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Biomedical subjects

F Perret

Publications and source records attributed to F Perret.

31 records · Page 2Linked to original sources
PubMed1991

Evaluation of arterial compliance-pressure curves. Effect of antihypertensive drugs.

A new high-precision ultrasonic device was developed to determine noninvasively arterial compliance as a function of blood pressure. Because of the nonlinear elastic properties of arterial walls, measurements of compliance can be appropriately compared only if obtained over a range of pressures. This apparatus was used to evaluate in a double-blind, parallel fashion the effect of three different antihypertensive drugs and of a placebo on radial artery compliance. Thirty-two normotensive volunteers were randomly allocated to an 8-day, once-a-day oral treatment with either a placebo, 100 mg atenolol, 20 mg nitrendipine, or 20 mg lisinopril. Blood pressure, heart rate, radial artery diameter, and arterial compliance were measured immediately before as well as 6 hours after dosing on the first and last days of the study. On the eighth day of administration, within 6 hours after dosing, lisinopril induced an acute increase in radial artery diameter, from 2.99 +/- 0.06 to 3.28 +/- 0.09 mm (mean +/- SEM, p less than 0.01). The compliance-pressure curve was shifted upward on day 1 (p less than 0.01) as well as on day 8 (p less than 0.05). None of the other drugs induced any significant modification of these parameters. Arterial compliance has a strong nonlinear dependency on intra-arterial pressure and therefore has to be defined as a function of pressure. Antihypertensive drugs acting by different mechanisms may have different effects on the mechanical properties of large arteries.

Adrenergic beta-Antagonists↗
PubMed1991

[Breast cysts].

The mammary cyst is part of the fibro-cystic disease. Only cysts with a diameter of more than 3 mm would have a pathological significance. Its clinical symptomatology is well known. The clearing puncture is the essential diagnostic and therapeutic act. Mammography, sustained by cystography, furnishes highly worthy information. Thermography and ultra-sonography may also be useful. Its pathogeny is still being very much discussed. Hormonal factors are incriminated: hyperestrogenemia, luteal deficiency, dysprolactinemia are inconstant. They are neither necessary nor sufficient to induce the cystic disease. The titration of TeBG may perhaps open an interesting path for research. The study of intracystic steroids (among which DHEAS) furnishes instructive results. Intracystic glycoproteins, proteins and electrolytes are also the objects of promising research. Recently, the interest lying in the study of EGF, its possible relation to DHEAS and the intracystic Na/K ratio were emphasized. It is also important to notice the presence of cysts with a flat wall or with a hyperplastic wall, of the apocrine type. The psychogenic factors seem to be determining in the cystic flare-ups. The relations with breast cancer remain the fundamental problem. Although the cyst itself only exceptionally degenerates into cancer (cyst-epithelioma), the very presence of a macrocytic disease multiplies by 3 or 4 the risk of cancer. The treatment is composed of psychotherapy, tranquillizers and a clearing puncture of the strained cysts. The administration of phlebotonics, anti-prostaglandins, colostrum extracts, can give substantial results. The author gives details about the part of hormonal treatment as a function of the titrations and the severity of the case. If it appears necessary to block the gonadotropic function, Danazol is a very effective agent. Surgery has but a small place. Indication of subcutaneous mastectomy will rest upon a very severe case-selection.

Adolescent↗
PubMed1989

Need for plasma angiotensin measurements to investigate converting-enzyme inhibition in humans.

Since only a minute proportion of total angiotensin-converting enzyme (ACE) is present in plasma, the reliability of conventional in vitro measurements of ACE activity has been questioned. Data presented here demonstrate that the definition of ACE inhibition depends on the methodology used, with different results obtained with different substrates. We have developed a method that provides accurate and precise determinations of "true" angiotensin levels and in vivo ACE activity was estimated by measuring the plasma angiotensin II/angiotensin I ratio. Since the initial interruption of angiotensin II production by an ACE inhibitor stimulates renal renin release, the response can be quantitated by measuring changes in plasma levels of angiotensin I. The actual state of the renin-angiotensin system during ACE inhibition is represented by the plasma angiotensin II level. When ACE inhibition is no longer complete, increased angiotensin I levels bring the system back toward initial angiotensin II concentrations.

Administration, Oral↗
PubMed1989

Effect of cold pressor test on the internal diameter of the radial artery.

The aim of this study was to investigate in normal subjects the effect of a cold pressor test on the caliber of the radial artery, a muscular artery of medium size. The internal diameter of this artery was measured continuously using a recently developed ultrasonic device. Immersion of one hand in ice water for two minutes increased blood pressure from 115/75 +/- 3/2 (Mean +/- SEM) to 136/90 +/- 6/2 mm Hg (P less than .001) and decreased the internal diameter of the radial artery from 2.82 +/- 0.12 to 2.60 +/- 0.09 mm (P less than .01). These data therefore indicate that the vasoconstriction induced by the cold pressor test involves not only arterioles, but also medium-size arteries.

