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Biomedical subjects

M Menozzi

Publications and source records attributed to M Menozzi.

At least 19 recordsLinked to original sources
PubMed1995

[Personal computer used in visual function screening].

BACKGROUND: The number of medical screenings is increasing. This fact is specially pronounced in the field of occupational health. Due to restricted financial resources and limitations in time there is a need for rationalisation in medical screenings. MATERIALS AND METHODS: Possible uses of personal computers (PC) enabling organisational and financial benefits in medical screenings are suggested. By means of a test for colour-blindness it is shown how unfavourable technical conditions may be by-passed. RESULTS AND DISCUSSION: Rationalisation in medical screenings can be achieved when using the PC as a multi-functional screening-device as well as an expert system, measuring apparatus and as a communication-device. Due to a lack of literature it is difficult to discuss possible effects of technical differences between PC-based screenings of visual functions and screenings where "traditional". Reliability, sensitivity and validity is insufficiently investigated for many of the commercial available screening-devices based on a PC.

Color Perception Tests↗
PubMed1995

Treatment of choroidal neovascularization in age-related macular degeneration with interferon alpha-2a: a short term, nonrandomized pilot study.

A total of 11 patients exhibiting in 11 eyes a subfoveal or juxtafoveal choroidal neovascular membrane due to age-related macular degeneration (AMD) were treated with interferon alpha-2a (Roferon) according to a protocol that was designed for an independent, randomized, open-label pilot study to evaluate the efficacy and safety of this therapy. However, none of the patients agreed to be randomized and all elected to be treated. The average follow-up period after treatment was 8.2 months. In 6 of 7 eyes with classic choroidal neovascularization the membrane increased in size during and after treatment. Of these 6 eyes, 5 lost more than 6 lines of visual acuity. In 2 of 4 eyes with occult neovascularization the lesion enlarged. In the other 2 eyes the lesion became atrophic in 1 case and remained stable in size in the other. Visual acuity decreased by 3-9 lines in 3 eyes with occult neovascularization. Of the 11 patients, 2 discontinued interferon treatment after 8 weeks because of severe adverse reactions. From the data collected thus far in this study and in the majority of published series, we conclude that interferon alpha-2a in the dose range of 3-6 million IU given three times weekly over 8-12 weeks is neither effective nor safe for the treatment of subfoveal neovascularization in AMD.

Aged↗
PubMed1994

Direction of gaze and comfort: discovering the relation for the ergonomic optimization of visual tasks.

Perceived exertion caused by the extraocular muscles was assessed as a function of the direction of gaze and recorded in 114 subjects using a psychometric method. The results confirm statements in the literature that maximum comfort is achieved when gaze is aimed downwards. We found no correlations between perceived exertion and age or viewing distance. The relationship is relevant to ergonomics, for example in lens fitting and workplace layout.

Adult↗
PubMed1991

[Eyeglass frame for detection of eye, head movements and pupillary diameter].

Up till now, the simultaneous recording of the movements of the eyes, the movements of the head and the diameter of the pupil required the combined use of several apparatus. In this paper we present a new apparatus developed for the simultaneous recording of the movements of the eyes and of the head, and the diameter of the pupil. The apparatus consists of a portable frame (weight 215 g) a 19" rack containing electronics, and a PC for storing and analyzing the recorded data. In comparison with other systems providing similar measuring possibilities the present apparatus has the advantage of smaller dimensions and lower weight.

Computer Terminals↗
PubMed1990

Natural history of congestive gastropathy in cirrhosis. The Liver Study Group of V. Cervello Hospital.

In a prospective study of the natural history of congestive gastropathy, 212 consecutive cirrhotic patients (75 treated with sclerotherapy) were included. Mean follow-up was 46 months. Mild gastropathy (mosaiclike pattern) was found in 110 patients and severe gastropathy (granular mucosa with cherry spots) was found in 20. Prevalence of Helicobacter pylori, formerly Campylobacter pylori, was 50% in patients without, 43% in those with mild, and 28% in those with severe gastropathy. Congestive gastropathy was significantly more frequent in patients treated with sclerotherapy (83% vs. 50%, P less than 10(-5)). Sixty-month actuarial proportions of patients free of anemia (in the absence of hematemesis or melena), were 17% with severe, 62% with mild, and 93% without gastropathy (P less than 10(-8]. Corresponding figures for overt bleeding were 25%, 73%, and 87% (P less than 10(-7], whereas those for survival were 46%, 72%, and 85% (P = 0.0005), respectively. A multivariate regression analysis supported the following conclusions: (a) sclerotherapy and the presence of large esophageal varices significantly increase the risk of congestive gastropathy, which (b) is a significant risk indicator of both chronic and overt bleeding but does not independently affect survival.

Adult↗
PubMed1989

Kinetic studies of anthracycline-DNA interaction by fluorescence stopped flow confirm a complex association mechanism.

