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Biomedical subjects

E Bertrand

Publications and source records attributed to E Bertrand.

At least 55 records · Page 3Linked to original sources
PubMed1998

Progressive multifocal leukoencephalopathy (PML) and cerebral toxoplasmosis in an adult patient, with no symptoms of underlying immunosuppressing illness.

We present a case of the coincidence of progressive multifocal leukoencephalopathy (PML) and central nervous system (CNS) toxoplasmosis in an adult patient, without a detectable cause of cell-mediated immunity impairment. The proper diagnosis was made postmortem on the basis of histological changes typical of both pathological processes. PML was characterized by the presence of subcortical focal demyelination, containing enlarged, densely basophilic oligodendrocyte nuclei, often with intranuclear inclusion, and bizarre astrocytes, mimicking neoplastic cells. PML was confirmed by detecting numerous papova virus particles in oligo- and astroglial nuclei by thin-section electron microscopy. Cerebral toxoplasmosis was characterized by the presence of multiple well-circumscribed necrotizing abscesses. Numerous Toxoplasma gondii (T. gondii) cysts and free, non-encysted protozoan parasites were found among the inflammatory infiltrates. The diagnosis of cerebral toxoplasmosis was further confirmed by immunocytochemistry. In order to detect putative immunosuppressive background underlying both pathological processes, HIV infection was taken into consideration, however, no histopathological changes indicative of AIDS either in the CNS or in the peripheral organs were eventually found. Moreover no HIV provirus genome was identified in the formalin-fixed, paraffin embedded brain tissue by the polymerase chain reaction (PCR). Current view on the selected aspects of the pathogenesis of both disorders were discussed.

Antigen Presentation↗
PubMed1998

On auscultation.

Explore the source record for details and available documents.

Africa↗
PubMed1997

In vivo footprinting of the interaction of proteins with DNA and RNA.

Analysis of the interaction of proteins with either DNA or RNA sequences by in vivo footprinting involves two steps: (i) the in situ modification of nucleic acids by the footprinting reagent and (ii) the visualization of the footprints. Ligation-mediated PCR (LM-PCR) procedures provide a level of sensitivity and specificity that is suitable for visualization of footprints of single-copy genes or low-abundance mRNAs in higher eukaryotes. In this article, we discuss several of the technical aspects of these multistep procedures that contribute to the quality of the results, particularly the parameters that affect the specificity and fidelity of the reactions: (i) the design of the primers, which is important to achieve optimal specificity; (ii) the choice of polymerases so that the amplified material represents faithfully the initial nucleic acid population; and (iii) the impact of the plateau effect within the PCR on the interpretation of the data. We then discuss aspects of in vivo nucleic acid manipulation that may affect the quality of the footprinting image, in particular the choice of the footprinting reagent and its condition of use (e.g., on intact or permeabilized cells or prepared nuclei) and the extent of nucleic acid modification. Finally, we provide detailed experimental procedures corresponding to the techniques we have developed or modified: LM-PCR, reverse ligation-mediated PCR, and nuclease treatment of RNAs in vivo.

Base Sequence↗
PubMed1997

Social interaction increases the extracellular levels of [Met]enkephalin in the nucleus accumbens of control but not of chronic mild stressed rats.

Chronic application of various mild stress has been shown to decrease the responsiveness to reward in rats. This effect, which was suggested to mimic anhedonia, one of the main symptoms observed in depressive patients, can be measured by various tests. Thus chronic mild stress was shown to reduce the consumption of a palatable sucrose solution, and to decrease the acquisition of preferences for a distinct environment paired with a variety of reinforcing substances. These negative responses could be prevented by chronic treatment with tricyclic or atypical antidepressants. The behavioural changes, induced by exposure to chronic mild stress, were shown to be associated with a number of changes in dopaminergic neurotransmission in the mesolimbic system, especially in the nucleus accumbens. The nucleus accumbens contains a large number of enkephalinergic cell bodies giving rise to local collaterals and axons projecting to the globus pallidus-ventral pallidum region (for review see Ref. 9). Furthermore, there is evidence that this structure is instrumental in mediating the reward effects of exogenous and endogenous opioids (for reviews see Refs 5,7,17). This study was carried out to analyse the possible contribution of the enkephalinergic system in the anhedonic-like state induced by chronic mild stress. Microdialysis was used to study the extracellular levels of [Met]enkephalin-like material in the rostral part of the nucleus accumbens of freely moving rats exposed or not to chronically mild stress. In both groups, the basal levels of [Met]enkephalin-like material were found to be similar. Exposure of the two groups to a congener, increased the extracellular levels of [Met]enkephalin in the controls but not in chronic mild stressed rats. This suggests that the reactivity of the endogenous opioid system could be reduced in stress induced model of anhedonia.

