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Biomedical subjects

C Picard

Publications and source records attributed to C Picard.

At least 73 records · Page 4Linked to original sources
PubMed1997

Morphology of the acetabulum in hip dislocations caused by cerebral palsy.

Twenty-four hip joints in 20 children with spastic cerebral palsy were assessed by standardised three-dimensional reconstructions from computed tomographic scans. All the hip joints showed a channel-like ebony deformity of the acetabulum along which the femoral bead had slid out, indicating a unidirectional instability. The channel was oriented along the longitudinal axis of the body within a sector of 25 degrees anteroposteriorly. In relation to the pelvis, the dislocation was directed more dorsally by 20 degrees as a result of a flexion contracture of the hip. The size of the femoral head corresponded with the size of the acetabulum in every case, even in long-standing dislocations.

Acetabulum↗
PubMed1997

Embodied soul. The focus for nursing praxis.

This article explores the nature of embodied soul as a phenomenon of concern to nursing. Examples of the body/soul debate from early Greek philosophers to the present day are examined. Early writings on the subject echo in medieval writings and in present-day knowledge of neuroscience and physics, as well as in the writings of Merleau-Ponty. The author proposes that nursing embrace the concept as it relates to Berry's patterns of differentiation, subjectivity, and communion in the universe. These patterns exist from the cellular to the cosmic level. It is through the embodied soul that one engages in this process. The works of selected nurse theorists are examined as they relate to the topic. Both the subject of the client and of the nurse as embodied souls are addressed.

History, 17th Century↗
PubMed1997

Polyarthritis with cutaneous mucinosis and intrasynovial mucin deposits.

We report the first case of cutaneous and articular mucinosis with presence of mucin deposits within the synovium in an HIV-positive patients. Presentation was asymmetric polyarthritis, and subcutaneous nodules developed two months later. Treatment was with hydroxychloroquine. The outcome of both the skin and joint lesions was favourable.

Adult↗
PubMed1996

The immunosuppressant SR 31747 blocks cell proliferation by inhibiting a steroid isomerase in Saccharomyces cerevisiae.

SR 31747 is a novel immunosuppressant agent that arrests cell proliferation in the yeast Saccharomyces cerevisiae, SR 31747-treated cells accumulate the same aberrant sterols as those found in a mutant impaired in delta 8- delta 7-sterol isomerase. Sterol isomerase activity is also inhibited by SR 31747 in in vitro assays. Overexpression of the sterol isomerase-encoding gene, ERG2, confers enhanced SR resistance. Cells growing anaerobically on ergosterol-containing medium are not sensitive to SR. Disruption of the sterol isomerase-encoding gene is lethal in cells growing in the absence of exogenous ergosterol, except in SR-resistant mutants lacking either the SUR4 or the FEN1 gene product. The results suggest that sterol isomerase is the target of SR 31747 and that both the SUR4 and FEN1 gene products are required to mediate the proliferation arrest induced by ergosterol depletion.

Amino Acid Sequence↗
PubMed1995

Structural elucidation of novel methylglucose-containing polysaccharides from Mycobacterium xenopi.

The structures of methylglucose-containing polysaccharides (MeGlc PS) from Mycobacterium xenopi were investigated using high-pH anion-exchange chromatography and liquid secondary-ion mass spectrometry. We report the structure of two novel MeGlc PS, referred to as A and B. MeGlc PS A is composed of 16 D-glucopyranose residues, 11 of which are methylated, and MeGlc PS B contains 15 D-glucopyranose residues, 10 of which are methylated. The main structural feature of both MeGlc PS A and B, compared to the previously described structures, is the absence of the tetrasaccharide non-reducing end 3-O-Me-D-Glcp-[alpha(1-->4)-D-Glcp]3. The MeGlc PS A structure is similar to the synthetic polysaccharide [Saïer, M. H. & Ballou, C. E. (1968) J. Biol. Chem. 243, 992-1005], having a lower affinity for fatty acids than the MeGlc PS of Mycobacterium smegmatis [Kiho, T. & Ballou, C. E. (1988) Biochemistry 27, 5824-5828]. Thus, the occurrence of MeGlc PS A and the consequences on the regulation of fatty acid synthetase I activity involved in the biosynthesis of fatty acids, precursors of mycolic acid biosynthesis, is discussed.

3-O-Methylglucose↗
PubMed1995

A simple and automated HPLC method for determination of total hydroxyproline in urine. Comparison with excretion of pyridinolines.

