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Biomedical subjects

M Dumitriu

Publications and source records attributed to M Dumitriu.

17 recordsLinked to original sources
PubMed1992

Bioactive polymers: in vitro and in vivo study of controlled release neomycin.

Neomycin is coupled on xanthan-a polysaccharide of microbial biosynthesis produced by Xanthomonas campestris-through ionic complexation. The kinetics of neomycin release, in vitro, at pH = 8.2 is studied. A controlled release of neomycin, following a zero order kinetics is observed, regardless of the eluent flow. Neomycin complexed on xanthan, administered in a unique daily dose to patients suffering from dysentery in the 100 cases taken in study, has shown a high clinical efficiency as compared with the treatments with ampicillin or furazolidone, administered for 5-10 days or longer.

Adult↗
PubMed1992

Bioactive polymers. 70. The kinetics of controlled release of neomycin in an alkaline medium.

Neomycin is coupled on xanthan--a polysaccharide of microbial biosynthesis produced by Xanthomona campestris--through ionic complexation. The kinetics of neomycin release, in vitro, at pH = 8.2 is studied. A release of neomycin, following a zero order kinetics, is observed, regardless of the eluent flow-rate. The neomycin-xanthan complex, protected by a cellulosic membrane, behaves like a monolithic-type device. Diffusion coefficients--increasing with increasing the eluent flow-rate--are also calculated.

Delayed-Action Preparations↗
PubMed1991

[The provocation of dynamic obstruction of the left ventricular outflow tract in secondary myocardial hypertrophy].

The effect of the Valsalva manoeuvre before and after sublingual administration of 1.6 mg nitroglycerin on maximal velocity (Vmax), acceleration time (AT) and ejection time (ET) of left-ventricular outflow was measured by Doppler echocardiography in 49 patients (28 men and 21 women; mean age 65 [48-84] years) with secondary left-heart hypertrophy, and in 8 controls. Changes in flow profile typical of dynamic obstruction in the left-ventricular outflow tract (LVOT) occurred in 30 of the patients, Vmax increasing from a mean of 137 to 302 cm/s. Latent LVOT obstruction was associated with a thickened posterior wall, an accelerated left-ventricular outflow even at rest and systolic anterior motion of the anterior mitral leaflet (SAM phenomenon). The size of the provoked LVOT gradient correlated significantly with Vmax or the AT/ET ratio at rest. Obstruction of the LVOT is apparently a non-specific phenomenon which also occurs in secondary left-heart hypertrophy. These findings may have therapeutic consequences.

Aged↗
PubMed1991

Bioactive polymers 66. Theophylline retardation in xanthan-based hydrogels.

Xanthan has been reticulated with epichlorohydrin to obtain a hydrogel for use in drug retardation. The obtained gel shows swelling degrees up to 1000. Theophylline has been inserted by diffusion into this gel; concentrations around 150 mg theophylline/g dry hydrogel being obtained. Controlled release of theophylline has been established by elution in a close recirculation system. Zero-order kinetics has been obtained in the diffusion process of theophylline into the eluent, within a 14 h time interval.

Drug Carriers↗
PubMed1991

Bioactive polymers 54. Pharmacological properties of modified neomycin.

Modified neomycin prepared by the ionic coupling on xanthan with an activity of 380 UI/mg was characterized in regard to its in vitro and in vivo release rate and therapeutic action with artificial tear eluent. The dynamic system in vitro release showed that after 4 h, there appears a "zero-order" kinetic. Ophthalmic inserts were prepared from modified neomycin and they are used in treating bacterial conjunctivitis. Sterilization of the conjunctival sac is obtained 12 h after insert administration.

Conjunctivitis, Bacterial↗
PubMed1976

[Myocardiopathy of progressive muscular dystrophy].

The authors have effected a clinical, radiological, electrocardiographic and apexocardiographic survey in 13 patients with progressive muscular distrophy (PMD) and in 6 healthy subjects belonging to families affected by the disease, in parallel with a group of 11 patients with severe myasthenia and 23 healthy subjects. Comparing the results with those found in the literature lead to the following results: 1) The ECG modifications and above all the abnormalities of the ventricular complex develop precociously in the PMD and express the pleiotropism of the myopathic gene. 2) The myocardial dyssynergia represents a link in the physiopathological chain of the cardiac distress. 3) The precociousness of electro and apexocardiographic modifications and their presence in healthy parents recommend these investigations in the genetic enquiry. 4) Clinical, histological and haemodynamic data individualize the myocardial distress as a true myocardiopathy.

Adolescent↗
PubMedDate not supplied

[Late hemorrhage after traumatic rupture of the spleen].

A study was performed of 31 late hemorrhages following traumatic rupture of the spleen. The authors make some considerations in connection with problems of diagnosis and treatment. The difficulty is stressed, encountered in the diagnosis of splenic rupture immediately after the causative trauma, and the high death-rate that ensues. In view of impriving the present results by early surgical treatment, the utility is stressed of clinical observation, as well as of hematologic, radiologic and angiographic explorations of these patients.

Adult↗
PubMedDate not supplied

[Ergonomic study of neuropsychic impairment in relation to health status in printing occupations].

The exertion and risk factors in relation with the state of health, with the psychophysiological reactivity and with the adaptation and fatigue symptomatology were studied by means of complex psychological, psychophysiological, medical) methods in two professional groups that perform an activity implying important mental and sensorial components: monotasterers and correctors, from three polygraphic enterprises and two publishing houses, totalling 167 subjects (74 monotasterers and 93 correctors). The ergonomic work analysis demonstrated that the exertion and risk factors are conditioned both by the contents of work and by the working environment. The occupational exertion is more complex in monotasterers (mental, sensorial and physical) and predominantly sensorial (visual) in correctors. The work hazards are especially brought about by overstraining of the attention and of the visual analyser, with consequences both on the health of workers and on the quality of production. The investigation of the state of health, of the psychophysiological reactivity, as well as of the adaptation and fatigue symptomatology has detected maladjustment and fatigue phenomena, with impairments of the psychosomatic balance, more marked in monotasterers. The suggestions regarding improvement measures were directed both towards aspects of medico-psychological prophylaxis and elements of corrective ergonomics.

Ergonomics↗
PubMedDate not supplied

New devices: the McDermott spirometer.

The assessment of a new bellows spirometer against a water spirograph showed: slight alinearity, minimal overestimation of FVC (1.7%) and underestimation of FEV 1-0 (2.9%) as well as of the ratio FEV 1-0/FVC (4.8%). The main advantages of the instrument are: lightness, easy operation, ruggedness and low cost; it seems mainly indicated for use in large scale field surveys.

Spirometry↗