PubMed Health⌕ Search

Biomedical subjects

J F Merlen

Publications and source records attributed to J F Merlen.

At least 19 recordsLinked to original sources
PubMed1989

[The value of studying the ocular conjunctiva in case-finding in prediabetic states].

Capillaroscopy, the only method available for the study of the microcirculation, without modifying its hydraulics, often provides a wealth of information in certain systemic diseases in which the microcirculatory involvement precedes clinical manifestations and of course, macrovascular complications. The prospective study of a healthy population is particularly demonstrative and the authors proposed scores on which diabetic microangiopathy could be suspected. The latter was confirmed by detailed laboratory investigations on one hand, and by the course of the disease on the other. For this reason, any subject at risk of diabetes should undergo at least one annual capillaroscopic examination of the ocular conjunctiva or if not, of the peri-ungual region. Furthermore, the study of microvessels in subjects with controlled and treated disease showed a regression of the anomalies which depended on proper control of diabetes, and this particularly nontraumatic test procedure which can be repeated and provides a wealth of information, can give a good reflection of proper therapeutic control, especially if it is performed by a trained and experienced investigator.

Capillaries↗
PubMed1979

[Successive encephalic ischemic accidents in a young patient: Buerger's disease, buergerian syndrome, or juvenile atheroma? A report in clinical, angiographic, and anatomical findings in one case, compared to three other ones, in which a biopsy of the pulp of the toes was also performed (author's transl)].

A man of 19 years of age was found to have a diffuse livedo, a quadruple asphyxic acrosyndrome, and dementia. Angiography confirmed the presence of distal ischemia with multiple circulatory blocks and a reduced distal network. The patient died at the age of 25 years and histopathological examinations of the vessels demonstrated obstructive atheromatous lesions in the medium sized and small arteries of the brain and viscera. By comparing these findings with those observed in three other cases, in which biopsy of the pulp of the toe was also performed, the hypothesis can be advanced that these juvenile encephalic ischemic accidents are caused by atheroma, which can be detected, at an early stage, by studying the distal arteries in the finger or toe pulp.

Adult↗
PubMedDate not supplied

[The physiology of microcirculation].

Since the work of Harvey and Malpighi, there have been more questions than answers in the physiology of the microcirculation. The microvessels and the interstitial connective tissue form a true functional and structural unit in which the capillary is only a passive feature. It is subject to the constraint of the connective tissue that surrounds it, is only a reflection of the hydraulic conditions above and below it and is a luxury metabolic pathway compared with the importance of the derivative or shortcircuit arteriovenous pathway in which the metarteriole is of major importance. Continual renewal, apparent vasomotor character, and extreme permeability sum up the physiology of the microcirculation. The cybernetics is dominated by the arteriolo-venular functioning and by chain rections. Stasis, the opening of arterio-venous anastomoses, and sludge are the main pathological features. Investigation of capillary function remains difficult under clinical conditions, since different methods give a global picture, that of the vascular-tissue unit.

Capillaries↗
PubMedDate not supplied

[Calcinoses of the leg].

Calcinosis, wherever it appears, is no more than overloading of the conjunctive tissue with calcium. Arterial calcinoses are perhaps the type most frequently recognized : obliterating arteriopathy of middle aged and elderly subjects, arteritis in diabetics, Mönkeberg's arteriosclerosis. Venous calcinoses are either phleboliths, more rarely subcutaneous deposits, or atherocalcinosis of the inferior vena cava, or Cramer and Schilling's lesion. Subcutaneous calcinoses that appear to be nonvascular may give rise to some diagnostic problems. These concern the pathogenesis : calcium transfer by LERICHE and POLICARD, metaplasia of the conjunctive tissues and the elastic fibres, transformation of lipoproteins, hydraulic disturbances, Selye's calciphylaxia.

Arterial Occlusive Diseases↗
PubMedDate not supplied

[Microcirculation in white atrophy].

