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Biomedical subjects

C Morel

Publications and source records attributed to C Morel.

At least 37 records · Page 2Linked to original sources
PubMed2001

Influence of an educational program on medical students' attitudes to substance use disorders in pregnancy.

Substance use disorders (SUDs) in pregnancy are becoming increasingly prevalent. Our study aimed to measure the effect of a teaching module on alcohol, tobacco, and drug use on the attitude of second year medical students toward pregnant women with SUDs. A questionnaire was administered to 84 medical students before a 5-week systems block on human reproduction, which included specific learning events related to SUDs. The questionnaire was readministered at the completion of the block. Pre- and postintervention scores were compared. Students showed significant improvement (p < .05, reliability coefficient 0.90) in their level of comfort in dealing with womenwith SUD in pregnancy. Other positive trends relating to attitudes toward drug- and alcohol-dependent women during pregnancy were also identified. SUD teaching interventions among medical students can improve their comfort level and attitude toward pregnant women with SUDs. This supports the current initiative of Project CREATE (Curriculum Renewal and Evaluation of Addiction Training and Education) to implement a comprehensive undergraduate SUD teaching program in Canadian medical schools.

Attitude of Health Personnel↗
PubMed2001

Overactivation of the protein kinase C-signaling pathway suppresses the defects of cells lacking the Rho3/Rho4-GAP Rgd1p in Saccharomyces cerevisiae.

The nonessential RGD1 gene encodes a Rho-GTPase activating protein for the Rho3 and Rho4 proteins in Saccharomyces cerevisiae. Previous studies have revealed genetic interactions between RGD1 and the SLG1 and MID2 genes, encoding two putative sensors for cell integrity signaling, and VRP1 encoding an actin and myosin interacting protein involved in polarized growth. To better understand the role of Rgd1p, we isolated multicopy suppressor genes of the cell lethality of the double mutant rgd1Delta mid2Delta. RHO1 and RHO2 encoding two small GTPases, MKK1 encoding one of the MAP-kinase kinases in the protein kinase C (PKC) pathway, and MTL1, a MID2-homolog, were shown to suppress the rgd1Delta defects strengthening the functional links between RGD1 and the cell integrity pathway. Study of the transcriptional activity of Rlm1p, which is under the control of Mpk1p, the last kinase of the PKC pathway, and follow-up of the PST1 transcription, which is positively regulated by Rlm1p, indicate that the lack of RGD1 function diminishes the PKC pathway activity. We hypothesize that the rgd1Delta inactivation, at least through the hyperactivation of the small GTPases Rho3p and Rho4p, alters the secretory pathway and/or the actin cytoskeleton and decreases activity of the PKC pathway.

Actins↗
PubMed2001

Feeding colostrum, its composition and feeding duration variably modify proliferation and morphology of the intestine and digestive enzyme activities of neonatal calves.

We studied the effects of amounts of colostrum consumed on intestinal morphology and proliferation and digestive enzyme activities in neonatal calves. Group GrCmax calves were fed colostrum from the first milking undiluted on d 1-3 and diluted with 25, 50, 75 and 75 parts of a milk replacer on d 4-7. Group GrC1-3 calves were fed colostrum from milkings 1-6 up to d 3 and then a milk replacer up to d 7. Group GrF1-3 calves were fed a milk-based formula (containing only traces of growth factors and hormones) up to d 3 and then a milk replacer up to d 7. Calves were killed on d 8. Differences in feeding affected villus sizes and villus height/crypt depth ratios in the duodenum (GrCmax > GrC1-3), villus areas and villus height/crypt depth ratios in the jejunum (GrC1-3 > GrF1-3) and crypt depths in the colon (GrF1-3 > GrC1-3). Furthermore, different feeding protocols affected the proliferation rates of epithelial cells in the duodenum (GrC1-3 > GrCmax; GrC1-3 > GrF1-3) and the jejunum (GrF1-3 > GrC1-3; based on Ki-67 labeling). Lipase activities in the pancreas were influenced by colostrum feeding (GrC(max) > GrC(1-3)). Colostrum intake differentially affected intestinal epithelial surface and proliferation and enzyme activities. Feeding high amounts of first colostrum seemed to enhance the survival of mature mucosal epithelial cells in selected parts of the small intestine, whereas the lack of colostrum seemed to decrease epithelial growth.

