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Biomedical subjects

A Riva

Publications and source records attributed to A Riva.

At least 199 records · Page 11Linked to original sources
PubMed1987

Ciliated cells in the main excretory duct of the submandibular gland in obstructive sialadenitis: a SEM and TEM study.

The epithelium of the main excretory duct of the submandibular gland in five cases of obstructive sialadenitis was studied by TEM and SEM. In three cases we found a considerable increase in goblet and ciliated cells. As well as normal cilia, different kinds of ciliary anomalies, especially compound cilia, were noticed. Images of centriole formation and of ciliogenesis, both normal and abnormal, were also observed. Several hypotheses concerning the mode of formation of the compound cilia are discussed.

Adult↗
PubMed1987

[Recording of signals in ambulatory electrocardiography].

The different techniques for the acquisition of electrocardiographic signal in ambulatory monitoring are described in this paper. Direct and, frequency modulation systems are explained in details with their relative advantages and disadvantages. The basis of digital sampling and real time analysis of ECG signals are also explained.

Electrocardiography↗
PubMed1986

[Clinical and instrumental evaluation by multiple colonic manometry of tiropramide, trimebutine and octylonium bromide in irritable colon. II. Repeated oral administration].

Sixty out-patients with acute or sub-acute irritable colon were randomly allocated to receive 3 daily doses of 100 mg tiropramide, 150 mg trimebutine maleate or 20 mg octilonium bromide, orally during 5 consecutive days. Before and after treatment, multiple colonic manometry was performed, monitoring tonus, intensity and frequency of sinusoid contraction waves, transitories and vibrations, as well as the voluntary contraction capacity. Before treatment and after 2 and 5 days, the specific symptoms were also monitored, scored and recorded. Significant variations in tonus were not observed with any drug, but while tiropramide left unmodified the voluntary contractile ability, a significant inhibition was observed with trimebutine and, mainly, with octilonium. The overall power of spontaneous colonic contractions did not vary significantly with any drug. However, while with tiropramide a significant redistribution of muscular power was observed so as to increase propulsion waves and to decrease the ineffective transitory and vibrational contractions, with octilonium and trimebutine no clinically relevant redistribution of the power wasted in transient spasms was observed. Based on these observations, tiropramide was considered to be at least as effective an antispasmodic as octilonium and at least as effective a synchronizer as trimebutine, but was different from both reference drugs because it was the only one to act simultanously as both an antispasmodic and a synchronizer. The three drugs produced an improvement in each and all monitored symptoms as well as in the overall symptom intensity. Tiropramide, however, produced an improvement significantly faster, more progressively and to a greater extent than either reference drug.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1986

[Clinical and instrumental evaluation by multiple colonic manometry of tiropramide, trimebutine and octylonium bromide in the irritable colon: I. Administration by single i.v].

Sixty out-patients with acute or sub-acute irritable colon were randomly allocated to receive a single intravenous dose of 50 mg tiropramide, 50 mg trimebutine maleate or 10 mg octilonium bromide. Before and after injection, multiple colonic manometry was performed, monitoring tonus, intensity and frequency of sinusoid contraction waves, transitories and vibrations, as well as the voluntary contraction capacity. Significant variations in tonus were not observed with any drug, but, while tiropramide left unmodified the voluntary contractile ability, a significant inhibition was observed with trimebutine and octilonium. The overall power of spontaneous colonic contractions did not vary significantly with tiropramide, whereas some decrease was observed with trimebutine, and a substantial one with octilonium. Moreover, while with tiropramide and, to a lesser extent, with trimebutine there was a significant redistribution of muscular power so as to increase phasic propulsion waves and to decrease the ineffective transitory and vibrational contractions, with octilonium only a decreased wave amplitude was recorded without alteration of the frequency of transient spasms. Based on these observations, tiropramide was evaluated as being at least as effective an antispasmodic as octilonium and at least as effective a synchronizer as trimebutine, while setting itself aside from both reference drugs as it was the only one to act contemporarily as both an antispasmodic and a synchronizer.

Adult↗
PubMed1984

Cytochemical localization of ouabain-sensitive, K+ -dependent p-nitrophenylphosphatase and Ca++-stimulated adenosine triphosphatase activities in human parotid and submandibular glands.

K+ -dependent p-nitrophenylphosphatase (pNPPase) and Ca++ -stimulated adenosine triphosphatase (ATPase) activities were studied in human parotid and submandibular glands using cytochemical methods at the ultrastructural level. In both glands, only the striated-duct epithelium showed K+ -pNPPase reaction product, thereby indicating the localization of Na+, K+ -ATPase. The precipitate was concentrated on the deep invaginations of the basolateral plasma membranes, in close association with their cytoplasmic surface. Ca++ -ATPase activity was also found on the basolateral plasma membranes, but two striking differences from the K+ -pNPPase distribution were observed: firstly, Ca++ -ATPase appeared in both acinar and ductal cells, and secondly, it was localized on the outer side of the plasma membranes.

