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Biomedical subjects

C Masson

Publications and source records attributed to C Masson.

At least 163 records · Page 9Linked to original sources
PubMed1991

[Bone density in 20 black African young adults of the Bantu race is identical to that in subjects of white race].

Bone mineral content (BMC in g) as well as bone mineral density (BMD in g/cm2) were measured by dual photon absorptiometry in 20 black africans and 20 white individuals of the same age and sex. The BMC of african males, as well as their body mass index (BMI), were significantly less than those of the whites. In contrast, neither BMD nor the ratio of BMC to BMI differed between the two groups. These results suggest that morphotype plays a greater role than the ethnic factor in the determination of bone mass in the young adult.

Adult↗
PubMed1991

Developmental study of afferented and deafferented bee antennal lobes.

The role of antennal sensory projections on the ontogeny of the bee antennal lobe was analyzed using both light and transmission electron microscopy. Normal and deafferented developing antennal lobes were examined. The results obtained show that (1) initiation of synaptogenesis in the antennal lobe is independent of the arrival of sensory inputs; (2) sensory inputs are necessary for setting up the glomerular antennal lobe organization; (3) regressive events, such as the reduction of synapse density, occur during the development of the antennal lobe; and (4) glomeruli formation appears as related to glia development.

Animals↗
PubMed1991

A novel 43-kDa glycoprotein is detected in the nucleus of mammalian cells by autoantibodies from dogs with autoimmune disorders.

We have characterized a new antibody specificity in a panel of sera from dogs developing systemic lupus erythematosus (SLE) or clinically related autoimmune disorders. This antibody stains in a speckled fashion the nucleus of cells of different mammalian origins. The target antigen is a basic (pI 9.2) nuclear polypeptide with an apparent molecular weight of 43 kDa (p43) which is detected in various mammalian cell nuclei. p43, as studied in HeLa cells, appears to be cell cycle-independent. It is released from nuclei by salts (0.5 M NaCl or 0.25 M ammonium sulfate). Upon subfractionation of nuclear components, p43 is found in the fraction containing HnRNPs and is recovered in immunoprecipitates obtained with 4F4 monoclonal antibody to HnRNP C proteins. Immunoelectron microscopy revealed that p43 is concentrated over the dense chromatin periphery and interchromatin granule clusters. Another important feature of p43 is its ability to specifically bind wheat germ agglutinin lectin but not concanavalin A nor Ulex europaeus I, supporting the notion that p43 is a glycoprotein bearing an N-acetyl-glucosamine moiety. Consistent with this result, a radio-active p43 band is specifically immunoprecipitated by canine anti-p43 autoantibodies from HeLa cells metabolically labeled with [14C]glucosamine. Finally, anti-p43 antibodies do not immunoprecipitate SnRNA, indicating that p43 has no apparent association with SnRNPs.

Animals↗
PubMed1991

Behaviour of nucleolar proteins in nuclei lacking ribosomal genes. A study by confocal laser scanning microscopy.

The behaviour of nucleolar proteins in cycling PtK1 cells and in micronuclei with or without NORs was investigated by immunofluorescence using antibodies from autoimmune sera and confocal laser scanning microscopy. These antibodies were shown by electron microscopy to recognize antigens confined to only one of the three basic nucleolar components: fibrillar centres (FC), dense fibrillar component (DFC) and granular component (GC). Serial optical sections allowed us to determine the three-dimensional organization of these components in the nucleolus of cycling cells. Furthermore, clear differences were found in the distribution of the various antigens in micronucleated cells. Three patterns could be observed: (1) the FC antigens were found mainly in the nucleoli, but also in varying amounts in the dots; (2) surprisingly, the DFC antigens were found to accumulate preferentially in the dots; (3) the GC-specific marker stained intensively the nucleoli as well the dots. The results are interpreted with regard to possible mechanisms for targeting nucleolar proteins to the site of nucleolar formation.

Biomarkers↗
PubMed1991

[Left pseudothalamic cortical syndrome and pain asymbolia].

We report a case of left pseudothalamic cortical syndrome associated with asymbolia for pain in a right-handed male patient. The responsible lesion, detected at both CT and MRI, was infarction of the superficial territory of the middle cerebral artery, restricted to the posterior insula, the superior aspect of T1, the parietal operculum and the supramarginal gyrus. The ascending parietal gyrus and the thalamus were spared. This case, together with data from the literature, suggest that the somatosensory area II was responsible for the pseudothalamic syndrome. This interpretation is concordant with the hypothesis that S II plays the principal role in passive somatosensory discrimination, whereas S I plays the principal role in active discrimination implying stimulus exploration. The location of lesions that were responsible for asymbolia for pain is discussed. This case and those reported by Berthier et al. (1988), provide arguments in favour of Geschwind's hypothesis which attributes asymbolia for pain to sensory-limbic disconnection due to damage of the insula.

Cerebral Cortex↗
PubMed1991

[Epidemiological and clinical aspects of gout in equatorial Africa. Apropos of 60 cases followed in the Department of Rheumatology of the Teaching Hospital Center in Brazzaville].

