Surface and bulk tortuosity of porous ceramics near the percolation threshold.
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Journal Article↗
Biomedical subjects
M Bernard
Publications and source records attributed to M Bernard.
Isolation from mouse fibroblasts of a cDNA encoding a new form of the fibroblast growth factor receptor (flg).
Structural definition of the receptors for neurotropic and angiogenic modulators such as fibroblast growth factors and related polypeptides will yield insight into the mechanisms that control early development, embryogenesis, organogenesis, wound repair and neovessel formation. We isolated 3 murine cDNAs encoding different binding domains of these receptors (flg). Comparison of these ectoplasmic portions showed that two of the forms corresponded to previously described murine molecules whereas the third one had a different ectoplasmic portion generated by specific changes in two regions. Interestingly, expression of this third form seems to be restricted in its tissue distribution. Such modifications could influence the ligand specificity of the different receptors and/or their binding affinity.
Amino Acid Sequence↗
Molecular and cellular aspects of hydroxyindole-O-methyltransferase expression in the developing chick pineal gland.
The pineal gland influences circadian activity and seasonal breeding through the production of an indolic hormone, melatonin. The terminal step of melatonin biosynthesis is catalyzed by hydroxyindole-O-methyltransferase (HIOMT). Using an antibody directed against HIOMT, we examined the differentiation of the melatoninergic phenotype in the developing chick pineal gland. HIOMT first appeared 4 days before hatch and rose linearly until the 7th day posthatch. This was correlated with an increased immunoreactivity of the 38 kDa enzyme on Western blots and with an accelerated rate of HIOMT biosynthesis as demonstrated by [35S]methionine labeling. Immunocytochemistry revealed a growing number of HIOMT-positive cells between day 2 before hatch and day 15 posthatch. Until hatching HIOMT was expressed almost exclusively in modified photoreceptors. Parafollicular pinealocytes became HIOMT-positive mostly after hatching. Their different timings of functional differentiation emphasize the existence of two populations of melatonin-producing cells in the chick pineal gland.
Acetylserotonin O-Methyltransferase↗
Expression of nuclear matrix proteins in rat liver tissue.
We have studied the synthesis of nuclear matrix proteins as it occurs in the rat liver. To investigate their kinetics in tissue, nuclear matrix proteins were prepared from liver of rats injected with radioactive methionine. Synthesis of lamins was not observed in quiescent hepatocytes although they were the principal proteins of this subcellular fraction, suggesting that lamins are very stable in the liver. When hepatocytes were stimulated to divide by partial hepatectomy, only synthesis of lamin B was initiated. Many proteins not visible on Coomassie blue-stained gels were detectable by autoradiography. In the nuclear matrix extracts of quiescent hepatocytes, one of the most prominently labeled ones was a protein of 70 kDa. After hepatectomy, an additional protein of 62 kDa was detectable. These proteins were visible 1 h after the injection of radioactivity, but were no longer observed in nuclear matrices prepared 24 h after injection. These experiments indicate that in addition to lamins, two nuclear matrix proteins are present in the rat liver that were not detected previously, perhaps because of their rapid turnover.
Animals↗
Evaluation of somatic cell variants deficient in glycosylphosphatidyl-inositol anchoring as candidates for genetic correction.
Many cell surface glycoproteins are anchored in the lipid bilayer by a glycosylphosphatidyl-inositol (GPI) structure. Recently, a number of cell lines which are deficient in the biosynthesis and/or addition of this anchor have been described. In this report, we summarize the current knowledge on these lines and discuss their potential use to isolate the genes involved in the GPI anchor biosynthetic pathway with a specific emphasis on L cell fibroblasts.
Animals↗
Hydrodynamic and energetic aspects of exogenous free fatty acid perfusion in the isolated rat heart during high flow anoxia and reoxygenation: a 31P magnetic resonance study.