4-Nitrophenylphosphatase↗
PubMed1984

Unreliability of conventional visual electrocardiographic monitoring for detection of transient ST segment changes in a coronary care unit.

Visual monitoring at the central station of coronary care units (CCUs) may not adequately assess the presence and frequency of transient asymptomatic ST segment changes in patients with unstable angina. We have performed continuous 24-h electrocardiographic recordings over a total period of 50 days in 10 patients admitted to our CCU with frequent attacks of angina at rest. Over the corresponding period, at the central monitoring station (6 beds), the nursing-staff detected only 31 transient ischaemic episodes (27 with ST elevation, 4 with depression, 9 of which were asymptomatic). By contrast the retrospective analogue analysis of tapes identified 213 ischaemic episodes: 143 with ST elevation (greater than or equal to 0.2 mV) and 70 with ST depression (greater than or equal to 0.2 mV); usual CCU monitoring failed to report changes during 13 episodes (8 with ST elevation, 5 with depression) accompanied by anginal pain. When the tapes were played back in real time on a CCU monitoring scope, a cardiologist (who had the option of interrupting the play-back whenever tired) recognized 48% of the episodes when presented in groups of 4 and randomly positioned on the screen together with 2 other electrocardiographic tracings not related to the study; he recognized 92% of the episodes when only one ECG was presented on the screen. Thus conventional visual monitoring in a CCU considerably underestimates the incidence of transient ischaemic ST segment changes, some of which were accompanied by pain. This low rate of detection is the result of the presentation on the central monitoring station of several ECGs and of fatigue.

Adult↗
PubMed1984

An electronic "diaphragm" for the gamma camera, with adjustable zooming and offset.

We describe a new device for data acquisition from a gamma camera using an electronic spatial "diaphragm," with variable offset and zooming. The device, mainly applied to cardiac studies, permits selection of the desired part of the field of vision to be digitized and to zoom, before the computer acquisition. The spatial diaphragm spans 0.4-0.9 of the diameter of the FOV, and the amplification factor from 1.1 to 2.5.

Computers↗
PubMed1983

[An unusual case of focal symptomatology, monoparalysis of the abducent nerve and vertebrobasilar ectasia].

Ectasia of the basilar artery is a well-defined form with a complicated clinical symptomatology. Angiography has made it possible to show that its pathogenesis springs from marked changes in the diameter and length of the artery. A case is presented in which the usual array of symptoms was replaced by homonymous diplopia only. It showed that CT can on its own provide information both for diagnosis of the specific lesion, and for assessment of changes in the bone structures, the cerebral parenchima, and the ventricular system.

Abducens Nerve↗
PubMed1983

Fine structure of the epithelium of the human ejaculatory duct.

Normal human ejaculatory ducts were examined by scanning and transmission electron microscopy. The lumen, which shows an irregular shape due to complex mucosal folds, is lined by a simple secretory epithelium. A strong cell polymorphism has been observed concerning cell height, nuclear shape, and amount of secretory organelles. Apart from small differences, the epithelium appears to be identical to that of the seminal vesicle and deferential ampulla. These observations demonstrate that the human ejaculatory duct is not only a passage for semen, but also contributes to its formation.

Aged↗
PubMed1982

[Clinical experiences with intra-aortic balloon pumping].

The clinical experience with intraaortic balloon pumping (IABP) in 16 patients in a hospital without cardiac surgery is described. The indications for IABP were cardiogenic shock in 8 cases, preshock in extensive myocardial infarction in 2 cases, unstable angina in 4 cases and ventricular septal rupture after acute myocardial infarction in 2 cases. The prognosis in cardiogenic shock after extensive acute myocardial infarction (CPK average 1545 U/l) or after reinfarction was poor in spite of treatment with IABP (survival only 25%). Important insertion of balloon pumping technique are percutaneous insertion of balloon catheters and transport of patients by ambulance with functioning IABP.

Adult↗
PubMed1982

The ampulla ductus deferentis in man, as viewed by SEM and TEM.

The epithelium of the human ampulla consists of rare basal cells and a single type of principal (secretory) cells. The principal cells, which vary in height from cuboidal to columnar, often have conical or club shaped apical portions projecting and bulging into the lumen. Their cytoplasm contains an abundant rough-surfaced endoplasmic reticulum, numerous mitochondria, and many lipopigment granules. The Golgi apparatus is well developed and originates the secretory vacuoles which are discharged by exocytosis. Though the majority of nuclei are ovoid, deeply fissured or even lobated nuclei are not uncommon. The basal cells are small, nonsecretory cells, whose cytoplasm shows numerous filaments having a diameter of 55 A. The lumen contains masses of amorphous secretions and some spermatozoa. The human ampulla is a gland endowed with the same morphological features as those of the seminal vesicles.