Between December 15, 1988 and November 30, 1990, the application of Rome and New York criteria enabled the diagnosis of 60 cases of gout among patients with arthritis or hyperuricemia seen as out-patients or hospitalised in the Department of Rheumatology of the Brazzavile T.H.G. There were 57 men and 3 women, with a mean age of 51. Gout is the primary form of inflammatory arthropathy in adults in the Congo. Affecting all socio-professional groups, it is diversely associated with obesity, alcoholism, hypertension and diabetes. Initial involvement affects the big toe. Oligo and polyarticular forms predominate because of the absence or delay in specific treatment. This series included 30 per cent of cases of chronic gout. Evidence of renal impairment was found in one third of patients. However, urate lithiasis was absent. Tophi were found preferentially over the elbows. Sickle cell disease was responsible for one case of tophaceous gout. In contrast with the results of studies undertaken before the 1980s, gout is seen to be a common condition in equatorial Africa.

Adult↗
PubMed1991

[Prospective study of rheumatic manifestations in human immunodeficiency virus infection. Apropos of 26 cases in Congo].

A 12-month prospective study of the osteo-articular complaints in HIV infected patients was carried out in the Department of Rheumatology, Brazzaville, Congo. Positivity of the HIV serology was systematically researched. And so the authors have observed rheumatic disorders in 26 patients, 12 males, 14 females, with a mean age of 36 years (ranged from 13 to 78). These disorders are as follow: linked to HIV oligo or polyarthritis, 18 cases; septic arthritis 3 cases; destructive spondylodiscitis 2 cases; bilateral sciatica with paralysis 3 cases; tropical myositis 2 cases. Contamination was heterosexual in 23 patients, iatrogenic in 3 other ones. HIV infection was at the CDC stades II (7 patients) or IV (19 patients). The prevalence of osteo-articular manifestations in HIV infected patients who are admitted in the hospital of Brazzaville, Congo is evaluated at only 4%.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Determination of nucleotides in fish tissues using capillary electrophoresis.

Capillary electrophoresis has been applied to quantitate nucleotide degradation in fish tissues, to provide a basis for determining the K value, an indicator of fish freshness. The three major compounds, inosine monophosphate (IMP), inosine (HxR), and hypoxanthine (Hx) were distinctively separated at 416 V/cm applied potential, 100 mM CAPS buffer, pH 11. There was a good correlation between the peak area and the nucleotide concentration. By using a short distance (22 cm) from the sample entrance to the detector, the identification and determination of these compounds in each sample were completed within 15 min. The results obtained correlated very well with those obtained by enzymatic assays. The capillary was completely regenerated with 1 N NaOH, to dissociate all bound materials from the capillary wall, mainly cations in the fish extract. This provided the same silica surface for repeated runs, resulting in reproducible electropherograms.

Animals↗
PubMed1990

[Schistosomiasis of the spinal cord. Contribution of magnetic resonance imaging].

The authors report a case of spinal cord schistosomiasis presenting as myelitis, with rapidly developing deficit, signs of severe cerebrospinal fluid inflammation, normal myelography and computerized tomography. The patient's country of origin suggested schistosomiasis, and the diagnosis was confirmed by serology and rectal biopsy which showed eggs of Schistosoma mansoni. Magnetic resonance imaging was helpful as it confirmed the absence of spinal cord compression and showed a lesion of the conus medullaris, this region being the most frequent site of schistosomial myelitis.

Adult↗
PubMed1990

[Eclampsia].

Eclampsia is the most serious manifestation of a toxaemic encephalopathy which may also have nonconvulsive manifestations, such as headache, visual disorders or retinal or cortical origin, confusion or disturbances of consciousness. Some authors consider eclampsia as being only one particular aspect of hypertensive encephalopathy. However, recent studies have drawn attention to the importance of angiospasm which might not be a pure reaction to hypertension but might result from a relative deficiency in vascular prostacyclin. These physiopathological factors, to which must sometimes be added disseminated intravascular coagulation, account for computerized tomographic and neuropathological findings showing cerebral oedema and, in complicated cases, ischaemic or haemorrhagic lesions. Medical treatment must rapidly control the convulsive attacks as well as the arterial hypertension. Magnesium sulfate is not much used outside the United States where it is now strongly controverted. The obstetrical management depends on the time when eclampsia occurs and on the efficacy of the medical treatment.

Abortion, Therapeutic↗
PubMed1990

Computer analysis of the exploratory behavior of insects and mites in an olfactometer.

A method of quantification of the exploratory behavior of small animals stimulated by an odorant in a four-choice olfactometer, taking into account the interindividual variability of responses, was developed: individual tracks were time sampled according to the animal's walking speed and its positions were recorded according to the X-Y coordinates of the grid set underneath the device, the mesh of the grid suiting the animal's body size. A software, written in BASIC APPLESOFT on an APPLE IIe computer, allowed us to analyze the coordinates either of a single individual or of an experimental sample, leading to: a) the quantification of the insect distribution all over the experimental chamber, expressed in a table numbered according to the grid, where the percentage of position per square either for a given time fraction or the total observation period were reported, b) a graphic representation of the data according to several levels of greys, expressing the frequentation for each square for a given duration of observation. An analysis per time fraction allowed the chronological setup of events to appreciate. c) The collection of the positions among each flow field of the olfactometer for each individual of the experimental sample, for a given duration, was translated as the percentage of time spent in each flow field. Data files gathered these percentages for further statistical treatments. This computer method, which requires little equipment and appears to be easily adaptable to the study of biological models of various size and speed such as honeybees, trichogrammas and varroas mites, is a powerful tool for behavioral studies of small organisms tested in restricted areas.

Animals↗