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Biomedical subjects

P Gasser

Publications and source records attributed to P Gasser.

At least 55 records · Page 3Linked to original sources
PubMed1991

Video-nailfold-microscopy and local cold test: morphological and hemodynamic correlates in 124 healthy subjects.

Video-nailfold-microscopy in combination with a local cooling test were used to determine morphological and hemodynamic reference values with their variabilities such as sex, age, blood pressure and smoking habits in 124 healthy volunteers. In our non-smoking population (n = 90) neither arterial blood pressure nor age or the sex of the subjects had any significant influence on the morphological or hemodynamic parameters, even after the local cooling test. However, cooling the skin caused in all cases a rapid, temporary decrease in the velocity of blood flow through the capillaries. The small group of chronic smokers (n = 34) showed no sex differences in any of the measured variables even when compared with sex and age matched non-smokers. It may be concluded that video-capillaroscopy, a non-invasive technique, can be used in clinical practice for studying the physiology and pathophysiology as well as the dynamic response to local cooling in microcirculatory diseases of the human skin.

Adult↗
PubMed1990

Exposure to mercury vapor during setting, removing, and polishing amalgam restorations.

The level of mercury vapors in the oral cavity was determined by analyzing 242 samples of intra-oral air before and after removing, setting, and polishing dental amalgam. The analysis was effected using atomic absorption spectrometry in cold vapors with the detection limit of 6 micrograms/m3. A score of 1 to 3 was assigned to each restoration to adjust the differences of the amalgam sizes. The present study showed that the vapor was released during any procedure: removing, setting, and polishing amalgam. The mean levels were between 85 and 326 micrograms/m3. However, before the restorative procedures, no mercury vapors had been detected in the oral cavity. This investigation has also demonstrated a significant direct correlation between Hg vapor concentrations in intra-oral air and the sizes of amalgam restorations during each procedure: removing, setting, and polishing. The statistic analysis showed no significant difference of mercury vapors in the oral cavity between the use or nonuse of water coolant during the amalgam polishing.

Air↗
PubMed1990

Capillary blood cell velocity in finger nailfold: characteristics and reproducibility of the local cold response.

The characteristics and reproducibility of nailfold capillary blood cell velocity (CBV) of the local cold response was evaluated in 30 cases by video-microscopy using a flying-spot technique. CBV, as well as flow stop duration during cooling, from a first and second test was significantly (P less than 0.05) reproducible, whether or not the test was repeated after 60 min or after an interval of 12 weeks. Because of interindividual variations in rest CBV, and a better reproducibility of the flow stop duration, this last parameter is more useful in clinical practice for follow-up evaluations of the local cold response test. The usefulness of the flying-spot generator for rapid and accurate measurement of CBV in finger nailfold capillaries is demonstrated in normal subjects and patients with primary Raynaud syndrome during a local cooling test.

Adult↗
PubMed1990

Development of an automated experimental setup for the study of ionic-exchange kinetics. Application to the ionic adsorption, equilibrium attainment and dissolution of apatite compounds.

An ion-selective electrode and microcomputer-based experimental setup for the study of ionic-exchange kinetics between a powdered solid and the solution is described. The equipment is composed of easily available commercial devices and a data acquisition and regularization computer program is presented. The system, especially developed to investigate the ionic adsorption, equilibrium attainment and dissolution of hard mineralized tissues, provides good reliable results by taking into account the volume changes of the reacting solution and the electrode behaviour under different experimental conditions, and by avoiding carbonation of the solution. A second computer program, using the regularized data and the experimental parameters, calculates the quantities of protons consumed and calcium released in the case of equilibrium attainment and dissolution of apatite-like compounds. Finally, typical examples of ion-exchange and dissolution kinetics under constant pH of enamel and synthetic hydroxyapatite are examined.

Adsorption↗
PubMed1990

Do vasospasms provoke ocular diseases?

Vasospasms in the eye are often combined with digital vasospasms, as can be diagnosed with a nailfold capillaroscopic local cooling test. In 16 patients with a history of cold hands and feet the presence of peripheral vasospasms without any underlying disease was demonstrated by means of nailfold video-capillaroscopy. These patients showed the phenomenologic diagnosis of low-tension glaucoma with visual field defects characteristic of glaucoma even though intraocular pressure above 21 mmHg was excluded. The visual field defects were not homonymous, indicating a prechiasmal location of the vascular disturbance. Ocular vasospasms cause visual field damage that can be aggravated or provoked by cooling one hand in cold water and that often improves after treatment with the calcium channel blocker nifedipine. The results suggest that vasospasms not only are present in Raynaud's disease, migraine, and Prinzmetal's variant angina but also may be an important factor in the genesis of low-tension glaucoma. This is a new finding and may be related to a general vasospastic syndrome.

