The barbarians are at the gate.
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Adolescent↗
Biomedical subjects
N Girard
Publications and source records attributed to N Girard.
Blood products replacements processed in the surgical field.
This article summarizes the main blood products that can be gathered from, treated, and returned to the trauma patient in the operating room. A brief description of the physiology of blood and clotting mechanisms is given. A focus on plasma pheresis is provided, as well as a suggested procedure for plasma collection.
Blood Banks↗
Anesthesia and learning: the mind-body connection.
Patient learning depends on the ability to process information during the perioperative experience. This article provides a brief review of cognition/anesthesia. It then presents findings of an exploratory study (N = 49) that looked at recognition recall, free recall, and psychomotor performance ability immediately preoperatively and 2 hours after surgery in patients having ambulatory surgery with general anesthesia. Findings showed a decrease in all three mental abilities from the preoperative to postoperative time, regardless of length of time of anesthesia administration, or number or kind of anesthetic agent.
Anesthesia, General↗
Perineuronal nets provide a polyanionic, glia-associated form of microenvironment around certain neurons in many parts of the rat brain.
The nature and function of previously described perineuronal nets are still obscure. In the present study their polyanionic components were demonstrated in the rat brain using colloidal iron hydroxide (CIH) staining. In subcortical regions, such as the red nucleus, cerebellar, and vestibular nuclei, most neurons were ensheathed by CIH-binding material. In the cerebral cortex perineuronal nets were seen around numerous nonpyramidal neurons. Biotinylated hyaluronectin revealed that hyaluronan occurs in perineuronal nets. Two plant lectins [Wisteria floribunda agglutinin (WFA) and Vicia villosa agglutinin (VVA)] with affinity for N-acetylgalactosamine visualized perineuronal nets similar to those rich in anionic components. Glutamic acid decarboxylase (GAD)-immunoreactive synaptic boutons were shown to occupy numerous meshes of perineuronal VVA-positive nets. Electron microscopically, VVA binding sites were scattered throughout perisynaptic profiles, but accumulated at membranes and in the extracellular space except not in synaptic clefts. To investigate the spatial relationship between glial cell processes and perineuronal nets, two astrocytic markers (S100-protein and glutamine synthetase) were visualized at the light and electron microscopic level. Two methods to detect microglia by the use of Griffonia simplicifolia agglutinin (GSA I-B4) and the monoclonal antibody, OX-42, were also applied. Labelled structures forming perineuronal nets were observed with both astrocytic, but not with microglial, markers. It is concluded that perineuronal nets are composed of a specialized type of glia-associated extracellular matrix rich in polyanionic groups and N-acetylgalactosamine. The net-like appearance is due to perisynaptic arrangement of the astrocytic processes and these extracellular components. Similar to the ensheathment of nodes of Ranvier, perineuronal nets may provide a special ion buffering capacity required around various, perhaps highly active, types of neurons.
Acetylgalactosamine↗
In vivo MRI of the fetal brain.
We report MRI of the brain in 45 fetuses; the findings were confirmed by pathological examination or postnatal neuroradiological studies. MRI necessitates medication to eliminate fetal motion; curare was injected into the umbilical cord, and MRI is therefore limited to cases in which umbilical cord puncture is indicated. T1-weighted images were obtained in axial, sagittal and coronal planes; the last of these were generally as the most useful as regards morphology. We demonstrated cerebral malformations (n = 13), brain haemorrhage (n = 1), a facial angioma (n = 1), a facial mass (n = 1), hydrocephalus (n = 5), unilateral ventricular enlargement (n = 1), atrophy (n = 4), a porencephalic cyst (n = 1) and normal appearances of the brain in 18 cases. Twenty-two of the fetuses were born alive, and the clinical and/or neuroradiological examination confirmed the antenatal findings. The diagnosis was also confirmed in 8 cases in which a neuropathological examination was possible.
Agenesis of Corpus Callosum↗
Prenatal diagnosis of fetal cerebral abnormalities by ultrasonography and magnetic resonance imaging.