Animals↗
PubMed1997

Expression of small, therapeutic RNAs in human cell nuclei.

Effective intracellular expression of small RNA therapeutics depends on a number of factors. The RNA, whether antisense, ribozyme, or RNA aptamer, must be efficiently transcribed, stabilized against rapid degradation, folded correctly, and directed to the part of the cell where it can be most effective. To overcome a number of these problems we have been testing expression cassettes based on the human tRNA(met) and U6 snRNA promoters, in which transcripts encoding small RNA inserts are protected against attack from the 3' and Transient expression in cultured cells results in 10(9)-2 x 10(7) full-length transcripts per cell, depending partially on the promoter construct used but also on the nature of the insert RNA 5' gamma-Phosphate methylation (capping) depended, as expected, on the inclusion of specific U6 snRNA sequences from positions +19 to +27. In situ localization of the transcripts shows that both tRNA and U6 promoter transcripts give primarily punctate nuclear patterns, and that capping of transcripts is not required for nuclear retention. Several different insert RNAs directed against HIV-1 were tested by cotransfection with HIV-1 provirus and assay for subsequent viral reverse transcriptase production. These include antisense RNA, hairpin and hammerhead ribozymes, and RNA ligands (aptamers) for Tat and Rev RNA binding proteins. Results show that Rev-binding RNAs efficiently block HIV-1 gene expression, whereas other RNAs have little or no effected when expressed in these cassettes.

Base Sequence↗
PubMed1997

Glass wool column filtration, an advantageous way of preparing semen samples for intracytoplasmic sperm injection: an auto-controlled randomized study.

The characteristics of the glass wool filtration technique for the preparation of semen samples in an intracytoplasmic sperm injection programme (ICSI) were compared with a two-layer Percoll density gradient procedure. Half of each of 25 semen samples were prepared by each technique. The oocytes from each patient were randomly injected, half with spermatozoa prepared by glass wool filtration and half with Percoll-separated spermatozoa from the same semen sample. The percentage of recovered motile spermatozoa, the total motile sperm count, the percentage of morphologically normal forms, the fertilization rate, the cleavage rate and embryo quality obtained with both preparations were analysed. The 95% confidence intervals obtained through the Altman-Bland analysis showed that the percentage of motile spermatozoa recovered was 3.5-9.9% higher with the glass wool filtration technique, and this was highly correlated (r = 0.92, P = 0.0001) to the method. Similarly, the total number of spermatozoa available for ICSI was 0.18 x 10(6)-2.44 x 10(6) higher with the glass wool column and was highly correlated to the method (r = 0.956, P = 0.0001). Also, the percentage of normal forms was 1.25-3.31% higher after glass wool filtration but was poorly correlated to the method (r = 0.47, P = 0.017). Out of 100 metaphase II oocytes injected with glass wool-extracted spermatozoa, 77 fertilized and 72 cleaved. Out of 97 metaphase II oocytes injected with Percoll-selected spermatozoa, 71 fertilized and 69 cleaved. These results were not statistically different. The mean +/- SEM embryo quality score for the glass wool group (2.90 +/- 0.27) was the same as that for the Percoll group (2.80 +/- 0.24). No fertilization failures occurred and 11 patients (44% per oocyte retrieval) became pregnant. It was concluded that glass wool filtration for semen preparation in an ICSI programme offers higher sperm recovery and sperm morphology of superior quality than with the classic two-layer Percoll gradient method, without affecting the fertilization rate and embryo quality.

Cell Separation↗
PubMed1997

The expression cassette determines the functional activity of ribozymes in mammalian cells by controlling their intracellular localization.

