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Biomedical subjects

M Colonna

Publications and source records attributed to M Colonna.

At least 181 records · Page 10Linked to original sources
PubMed1990

[Can oximetry contribute to the detection of apnea? The use of a mathematical analysis of the oximetry signal].

The aim of this study was to test the efficacy of nocturnal oximetry as a means of continuous recording of SaO2 in the identification of apnoeic events in the recognition of non-apnoeic desaturation. The oscillations of SaO2 in relation to successive periods of apnoea during the course of the sleep apnoea syndrome (SAS) or with apnoeic episodes in patients with chronic airflow obstruction (BPCO) or restricted disease, were identified using a new delta index quantifying the variations of SaO2 during the night. 26 successive patients in whom there was an indication for nocturnal oximetry were included in a prospective study comparing nocturnal oximetry and polysomnography during 34 nights. In the apnoeic patients we found a strong correlation (r = .85. p. less than .01) between the apnoeic period and the delta index. In BPCO the number of apnoea was correlated with the delta index (r = .96. p. less than .01). A minimal threshold of the delta index fixed at 1.5 was satisfactory for detecting apnoea if the initial SaO2 was less than 93%. The value of the adequate for affected detection ought to be fixed at .8 (95% sensitivity) when the initial SaO2 was greater than 93%. A detection of apnoeic events thus seems possible by this method.

Apnea↗
PubMed1990

[Critical analysis of a clustering method applied to the study of geographic distribution of cancer].

Cancer registration permits to elaborate atlases that describe the spatial distribution of incidence within the registration area. The division of this area in small units is usually an administrative one, leading a wide range of unit sizes. Hence, results of indirect standardization are often difficult to interpret, due to the large variability of the observed cases. We used Huel's method (1986), which is based on the grouping of contiguous geographical zones that have the same incidence level. Here are displayed the results for cancer incidence within the "département de l'Isère" (France). We focus on method mechanisms and on the impact of the choice of the risk level.

Cluster Analysis↗
PubMed1989

Serological detection and molecular localization of allelic HLA-DP supertypic epitopes.

A DP serological allospecificity was identified using 125I-labeled preparations of HLA class II molecules isolated from cells of HLA homozygous typing cell lines, SLE (DRw6, DQw1, DPw3) and WT46 (DRw6, DQw1, DPw2), and depleted of DR molecules by absorption with an anti-DR monoclonal antibody. The specificity, provisionally called WT, was carried by class II molecules possessing the characteristics of DP molecules on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and detected primarily in DPw1, DPw3 and DPw5 cells and exceptionally in some DPw2 cells including WT46 and DPw4 cells on a large panel of DP-pretyped B cell lines mostly derived from the 10th International Histocompatibility Workshop B cell reference panel. It was apparently allelic to another DP serological specificity BUT previously defined on DP molecules isolated from cells of DPw2+ HLA deletion mutant cell line LCL 721.82. On the same cell panel; the BUT specificity was negative in all DPw1, DPw3 and DPw5 cells, and positive in all DPw2 and DPw4 cells and also in DPw2B and DPw4B cells except the cells typed WT+. This DP association pattern was similar to that of the known allelic sequences, GGPM and DEAV, in DP beta F segment, one of the six variable segments in the second exon of DP beta gene. Thus, genomic DNA from 22 B cell lines pretyped for BUT and WT specificities were enzymatically amplified for the second exon of DP beta gene by the use of locus-specific oligonucleotide primers and hybridized with 32P-labeled oligonucleotide probes corresponding to the F segment sequence variations. This oligonucleotide typing showed perfect one-to-one correlation with the BUT and WT serological typing. The typing also revealed that WT46 cells, although typed DPw2, have the DEAV sequence common to DPw1, DPw3 and DPw5.

Alleles↗
PubMed1989

[Respiratory chain diseases in infancy. Clinical presentation and diagnosis].

