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Biomedical subjects

A Simon

Publications and source records attributed to A Simon.

At least 415 records · Page 23Linked to original sources
PubMed1987

Prostatic invasion of rectal carcinoma: does transurethral surgery alter prognosis?

Two cases of colorectal carcinoma invading the prostate are presented. Each patient initially had an abdominoperineal resection for colorectal carcinoma followed by a transurethral resection of the prostate (TURP) for benign prostatic disease. In both patients colonic carcinoma developed subsequently in their prostatic fossae. Pathogenesis of late tumor invasion into the prostate is reviewed and consideration given to a more conservative surgical approach.

Adenocarcinoma, Mucinous↗
PubMed1987

Overview on atherosclerotic systolic hypertension.

Hypertension in older atherosclerotic patients is characterised by a disproportionate elevation of systolic and pulse pressure contrasting with a subnormal diastolic level. Increased systolic pressure is strongly related to the excess of cerebrovascular complications and congestive heart failure observed in these patients. The physiopathological pattern is marked by a strong reduction in compliance of large arteries directly responsible for the predominant high systolic pressure because of the impairment of the buffering function of the arteries on the cardiac pulse wave. Clinical management is directed to the elevation of athero-arteriosclerotic changes of large arteries by means of appropriate non-invasive ultrasonic techniques and specific lowering in systolic pressure. Antihypertensive treatment must specifically decrease systolic pressure without superimposing adverse effects on the generalized and focalized atherosclerotic process. In this respect, new pharmacological agents capable of direct actions on large arteries might be suitable.

Aged↗
PubMed1987

Calcium uptake by cardiac sarcoplasmic reticulum in human dilated cardiomyopathy.

To determine the biochemical basis of abnormal diastolic properties in human dilated cardiomyopathy calcium uptake by the sarcoplasmic reticulum in ventricular homogenates of biopsy specimens from 21 patients with dilated cardiomyopathy was compared with that in nine normal controls. As a group, patients with cardiomyopathy had considerably lower calcium uptake rates (3.3(0.6) nmol.mg-1.min-1 vs 6.5(0.5) nmol.mg-1.min-1, p less than 0.01). Calcium uptake rates correlated modestly with resting haemodynamic values and significantly with plasma noradrenaline concentrations but not with plasma renin activity. These results show that sarcoplasmic reticulum function is impaired in human dilated cardiomyopathy and that this impairment is related both to the severity of haemodynamic dysfunction and to the extent of sympathetic nervous system activation.

Adolescent↗
PubMed1987

Haemodynamic basis of early modifications of the large arteries in borderline hypertension.

Quantitative evaluation of brachial artery diameter, blood velocity and flow (pulsed Doppler velocimetry) and of forearm arterial compliance (FAC)--mathematical analysis of the simultaneous diastolic pressure and flow according to a first-order arterial model--was carried out in 10 normotensive controls, and in 23 borderline hypertensive patients, of the same age. Using a value of 2 standard deviations above the average cardiac index of 20 normotensive subjects, enabled us to classify 12 patients as having a normal cardiac output and 11 patients as having a high cardiac output. Each group was of similar age and pressure. FAC was lower in patients with a normal cardiac output than in normal controls (P less than 0.01) and also lower than in patients with high output (P less than 0.01). Brachial artery diameter and flow were higher in patients with high output than in normal controls (P less than 0.01, P less than 0.001) and also higher than in patients with a normal output (P less than 0.001). A positive correlation (r = 0.55; P less than 0.01) was found between heart rate and brachial artery diameter in the 23 patients. These results demonstrate a non-homogenous pattern of brachial artery characteristics of patients with borderline hypertension. Patients with normal cardiac output exhibited a clear reduction of the distensibility of the forearm arteries while patients with high cardiac output had strong dilation of the brachial artery.

Adult↗
PubMed1987

Brachial arterial changes in response to wrist occlusion in normotensive and hypertensive men.