Adolescent↗
PubMed1989

Ambulatory blood pressure measurement and antihypertensive therapy.

The traditional basis for assessing the effect of antihypertensive therapy is the blood pressure reading taken by a physician. However, several recent trials have been designed to evaluate the blood pressure lowering effect of various therapeutic agents during the patients' normal daytime activities, using a portable, semi-automatic blood pressure recorder. The results have shown that in a given patient, blood pressure measured at the physician's office often differs greatly from that prevailing during the rest of the day. This is true both in treated and untreated hypertensive patients. The difference between office and ambulatory recorded pressures cannot be predicted from blood pressure levels measured by the physician. Therefore, a prospective study was carried out in patients with diastolic blood pressures that were uncontrolled at the physician's office despite antihypertensive therapy. The purpose was to evaluate the response of recorded ambulatory blood pressure to treatment adjustments aimed at reducing office blood pressure below a pre-set target level. Only patients with high ambulatory blood pressures at the outset appeared to benefit from further changes in therapy. Thus, ambulatory blood pressure monitoring can be used to identify those patients who remain hypertensive only when facing the physician, despite antihypertensive therapy. Ambulatory monitoring could thus help to evaluate the efficacy of antihypertensive therapy and allow individual treatment.

Antihypertensive Agents↗
PubMed1988

Non-invasive measurement of internal diameter of peripheral arteries during the cardiac cycle.

An ultrasonic device was developed for continuous monitoring of the internal diameter of human peripheral arteries. The diastolic internal diameter of the radial artery measured in 10 supine normotensive subjects averaged 2.36 +/- 0.12 mm (mean +/- s.e.) and the change in diameter during the pulse wave was 0.037 +/- 0.003 mm. It was surprising to find that when the transducer was used to apply pressure on the radial artery, the difference between the systolic and the diastolic diameter was significantly increased while the diastolic diameter was reduced. This method therefore allows continuous, accurate and non-invasive measurement of the internal diameter of the human radial artery.

Arteries↗
PubMed1984

A French double-blind crossover study (danazol versus placebo) in the treatment of severe fibrocystic breast disease.

The Authors report their experience in a double-blind, crossover study (danazol versus placebo) in 38 patients suffering from severe benign mastopathy. The results were evaluated with regard to clinical data (mastodynia, breast nodularity) and data from comparative infrared thermography. Danazol was given in a dose of 400 mg/day for 3 months. Placebo, in identical packing, was also given for a three month period. In 32 cases out of 38, there was an improvement with Danazol treatment. For some patients, thermography was more precise than clinical part. Side effects consisted predominantly of menstrual disorders recorded in 30 cases and a generally moderate weight gain in 23 cases. In the light of these results it appears that danazol constitutes a powerful agent in the treatment of severe benign mastopathy of the breast. The best dosage and best duration of treatment remain to be specified. Finally, the original contribution of the thermographic document deserves to be underlined.

Adult↗
PubMedDate not supplied

[Hormone replacement therapy in breast cancer patients: a study of 230 patients, with a case-control study].

OBJECTIVES: After recalling the classical contra-indication of hormone replacement therapy (HRT) concerning patients with a personal history of breast cancer (BC), and arguments that may be opposed, the authors report the present results of a prospective study undertaken in the Center of Breast Diseases in Saint-Louis hospital in Paris since February 1992. PATIENTS AND METHODS: By April 2001, 230 patients had been included. A free interval of 2 years at least since the treatment of the primary BC has been observed. The reasons for prescribing HRT were vasomotor troubles (flushes, nightly sweats) or a dyspareunia, which were severe and not controlled by non-hormonal treatments. There was also an indication of a major osteoporotic or cardiovascular danger. In fact, many of these patients had a premature, artificial, chemo-induced menopause. The HRT most often used was an estro-progestin association (estradiol + a progestin compound) given either continuously or with a 5-d interruption each month. The mean duration of treatment was 2.5 years. RESULTS: Results, concerning the improvement of menopause troubles, were remarkable in the great majority of troubles. HRT had to be stopped in 39 cases, reading as follows: 17 cases for relapses (seven local, six in the contro-lateral breast and four metastases (7%)). Also, 22 patients (9%) interrupted their HRT for serious side-effects. A case-control study did not show any significant difference between with and without HRT patients concerning the overall survival without relapse. DISCUSSION AND CONCLUSIONS: Quality of life of patients was often substantially improved, and a deleterious effect on the cancer disease was not found. Our results are in agreement with the literature from other countries. However, one must be cautious. In such circumstances, HRT must be prescribed with the informed consent of the patients and delivered in appropriate hospital and university centers. It is wished that large randomised prospective studies may be undertaken.

Adult↗