An HPLC method for measuring total hydroxyproline in human urine was validated. Hydroxyproline derivatization was achieved with 9-fluorenylmethyl chloroformate after blocking primary amino acids with orthophthaldialdehyde. The derivatives (hydroxyproline and internal standard) were separated by reversed phase high-performance liquid chromatography and detected by absorbance at 254 nm. Duplicate measurements of hydroxyproline have a coefficient of variation of 3.9% and the recovery in spiked urine samples is between 99.5 and 100.8%. We have compared the HPLC procedure with a commercial colorimetric assay. Analytical criteria of these methods are identical. Regression analysis, involving 50 samples, shows an excellent correlation between hydroxyproline chromatographic (y) and colorimetric (x) procedures: y = 0.989x + 2.99 (r = 0.976). Hydroxyproline excretion was determined in urine samples from 76 women more than 5 years post-menopause. The mean hydroxyproline/creatinine ratio in this group was 19.3 +/- 5.6 mumol/mmol (range 10.6-34.7). Finally, we compared in the same urinary samples hydroxyproline excretion with pyridinoline excretion (hydroxylysylpyridinoline and lysylpyridinoline), a new marker of bone resorption. The values show a significant correlation, with r = 0.417 for hydroxylysylpyridinoline and r = 0.443 for lysylpyridinoline.

Aged↗
PubMed1995

Multiple molecular forms of pyridinolines cross-links excreted in human urine evaluated by chromatographic and immunoassay methods.

The measurement of the collagen cross-links, hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP), excreted in urine either in free or peptide-bound forms represents the most extensively investigated biochemical marker of bone collagen degradation. We studied the urinary molecular forms of pyridinolines after separation in free and peptide-linked fractions by chromatography and serial dialysis. The pyridinoline amounts of molecular species (free, < 1000 D, 1000-3500 D, 3500-10,000 D, and > 10,000 D) were evaluated by high performance liquid chromatography (HPLC) as well as with the two newly introduced enzyme-linked immunosorbent assay (ELISA) methods for determination of free pyridinolines (collagen Pyrilinks and collagen Pyrilinks-D). The variability of urinary pyridinoline forms were studied in healthy adult control subjects (n = 10, 38.4 +/- 7.5) years), in adolescents (n = 10, 16 +/- 3.3 years), and in elderly subjects with vitamin D insufficiency (n = 10, 87.3 +/- 4.3 years). Free and peptide-conjugated pyridinolines with MW < 1000 D constitute the major part of urinary cross-links in all groups, with a significantly lesser excretion in elderly patients than in adolescent groups. Expressed as a percent of total cross-links, urinary free pyridinolines assessed by direct HPLC are less in elderly subjects (HP = 34.2 +/- 6.2%, LP = 32.7 +/- 7.6%) than in adolescents (HP = 45.8 +/- 10.8%, p = 0.0065 and LP = 47.8 +/- 12.1%, p = 0.012) and in healthy adults (HP = 39.3 +/- 11.5%, NS and LP = 38.1 +/- 9.3%, NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Images of caring in nursing and dance.

This article explores the existence of common images in nursing and dance. Nurses can look to the performing arts and music to sustain their commitment to clinical practice. The dancer must bring the whole self to the dance: history, mind, body, and spirit. The dancer creates beauty and grace and interpretive images for the audience. Nursing involves "dancing on the edge" where one must balance Roach's five elements of caring with one's self to meet the needs of the patient. For both nursing and dance, excellence begins with a centering of the self in order to create and relate to the other. Through the dance, one comes to experience beauty and grace. Images from dance can nourish one's creative caring spirits.

Dance Therapy↗
PubMed1994

Rat platelets contain glycosylated and non-glycosylated forms of platelet factor 4. Identification and characterization by mass spectrometry.

Platelet factor 4 is a heparin-binding protein released from the alpha granules of activated platelets. This study describes the purification and identification of two forms of rat platelet factor 4, the previously characterized non-glycosylated form of 7 kDa and an additional glycosylated form of molecular mass 9 kDa. The two proteins both neutralized the antithrombin-III-dependent inhibitory activity of heparin. Although their amino acid composition was found to be the same, in the N-terminal sequence of the 9-kDa protein, the second threonine residue could not be detected and a difference of 976Da was determined by mass spectrometry. After digestion with O-glycanase and sialidase, the two proteins showed the same molecular mass. Overall consideration of these data led to identification of the higher-molecular-mass protein as a glycosylated form of rat platelet factor 4 with O-glycosylation at the second N-terminal amino acid, while the structure of the oligosaccharide core was established by mass spectrometry and sugar differentiation with lectins. The two forms of platelet factor 4 are both present in platelets and secreted after platelet activation.

Amino Acid Sequence↗
PubMed1994

Zaidel's model of interhemispheric dynamics: empirical tests, a critical appraisal, and a proposed revision.

Zaidel has proposed a model of intra- and interhemispheric dynamics which attempts to explain field and hand effects in visual reaction time experiments. The model includes prototypes of two extreme cases: a "callosal relay" pattern, in which interhemispheric transfer is inferred, and a "direct access" pattern, in which each hemisphere is inferred to execute the task independently. Five visual reaction time experiments were carried out to test six predictions which Zaidel has made within the framework of his model. Some of these predictions were supported but others were rejected. These findings, in conjunction with findings of other researchers, were critically analyzed in view of determining the extent to which Zaidel's model can be revised in order to fit the ensemble of relevant findings. It was concluded that the model can indeed be revised but that this requires a redefinition of conditions indicative of presence or absence of interhemispheric relay. A new model is proposed assuming exclusively excitatory callosal relay and focussing on magnitude and valence of field effects obtained at each hand, considered in their interrelation.

