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Biomedical subjects

C Bernard

Publications and source records attributed to C Bernard.

At least 253 records · Page 14Linked to original sources
PubMed1988

Clinical, functional and pathological correspondence in early stage idiopathic pulmonary fibrosis: evidence for small airway obstruction 1-2.

We describe the clinical, physiological and pathological features of 23 subjects with early stage idiopathic pulmonary fibrosis. Thirteen subjects who had no symptoms had been fortuitously recruited by a routine chest radiograph, whereas the 10 other subjects complained of dyspnea. Twenty-one subjects showed only light to moderate extent of abnormalities on the chest radiograph. Fourteen subjects had a reduced vital capacity whereas 16 and 17 showed a reduced pulmonary compliance and an increase in lung elastic recoil, respectively. Transfer factor was significantly reduced in 18 subjects. Evidence for significant airway obstruction, mainly located at the peripheral level, was demonstrated by a reduced specific lung conductance and upstream conductance in 13 subjects. Airway obstruction was not associated with smoking habits. Bronchial hyperresponsiveness was noted in 50% of the 18 subjects studied. Although fibrosis was mild to moderate in 15 instances, it was only focal, i.e. at least one zone of normal parenchyma in the lung specimen in 17 subjects. Peribronchial fibrosis was established in 8/11 satisfactory biopsy specimens. Significant correlations were observed between rales, the radiological score, some functional indices and the characteristics of fibrosis. We conclude that small airway obstruction documented by physiological and pathological means is frequent in early stage idiopathic pulmonary fibrosis.

Adult↗
PubMed1988

Calcium and the inner ear fluids.

Total calcium (Ca) concentration in inner ear fluids was determined by fluorimetry, emission and absorption spectrophotometry, and electron probe analysis. The ionized Ca was measured with selective microelectrodes. In perilymph, the total Ca concentration (1.2 mM) was similar to the ultrafiltrable Ca concentration in plasma. The fraction of ionized Ca was 80%. In endolymph, a total Ca concentration of 0.5 mM contrasted with a reported ionized Ca concentration of 0.02 mM, which suggests, as a working hypothesis, that most of the Ca could exist as bicarbonate and/or phosphate undissociated salts. The decrease in the endocochlear potential induced an increase of the ionized fraction of the Ca. The electrochemical potential of Ca across the perilymph-endolymph barrier implies an active entry of Ca into the endolymph.

Calcium↗
PubMed1988

Possible role of Ca ions in the vestibular system.

The Ca++ messenger system is nearly universally present in the control of cell functions by extracellular messengers. It elicits different kinds of responses: either brief, as in neurotransmission and in skeletal muscle contraction, or sustained, as in smooth muscle contraction and in the regulation of transepithelial transport systems. In this latter function the Ca++ messenger system interacts with other cellular modulation systems such as cAMP production and arachidonic acid cascade. In the vestibular apparatus, the Ca++ messenger system is involved in the transduction processes in that it controls both the release of neurotransmitter at the basal pole of the hair cell and the electrical resonance of the cell. It also figures in the contractile properties of cochlear outer hair cells. The Ca++ messenger system as well as adenylate cyclase and prostaglandins may play an important role in the modulation of endolymph secretion.

Animals↗
PubMed1988

[Gastro-entero-pancreatic production and hepatic uptake of gastrin and somatostatin in the preruminant calf receiving milk proteins or milk serum].

In preruminant calves total splanchnic production of immunoreactive somatostatin and gastrin did not change when casein was replaced by whey protein in the diet, but gastrin secretion was more rapid for the first 3 postprandial hours. Loss during passage through the liver was equivalent to splanchnic production for somatostatin, but was very low for gastrin.

Animals↗
PubMed1988

[MRI in the diagnosis of lissencephaly. Apropos of a case].

In a patient with clinical manifestations suggestive of brain malformation, CT showed lissencephaly with absent opercularization. The child had seizures but not a typical EEG of hypsarhythmia. MRI confirmed the diagnosis and showed heterotopic grey matter and abnormal basal ganglia. High grey-white matter contrast and the possibility of imaging the brain in sagittal, coronal and transverse planes make MRI the methode of choice for the evaluation of lissencephaly and other brain malformations.

Brain↗
PubMed1988

[X-ray computed tomography and MRI in Krabbe's disease].