STUDY OBJECTIVE: The aim was to show differences between the effects of various dietary long chain fatty acids (palmitic, oleic, linoleic, alpha and gamma linolenic acids) perfused in isolated rat hearts subjected to a sequence of high flow anoxia and subsequent reoxygenation. DESIGN: Isolated working rat hearts perfused with selected exogenous fatty acids were allowed an initial 30 min equilibration period followed by 60 min of high flow anoxia and 40 min of reoxygenation. Ventricular function and tissue contents of phosphorylated metabolites were monitored concomitantly using standard procedures and 31P magnetic resonance spectroscopy respectively. EXPERIMENTAL MATERIAL: Hearts were removed from male Wistar rats weighing 350-400 g. Results from eight hearts were pooled for each of the five fatty acids perfused. MEASUREMENTS AND MAIN RESULTS: High coronary flow maintained during anoxia led to an increased extracellular washout of lactate and only to mild intracellular acidosis, limiting myocardial damage by metabolites of anaerobic glycolysis. Under these conditions, marked differences between the classes of perfused fatty acids were observed. Hearts which received oleic acid showed the most depressed ventricular function and a greater depletion in high energy phosphates content. These deleterious effects were completely reversed by the separate administration of two fatty acid metabolism blocking agents, nicotinic acid and oxfenicine. Cardioprotection was enhanced by perfusion of polyunsaturated fatty acids (linoleic acid, alpha and gamma linolenic acids). Hearts perfused either with glucose or with palmitic acid behaved similarly and showed an intermediate functional and metabolic postanoxic recovery. CONCLUSION: This study documents the relation between the chemical structure of exogenous fatty acids used in heart perfusion and their ability to improve or impair postanoxic myocardial recovery. The cardioprotective effect of polyunsaturated fatty acids was documented by simultaneous evaluation of mechanical performance and metabolic response.
Animals↗
[The malunited juvenile fracture--Monteggia defect].
Late reconstruction after neglected Monteggia lesions in children is discussed. On the basis of the literature (20 cases) and 2 personal cases it is deduced that open reduction of the radial head should be combined with osteotomy of the ulna according to the pathophysiology of the lesion. Details of the operative procedure are given. Reconstruction of the annular ligament is the least important part. Reconstruction is indicated in children under the age of 10-12 years even if the dislocation has been present for years. Unfavorable conditions for operative reconstruction are long-lasting dislocations in older children, deformation of the radial head, and imminent skeletal maturity.
Adolescent↗
[Alpha-L-fucosidase of normal and pathological blood cells].
The glycosidases, enzymes which participate in the degradation of glycoproteins and glycolipids inside the lysosomes are themselves glycoproteins and, for one enzyme, several forms may be isolated in tissues and in biological fluids, corresponding to variations in the composition or the structure of their glycanic moiety. We have previously studied the different forms of alpha-L-fucosidase in human serum, kidney and urine. Some modifications of the glycanic fraction of glycoproteins have been described in various forms of tumoral cells; therefore, we have attempted to verify if the alpha-L-fucosidase of blood cells might be a useful marker in the diagnosis of leukemias, using the enzymic pattern obtained by chromatographic or electrofocusing methods. Detergent extracts from normal lymphocytes, submitted to ion-exchange chromatography as well as to chromatofocusing, revealed the presence of two forms of alpha-L-fucosidase, A and B, with respective pIs of 5.7 and 6.2. After treatment by neuraminidase, these two forms remain distinct, showing that the degrees of sialylation is not the only difference. Moreover, after desialylation, the two forms have not the same affinity for concanavalin A, an argument for the heterogeneity of the glycanic structures. The determination of the total activity, and of enzymic patterns of alpha-L-fucosidase from leukemic cells led to the observation of three types of modifications, in comparison with normal lymphocytes: quantitative variations in the total activity; variations in the proportions of the two forms; variations due to the modification of pIs. We have studied the lymphocytes from four patients with a hairy-cell leukemia (HCL), four patients with chronic lymphoid leukemia (CLL) and the MO cell-line, proceeding from a HCL. In all cases, the total fucosidase activity is strongly decreased in comparison with normal lymphocytes activity. The chromatofocusing pattern for CLL cells reveals the presence of the A and B forms, without modification of their eluting pH. A characteristic pattern is obtained with hairy cells, presenting only the B form, eluted in more acidic conditions. The normal lymphocytes in peripheral blood are for 80 per cent of the T phenotype, and the CLL lymphocytes exhibit the phenotypic markers B, as well as the hairy cells, but the MO cell-line acquires in culture the T markers. As these last cells express both the A and B forms of enzyme, the absence of the A form of alpha-L-fucosidase seems to be a marker of the HCL.(ABSTRACT TRUNCATED AT 400 WORDS)
Biomarkers↗
Application of reverse-DEPT polarization transfer pulse sequence to study the metabolism of carbon-13-labeled substrates in perfused organs by 1H NMR spectroscopy.
Metabolism of 13C-enriched metabolites can be advantageously studied by reverse-polarization transfer methods. In this work an improved reverse-DEPT sequence has been applied for the first time on perfused organs in a 20-mm probe. The metabolic fate of 99% enriched [2-13C]acetate perfused in excised rat liver and heart has been documented.
Acetates↗
Human urinary and renal alpha-L-fucosidases. A comparative study.