Animals↗
PubMed2001

[Retinal involvement in hemoglobinopathy].

Sickle cell disease is the most common and severe hemoglobinopathy. Ocular complications are related to ischemic retinopathy. Retinal examination has to be done in homozygous or double heterozygous patients and when the sickle trait is present with additional systemic vascular conditions. Fluorescein angiography is the main investigation. Photocoagulation to ischemic areas is effective in achieving regression of neovascularization. Various measures to reduce ischemia are recommended for surgical procedure. Multidisciplinary teams should take on severe cases.

Anemia, Sickle Cell↗
PubMed2000

mRNA of insulin-like growth factor (IGF) quantification and presence of IGF binding proteins, and receptors for growth hormone, IGF-I and insulin, determined by reverse transcribed polymerase chain reaction, in the liver of growing and mature male cattle.

Plasma insulin-like growth factor-I (IGF-I) concentrations were related to hepatic levels of IGF-I mRNA measured by competitive reverse transcription polymerase chain reaction (PCR) (RT-PCR) in neonatal (8 d old) calves, veal calves, fattened castrated bulls and mature intact bulls. Furthermore, the presence of mRNAs of IGF-II and of receptors for IGF-I (IGF-IR), growth hormone (GHR) and insulin (IR), as well as mRNAs of IGF binding proteins (IGFBP-1, -2 and -3) were assessed by RT-PCR. Hepatic IGF-I mRNA levels and plasma IGF-I concentrations in veal calves, fattened castrated bulls and in intact bulls were 4 to 8 times higher than in 8-d old calves and were 2 to 3 times higher in calves fed colostrum than in calves fed only milk replacer. Hepatic IGF-I mRNA concentrations were closely correlated (r = 0.92) with plasma IGF-I concentrations, suggesting that hepatic IGF-I production largely determines plasma IGF-I levels. The presence of IGF II, IGF-IR, GHR, IR and IGFBP-1, -2 and -3 mRNA was confirmed in the liver of 8-d old calves and older cattle as well, and among newborn calves their presence was independent of differences in nutrition. In conclusion, the major hepatic components of the GH-IGF axis were present in neonatal calves, but the IGF-I expression and therefore also plasma IGF-I levels were relatively low.

Amino Acid Sequence↗
PubMed2000

New xanthones from Calophyllum caledonicum.

Four new xanthones, caledonixanthones A-D (1-4), were isolated from the trunk bark of Calophyllum caledonicum, in addition to 17 known compounds. The structures of 1-4 were determined by means of spectroscopic analysis and chemical derivatization.

Magnetic Resonance Spectroscopy↗
PubMed2000

Reversion of hepatobiliary alterations By bone marrow transplantation in a murine model of erythropoietic protoporphyria.

Erythropoietic protoporphyria (EPP) is characterized clinically by cutaneous photosensitivity and biochemically by the accumulation of excessive amounts of protoporphyrin in erythrocytes, plasma, feces, and other tissues, such as the liver. The condition is inherited as an autosomal dominant or recessive trait, with a deficiency of ferrochelatase activity. A major concern in EPP patients is the development of cholestasis with accumulation of protoporphyrin in hepatobiliary structures and progressive cellular damage, which can rapidly lead to fatal hepatic failure. The availability of a mouse model for the disease, the Fech(m1Pas)/Fech(m1Pas) mutant mouse, allowed us to test a cellular therapy protocol to correct the porphyric phenotype. When Fech/Fech mice received bone marrow cells from normal animals, the accumulation of protoporphyrin in red blood cells and plasma was reduced 10-fold but still remained 2.5 times above normal levels. Interestingly, in very young animals, bone marrow transplantation can prevent hepatobiliary complications as well as hepatocyte alterations and partially reverse protoporphyrin accumulation in the liver. Bone marrow transplantation may be an option for EPP patients who are at risk of developing hepatic complications.

Animals↗
PubMed2000

[Central nervous system neurocytomas: clinicopathological analysis of tree cases].

Central nervous system neurocytoma is a rare benign tumor of neuronal origin. Because of some clinical and radiological findings CNS neurocytomas were confused with other intraventricular lesions (ependymomas, choroid plexus papilloma, oligodendrogliomas, subependymal astrocytomas). Pathological diagnosis improved with immunohistochemical and electron microscopic studies. We present three cases of intraventricular neurocytomas confirmed by immunohistochemical studies. According to the literature clinical signs, radiological features, surgical and pathological findings are discussed.