Diameter, blood velocity, and flow of the brachial artery and vascular resistance of the brachial circulation were evaluated with a pulsed Doppler velocimeter before and after wrist occlusion in 8 younger and 8 older normotensive subjects and in 11 younger and 11 older hypertensive patients. Before occlusion, no differences existed between younger and older normotensives. However, in hypertensives, systolic peak velocity was higher in younger than in older hypertensives (P less than 0.001) and correlated to age in the overall patients (r = -0.57, P less than 0.01). Occlusion decreased velocity and flow and increased vascular resistance in all groups, but the change in resistance was not correlated with the base-line resistance. During occlusion, no differences existed between younger and older normotensives. However, in hypertensives mean and systolic peak velocity was higher (P less than 0.01), and vascular resistance was lower (P less than 0.01) in younger than in older patients. In hypertensive patients, during occlusion mean and systolic peak velocity were negatively correlated to age (r = -0.72, P less than 0.001; r = -0.59, P less than 0.01), and vascular resistance was positively related to age (r = +0.66, P less than 0.001). Thus wrist occlusion modified the brachial circulation in normotensive and hypertensive populations but revealed age-related differences only in hypertensive patients, suggesting a combined effect of age and hypertension on the muscle vascular bed.

Adult↗
PubMed1987

Persistence of retinal dopamine cells in the degenerated eye of the cave salamander, Proteus anguinus L.

The Proteus anguinus L. is a blind cave perennibranch amphibian whose visual system undergoes an important morphogenetic degeneration in adulthood. The eyeball becomes atrophied and disappears under the fat tissue of the head. However, a retina can still be identified and a photophobic behavior of the animal indicates a remaining photosensitivity. In the oldest animal observed, some photoreceptor cells are still present as well as other types of retinal neurons. Characteristic synapses are observed in both the inner and outer plexiform layers. Dopaminergic amacrine cells, with processes in the inner plexiform layer, can be identified by their tyrosine-hydroxylase immunoreactivity. Taken together, these results indicate a possible functional role of the remaining retina. Since dopamine is especially involved in light adaptation from darkness, the residual retina could act in triggering the turning behavior of Proteus in response to lightening.

Animals↗
PubMed1987

Alterations of pathological fetal heart rate patterns in labor following vibroacoustic stimulation.

Vibroacoustic stimulation of the fetus in labor was previously shown to result in a transient fetal heart rate (FHR) tachycardia followed by a return to prestimulation FHR pattern. We presently report 3 cases in which FHR patterns of repeat decelerations were changed to normal following vibroacoustic stimulation. These changes may be related to the strong fetal movements evoked by the stimulation and removal thereby of a mechanical problem such as cord compression.

Adult↗
PubMed1987

Ultrasonographical evaluation of the incidence of simultaneous and independent movements in twin fetuses.

Fetal movements (FM) may be spontaneous, originating in the fetus itself, or evoked by external stimuli. The relative rate of spontaneous and evoked FM has not yet been documented. As it is impossible to differentiate in a singleton pregnancy between these types of movements - the natural model of twin pregnancy was used. The FM of 10 normal twin pregnancies between 33 and 39 weeks of gestation were studied by two realtime ultrasounds, and were operated by two ultrasonographers over a period of 10 min. The mean number of independent FM of each fetus which occurred while the other fetus was resting was 7.9 FM and 7.7 FM, respectively (average 7.8 FM). A mean of 2.5 FM occurred simultaneously. The rate of independent FM was 75.7% and that of simultaneous FM was 24.3%. Vibroacoustic stimulation applied to the maternal abdomen evoked simultaneous movements of both fetuses in all cases. It is suggested that the independent FM may represent spontaneous FM and that the simultaneous FM may indicate the presence of an external stimuli and are therefore evoked responses.

Female↗
PubMed1987

[Study of the visco-elastic response of the aortic wall to angiotensin and noradrenaline in the conscious dog by analysis of the instantaneous pressure-diameter relation in the descending aorta].