In order to better understand the influence of RNA transcript context on RNA localization and catalytic RNA efficacy in vivo, we have constructed and characterized several expression cassettes useful for transcribing short RNAs with well defined 5' and 3' appended flanking sequences. These cassettes contain promoter sequences from the human U1 snRNA, U6 snRNA, or tRNA Meti genes, fused to various processing/stabilizing sequences. The levels of expression and the sub-cellular localization of the resulting RNAs were determined and compared with those obtained from Pol II promoters normally linked to mRNA production, which include a cap and polyadenylation signal. The tRNA, Ul, and U6 transcripts were nuclear in localization and expressed at the highest levels, while the standard Pol II promoted transcripts were cytoplasmic and present at lower levels. The ability of these cassettes to confer ribozyme activity in vivo was tested with two assays. First, an SIV-growth hormone reporter gene was transiently transfected into human embryonic kidney cells expressing an anti-SIV ribozyme. Second, cultured T lymphocytes expressing an anti-HIV ribozyme were challenged with HIV. In both cases, we found that the ribozymes were effective only when expressed as capped, polyadenylated RNAs transcribed from Pol II cassettes that generate a cytoplasmically localized ribozyme that facilitates co-localization with its target. We also show that the inability of the other cassettes to support ribozyme-mediated inhibitory activity against their cytoplasmic target is very likely due to the resulting nuclear localization of these ribozymes. These studies demonstrate that the ribozyme expression cassette determines its intracellular localization and, hence, its corresponding functional activity.

Animals↗
PubMed1997

[Epidemiological course of cardiovascular diseases in developing countries].

Though the environmental and medical conditions are very different, similar population characteristics can be observed in the developing countries. The mean age of the population is young. Most people have a rural way of life, but migrations towards towns result in a disorganized urbanization and in habits more predisposing to cardiovascular diseases. Care access is often difficult for the patients. With respect to risk factors, smoking is increasing, hypertension is highly prevalent and severe, a trend towards obesity is frequent in medium or high economical level people. S or C hemoglobin diseases seem to be associated with coronary heart disease. In spite of very insufficient statistical data, it appears that: cardiovascular disease mortality is increasing when total mortality is decreasing: ischemic and hypertensive heart diseases are increasing when streptococcal or nutritional heart diseases are stabilizing or decreasing. The authors seem to be the different developing countries in respect to the crossing of these curves. Some countries have not reached the crossing. Subsaharan Africa for instance. Others have gone beyond the crossing, some Asian countries for instance. Other countries seem to be at the intersection (Mediterranean or Latin American countries). But many countries suffer the double burden of increasing and decreasing diseases. There is a general lack of prevention owing to other competing priorities and also to economical, social and educational difficulties. However in some developing countries feasibility and efficacy of preventive measures have been proved.

Cardiovascular Diseases↗
PubMed1997

Qualitative and quantitative analysis of locus coeruleus neurons in Parkinson's disease.

The analysis of qualitative changes in the locus coeruleus (LC) was performed on brains from 21 cases of Parkinson's disease. Eleven cases were selected for quantitative analysis of the loss of LC noradrenergic pigmented neurons. The qualitative studies revealed uneven dissemination of the noradrenergic cells loss of overall structure of the LC. Few preserved neurons showed degenerative changes. Extracellular neuromelanine granules, traces of dying neurons, were also observed. A weak astro- and microglia proliferation corresponded with neuronal loss. Lewy bodies were found in the LC in all cases. The quantitative analysis revealed that the average loss of adrenergic neurons in the LC accounts for about 70% in relation to the control group. The degenerative changes were observed in the whole LC, but they were most intensive in its caudal and next in the middle segment. The results suggest also that the degenerative process began in the middle segment and then it spread towards caudal segment of the LC as the stages of disease advanced.

Aged↗
PubMed1997

Cardiovascular disease stoppable in developing countries?

The author discusses factors with a bearing on cardiovascular disease which are shared by many developing countries, and outlines the difficulties that have to be overcome if significant prevention is to be achieved.

Cardiovascular Diseases↗
PubMed1997

Quantitative study of pathological forms of astroglia in Wilson's disease.

The number and distribution of Alzheimer type I and II cells (Alz I and II) as well as Opalski cells (Opl) were estimated in chosen brain regions of seven autopsied cases with Wilson's disease (WD). The authors of this study focused especially on the question whether the kind and intensity of astrocytes is linked to the clinical form of the disease and to the intensity of brain damage. Alz I and II cells were counted by the use of the HE method, whereas the number of Opl cells was calculated using the PAS method. The study revealed that among the three types of cells the number of Alz II cells was the highest and that of Alz I cells was the lowest. The distributional patterns of these three types of cells were different. Alz I cells were found mainly in the putamen. Alz II cells were observed diffusely, although they occurred in different numbers in the whole brain. The highest number of Opl cells was found in the putamen. Alz I cells were found only in the neurological type of the disease. The highest number of Alz II cells was seen in the hepatic type of the disease, whereas the highest number of Opl cells was observed in the neurological "mixed" forms. Moreover, intensity of tissue damage with presence of necroses was greatest in neurological WD. In the hepatic type dispersed areas of status spongiosus were observed, without presence of necroses. Our study revealed that the type and amount of the pathological astroglia may correlate both with the clinical form of WD and intensity of tissue damage. Alz II cells seem to be a characteristic feature of the early stage of astroglial response to the pathogenic factor whereas Alz I and Opl cells occur in WD only in the advanced stage of tissue damage.