There are two clinical phenomena which, owing to the French School, are still subject to violent criticism: the phenomenon described by M. Raynaud (1862) and the white atrophy termed Milian's (1929). Perhaps badly defined by the authors, the facts have been reviewed, but microcirculation - that of gauges less than 30 to 50 m - does not occupy the whole picture. The proof is that in direct capillaroscopy, functional explorations and biopsy are strikingly monotonous and lacking in exactitude. Capillaroscopy provides the usual aspects of cicatrization, "capillary" neogenesis and their histogenic disorders: central avascular zone, corona limited with loops in "club" formation, or in "clusters" owing to their confluence, "key" loops at the periphery near to the normal loops. These "neocapillaries" pose problems of the immaturity of the neovascular elements and of hydraulics in venous stasis. Of course, there are disorders of capillary permeability, and these are linked especially with vascular neogenesis, but it would not be reasonable to speak of "cutaneous infarctus", or "vascularitis", the necessary criteria being absent. On the contrary, we believe that it all comes down to a "histoangiopathy" by deterioration of the pericapillary sheath of proteoglycanes and of the interstitial conjunctiva. The anomalies are of the type of the deteriorations in plastic polymers and the apparatus of the endarterial bloc, which are included. A "trapping" of the leucocytes in the declivitous areas must also play a part.

Atrophy↗
PubMedDate not supplied

[Drug therapy of angiolopathies].

The treatment of angiolopathies is rather difficult, at this time, at least concerning functional angiopathies. It is a fact that protection against cold represents, in all angilopathies, one of the main elements of the treatment besides medications which are essentially vasoactive drugs, myorelaxants or alpha-blockers, and possibly venous tonics. Fluorescein or Sodium fluoresceinate at 5%, administered in slow intra-venous injections, represents one of the best treatment of acrocyanosis, in combination with vitamins A and D, given at the beginning of fall. Other angiolopathies, especially those of organic nature, are represented by allergic vascularitis and will be treated accordingly. In infectious and toxic forms, antibiotics should be prescribed in addition to steroids, preferred in allergic forms, especially granulomatous forms. In conclusion, the treatment of angiolopathies is extremely difficult, and must be particularly adapted to the clinical forms.

Adrenergic alpha-Antagonists↗
PubMedDate not supplied

[Tissue pressure of the leg].

The underlying concepts of the study of subcutaneous and intramuscular tissue pressure, which began in 1952, have been highly modified. Three types of methods are now used: direct needle puncture, the perforated capsule, and the microcatheter. The capsule and the catheter are sensitive to osmotic and hydrostatic tissue pressure, and the needle indicates an interstitial hydrostatic T.P. We prefer the latter method, which allows the total T.P. to be measured.

Catheterization↗
PubMedDate not supplied

[Muscular compartment leg syndrome].

Certain forms of claudication are due to excess tissue pressure of the muscles of the aponeurotic chambers of the leg. These have been well described by Reneman, especially in their chronic form and for the anterior and lateral chambers. The claudication is due to an overworking of the muscles caused by walking, running or effort. It has its own characteristics, with direct measurement of the tissue pressure and phlebography aiding the diagnosis and attention being drawn by the presence of a "muscular hernia of the leg". Fasciotomy is the corrective treatment for cases of hyperalgia and beginning with a certain gradient of muscle pressure. The pathogenic reasons for this are discussed.

Anterior Compartment Syndrome↗
PubMedDate not supplied

[Cellulitis, a conjunctive microvascular disease].

While the term cellulitis is incorrect, it is commonly used and deserves a nosological classification. "Cellulitis is a dermohypodermosis and an oedemato-sclerous panniculopathy- It is indeed a true histangiography in which the fibroblastic reaction predominates over capillaro-veinular changes. Adipocytes of exaggerated size interpenetrate into micro- and later into macronodules marked off by more or less structured conjunctive fibrilla, thereby making treatment difficult.

Cellulitis↗
PubMedDate not supplied

[Hemodynamic relations between capillary and venule].

Following a nosological discussion of the varicose vein, its histological, biochemical and immunological elements are detailed. The hydraulic conditions are described, and attention is drawn to the microvasculartissue consequences of the stasis, the degree of constraint exercised by the interstitial tissue, and the role played by the intricate "micro fiber" network of the microcirculation: only a part of the capillaries reconnect with the veinlet of the same circulatory unit, the others having to flow toward the veinlet of other units and only one initial lymphatic vein contributing to the evacuation of 3 to 4 veinlets. The slightest hydraulic imbalance due to the stasis, sets of a whole series of chain reactions that can rapidly become harmful, with chronic veinous deficiency setting in.

Capillaries↗