We found magnetic resonance imaging (MRI) of the fetal brain to be effective in confirming or denying diagnosis of fetal cerebral defects when ultrasonography was inconclusive or incomplete. In this paper we describe 31 cases in which ultrasonographic evidence of fetal brain defects was verified by MRI. MRI was performed after curarization of the fetus. In 21 cases, ultrasonographic evidence was confirmed by histological study of the fetus or postnatal radiological examination. In 10 cases, ultrasonographic diagnosis was denied by MRI and healthy infants were born. In one case of cerebral toxoplasmosis, ultrasonography detected periventricular calcifications but MRI was normal. In 20 cases MRI ascertained or further documented the ultrasonographic findings. However in 4 of these 20 cases autopsy of the fetus was required to determine the exact nature of the lesion.
Adult↗
Nursing care delivery models. The perioperative environment.
Changes in health care on the national level are affecting perioperative nursing drastically. Perioperative nursing needs innovative approaches to guide the delivery of nursing care for patients whose operative procedures are performed outside traditional institutions. Managed care and case management are gaining in importance as more surgical procedures are performed in the outpatient arena. New minimally invasive techniques call for new models of delivering professional nursing care. Any model that is developed must ensure that professional perioperative nursing is rewarded, quality patient care provided, and surgical procedure expenses reimbursed.
Humans↗
Professional nursing care delivery model. Implications for the perioperative setting.
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Delivery of Health Care↗
Hyaluronan and hyaluronectin in the extracellular matrix of human brain tumour stroma.
Hyaluronan (HA) and the hyaluronan-binding glycoprotein hyaluronectin (HN) were measured in 23 gliomas and 8 meningiomas and their location was revisited in 35 tumours. A clear-cut difference was found in the HN/HA ratio values of glioblastomas (below 0.5) and that of astrocytomas (above 0.5 P < 0.001). Besides their location in the intercellular part of gliomas, HA and HN displayed a perivascular location in 1/3 astrocytomas, 17/24 glioblastomas, and 3/7 meningiomas, suggesting they could be produced also by the vascular stroma of tumours and that they would characterise the neoangiogenesis. All cultivated glioma cells tested produced HA in vitro, whereas only 1/11 cell lines produced HN, at a low level. The results obtained suggest that glioma HA and HN are produced by both cancer cells and vascular stroma cells, which contribute to the edification of the extracellular matrix. In meningiomas only the stroma would be responsible for HA and HN production.
Adolescent↗
Preparing the CNS for participation in quality assurance activities.
Preparation of CNSs must include advanced knowledge in the area of clinical specialty and experience in the various subroles of the clinical specialist. In order to enhance students' knowledge and skills related to these subroles, the authors instituted a clinical project focusing on quality assurance activities for students enrolled in the medical-surgical nursing major in a large graduate nursing program. Students begin the project during the clinical practicum by identifying an area in need of quality assurance monitoring. Students then develop monitoring tools, collect data, and make recommendations for changes in clinical practice. The project gives the students practical experience in an important area of clinical specialist practice and can be adapted or expanded for any clinical major.
Education, Nursing, Graduate↗
Caffeine decreases glial cell number and increases hyaluronan secretion in newborn rat brain cultures.
Newborn rat brain astrocytes (type 1 astrocytes, O-2A progenitor cells, and O-2A progenitor-derived cells, i.e. oligodendrocytes and type 2 astrocytes) were cultivated to investigate the effect of addition of caffeine to the culture medium on glial cell development and secretion of hyaluronan (hyaluronic acid, HA). HA is a glycosaminoglycan, secreted by type 1 astrocytes especially, which is a major component of the extracellular matrix of immature brain involved in morphogenesis and differentiation. Caffeine was added to the culture medium of primary glial cell cultures at concentrations of 102 microM (20 mg/L) or 255 microM (50 mg/L), considered therapeutic and toxic levels, respectively, in human newborns. HA was measured in the culture medium by immunoenzyme assay using sheep brain hyaluronectin, a glycoprotein that exhibits a strong affinity for HA, as probe. In primary glial cell cultures, 102 microM (20 mg/L) caffeine had no visible effect on cell number or on HA secretion. At 255 microM (50 mg/L), there was a significant reduction of cell number (i.e. type 1 astrocytes, O-2A progenitor cells, and progenitor-derived cells) and a significant increase of HA secretion per cell. These results suggest that caffeine at a high concentration in brain could have a prejudicial effect on the number of proliferating glial cells (astrocytes and oligodendrocytes) and on the composition of the extracellular matrix, which could affect myelination onset.