Nineteen children with defects of the mitochondrial respiratory chain are described. First symptoms appeared during the first two years of their lives. Four types of clinical pictures were identified: 1/neonatal hypotonia. 2/cardiomyopathy. 3/progressive neurological deterioration. 4/multisystem disease. A study of pyruvate and fatty acids metabolism and a skeletal muscle biopsy were performed in all cases. Elevation of beta-hydroxybutyrate/acetoacetate and lactate were the most frequent biochemical abnormalities. Muscular biopsy in light microscopy showed in most cases abnormal lipid storage.

Biopsy↗
PubMed1988

Carboxyethyl gamma-aminobutyric acid, a polyamine derivative, improves the recovery of EBV-transformed lymphocytes.

A polyamine derivative, carboxyethyl - Aminobutyric Acid (CEGABA), induces the formation of a large number of Epstein-Barr Virus (EBV) transformed lymphocytes, when added to the culture medium immediately after EBV infection. However, CEGABA shows only a moderate effect on the stability of EBV-transformed cell lines over time, and does not affect the growth of stabilized cell lines. It is possible that CEGABA acts on cells other than EBV transformed lymphocytes (in fact, after EBV infection all types of mononuclear cells from the blood are present in the culture) and indirectly promotes the growth of EBV transformed lymphocytes.

Antibodies, Monoclonal↗
PubMed1987

Characterization of human DNA sequences synthesized at the onset of S-phase.

We developed a method of enrichment for DNA replicated at the onset of S-phase in synchronized human HL60 cells. About 200 such sequences were cloned. The analysis of this selected DNA sample showed that: 1) the cloned DNA fragments derive from a limited number (750-1500) of replicons; 2) there is no extensive homology between different DNA fragments; 3) they are not significantly enriched in highly repeated sequences; 4) they are enriched in snap-back (Cot = o) DNA. The sequence of the longest fragment revealed the presence of numerous signals collected in a few hundred nucleotides: 1) homology with the origin of replication of human Papovaviruses usually associated with potential stem-loop structures; 2) binding sites for known transcription factors and for another nuclear factor; 3) potential binding sites for the chromosome "scaffold".

Base Sequence↗
PubMed1986

Influence of SCH 23390, a DA1-receptor antagonist, on the behavioural responsiveness to small and large doses of apomorphine in rats.

SCH 23390 (SCH), a DA1-receptor antagonist, did not influence the decrease in locomotor activity elicited by a dose of apomorphine (20 micrograms/kg) believed to stimulate DA autoreceptors in rats. Conversely, SCH antagonized the effects on locomotion and the stereotyped behaviour elicited by a dose of apomorphine (1 mg/kg) which stimulates postsynaptic DA receptors. These results showing that the behavioural effects produced by small and large doses of apomorphine are differently affected by SCH, further confirm that DA autoreceptors can be pharmacologically distinguished from postsynaptic DA receptors.

Animals↗
PubMed1986

Computer-aided skull/face superimposition.

By use of a special optical device coupled with a TV camera to match a skull and a photograph of a face, superimposition for the purpose of personal identification was performed in controlled situations. A computer-aided method to evaluate the fit of the superimposition has been outlined by means of an original Shape Analytical Morphometry (SAM) software package yielding analytical descriptions by kth-order poly-nominal equations and Fourier harmonic analysis. The match was carried out by using point-cross error and sum of differences for the Fourier set amplitude. A final comprehensive evaluation exhibited marked differences between congruent and noncongruent superimpositions.

Face↗
PubMed1984

[Changes in the transparency of dentin: computerized densitometric analysis].

Computerized densitometry was utilized to carry out a quantitative and distributive study of dentin transparency in dental roots from different age individuals. By means of original software S.A.M. (Shape Analytical Morphometry) a densitometric reading of transilluminated whole dental root was performed and so obtained densitometric matrixes were worked for grey level classification and correspondent areas evaluation, false colour restitution, pseudotridimensional and row/column barr graphs, isodensity outlines and density inclination maps. Results are discussed for both age evaluation in forensic application and for altered dentin recognition in pathological conditions.

Adult↗