The kinetics of association and dissociation between calf thymus DNA and five anthracyclines, including doxorubicin, daunorubicin, and three synthetic analogues, were investigated with stopped flow using fluorescence detection. The sensitivity of this technique allowed us to work with submicromolar drug concentrations, thus excluding formation of aggregates, and with ratios of DNA base pairs to drug in the range 10-250, where site exclusion effects could be taken into account with a simple correction of DNA concentration and pseudo-first-order conditions were nearly fulfilled. In all cases, both association and dissociation reactions required a sum of three exponential terms to be fitted. However, satisfactory interpretation of reciprocal relaxation times as functions of DNA concentration was only achieved with kinetic models comprising a total of five steps. One of the extra steps was tentatively assigned to formation of a weakly bound, probably nonintercalated species. Another step was deduced from a comparison between results of association and dissociation experiments. The five steps are arranged, for convenience, in an association mechanism with two branches, though other mechanisms cannot be definitely ruled out. Correlation of cytotoxicity data with both association and dissociation rates is not found to be significant. This suggests that other factors must be involved in modulating the different biological properties of the investigated anthracyclines.

Animals↗
PubMed1989

Synthesis, DNA-binding properties, and antitumor activity of novel distamycin derivatives.

A group of potential alkylating agents have been synthesized that are structurally related to the oligopeptide antiviral antibiotic distamycin. All derivatives form complexes with native calf-thymus DNA but compounds 2, 3, and 6 give rise to covalent adducts. Cytostatic activity against both human and murine tumor cell lines in vitro is displayed by the new compounds. Compounds 3 and 4 are active on melphalan-resistant L1210 leukemia in mice.

Alkylating Agents↗
PubMed1989

Joint experimental and theoretical investigation of the comparative DNA binding affinities of intercalating anthracycline derivatives.

The comparative binding affinities for poly(dA-dT) and poly(dG-dC) of novel antitumor anthracyclines are reported. The data concern, besides the parent compound adriamycin (ADM), 4-demethoxy 6-deoxy 6-aminodaunomycin (II), 9-deoxy-ADM (III), 4-demethyl-6-O-methyl-ADM (IV), and 3'-deamino-3'-hydroxy-4'-epi-ADM (IV). Theoretical computations are performed in parallel for their comparative binding affinities to model double-stranded hexanucleotides, d(GCGCGC)2, d(TATATA)2, and d(CGTACG)2, using the SIBFA (sum of interactions between fragments computed ab inito) procedure. The computations reproduce in a very satisfactory manner the most salient features of the experimental comparative binding affinities. These encompass, in particular, a higher affinity for the d(TATATA)2 oligomer of II than that of ADM, despite the absence of the 14-OH substituent in II, a marked reversal of the CG versus TA sequence selectivity of the neutral compound V, favoring the d(CGCGCG)2 oligomer over the d(TATATA)2 one; and the deleterious effect incurred on the binding affinities by the presence of an O-methyl substituent at position 6 of the chromophore.

Antibiotics, Antineoplastic↗
PubMed1988

Studies of anthracycline--DNA complexes by circular dichroism.

A series of doxorubicin and daunorubicin analogues have been investigated in aqueous solution and as DNA-bound forms by means of circular dichroism (c.d.) spectroscopy. The structural variants comprise modifications on the amino sugar, on the aliphatic ring and the side chain of the aglycone moiety, and of the substitution pattern of the anthraquinone chromophore. Results with compounds having conformational constraints interfering with optimal fitting to DNA indicate that stereochemistry and conformation of the aliphatic ring predominantly affect c.d. spectra of anthracyclines in DNA-bound as well as in free form. Conformational correspondence with the known structure of the daunorubicin-oligonucleotide complex is inferred from the spectra of derivatives with modifications at position 6 or 11 in the anthraquinone chromophore. On the other hand, a different binding geometry is postulated for compounds either lacking the 4-methoxy group of daunorubicin (idarubicin and derivatives) or having a phenolic function in its place (carminomycin and derivatives). A possible relation with cytotoxic activity is discussed at a speculative level.

Antibiotics, Antineoplastic↗
PubMed1986

Synthesis, DNA binding and antiviral activity of distamycin analogues containing different heterocyclic moieties.

A series of novel distamycin analogues possessing an additional benzene or heterocyclic ring have been synthesised and tested for selective DNA binding properties and antiviral activity. Inhibition of herpes virus in cell culture appears to be related to AT base pair specificity. Some of the new compounds are also more potent than the parent distamycin against Moloney sarcoma virus.

Animals↗
PubMed1986

Blood culture and echocardiography in diagnosis of infective endocarditis: microbiological and clinical observations.

Short retrospective review of 77 cases of bacterial endocarditis, observed in the 1980-84 period, and diagnosed by means of echography and blood culture. Alfa haemolytic streptococcus strains were isolated (47.6% of 42 isolated strains) followed by Staphylococcus aureus (16.7%) and Staphylococcus epidermidis (11.9%). Positive bloodculture were more frequent in the patients with valvular prosthesis. The results are analysed and some comments are done.

Adolescent↗
PubMed1984

Self-association of doxorubicin and related compounds in aqueous solution.

The dimerization of doxorubicin, daunorubicin, and their 4-demethoxy, 4'-epi, and 4'-deoxy analogues was studied spectrophotometrically. Self-association was found to be influenced by buffer composition and ionic strength. Kd values were 1.3 X 10(4) and 2.3 X 10(4) M-1 for doxorubicin and daunorubicin, respectively, and ranged from 3.8 X 10(3) to 6.1 X 10(3) M-1 for the 4-demethoxy analogues. For 4'-epi- and 4'-deoxydoxorubicin, tetramerization has also been considered. On this basis, values of 2.0 X 10(4) and 2.2 X 10(4) M-1 were found, respectively, for the formation constant of the dimerization process. Stability of the dimeric species appears to be strongly influenced by substitution of the chromophore moiety.

Chemistry, Pharmaceutical↗