Adult↗
PubMed1994

Three-dimensional coronary arteriography.

In this paper we present a new imaging technique for three-dimensional (3-D) X-ray coronary arteriography. The goal is to provide in near to real-time a 3-D representation of the coronary arterial tree, helpful to better understand its topology and locate the possible lesions. The 3-D reconstruction of the coronary arteries is obtained from a set of X-ray conic projections acquired during a rotation of the imaging chain around the patient. Images are taken before and after injection of contrast agent. A subset of mask and opacified images is selected, corresponding to the same phase in the cardiac cycle. These images are subtracted and corrected for geometric distortion. The reconstruction is performed by using a two-step non-parametric detection/estimation method. Due to heart motion and propagation of the contrast agent, the number of available projections is very small. Typically 4 or 6 projections are available if the opacification is stable during 2 or 3 cardiac cycles and when using a biplane acquisition system. High resolution 512(3) reconstructions of the coronary arteries from a cadaver heart are presented, with a voxel size of 0.4 mm. The 3-D reconstruction provides a good 3-D representation of the global structure, even with a number of projections as small as 4.

Computer Graphics↗
PubMed1994

Urinary excretion of pyridinolines crosslinks measured by immunoassay and HPLC techniques in normal subjects and in elderly patients with vitamin D deficiency.

Hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) are specific constituents of mature skeletal collagens excreted in urine. Their measurement represents a sensitive index of bone resorption. In this study, we have measured urinary excretion of pyridinolines crosslinks by immunoassay (ELISA) and HPLC methods in 80 patients with different bone resorption rates. We chose a sample of 44 healthy adults (30 men and 14 women) and a sample of 36 elderly patients (7 men and 29 women) presenting a secondary hyperparathyroidism due to a vitamin D deficiency. The correlation between HPLC (x) and ELISA (y) was judged satisfactory (y = 0.794x + 6.947, r = 0.92). The sensitivity of pyridinolines estimation was 50 nmol/l for immunoassay and 20 nmol/l for HPLC. The intra-assay and inter-assay coefficients of variation for the two analytical methods was < 10%. The mean excretion of crosslinks (nmol/mmol of creatinine) measured by both methods in the sample of healthy adults was higher in women than in men. The amount of pyridinolines crosslinks excreted by elderly patients with vitamin D deficiency are three time higher than those of normal adults when measured by ELISA and HPLC methods. The distribution of different molecular forms of urinary pyridinoline crosslinks was investigated. Values of pyridinolines measured by HPLC in our samples of elderly patients have shown that free and peptide-bound pyridinolines with molecular weight (mol. wt.) smaller than 1000 Da represent approximately 80% of the total pyridinolines contained in urinary samples. A study on the evaluation of the antiserum used in the immunoassay for reacting with the different molecular forms isolated from urine showed a high affinity for free and peptide-bound pyridinolines with molecular weight smaller than 10,000 Da and that do not react strongly with peptide-bound with molecular weight greater than 10,000 Da. We conclude that, although this immunoassay does not measure total pyridinolines and does not distinguish between HP and LP, it seems convenient for diagnostic of metabolic bone diseases.

Adult↗
PubMed1994

In vivo evaluation of a new system for 3D computerized angiography.

A new system has been designed and built to validate the concept of 3D computerized angiography (CA). This system can acquire a set of 2D digital subtracted angiography images while rotating around a patient and then, using these images, reconstruct a 3D representation of the opacified vasculature. The design principles and main characteristics of the system are described, with special attention paid to data processing aspects. An initial in vivo evaluation of this system performed on anaesthetized animals and human volunteers is presented. The influence on the quality of the 3D reconstruction of different factors such as volume resolution, estimation method, source trajectory and number of projections is discussed.

Angiography↗
PubMed1994

Two-site immunoassay of recombinant hirudin based on two monoclonal antibodies.

Two monoclonal antibodies (mAbs), 10-2 and 10-5, both directed against recombinant hirudin variant 2-Lys47 (rHV2), were selected for their high affinity and epitopic specificities to develop a two-site immunoassay of rHV2. The mAb concentrations, incubation time, and temperature were optimized. The immunoassay has a detection limit for rHV2 of 45 ng/L in plasma and 30 ng/L in urine. The reactivity of the mAbs was tested against rHV2 and several forms of this protein truncated in the carboxyl terminus. The capture mAb 10-2 was found to be mainly directed against rHV2, whereas tracer mAb 10-5 was independent of the carboxyl-terminal region of the protein. This explains the high specificity of the immunoassay for the 65-amino acid form of hirudin.

Antibodies, Monoclonal↗