1. Enzymatic forms of alpha-L-fucosidase from human renal tissue and urine were investigated. 2. In renal tissue two different isoenzymatic patterns were obtained by chromatofocusing of either directly soluble or detergent solubilized extracts. 3. On the other hand the urinary isoenzymatic pattern is similar to that obtained for the renal soluble extract.
Adult↗
Umbilical cord blood gases for term healthy newborns.
Examination of paired umbilical arterial and umbilical venous blood gases for 147 term, healthy newborns revealed a strong correlation of pH, bicarbonate, and base excess with the 1-minute Apgar score. Although significantly different from each other, a strong correlation existed between the gas measurements of the two vessels. The lower limit of pH for the umbilical artery was 7.12 and for the vein, 7.25. The arterial-venous difference for bicarbonate but not pH, oxygen or carbon dioxide tension, or base excess was correlated with the 1-minute Apgar score.
Apgar Score↗
Intracellular pH and role of Na+/H+ exchange during ischaemia and reperfusion of normal and diabetic rat hearts.
STUDY OBJECTIVE: The aim was to investigate the role of intracellular pH (pHi) and ion exchange on the functional recovery of perfused hearts isolated from normal (N) rats either receiving or not receiving amiloride (an Na+/H+ exchange inhibitor), and from STZ induced diabetic (D) rats with decreased Na+/H+ exchange activity. DESIGN: Working heart preparations were submitted to a zero flow ischaemic period of 30 min at 37 degrees C and then reperfused for 30 min. The time course of pHi decline during ischaemia and of recovery on reperfusion was followed by means of 31P-NMR. MEASUREMENTS AND MAIN RESULTS: In N hearts without amiloride, ischaemia caused a progressive decrease in pHi. This was slightly, although not significantly, more abrupt in N hearts receiving amiloride. D hearts showed a slower fall in pHi, but the mean value reached after 30 min did not differ significantly from that of normal hearts. pHi recovery on reperfusion was markedly slower in the D hearts compared to N hearts. The mean value reached after 30 min did not differ significantly from that of N hearts. pHi recovery was also markedly slower in N hearts exposed to amiloride during both ischaemia and reperfusion. The higher functional recovery on reperfusion, as assessed by the recoveries of aortic flow and stroke volume, was observed for those hearts with slower pHi recovery. Improved recoveries of aortic flow and stroke volume as compared to normal non-treated hearts were 34% and 21% for the diabetic hearts, and 22% and 40% for the normal hearts receiving amiloride. CONCLUSIONS: The comparison of data from diabetic rat hearts with reduced activity of the Na+/H+ exchange process v normal hearts with pharmacological block of the exchanger provide support for a critical role of the Na+/H+ exchanger in the initial stage of reperfusion.
Amiloride↗
Effect of inhibitors on conformational changes in hen lysozyme around thermal transition point in solution and solid state.
Carbon-13 NMR spectroscopy has been used to further document the interaction, at low and high temperatures, of N-acetylglucosamine and its short polymers with hen egg-white lysozyme. The results have been compared with the corresponding X-ray crystallographic data. Two domains, the active site and the hydrophobic box, have been found by NMR to undergo conformational rearrangement while X-ray crystallography only detected changes located in the active site. The extent of the modifications induced by inhibitor binding was proportional to the inhibitor size. The two techniques concurred to show that even in the presence of monosaccharide (N-acetylglucosamine), more than one subsite of the enzyme was occupied at high temperature, the binding at the C-site being the best defined. The thermal transition of lysozyme still occurred in solution when inhibitors were bound. However, in the solid state, crystallographic data showed that the transition was hindered.
Acetylglucosamine↗
Pediatric acquired immunodeficiency syndrome: an unusually high incidence of twinning.
Surveillance data on incidence of twins among reported cases of pediatric AIDS in New York City are presented. Most pairs are concordant for HIV infection. Three discordant pairs have been described elsewhere. Possible reasons for the association are discussed, including the most likely explanation that twins show symptoms early and are overrepresented in the early years of surveillance of pediatric AIDS.
Acquired Immunodeficiency Syndrome↗
[Reconstruction of the proximal insertion of the anterior cruciate ligament. Studies on the accuracy of a non-instrumental method].
The isometry of the femoral and tibial insertion is of decisive importance for the stability of a prosthetic anterior cruciate ligament. A large number of techniques and instruments have been developed to determine the point of isometric femoral insertion. Experiments with 20 cadaveric knees show that the proximal insertion of the anterior cruciate ligament is accurately reconstructed by means of the surgical procedure briefly presented in this paper; the use of positioners is not necessary.