Adolescent↗
PubMed1996

Quality control in IVF with mouse bioassays: a four years' experience.

OBJECTIVE: We analyzed retrospectively the relevance of 4 years of quality control on homemade culture medium with the mouse IVF and zygote bioassay. DESIGN: In vitro or in vivo fertilized mouse oocytes were cultured in each batch of medium. Two-cell-stage and expanded blastocyst development was recorded for each batch of medium. Data on fertilization and embryo quality obtained in human in vitro fertilization were recorded for each batch. IVF treatment cycles for male infertility and cycles with sperm microinjection were excluded. RESULTS: Human oocyte fertilization dropped from 60 to 54%, respectively, from 57 to 41% in a significant way (P < 0.05 resp. P < 0.01) and the human mean embryo score decreased from 4.17 +/- 1.21 to 3.69 +/- 1.06 (P < 0.05) when media were used with a low two-cell-stage development (< or = 75%) for the mouse zygote or mouse IVF bioassay. The pregnancy rate was not affected. CONCLUSIONS: Media with high scores in mouse bioassays show higher fertilization rates and better embryo quality when used for human IVF.

Animals↗
PubMed1996

Is the subzonal-insemination procedure an efficient technique in the treatment of extreme oligoasthenoteratozoospermia?

OBJECTIVES: The present study evaluates the usefulness of the sub-zonal insemination (SUZI) for patients with previous IVF failures or affected by severe oligoasthenoteratozoospermia and the necessity of pre-treatment semen analysis. DESIGN: Twenty-five patients underwent 43 cycles of either SUZI or alternate SUZI/IVF procedures according to semen characteristics. RESULTS: Among the 571 retrieved oocytes, 398 were microinjected and 173 were treated by IVF. Among the microinjected oocytes, 19% fertilized (12% 2PN: 7% 3PN) and 96% of the 2PN oocytes developed into embryos. Thirty-one embryo transfers were performed, 8 pregnancies were obtained and 7 embryos were cryopreserved. The 2 PN rates in SUZI and IVF procedures in the same cycle were not significantly different. The analysis of the different semen samples obtained before and during the treatment reveals that the semen quality varies in such a way that the decision of the adequate microinjection strategy to follow should only be taken according to the semen quality at the day of treatment. CONCLUSION: SUZI is not a satisfactory technique for treatment neither in case of previous IVF failures nor for severe oligoasthenoteratozoospermia.

Adult↗
PubMed1996

Is intracytoplasmic sperm injection (ICSI) a safe procedure? What do we learn from early pregnancy data about ICSI?

The aim of this study was to evaluate the safety of the intracytoplasmic sperm injection (ICSI) procedure by analysing early pregnancy data from ICSI and in-vitro fertilization (IVF) patients. In all, 50 ICSI pregnancies were compared with 226 IVF pregnancies. Comparisons were made during the first 9 weeks after the theoretical last menstrual period (7 weeks after oocyte retrieval) with regard to epidemiological data, plasma hormonal concentrations and transvaginal ultrasonographical findings. Although patients were significantly (P < 0.001) younger in ICSI (31 years) than in IVF pregnancies (33 years), their duration of infertility was similar. Miscarriage and multiple gestation rates were not significantly different in ICSI pregnancies (respectively 24 and 24%) from those found after IVF (32 and 29%). The probability of developmental arrest of the intrauterine sac (miscarriages and vanishing twins) was similar in both ICSI (16%) and IVF (25%) cases. The mean plasma hormonal concentrations starting from day 11 after oocyte retrieval were similar in both groups. Every ICSI and IVF pregnancy showed an embryo with cardiac activity at 7 weeks. Early pregnancy data did not show any abnormal findings for pregnancies achieved using ICSI compared to those achieved by IVF.

Abortion, Therapeutic↗