Adolescent↗
PubMed2000

Growth performance, metabolic and endocrine traits, and absorptive capacity in neonatal calves fed either colostrum or milk replacer at two levels.

Colostrum (CO) contains high amounts, whereas whole milk and milk replacer (MR) contain small amounts, of bioactive and growth-promoting substances, such as IGF-I. An experiment was designed to study the effects of feeding CO or MR on the first 3 d to neonatal calves, followed by whole milk up to d 7, at low and high density. Intestinal absorptive capacity, plasma metabolite and hormone concentrations, and growth performance were measured during the 1st wk of life. Body weight increased (P < .05) similarly in calves fed low or high amounts of CO but did not rise in MR-fed calves. Loose feces were more frequent (P < .05) and absorption of xylose on d 5 was lower (P < .01) in MR- than in CO-fed calves, but there were no effects of feeding density within CO-fed or within MR-fed groups. However, high feeding density within CO-fed groups enhanced (P < .05) total protein, globulin, triglyceride, cholesterol, and insulin concentrations, whereas in the initially high and low MR-fed groups only plasma glucose and insulin after the first meal and plasma NEFA on d 2 were modified (P < .05) by different feeding density. Thus, feeding different amounts of CO partly influenced protein and fat metabolism in calves during the 1st wk of life, but it did not measurably affect intestinal function. However, feeding different amounts of MR, in the absence of CO, barely affected metabolic and endocrine traits and absorptive capacity. Thus, high density CO feeding, and therefore a high supply of nutrients, together with greater amounts of bioactive and growth-promoting substances influenced neonatal metabolism and growth more than a high density of MR feeding containing only small amounts of bioactive and growth-promoting substances. Factors in addition to nutrient density seem to be important for the development of neonatal calves.

Absorption↗
PubMed2000

[Spontaneously favorable course of an epiretinal membrane].

A 28-year-old female patient presented a macular epiretinal membrane. Her visual acuity had fallen to 20/80. Five years earlier, she had undergone focal peripheral photocoagulation for retinal degeneration. During the following 5 years, the membrane contracted spontaneously and detached itself. Visual acuity returned to 20/20. Six fluorescein angiographies were performed during this 5-year follow-up. As demonstrated here in this young patient, an epiretinal membrane can evolve favorably, suggesting surgery should be carefully discussed when visual function is not excessively deteriorated.

Adult↗
PubMed1999

RGD1 genetically interacts with MID2 and SLG1, encoding two putative sensors for cell integrity signalling in Saccharomyces cerevisiae.

The RGD1 gene was identified during systematic genome sequencing of Saccharomyces cerevisiae. To further understand Rgd1p function, we set up a synthetic lethal screen for genes interacting with RGD1. Study of one lethal mutant made it possible to identify the SLG1 and MID2 genes. The gene SLG1/HCS77/WSC1 was mutated in the original synthetic lethal strain, whereas MID2/SMS1 acted as a monocopy suppressor. The SLG1 gene has been described to be an upstream component in the yeast PKC pathway and encodes a putative cell surface sensor for the activation of cell integrity signalling. First identified by viability loss of shmoos after pheromone exposure, and since found in different genetic screens, MID2 was recently reported as also encoding an upstream activator of the PKC pathway. The RGD1 gene showed genetic interactions with both sensors of cell integrity pathway. The rgd1 slg1 synthetic lethality was rescued by osmotic stabilization, as expected for mutants altered in cell wall integrity. The slight viability defect of rgd1 in minimal medium, which was exacerbated by mid2, was not osmoremediated. As for mutants altered in PKC pathway, the accumulation of small-budded dead cells in slg1, rgd1 and mid2 after heat shock was prevented by 1 M sorbitol. In addition, the rgd1 strain also displayed dead shmoos after pheromone treatment, like mid2. Taken together, the present results indicate close functional links between RGD1, MID2 and SLG1 and suggest that RGD1 and MID2 interact in a cell integrity signalling functionally linked to the PKC pathway.

Calcium-Binding Proteins↗
PubMed1999

An object-oriented Monte Carlo simulator for 3D cylindrical positron tomographs.

