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Biomedical subjects

A Behar

Publications and source records attributed to A Behar.

At least 19 recordsLinked to original sources
PubMed1991

Increased capillary permeability to albumin and diabetic neuropathy.

An increase in the capillary permeability to albumin (CPA) has been reported in diabetic patients. We observed this frequently with a non-invasive isotopic test derived from the Landis method, using 99mTc-albumin and measuring residual radioactivity externally after removal of forearm venous compression. Evidence of the independent effects of hypertension and microangiopathy on CPA has already been found. The present work was designed to investigate CPA using the same test on diabetic patients without retinopathy and clinical proteinuria. Some of these patients had objective clinical distal and symmetrical polyneuropathy. Neuropathy was clearly present in 10 of the 11 patients with an abnormal test unexplained by causes other than diabetes and in only one of the 17 patients with a normal test. The most frequent abnormality affected the late radioactivity disappearance curve, which probably reflects an impaired lymphatic wash-out of interstitial albumin. These results strongly suggest a link between peripheral neuropathy and diabetic functional microangiopathy. An elevated blood flow secondary to sympathetic nerve failure may induce an increase in CPA and a saturation of lymphatic pumping which could also be deficient due to impaired lymphatic innervation.

Adult↗
PubMed1990

[Malignant angioendotheliomatosis].

Malignant angioendotheliomatosis is one of the terms used to describe the appearance of neoplastic cells resembling endothelium within the lumen of small and medium-sized blood vessels, mainly in the cerebral and meningeal vascular beds. A fatal systemic disease with dementia as the leading neurological manifestation may be associated with these pathological findings. Only recently has it become evident that this disease is a unique intravascular form of large cell lymphoma, affecting mainly the cerebral blood vessels but also present in the lumen of many small and medium-sized blood vessels in the systemic circulation.

Blood Vessels↗
PubMed1990

The high, medium, and low method--a better noise reduction rating?

This paper compares hearing protector attenuations calculated using National Institute for Occupational Safety and Health (NIOSH) method No. 1 ("long method") and the HML method. The study was done on 144 combinations of 12 noises and 12 protectors. In each case, the attenuation was calculated using each of the above methods. The difference between attenuations was used to define the accuracy of the high, medium, and low (HML) method. It was found that the attenuations calculated using the HML method are almost always lower than those calculated using the NIOSH method. However, the differences between both attenuations are well within the field noise level measurement errors. Consequently, the HML method appears to be an acceptable approximation of the NIOSH method, offering the additional advantage of being easier to apply. The higher accuracy of the HML method, when compared to the Noise Reduction Rating (NRR), makes is preferable for applications in industrial hearing conservation programs.

Ear Protective Devices↗
PubMed1989

[Edematous syndromes caused by capillary hyperpermeability. Diffuse angioedema].

Edema due to increased capillary permeability (ICP) may be diffuse or localized. Local edemas (Quincke edema, angioneurotic edema) are most often allergic or very rarely due to a defect in C1-inhibitor. Generalized edemas due to ICP share the following clinical features: Fluid retention (subcutaneous edema and diffused swelling) is predominant in lower limbs; it is worsened by orthostatism and warmth and alleviated by decubitus and cold, with important weight variations between morning and evening. It is associated with enhanced thirst, hypotension, oliguria, headaches and blood volume reduction; secondary hyperaldosteronism is the main mechanism. These troubles are due to ICP, associated with lymphatic drainage abnormalities; ICP is measured by the isotopic Landis Test. This abnormality is present in several diseases. Idiopathic orthostatic edema (IOE) is frequent and often unrecognized, occurring mainly in women, often associated with luteal insufficiency. Iatrogenic complications (diuretic and laxative abuses) are frequently superimposed. ICP may be corrected by vitamins P (rutin, anthocyanosides, diosmin, Ginkgo biloba extracts...) Cyclic shock due to ICP is rare. It is characterized by cyclic edema and shock with hypovolemia, hypoproteinemia; the mechanism of shock is a severe loss of fluid and protein from the vascular bed. It is often associated with monoclonal gammapathy and complement activation. In our personal case, the trouble in CP was present all along the disease with permanent edema and low blood pressure (especially in orthostatism). Vit "P" and Ginkgo biloba extracts were able to partially improve CP and the clinical troubles. However, in spite of this treatment a fatal shock occurred after ten years follow-up. Episodic angioedema associated with eosinophilia was first described by Gleich.(ABSTRACT TRUNCATED AT 250 WORDS)

Capillary Permeability↗
PubMed1987

Isotopic test of capillary permeability to albumin in diabetic patients: effects of hypertension, microangiopathy, and duration of diabetes.

