern reversal stimulus, in the protocol for visual evoked potentials.

Demyelinating Diseases↗
PubMed1998

Air- and bone-conduction brainstem auditory evoked potentials and flash visual evoked potentials in cats.

OBJECTIVE: To document normal values for air- and bone-conducted brainstem auditory evoked potentials (BAEP) and for flash visual evoked potentials (VEP) in cats. ANIMALS: 10 mixed-breed cats (5 males) with normal physical, neurologic, otoscopic, and funduscopic examination results. PROCEDURE: BAEP in response to air- and bone-conducted click stimuli and VEP in response to flash stimuli were recorded to document species normative data. Mean and SD values were calculated for amplitudes and latencies of 4 peaks in the BAEP in response to air- and bone-conducted stimuli, and for latencies to 5 peaks and the 4 associated peak-to-peak amplitudes in the VEP. RESULTS: BAEP peak latencies increased and peak amplitudes decreased with decreasing stimulus intensity. Latencies were shorter for bone-conducted stimuli owing to the shorter transit time to the cochlea through bone, compared with air, but there were no differences for interpeak latencies. The BAEP and VEP recordings were similar to those reported for cats in other reports and were similar to those seen in other species. CLINICAL RELEVANCE: Normative data will permit performance of noninvasive electrodiagnostic evaluation of feline auditory and visual systems.

Acoustic Stimulation↗
PubMed1998

Monopolar electrosurgical flash fire.

A 78-year-old man underwent ectropion repair with a monopolar electrosurgical unit. A flash fire occurred, resulting in a loss of eyelashes of the left upper and lower eyelids. A retrospective analysis of the case was conducted, including a review of the relevant literature. Although rare, the possibility of a flash fire should be considered when performing surgery with an electrosurgical unit. Minimizing supplemental oxygen and electrosurgical power settings may help to avoid such an incident.

Aged↗
PubMed1998

[Flash echo imaging].

Ultrasound transmission sometimes limits the lifetime of microbubble-based contrast agents. At this time, a very large echo signal (like a flash) is obtained for the initial transmission of the ultrasound after several seconds' suspension. Flash Echo Imaging (FEI) is a new technique which uses the signals of the bubble's collapse. This paper explains a principle of FEI and functions of the FEI's application for ultrasound diagnostic system. It is also shown that perfusion of the tissue can be visualized by using FEI methods.

Animals↗
PubMed2004

Postmenopausal estrogen for treatment of hot flashes: clinical applications.

Use of postmenopausal estrogen has changed since the release of the first results from the Women's Health Initiative in 2002. Professional organizations, the US Food and Drug Administration, and the US Preventive Services Task Force have issued new recommendations against use of estrogen and progestin or progesterone for prevention of chronic conditions. This article applies the current state of evidence for postmenopausal estrogen use to management decisions in 2 clinical scenarios initiating therapy in a perimenopausal woman with hot flashes and discontinuing estrogen use in a long-term user.

Climacteric↗
PubMed2004

[Selective serotonin reuptake inhibitors (SSRIs) antidepressants use in hot flashes in oncology].

INTRODUCTION: Menopausal women or patients treated by chemotherapy or hormonotherapy for breast cancer have often disabled hot flashes. Men with prostate cancer confronted to castration can also suffer from the same problem. In both situations, many arguments go against implementation of estrogenic treatment. Albeit, many complementary therapeutics exist, they are often unsatisfying. CURRENT KNOWLEDGE AND KEY POINTS: Since some years, anecdotal case reports and controlled studies have reported interest of selective serotonin reuptake inhibitors (SSRIs) antidepressants in this indication. These treatments often appear efficient and well tolerated. FUTURE AND PROJECTS: Through a review of literature and clinical vignette, we will specify physiopathology and prescription modalities in this new type of indication.

Female↗
PubMed2006

Pilot evaluation of selective serotonin reuptake inhibitor antidepressants in hot flash patients under androgen-deprivation therapy for prostate cancer.

PURPOSE: Hot flash (HF) is a common side effect in prostate cancer patient undergoing androgen-deprivation therapy (ADT). In this study, we evaluated the efficacy of paroxetine (selective serotonin reuptake inhibitors (SSRIs)) for HF. PATIENTS AND METHODS: In total, 10 men with prostate cancer under ADH who were suffering with HF entered this study. Self-report questionnaire was used for the evaluation. RESULTS: The average rating for HF frequency decreased (P=0.009) and HF severity decreased (P=0.0332) also, reported QOL score increased (P=0.0218). CONCLUSION: These preliminary data suggest that low dose (10 mg/day) of antidepressant paroxetine can be helpful in the treatment of HFs in patients under ADT for prostate cancer. Further controlled studies are needed to more fully evaluate the efficacy of the SSRIs.

Aged↗