The viscoelastic behaviour of the aorta has been studied in 7 adult non-anesthesized mongrel dogs, chronically instrumented with a microtransducer pressure (Konigsberg P7) implanted inside the aortic lumen, and 2 ultrasonic crystals diametrically opposed and fixed in the adventitia of the thoracic aorta. Pressure and diameter were analysed in terms of mean values and of systolic diastolic variations, enabling to calculate the elastic modulus of Peterson. After recovery from surgery, and under autonomic blockade by atropine and propranolol, perfusions of angiotensin and norepinephrine were performed at incremental steps of doses. In individual dogs, instantaneous pressure-diameter relationships were formed by the different pressure diameter hysteris loops obtained at each dose of the same drug; the relationships obtained with the two drugs were curvilinear and were mixed at lower pressure ranges, but at highest levels of pressures it was found, that comparatively to angiotensin curve, that of norepinephrine had shifted toward lower diameter. The percent increase in mean diameter from baseline obtained at each dose of the same drug, was positively correlated to the corresponding per cent increase in mean pressure, with angiotensin (r = 0.83 P less than 0.001), and for norepinephrine (r = 0.82 P less than 0.001), but the slope of the relation was lower with angiotensin (22.3 +/- 3.2) than with norepinephrine (12.8 +/- 1.9) (P less than 0.001); likewise, the elastic modulus, for each dose of a same drug, was positively correlated to the corresponding mean pressure for angiotensin (r = 0.53 P less than 0.01), norepinephrine (r = 0.69 P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗
PubMed1987

Normalization of sympathetic nervous system function after orthotopic cardiac transplant in man.

Plasma norepinephrine (PNE) levels are significantly elevated in patients with endstage congestive heart failure. To assess whether this abnormality is reversible, 32 patients were studied before and 3 to 9 months after orthotopic cardiac transplantation. PNE decreased after the transplant procedure form 739 +/- 363 to 301 +/- 161 pg/ml (p less than .05). In 13 patients, PNE was measured sequentially during the first 3 months after the transplant procedure. PNE decreased from 590 +/- 293 to 321 +/- 208 pg/ml at 2 weeks and remained stable at 1 month (308 +/- 239 pg/ml), 2 months (307 +/- 196 pg/ml), and 3 months (331 +/- 131 pg/ml), even while arterial hypertension developed. No correlation was found between PNE, systolic, diastolic, or mean arterial pressure and cyclosporine A blood levels. These data demonstrate that normalization of plasma levels of norepinephrine occurs shortly after cardiac transplantation in man. This decrease in PNE is probably independent of immunosuppression therapy. Finally, the development of arterial hypertension in cyclosporine A-treated cardiac transplant patients is not due to activation or persistent activation of the sympathetic nervous system.

Adult↗
PubMed1987

Platelet cytosolic free Ca2+ concentration and plasma cholesterol in untreated hypertensives.

It has been proposed that plasma cholesterol, a major risk factor for atherosclerosis, may modify cellular Ca2+. In particular, higher membrane cholesterol contents induce higher Ca2+ influx and decrease the activity of the Ca2+ pumps. Cellular Ca2+ may also control the number of accessible low density lipoprotein receptors. We investigated the question of whether plasma cholesterol influences cellular Ca2+ metabolism, by analysing the cytosolic free Ca2+ concentration [( Ca2+]i) in unstimulated platelets from 61 untreated hypertensive patients [systolic and diastolic arterial pressure: 157 +/- 3/95 +/- 2 mmHg (mean +/- s.e.m.), respectively, age 41.8 +/- 1.7 years, body mass index 24.7 +/- 0.6 kg/m2]. The subjects' plasma total cholesterol (5.5 +/- 0.5 mmol/l) and platelet [Ca2+]i concentration (228 +/- 7 nmol/l) were positively correlated (r = 0.375, P less than 0.003). This correlation persisted at constant age, arterial pressure or body mass index. Platelet [Ca2+]i tended to increase with plasma low-density lipoprotein concentration (n = 21, P = 0.01), and to decrease with the ratio of high-density lipoprotein cholesterol to total cholesterol (n = 21, P = 0.08). The observation that in normocholesterolaemic hypertensive patients [Ca2+]i concentration in unstimulated platelets was correlated with plasma cholesterol suggests that cell activation may be modulated by membrane fluidity or that cholesterol metabolism is influenced by cell Ca2+.

Adult↗
PubMed1987

[Lymphography in Hodgkin's lymphoma. Diagnostic value based on the current status of experience and knowledge].