Animals↗
Expression of the hyaluronan-binding glycoprotein hyaluronectin in leukemias.
Hyaluronectin (HN), a hyaluronan (hyaluronic acid, HA)-binding glycoprotein is normally expressed in the nervous system, found in the desmoplasia of tumours, and is also produced in vitro by peripheral blood mononuclear cells. We have therefore investigated the expression and the production of HN by leukemic cells, with the hypothesis that HN would be expressed in leukemias of the myeloid lineage. Fresh and frozen leukemic cells were studied from 70 patients of whom 53 had acute myeloblastic leukemia (AML). HN was strongly expressed (> 80% blood cells) in two out of 13 M4 AMLs and four out of four M5B AMLs. One further M4 AML displayed 25% positive cells and two 20% cell positivity cases were seen, in one case of M4 AML and in one case of chronic myelomonocytic leukemia (CMML). The rest of the cases of AML as well as all cases of acute lymphoblastic leukemia (ALL) showed almost no positivity (< 1%). The residual positive cells appeared to be normal blood promonocytes. Taken together > or = 20% positive cells was seen in eight out of 56 (14%) examined myeloid leukemias. The HN production was significantly higher (p < 0.0001) in cell culture media of M4 and M5 AML cells than in other AML or ALL cell culture media. A significant correlation was found (p < 0.0001) between the number of HN-positive leukemic cells and the number of cells with a monocytic morphology, suggesting that HN is a marker for the promonocyte.
Acute Disease↗
111In-hyaluronectin, a new probe for radiodetection of tumours: biodistribution and imaging in grafted mice.
Hyaluronectin (HN), a glycoprotein which shows a strong specific affinity for Hyaluronic Acid (HA), a very high molecular weight glycosaminoglycan expressed in the stroma reaction of all tumours, was used to radiolocalize grafted autologous carcinomas (CB33 and CB03) in mice. After conjugation to DTPA (0.5-3.7 DTPA/HN) and radiolabelling with 111In (5 microCi/micrograms HN) HN retained 93% of its affinity for HA. Different preparations of HN purified from lamb brain were assayed. The best results were obtained when the HN molecules reactive with HA were selected by gel permeation to discard unreactive molecules which were unable to complex with HA. At 48 hours the tumour to blood ratio was 7.7 with a localization index of 2.2 in CB33; there was 2.8% uptake of the injected dose (ID) into CB33 and 1.6% into CB03. 111In-HN uptake per gram of tumour was tumour-size dependent: the smaller masses had the higher uptake. Tumours were visualized and either early images of 111In-HN distribution or simultaneous distribution images of 99mTc-phytate or 201Tl-DTPA were used for the subtraction treatments.
Animals↗
Evaluation of three-dimensional MRI exploration of prolactin-secreting microadenomas.
Over an 8-month period (July 1990-to February 1991), we explored 21 women presenting with a clinical and laboratory profile of prolactin-secreting microadenoma of the pituitary gland. Magnetic resonance imaging (MRI) is undoubtedly the most efficient method to explore microadenomas, especially when carried out in the absence of any treatment. In 8 cases, MRI was performed in the absence of medical treatment and gave a positive result, i.e. always showed a focal lesion. In the remaining 13 cases the patients had been treated before the exploration, and MRI detected a microadenoma in only 4 cases. The duration of treatment and the time elapsed between its withdrawal and the MRI examination did not seem to influence the positivity or negativity of the imaging results. Among the 9 cases where MRI failed to show a focal lesion, the image was normal in 3 cases and displayed an arachnoidocele in 3 cases; the pituitary gland was convex and homogeneous in 1 case and convex and heterogenous in 3 cases, which raised the problem of the effects of bromocriptine on the MRI images. As regards signals, in 5 cases the microadenoma was hyperintense on the spin-echo sequence without contrast injection; it was undetectable on the same sequence in 2 cases. In 4 cases the lesion was contrast-enhanced after gadolinium injection. Using millimetric sections enables small-size adenomas (2.5 x 3 mm) to be visualized.
Adolescent↗
MRI exploration of the intrapetrous facial nerve.