Adult↗
PubMed1981

The epithelium of the excretory duct of the human submandibular gland: a transmission and scanning electron microscopic study.

The duct of the human submandibular gland (Wharton) is lined by a pseudostratified epithelium consisting of principal and basal cells. Scattered among them are a few goblet and ciliated cells. The principal cells are columnar in shape with many mitochondria, numerous dense bodies and a central nucleus with some indentations. Their apical cytoplasm shows a number of clear vesicles, some of which are reactive to silver and are extruded by exocytosis into the lumen. Other vesicles, which are unreactive, may represent the products of the absorption process. A mechanism of apocrine secretion is also observed in the principal cells. Thus, with regard to its functions, the duct of the human submandibular gland modifies the composition of saliva by adding a secretory component to it. This latter material is derived from the goblet cells but chiefly from merocrine (exocytosis) and apocrine secretion of principal cells.

Adult↗
PubMed1980

[Electrocardiographical changes and rhythm disorders in Barlow's syndrome].

Mitral valve prolapse ( MVP ) , responsible for most of the symptoms which had previously been interpreted as being due to neurocirculatory disorders or cardiac neurosis , is being recognised more often and has an incidence of about 6-8 % in an unselected population . Although this condition was considered for a long time to be a benign auscultatory abnormality , it may be the cause of serious cardiac complication . Arrhythmias predominate with an incidence of 60 to 80 % on continuous electrocardiography . In a series of 245 patients with mitral valve prolapse confirmed on echocardiography , 52 patients chosen at random were studied to determine the incidence pf ST changes , disturbances of heart rate , QT interval , changes of QRS , arrhythmias with resting , exercise and continuous ECG over 24 hours ( HMS = Holter Monitoring System ) . Abnormalities of ventricular repolarisation , especially flattening of the T wave and , less commonly , St depression were observed in about one third of the patients . These changes were more common in the inferior but were also found in the left precordial leads . 73 % of the 52 patients had a heart rate of 75/mn and their QT intervals showed the following changes : 30.7 % Had a duration greater than the 120 th percentile ; 19.2 % had a duration greater than the upper limit of normal . The other 50 % had a QT interval of around the 100 th percentile . None had a duration of less than the 90 th percentile . In 22.5 % patients , QRS changes due to conduction defects were recorded ( 15 % right bundle branch block - RBBB - , 7.5 % incomplete RBBB ) . HMS is the method of choice for detection of arrhythmias . Resting ECG only showed premature ventricular contractions ( PVCs ) in 12.5 % , compared to 32.5 % on exercise ECG and 62.5 % on HMS . 50 % PVCs were monomorphic , 5 % polymorphic , 7.5 % in salvos and 7.4 % supraventricular in origin . The circadian variation of PVC was striking with a high incidence during periods of activity . There was no statistical correlation between the incidence of PVCs , age , sex , type of MVP and the symptoms and auscultatory findings . The theories on the pathogenesis of the arrhythmias are divided between that based on an underlying cardiomyopathy ( confirmed by the presence of degenerated myocytes on electron microscopy ) and the mechanical hypothesis ( chordae tendinae irritating the endocardium or traction on the papillary muscle with resulting ischaemia ) which provide a better explanation of the clear predominance of monomorphic PVCs . The treatment of Barlow's syndrome is discussed . In our opininon , therapy is only required for ventricular arrhythmias detected by a sufficiently sensitive method such as HMS . Most authors use beta blockers , eventually in association with quinidine Therapeutic successes have also been observed with mexiletine , amiodarone , aprindine and less commonly with disopyramide .

Adolescent↗
PubMed1980

Glycosaminoglycans from pig duodenum.

A polysaccharide extract from pig duodenum, used in therapy as antilipemic, was shown by chromatographic and electrophoretic methods to be a mixture of the glycosaminoglycans (GAG) heparin (HEP), heparan sulfate (HS), dermatan sulfate (DeS), chondroitin sulfates (ChS) and hyaluronic acid (HA), in the ratio 24:31:23:9:13. The GAG mixture was fractionated with alkyl-ammonium salts, and, for DeS, with copper salts. Further purification of the fractions either by repeated complexation or by removal of residual impurities using specific enzymes or chemical reactions, permitted obtaining individual GAG more than 97% pure by electrophoretic and 1H-NMR analysis. These preparations will be used to assess the contribution of individual GAG to the biological activity of duodenal GAG extracts.

Animals↗