Krabbe's disease whose CT appearance is well known should benefit of the development of MRI as this method is more accurate. MRI permits early diagnosis of leucodystrophy. Yet it must be emphasized that abnormal white matter patterns are not sufficient to permit the diagnosis of Krabbe disease. In the case reported atrophy of the brain, the cerebellum and the brain-stem, demyelination of the white matter and necrosis of corpus callosum were observed. The abnormalities of the brain on MRI pictures help in the diagnosis as they may alert clinicians to the possibility of Krabbe disease in infants with progressive encephalopathy. A definitive diagnosis can be established thanks to the laboratory tests.

Female↗
PubMed1988

[Contribution of MRI to the diagnosis of double aortic arch].

The authors present a case of double aortic arch explored by MRI and discuss the advantages and disadvantages of MRI as compared to other noninvasive imaging methods, such as ultrasounds and digital angiography, in congenital pathology of the aorta. Because it provides good quality images, can explore the aorta in all three dimensions, has optimal vascular contrast without contrast injection and carries no risk, MRI is indispensable in all cases where ultrasonography finds its limitations. Besides, the subjective factor inherent in the operator is very small, and MRI is the best available method to study the relations between the aorta and the surrounding organs; this is particularly important in case of double aortic arch owing to compression of the neighbouring organs with, notably, stridor. However, the vascular map is less accurate than with angiography, and the cost, the problem of access to the machines and the long time required for acquisitions limit the use of MRI.

Aorta, Thoracic↗
PubMed1987

Microvascularization of the intracranial dura mater.

The authors have studied the microvascularization of the intracranial dura mater by microradiographic and histologic examination of 73 injected anatomic specimens. There exists a very abundant superficial arterial plexus which also serves to supply the inner table of the cranial vault. This plexus is continuous, even at the walls of the venous sinuses and the dural septa. The arteries are for the most part tortuous. The veins may be satellites of the arteries or, on the contrary, from a plexiform network passing through crevices in the interior of the dural layer. The walls of these veins consist only of an endothelium to be seen within the fibrous layer of the dura. Often, the arteries compress the venous lumen; this dangerous situation probably explains the frequent occurrence of arteriovenous fistulae of the dura mater, known by the name of dural fistulae.

Adult↗
PubMed1987

Oxidation-reduction potential studies: a new method in pharmacology principles, materials, and methods.

Oxidation-reduction (redox) potential measurement is not used in pharmacology at the present time. However, it represents a physicochemical parameter that may be as important as the other currently used physicochemical parameters, such as pH and pKa. Redox potential variations include conformational modifications that may influence bioavailability of drugs. We report here an original and convenient equilibrium method to determine this potential in biological fluids, especially in blood.

Female↗
PubMed1987

Prostaglandins in the semicircular canal of the frog.

The synthesis of prostaglandins by ampulla and duct tissue isolated from the frog posterior semicircular canal was investigated in vitro. Ampulla and duct produced PGE2 (9 and 6 pg/structure, respectively) and prostacyclin (26 and 12 pg/structure). In the ampulla, prostaglandins mostly originated from the part containing dark and sensory cells and was not altered by 10(-3) M streptomycin. Prostaglandin levels were time-dependent and temperature-dependent. Arachidonic acid (3 X 10(-5) M) stimulated PGI2 synthesis by ampulla and duct (by 11.4 and 17 times) and PGE2 synthesis by 50 times in both structures. Ionophore A23187 stimulated ampulla and duct PGI2 synthesis (by 4.8 and 5.6 times) and PGE2 synthesis (by 2.4 and 1.8 times). Subcutaneous 100 mg/kg aspirin reduced PGI2 and PGE2 synthesis (ampulla: -87%, -33%; duct: -100%, -33%). Indomethacin (10(-6) M), in vitro, decreased PGI2 and PGE2 synthesis (ampulla: -47%, -47%; duct; -22%, -77%). Within 3 h, aspirin (5 X 10(-6) M) or arachidonic acid (2 X 10(-5) M) did not change Na and K concentrations in endolymph. It is concluded that frog inner ear produces PGI2 and PGE2, mostly from the part containing the dark cells, and that prostaglandins could be involved in the physiology of inner ear.

Animals↗
PubMed1987

[Rare localizations of digestive adenocarcinoma in children. Apropos of 2 cases].

The authors report two cases of adenocarcinoma of the digestive system in children both of which were located in unusual sites. A child of 9 years old had an adenocarcinoma of the small bowel and a boy of 16 years who was known to have a long-standing hiatus hernia developed an adenocarcinoma of the oesophagus. In children these tumors have some characteristic features. They develop on a preexisting lesion. Evolution is rapid. From the pathological point of view, anaplasic and colloide patterns are frequent.

Adenocarcinoma↗