Monte Carlo simulation is a very powerful tool in understanding performances of positron tomographs as well as in assessing image reconstruction algorithms and their implementations. We present an object-oriented Monte Carlo simulator developed for 3D positron tomography. Results from phantom simulation studies including absorption and scattering of the photons in the field-of-view are presented. Scatter fractions determined from these studies are in good agreement with measured scatter fractions published in the literature. Limitations and future prospects are discussed.

Algorithms↗
PubMed1999

[Moyamoya disease: advantage of early diagnosis and survival treatment. Review of three cases].

A diagnosis of moyamoya disease was made in three children aged five, eight and 13 years (including two Turkish sisters). Clinical presentation was recurrent episodes of cerebral ischemia and stroke. CT scans and MRI showed infarcts in various distributions. Angiography revealed anterior bilateral stenosis of the circle of Willis and development of Moyamoya collateral pathways. In one case there was coagulopathy with protein C deficiency. To increase transdural collateral flow, revascularisation with encephalo-duro-arterio-synangiosis was attempted in all three children. Outcome was clinically and angiographically satisfactory and none of the children developed further neurological complications. The current state of study on Moyamoya disease is also presented.

Adolescent↗
PubMed1999

In-vitro antibacterial activity of levofloxacin against hospital isolates: a multicentre study.

The objective of this study was to evaluate the activity of the fluoroquinolone, levofloxacin, against hospital isolates of bacteria. MICs of levofloxacin were determined for 2154 strains by agar dilution. Breakpoints for susceptibility testing were calculated using the agar diffusion technique with 5 micrograms discs. The activity of levofloxacin against nalidixic acid- and pefloxacin-susceptible Enterobacteriaceae (n = 668) was higher (MIC50/90 0.06-0.12 mg/L) than previously reported for ofloxacin. As seen with other fluoroquinolones, this activity was reduced against nalidixic acid-resistant and pefloxacin-intermediate and -resistant strains (MIC 1-8 mg/L). MICs for Pseudomonas aeruginosa (n = 104) were between 0.12 and 128 mg/L. Levofloxacin had good activity against nalidixic acid- and pefloxacin-susceptible Acinetobacter baumannii (n = 12; MIC 0.06-0.25 mg/L), but the activity was reduced against nalidixic acid- and pefloxacin-resistant strains (n = 80; MIC 1-32 mg/L). Haemophilus influenzae (n = 70), Haemophilus parainfluenzae (n = 47) and Moraxella catarrhalis (n = 64) were inhibited by low concentrations of levofloxacin (MICs 0.016-0.03 mg/L, 0.03-0.12 mg/L) and 0.03-0.12 mg/L, respectively). Clostridium perfringens (n = 23; MIC 0.25-1 mg/L) was more susceptible than Bacteroides fragilis (n = 60; MIC 0.5-4 mg/L). Levofloxacin showed superior activity compared with ofloxacin against methicillin-susceptible staphylococci (n = 107; MIC 0.03-0.5 mg/L); the resistant strains (MICs 2-32 mg/L) were usually also resistant to methicillin. Levofloxacin was less effective against enterococci (n = 105; MIC 1-32 mg/L), but streptococci (n = 192) and pneumococci (n = 129), including 58 penicillin-non-susceptible strains, were inhibited by low concentrations (MICs 0.5-2 mg/L). According to the regression curve, zone diameters were usually 20-22 mm, 17-19 mm and 15-16 mm for MICs of 1, 2 and 4 mg/L, respectively. In conclusion, this study, performed on a large number of strains, confirms the superior anti-bacterial activity of levofloxacin compared with ofloxacin, especially against pathogens isolated from respiratory tract infections.

Acinetobacter↗
PubMed1999

TPA-assisted vitrectomy for proliferative diabetic retinopathy: results of a double-masked, multicenter trial.