Lymphography was carried out at least once in 355 patients with Hodgkin's lymphoma (HL). In 229 patients, there was a histological subclassification: 26 LP, 63 NS, 122 NC and 18 LD cases. The lymphographic manifestations could be subdivided empirically into two superordinate groups: 1. lymph nodes closely linked together in chains (LC) with dense structures as well as LC destructions, LC debris and 2. LC of varying size with pathological internal structure. Apart from in the NS type, a correlation between the lymphological appearance and the histological subtype could not be discerned in any other histological subgroup. After lymphography, 61.6% of stages I and II were assigned to stage III. The staging of the lymphography was: stage I 24.5%, stage II 47.3%, stage III 10% and stage IV 9%, and after lymphography: stage I 9.9%, stage II 17.7%, stage III 63.1% and stage IV 9.3%. From a qualitative point of view, lymphography is superior to all other methods in the diagnosis of malignant lymphomas and should hence be carried out obligatorily in suspicion of a malignant lymphoma.

Adolescent↗
PubMed1986

[Does arterial compliance play a role in the physiopathology of hypertension?].

The buffering function of arteries consists of damping down cardiac pulsatility. This function can be evaluated by measuring arterial compliance using pulsed Doppler and pulse wave velocity measurements and analysis of pressure and flow waves in arteries. In human hypertension, the reduction of arterial compliance is well-documented; it is not only due to increased stretching of the arteries consecutive to the rise in blood pressure, but also to the fact that structural and/or functional changes in these vessels, as suggested by the fact that compliance is reduced in patients with borderline and mild hypertension and does not necessarily vary in parallel to drug-induced changes in blood pressure. Furthermore, arterial compliance is heterogeneously altered in borderline hypertension according to the level of cardiac output and in sustained hypertension according to the degree of arterial aging. Finally, reduced arterial compliance, by impairing the buffering function of arteries, increases arterial pulsatility and its adverse effects on cardiac load and on cyclic stress of arteries.

Arteries↗
PubMed1986

Extracellular and interstitial fluid volume in obesity with and without associated systemic hypertension.

Fluid volumes and cardiac and renal hemodynamics were investigated in 44 obese men, 22 with normal blood pressure and 22 with sustained essential hypertension. For the same degree of obesity hypertensive patients had a higher value in extracellular (p less than 0.05) and interstitial fluid (p less than 0.01) volumes than normotensive subjects, while plasma volume, total body water, body cellular water, cardiac output, renal blood flow and glomerular filtration rate were similar. For the same level of blood pressure, the expansion of extracellular and interstitial fluid volume paralleled the degree of obesity. Thus, obese patients with hypertension have an absolute increase in extracellular and interstitial fluid volumes. The increase was related both to the degree of overweight and to the mechanisms of hypertension.

Adult↗
PubMed1986

Fetal activity in pregnancies complicated by systemic lupus erythematosus.

Fetal movements were assessed in 7 cases of systemic lupus erythematosus (SLE). The daily fetal movement count was lower than normal in 4 cases. Three patients with renal disease and raised blood pressure had decreased fetal movements until cessation and poor fetal outcome. Uncomplicated cases of SLE did not manifest cessation of fetal movement, and their fetal outcome was favorable. When a decrease in fetal movements becomes apparent and the condition is verified by other biophysical tests, the patient should be delivered provided the fetus is viable.

Female↗
PubMed1986

Co-localization of tyrosine hydroxylase and phenylethanolamine-N-methyltransferase immunoreactivity in the rat retina: a re-examination using double labeling on semi-thin sections.

The precise morphology and distribution of phenylethanolamine-N-methyltransferase (PNMT)-immunoreactive cells has been observed and compared with the previously described tyrosine hydroxylase (TH)-immunoreactive cells, in the rat retina. The PNMT-positive cells are small amacrine neurons, located either in the inner nuclear layer or in the ganglion-cell layer. They send processes mainly to the middle sublayer and to a lesser extent to the outermost sublayer of the inner plexiform layer. They resemble the small TH-positive bouquet cells described previously. In order to ascertain the relationship between PNMT-positive cells and TH-positive bouquet cells, a double immunohistochemical labeling technique, using anti-TH and anti-PNMT antisera, has been developed on semi-thin sections. The result of these experiments clearly indicate that the populations of TH-positive cells and PNMT-positive (presumably epinephrinergic) cells are separated. The absence of TH enzyme in the PNMT-positive cells raises the question of the enzymatic activity of PNMT, which appears to be different from the classical pathway of catecholamine biosynthesis in the retina.

Animals↗