Anterior Cruciate Ligament↗
[Qualitative and quantitative assessment of lipid consumption in the intake of a community].
Most nutritional studies assess the nutriment allowance of a selected population from inquiries and tables of food components. Very few of them use biochemical analysis of lipid extraction, which is a more reliable process. In other respects, the investigations on the real consumption of the population are scarce. Our study aims to assess the lipid consumption of subjects submitted to normal feeding in hospital food service, from biochemical analysis of allowances and of non-consumed food. The allowances of 10 dietary days and the whole of the non-consumed food a 10 subjects by dietary day have been assessed. The results show that: 1) the ratio of fat in the non-consumed food (7.5% in wet weight) exceeds that of the proposed intake (6.6%); 2) the consumed food (1,900 KCal/d) represents 80% of the initial total calorie allowance and includes 37.5% lipid calories (71% of initial lipid allowance); 3) the distribution of the consumed fatty acids (FA) is identical to that of the fatty acids of the initial intake and not in conformity with the recommendations of the FAO/WHO Board: 53% saturated FA, 34% mononunsaturated FA, 13% polyunsaturated FA and P/S ratio: 0.23; 4) mono and polyunsaturated FA are eliminated in the non-consumed food, more particularly in unclean plates where the distribution is very near the recommended one: 48% monounsaturated FA, 21% polyunsaturated FA, 31% saturated FA and P/S ratio: 0.8; 5) in spite of these data, the consumption of essential FA remains satisfactory: 7 g of linoleic acid, and 1.5 g of linolenic acid; 6) the consumption of cholesterol (215 mg/d), corresponding to 3/4 of the initial allowance, is satisfactory. The whole of these results are correlated with the Table of Food Components and two dietary softwares.
Aged↗
Failure to detect complement-mediated antibody-dependent cytotoxicity against human orbital tissue cells in the serum of patients with thyroid-associated ophthalmopathy.
Antibodies which are cytotoxic to human eye muscle cells and orbital fibroblasts in antibody dependent cell-mediated cytotoxicity (ADCC) are routinely detected in the serum of patients with thyroid-associated ophthalmopathy (TAO). In the present study sera from patients with TAO, most of which were shown to be positive in ADCC against eye muscle cell targets, were tested for complement-mediated antibody-dependent cytotoxicity (CMAC) against human and pig eye muscle cells, human (abdominal) skeletal muscle cells and human orbital fibroblasts, in 51Cr release assays. Several different assay protocols and complement sources were used and patient and age, sex matched normal sera compared. In preliminary studies tests were always negative when eye muscle cells, other skeletal muscle cells, or orbital fibroblasts were used as targets, regardless of the complement source, or concentration, or assay conditions used. When larger numbers of patients and normals were tested in a single assay mean (+/- SE) % specific lysis for patients with TAO was not significantly different from that for normals for either eye muscle cells or other skeletal muscle cells and taking the upper limit of normal as mean + 2 SD for the normals, tests were positive in no patient with either target. On the other hand ADCC tests were positive in 57% of the same sera tested with the same eye muscle cell targets. When human thyroid cells were used as targets, tests were positive in 10 of the 14 patients tested and monoclonal antibodies, in enzyme-linked immunosorbent assay, reactive with eye muscle antigens gave positive lysis of eye muscle cells.2+ t
Adult↗
[Optimal treatment of complex ligament injuries and biomechanical aspects].
Certain guidelines may be established for surgical treatment of complex lesions of genicular ligaments. Preferential treatment should be given to the central stabilizers, anterior and posterior cruciate ligaments. Suturing with autologous augmentation is the rule for the anterior cruciate ligament, whereas the posterior cruciate ligament should be stabilised by both suturing and relief, using a transosseous PDS cord. The main peripheral ligaments, internal and external ligaments as well as arcuatum complex, have to be sutured, once instability has been confirmed. In cases of complex injuries, lateral structures are more important than median peripheral structures. Sutures should be tied for good stability. Non-absorbable material is used in cases in which stability of anchorage should enable no-plaster after-care. Sutured ligaments should be tension-adjusted close to stretching position (Lachman position, for main ligaments) and with neutral rotation. Sutures in shortened position may undergo rupture and thus jeopardize suturing at all. Only sutures for the posterior cruciate ligament should be strained close to rectangular position, since this actually represents maximum tension of the posterior cruciate ligament. Knee joint luxation is usually based on damage to all three ligaments, though two-ligament injuries are possible. Surgery is the optimum approach, since it is the only way to accomplish mechanically favourable adaptation of the central stabilizers.
Biomechanical Phenomena↗