Adolescent↗
PubMed1989

[Raynaud's syndrome: diagnosis and therapy in general practice].

The vasospastic diseases form an important group of ailments. The recognition of the different types of vasospasms is essential if the physician is to correctly advise and treat. Attention must be paid to the history of attacks of cold hands and feet combined with a predisposition to migraine and hypotension. The high prevalence of migraine, Raynaud's phenomenon. Prinzmetal's variant angina and visual acuity disturbance of ophthalmologically unexplained origin in patients with peripheral vasospasms indicates the existence of a generalized vasospastic disease. There is most often no underlying disease detectable. In cases of unknown origin, supplementary investigations are necessary. The management of vasospastic disorders is still unsatisfactory at the present time. These difficulties reflect the uncertainty in the etiology and pathogenesis of the disorder.

Fingers↗
PubMed1989

Ocular vasospasm: a risk factor in the pathogenesis of low-tension glaucoma.

The typical morphological and consequent functional damage caused by disease entities covered by the term 'glaucoma' is the result of inadequate circulation to the optic nerve fibres, predominantly in the papillary region, as a result of elevated intraocular pressure. The aim of this study is classification of different forms of glaucoma on the basis of blood flow parameters. Physiological and pathophysiological aspects of ocular blood flow and of microcirculation and hemorrheology will be considered and the significance of ocular vasospasm in low-tension glaucoma discussed. The frequent occurrence of vasospasm in the nailfold capillaries and of visual field deterioration after a cold-water test demonstrates that vasospasm is an expression of different underlying phenomena. Our results show that, in patients with ocular vasospasm, treatment with a calcium antagonist brings about a clear reversal of their visual field defects.

Animals↗
PubMed1989

[Magnetic resonance imaging and dentistry].

At the present time, the research in and the utilization of magnetic resonance imaging in odontostomatology remains limited. It appeared interesting to access the advances made in this technic and to attempt an evaluation of the longrange perspectives of MRI in this field. In order to more clearly understand the images produced by this technic, the principles of nuclear magnetic resonance are summarized, followed by an account of the principle applications with respect to the buccal cavity and the temporo-mandibular joints. Studies showing the influence of different alloys used in dentistry on the quality of the nuclear magnetic images remain for the moment, rather limited. MRI of the oropharyneal area permits a glimpse of interesting perspectives such as the detection of tumorous lesions or the visualization of meniscus of the TMJ. Nevertheless, three factors constitute considerable obstacles in the broad utilization of MRI in the field of odontostomatology: the time lapse of image production, the relatively limited special resolution and finally the prohibitive cost of examinations.

Dental Alloys↗
PubMed1988

[The use of calcium antagonists in the treatment of ocular circulation symptoms in the framework of a vasospastic syndrome].

In a number of patients with etiologically unexplained visual field loss, a vasospastic syndrome was found with the aid of capillaroscopic local cooling test on the fingers. After therapy with calcium entry blockers the visual field of the patients with vasospastic syndrome underwent a marked and statistically significant improvement. The control group showed a slight but statistically insignificant tendency towards improvement.

Calcium Channel Blockers↗
PubMed1987

Influence of vasospasm on visual function.

In a number of patients with etiologically unexplained visual field loss, a vasospastic syndrome could be found with the help of a capillaroscopic local cooling test on the fingers. In the patients with proven vasospastic syndrome, the visual field defects were increased after a cold water test and decreased after a therapy with calcium entry blockers. General aspects of the physiology and pathophysiology of the circulation and especially of the circulation in the eye are presented.

Calcium Channel Blockers↗
PubMed1986

Optic neuropathy of Graves' disease. A report of a perimetric follow-up.

Endocrine ophthalmopathy is one of the most common space occupying lesions of the orbit. The optic nerve can be involved to varying degrees in the disease. Marked optic neuropathy may be found in cases with normal visual acuity and normal optic nerve head. Perimetry is, therefore, recommended to diagnose or rule out a neuropathy. A case report will demonstrate that a quick screening perimetry with the Octopus program 07 allows a diagnosis and follow-up of the neuropathy. It is helpful in deciding on therapeutic measures and permits a safe monitoring of the therapeutic effect during the treatment period. The case further demonstrates a very quick recovery of the visual field following radiotherapy.

Combined Modality Therapy↗
PubMed1983

[Authority between discourse and consultation].

Since the turn of the century the practice of general upbringing has been shaken by a number of authority crises. In this field a new way is currently being paved in the comprehension of education in which the authoritative powers are limited to two directions: on one hand to discussion (discourse) between equal partners and on the other hand in counselling that neither binds nor obliges. Authority lies between discussion and counselling: it must materialize as a social, communicative and identity-promoting competent form of action.

Authoritarianism↗