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Biomedical subjects

M Ungureanu

Publications and source records attributed to M Ungureanu.

At least 19 recordsLinked to original sources
PubMed2004

[Antimicrobial activity of new 4,4'-bipyridine derivatives: and in vitro study].

The antimicrobial and antifungal activity of some 4,4'-bipyridine derivatives were studied. The diffusimetric gelose surface diffusion method with stainless steel cylinders was used to study bacteria and Sabouraud fields for Candida albicans. Comparative analysis of the results led to the following conclusions. Diquaternary salts of 4,4'-bipyridinium possess a remarkable antimicrobial and antifungal activity. The influence of R1 and R2 substitutes in the para or meta position of the benzoylic radical affects selectivity but does not greatly influence activity.

Anti-Infective Agents↗
PubMed2002

[In vitro antimicrobial activity of new 1,10-phenantroline derivatives].

The antimicrobial and antifungical activities of some 1,10-phenanthroline derivatives are described. The test was performed using the diffusimetric method with stainless steel cylinders based on diffusion of the substances on the gelose surface for bacteria and Sabouraud field for Candida Albicans yeast. The comparative analysis of the obtained data leads to the following conclusions concerning the relation between structure and activity

Anti-Bacterial Agents↗
PubMed1999

[New derivatives of 1-methyl-phthalazine with antimicrobial and fungistatic action].

In this paper we present the antimicrobial and antifungical action of some new salts of 1-methyl-phtalaziniums and their corresponding ylids. We also present conclusions concerning the relation between structure and biological activity. The test was performed using the diffusimetric method with rustless steel cylinders based on the diffusion on the tested substances on gelose surface. The salts of 1-methyl-phtalaziniums are always more active comparatively than their corresponding ylids. All the compounds but not all derivatives are more active on the Candida albicans.

Anti-Bacterial Agents↗
PubMed1998

Myoelectric signal classification using neural networks.

A feed-forward neural network is used for diagnosis of spastic paralysis. It is a two-layer perceptron and it is able to classify two kinds of myoelectric signal recorded in surface electromyography: the normal EMG and the EMG in the case of spastic paralysis. The myoelectric signal was recorded with a surface electrode pair and sampled at 10 kHz. The EMG activity is stochastic and the instantaneous amplitude distribution for a fixed level of contraction is Gaussian. The signal variance is considered a measure of muscle force. We can describe any kind of this process by the AR model. For a precisely modeling of EMG there are necessary many AR model parameters. In the classification problem we have it is not necessary to use a high order AR model. We find a 4-th order AR model is good enough for this study. The Hopfield algorithm is used to calculate the parameters of the autoregressive model.

Electrodes↗
PubMed1998

[Antimicrobial activity of some derivatives of pyrimidine].

In this paper the authors present the antimicrobial and antifungical tests of some new 3-methylpyrimidine compounds. The test was performed using the diffusimetric method with rustlessteel cylinders based on the diffusion of the tested substances on the gelose surface. The comparative analysis of the obtained data leads to the following conclusions concerning the relation between structure and biological activity in the pyrimidine series: 1. The pyrimidinium ylides are less active comparatively with the corresponding salts. That means that the zwitter ionic structure did not favour the activity. 2. Comparative with the corresponding pyridazine(1,2-diazine) derivatives, the pyrimidine(1,3-diazine) compounds are more active. The increase of activity of the pyrimidine compounds could be attributed of the influence of the pyrimidine ring. 3. The most active pyrimidine compound which is tested is that one in which radical R is an amide group. 4. In the case when the radical R is a phenyl ring, the substitute from para position of benzoylic radical does not appear decisive towards activity, these affecting especially the selectivity.

Anti-Bacterial Agents↗
PubMed1997

[Antimicrobial activity of new pyridazine derivatives].

Continuing the investigations concerning synthesis-structure-biological activity in the pyridazine series, the results of the antimicrobial and antifungal tests of some new pyridazinium compounds are presented. The test was performed using the diffusimetric method with rustles steel cylinders based on the diffusion of the tested substances on the gelose surface. The comparative analysis of the obtained data leads to the following conclusions concerning the relation between structure and activity in the pyridazine series: 1. The cis-isomers are always more active comparatively with similar trans- isomers: 2. In the pyrrolopyridazine series we remark that the saturated or partial saturated compounds have always a stronger activity as the related aromatics derivatives. We also noticed that the saturated, partial saturated and aromatic compounds have different selectivity. Thus, the saturated are more active on the Pseudomonas aeruginosa and Candida albicans, the partial saturated are more active on the Staphylococcus aureus and Bacillus subtilis while the aromatic compounds are active on the Bacillus subtilis. 3. The influence of the Y-substitutes of para position of benzoylic radical and the substitutes of pyrrolo ring is not decisive towards activity, these affecting especially the selectivity.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Hydrazide derivatives with biologically active 1,2,4-triazole support].

This study presents the synthesis of ten new hydrazides with 1,2,4-triazole support. The structures of the obtained compounds were elucidates by means of the elemental analysis data as well as by IR spectral measurements. The antimicrobial and antifungal actions of this derivates are also tested. The results show that the compounds with the functional group 4-chlore-2-methoxyphenyle are more active.

Anti-Bacterial Agents↗
PubMedDate not supplied

Original method for nicorandil synthesis.

Nicorandil (N-(2-hydroxy-ethyl)-nicotine amide nitrate), drug recently introduced in therapy, is used as a vasodilator through potassium channel activation. Nicorandil is obtained by treating nicotinic acid chloride hydrochloride with nitro-oxy-ethyl-amine nitrate in an organic solvent. The authors suggest a method that uses ethyl nicotinate as raw material. Thus, the drug can be obtained from indigenous raw materials, at a lower price than the imported ones, with a high purity and a good yield.

Humans↗
PubMedDate not supplied

[Phthalazinilides. The action of ethyl bromopyruvate on phthalazine].

Our investigation for obtaining carbon-nitrogen stable ilides continued by the synthesis of new phthalazinic derivatives by the action of ethyl brompyruvate. The structure of the obtained products was confirmed by chemical and spectral analyses. The results regarding their antimicrobial action are also presented.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Ilide derivatives of pyridazines with biological activity].

Continuing the investigations on the synthesis and pharmacodynamic action of some pyridaziniu-ilides, this paper presents the results of the preliminary investigations on the antimicrobial activity of the synthetized products. Their action against Staphylococcus aureus Oxford and the anti-yeast action of the cycloimonium salts is underlined.

Anti-Bacterial Agents↗
PubMedDate not supplied

[The synthesis and anti-inflammatory properties of 7-theophyllineacetic acid derivatives].

Some esters of 7-theophyllinylacetic acid were synthetized, characterized physicochemically and tested for their anti-inflammatory properties. As compared to indomethacin, reference anti-inflammatory drug, all synthetized compounds were less toxic. The anti-inflammatory properties are influenced by the nature of the ester group radicals, the more active having ramified alchils.

Animals↗
PubMedDate not supplied

[The synthesis of aldoxime ester derivatives with biological activity].

Continuing our investigations for obtaining etheric derivatives from the oximes of some carbonylic compounds, five carboxymethylic ethers of some aldoximes were synthetized. Their structure was confirmed by chemical and spectral analyses. The antimicrobial activity of the obtained products towards 6 microorganisms species was determined.

Anti-Bacterial Agents↗