OBJECTIVE: Some complications of vitrectomy are related to adherence of the vitreous body to the retina. We studied whether these complications could be decreased by injecting a proteolytic enzyme, tissue plasminogen activator (TPA), at the beginning of surgery to aid separation of the vitreous from the retina. METHODS: Fifty-six patients receiving surgery for complications of proliferative diabetic retinopathy were divided into two groups in this prospective, randomized, double-blind study. Group I patients received 25 microg of intravitreal TPA in buffered salt solution (BSS) 15 minutes before vitrectomy. Group II received BSS alone. Postoperative follow-up lasted up to 3 months. The major criteria for comparison were the number of perioperative iatrogenic tears, the gain in visual acuity, and the reattachment rate of tractional retinal detachments. RESULTS: No difference was found between the two groups for the principal indicators or for complications. CONCLUSION: In proliferative diabetic retinopathy, the use of 25 microg of TPA by intravitreal injection 15 minutes before vitrectomy does not improve the results. No specific complications of the method were noted. The failure can be attributed to a too-short delay between TPA injection and beginning of surgery, an insufficient dose, or an insufficient quantity of plasminogen in the vitreous at the beginning of the intervention.

Diabetic Retinopathy↗
PubMed1998

Monoallelic expression of the interleukin-2 locus.

The lymphokine interleukin-2 (IL-2) is responsible for autocrine cell cycle progression and regulation of immune responses. Uncontrolled secretion of IL-2 results in adverse reactions ranging from anergy, to aberrant T cell activation, to autoimmunity. With the use of fluorescent in situ hybridization and single-cell polymerase chain reaction in cells with different IL-2 alleles, IL-2 expression in mature thymocytes and T cells was found to be tightly controlled by monoallelic expression. Because IL-2 is encoded at a nonimprinted autosomal locus, this result represents an unusual regulatory mode for controlling the precise expression of a single gene.

Alleles↗
PubMed1998

Reflections on the management of cerebral arteriovenous malformations.

BACKGROUND: The authors report their personal experience in the management of cerebral arteriovenous malformations (AVMs), using the three techniques now available: surgical resection, endovascular embolization, and radiosurgery. They review the recent literature on this topic and present their current management algorithm based on this experience. METHODS: A series of 90 patients treated for cerebral AVMs is reported (68% Grade I-III and 32% Grade IV-V, Spetzler scale). The three methods of treatment were used, either individually or in combination, based on the size and the location of the malformation. The first intervention was surgical resection in 26% of cases, endovascular embolization in 57%, and radiosurgery in 17%. Surgery and embolization were followed by another technique in some cases and eventually single modality treatment was used in 58% of cases (surgical resection 21%, endovascular embolization 20%, radiosurgery 17%) and multimodality treatment in 42% (embolization + resection, 21%; embolization + radiosurgery, 17%; resection + radiosurgery, 4%). Embolization was used as reductive therapy in 38% of the overall series (65% of all embolized patients), and was followed by surgery in 56% of cases or by radiosurgery in 44%. Angiography was used to assess the cure rates. RESULTS: The following cure rates were obtained, when each technique was used as a first treatment: surgical resection, 82%; embolization, 6%; and radiosurgery, 83% (2-year angiographic follow-up). After combined treatment, embolization and resection resulted in a 100% cure rate, embolization and radiosurgery produced a 90% cure rate. The clinical outcome was evaluated in terms of deterioration attributable to treatment. Seventy-one percent of patients had no complication, minor complications were observed in 18%, and severe complications in 11%. Treatment mortality was 3%. All deaths were attributable to hemorrhage during the embolization procedure. CONCLUSIONS: In this management algorithm, AVMs submitted directly to surgery or to radiosurgery were considered "good risk" malformations, and the outcome for these cases was good in terms of clinical result and cure rate. AVMs submitted first to endovascular embolization were considered "poor risk" malformations, including a majority of Spetzler Grade IV-V lesions. Not surprisingly, the majority of severe complications occured in this group during embolization. Thus, the major risk of the treatment of AVMs has now shifted from surgery to endovascular techniques. Endovascular embolization as sole treatment gave a low rate of complete occlusion, but proved to be very useful as a reductive therapy, in preparation for further surgery or radiosurgery. Partial embolization permitted high rates of complete cure in difficult AVMs. Embolization should be used to the maximum extent possible as a reductive technique, despite the risks of the procedure. Because of its risks however, this technique of reductive embolization should be used only if absolutely necessary to allow the complete cure of the malformation. Thus, the use of embolization should be considered very cautiously in small malformations as well as in very large and complex AVMs in which partial embolization will not be sufficient to allow complete cure with either endovascular or surgical techniques.

Adolescent↗