Capillary permeability to albumin (CPA) was studied by performing an isotopic noninvasive test with venous compression on 87 nonselected diabetics with no edema, no cardiac failure, and no peripheral vascular disease. Excessive albumin retention (AR greater than or equal to 8%) ten minutes after removal of the compression was found in 27 patients (31%). The radioactivity disappearance curve was then analyzed using the Fast Fourier Transform (FFT). An abnormal isotopic CPA test was thus found in at least 45 out of the 87 patients. The prevalence of an abnormal test was not different in type 1 and type 2 diabetics. We studied the independent effects of hypertension, presence of specific clinical signs of microangiopathy (retinopathy and/or significant proteinuria), and duration of diabetes. Among diabetics free of specific clinical signs of microangiopathy, the prevalence of an AR greater than or equal to 8% was significantly higher in those with hypertension (11/19) than in those with normal blood pressure (2/28) and in nondiabetic hypertensive patients (0/16). Among normotensive diabetics, the prevalence of an abnormal test was higher, but not significantly, in patients with specific clinical signs of microangiopathy (8/11) than in those free of them (7/18). Seven normotensive diabetics without specific clinical signs of microangiopathy had an abnormal test; five of them had had diabetes for more than five years. The prevalence of diabetes of more than five years duration was significantly higher in patients with an abnormal test (35/45) than in normotensive diabetics free of specific clinical signs of microangiopathy with a normal test (4/11).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[Idiopathic cyclic edema. The role of capillary hyperpermeability and its correction by Ginkgo biloba extract].

Idiopathic cyclic oedema is a frequent and often unrecognized condition in young women. It is characterized by water and sodium retention with secondary hyperaldosteronism due to capillary hyperpermeability. Treatment is not easy. It includes spironolactone, sometimes sympathomimetics and hygienic-dietetic measures. Thiazide diuretics and laxatives must be avoided. Correcting the capillary defect is of paramount importance. This defect is detected and measured by Landis' labelled albumin test. The authors have tried Ginkgo biloba extract administered either orally or by intravenous infusion. Full correction of the biological anomaly was obtained in 10 cases in which Landis' test was performed before and after oral treatment, and in the 5 cases treated by intravenous infusion.

Capillary Permeability↗
PubMed1985

Noise exposure--sample size and confidence limit calculation.

In a previous paper a method for assessing noise exposure levels of workers from the same trade was presented. There was also discussed how to apply the NIOSH sample size method to noise exposed populations. In this paper both subjects are further discussed by including the calculation of confidence limits for the mean noise exposure as well as for the percentage of workers with noise exposure levels beyond a certain level. The calculation of the sample size of a population where standard deviation is known is also discussed.

Environmental Exposure↗
PubMed1979

Idiopathic edema.

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Diagnosis, Differential↗
PubMed1979

Systemic leishmaniasis mimicking malignant histiocytosis.

A 22-year-old man with fever, hepato-splenomegaly and severe pancytopenia is described in whom the histologic features of the spleen, liver and lymph nodes were consistent with malignant histiocytosis. Characteristic Leishman-Donovan bodies were demonstrated on a bone marrow aspirate, and the diagnosis of visceral leishmaniasis was confirmed by culturing the flagellated forms of the pathogen, and by an excellent response to sodium stibogluconate. In view of the similarity in clinical and histologic appearance, visceral leishmaniasis must be considered in the differential diagnosis of malignant histiocytosis in geographic areas where leishmaniasis is still endemic.

Adult↗
PubMed1979

[Study of muscle hemodynamics during exercise: Physiological and pathological variations in Xe 133 elimination: A new method of interpretation (author's transl)].

Muscle blood flow measurements are of physiological (and pathological) significance only during effort. For this reason, the authors used Xe 133, which has been known since 1964, to measure regional muscle blood flow after its injection into the muscle, to quantify results during effort (pedalling). Effort is controlled by two measurable parameters: the weight lifted by the pedal and the frequency of movements. Curves showing the reduction in intramuscular Xe 133 levels cannot be mathematically formulated. It is easy, however, to measure their areas and thus define a mean elimination time (Tm) between times T1 and T2, beginning and end of effort, corresponding to activities A1 and A2 such that: formula: (see text). Normal Tm value, measured in 58 normal subjects with variable frequencies and weights lifted is: Tm = 1.70 +/- 0.38 min. The values in 70 patients with arteritis were significantly longer and can be greater than 3.5 min. This objective test could be of value in quintifying the effects of so-called vasodilators, both in patients with arteritis and venous insufficiency.

Humans↗
PubMed1978

Teratoid intraocular medulloepithelioma.

The right eye of a 1-year-old black infant with a painful blind eye was studied histologically. It contained a tumor at an advanced stage of growth. The tumor consisted of moderately large, round, and elongated undifferentiated cells and anaplastic cells with mitotic figures combined with multilayered, poorly differentiated epithelial cells that resembled the medullary epithelium of embryonic retina. Strap cells with cross striation typical of striated muscle were also present, together with islands of hyaline cartilage and areas of calcification.

Ciliary Body↗