We report our experience of intrapetrous facial nerve evaluation in 33 patients examined by three-dimensional MRI (3D-FT) with intravenous gadolinium injection. The examinations were performed by a 1 Tesla magnet, using Flash and Turbo-Flash sequences which enabled us to obtain contiguous millimetric sections and to make reconstructions in all planes. Among these 33 patients, 31 had facial palsy and 2 a facial nerve lesion without clinical signs and discovered by chance. Facial palsy had started rather abruptly in 26 cases. It was either idiopathic (n = 20) or caused by herpes zoster (n = 1), injuries (n = 2), metastasis (n = 1) and tumour (n = 1); it was concomitant with a granuloma in 1 case. Five patients seen or explored late had congenital cholesteatoma (n = 2), facial nerve neurinoma (n = 2) or persistent idiopathic facial palsy (n = 1). There was no contrast enhancement in "chronic" non tumoral facial palsy. All tumours (neurinoma, neurofibroma, metastasis) were contrast-enhanced, as were the 2 cases of traumatic palsy and the case with granuloma of the labyrinth. In acute idiopathic facial palsy (n = 20), contrast enhancement was demonstrated in 11 patients; among these, recovery was complete at 2 months in 1 case and incomplete in 9 cases; 1 patient was lost sight of. In the 9 patients without contrast enhancement, recovery was complete in 7; 2 patients were lost sight of. This study shows that minute lesions of the facial nerve can be detected with millimetric MRI T1-weighted sequences and contrast enhancement. It also suggests that contrast enhancement has some prognostic value in patients with acute idiopathic facial palsy.
Acute Disease↗
Hyaluronan (hyaluronic acid) and hyaluronectin in the extracellular matrix of human breast carcinomas: comparison between invasive and non-invasive areas.
We performed quantitative determination of the distribution of hyaluronan (hyaluronic acid, HA) and the HA-binding protein, hyaluronectin (HN), 2 components of the extracellular matrix of tumor desmoplasia, within 71 human breast carcinomas. Results showed that HA and HN were more elevated in tumoral than in non-tumoral adjacent tissue, and that the peripheral invasive area of tumors contained increased levels of HA and HN as compared with the central non-invasive area (p less than 10(-3) and p less than 10(-5) respectively). HN and HA levels of 61 ductal carcinomas were related to the histological grade of tumors; no significant difference was found between grades for HA; HN was found to be significantly lower in grade III than in grade II tumors (p less than 0.01). HA and HN rates were correlated in grade I and grade II tumors and were not correlated in grade III. Mean percentage of HA saturation level by HN for whole tumors was found to be less than 4%, indicating that HA is essentially free of proteins and could be used as a target for cancer diagnosis or therapy.
Breast Neoplasms↗
Staining of hyaluronan in rat cerebellum with a hyaluronectin-antihyaluronectin immune complex.
The presence of hyaluronan was studied histochemically in the adult rat cerebellum. We used the hyaluronectin--antihyaluronectin immune complex technique based on the high affinity of hyaluronectin for hyaluronan. The immune complex was prepared with hyaluronectin from a human brain extract and an anti-hyaluronectin monoclonal antibody, which does not react with rat hyaluronectin. This is a specific probe for detecting hyaluronan in rat tissues without any reaction for tissue hyaluronectin. Hyaluronan was found at the nodes of Ranvier, in the perineuronal microenvironment of the deep nuclei and at the Purkinje cells surrounding the initial segment of the axon. It was located at the same places as hyaluronectin, in areas specialized in ion exchanges and neurotransmission. This suggests that the hyaluronectin-hyaluronan complex could be involved in these processes. The immune complex technique with anti-hyaluronectin monoclonal antibody thus seems to be a specific and valuable tool for investigations of the distribution of hyaluronan in the rat cerebellum.
Animals↗
Amplification of a particular DNA sequence in Streptomyces ambofaciens RP181110 reversibly prevents spiramycin production.
Streptomyces ambofaciens RP181110 produces the macrolide antibiotic spiramycin. After treatment with ethidium bromide, 7 strains presenting an amplified sequence of DNA (ADS) were found in its progeny. These ADS were localized within the same amplifiable region of the RP181110 genome. It has been established that these amplified strains were non-producers (Spi-) and that the loss of one particular ADS was correlated with restoration of spiramycin production. Genome rearrangements such as deletions were detected on the same side of the amplifiable region in both amplified and deamplified strains.
DNA Mutational Analysis↗