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Biomedical subjects

M Roy

Publications and source records attributed to M Roy.

At least 127 records · Page 7Linked to original sources
PubMed1996

Influence of genetic variability in the nondeletion LDL-receptor allele on phenotypic variation in French-Canadian familial hypercholesterolemia heterozygotes sharing a 'null' LDL-receptor gene defect.

We investigated the associations between low density lipoprotein (LDL)-receptor gene haplotypes and lipid and lipoprotein levels in French-Canadian individuals with familial hypercholesterolemia (FH). The 112 unrelated patients studied shared the same > 10 Kb deletion in the 5' region of the LDL-receptor gene, leading to a null allele. Support for the hypothesis that the deletion is carried on only one LDL-receptor restriction fragment length polymorphism (RFLP) haplotype in this sample has previously been demonstrated [1]. We studied associations of genetic variability in DNA polymorphisms of the nondeletion LDL-receptor allele with variation in plasma lipid levels in these patients heterozygous for the deletion. All analyses were done separately in males and females. The traits were adjusted for variation in the concomitants age, height and weight, and for variation in apolipoprotein (apo) E phenotype, and then the association between variability in haplotypes defined by two RFLP loci and variation in trait levels were tested. The results indicated that in this sample of French-Canadian > 10 Kb deletion FH heterozygotes, variability at the LDL-receptor gene contributes to quantitative variation in measures of lipid metabolism and that the effects are different in males and females. The results indicated that variability at the LDL-receptor gene defined by two RFLP loci contributes to quantitative variation in high density lipoprotein (HDL)-cholesterol and LDL-cholesterol concentrations in French-Canadian FH women heterozygous for the > 10 Kb deletion and not in men.

Alleles↗
PubMed1996

Vaginal radical hysterectomy versus abdominal radical hysterectomy in the treatment of early-stage cervical cancer.

The purpose of this study is to compare the safety, efficacy, and potential benefits of vaginal radical hysterectomy (VRH) versus abdominal radical hysterectomy (ARH) in the treatment of early-stage cervical cancer. We reviewed the charts of our first 52 patients with cervical cancer. We reviewed the charts of our first 52 patients with cervical cancer who underwent a laparoscopic pelvic lymphadenectomy (LPL), followed either by a VRH (Schauta) in 25 cases or ARH in 27 cases. For the 52 patients, the mean lymph nodes count obtained by LPL was 27 (range 8-59), and the only complication was an external iliac vein trauma requiring laparotomy. Both VRH and ARH groups were comparable in terms of age, weight, parity, stage, histology, and tumor volume. The mean blood loss was 400 cc for VRH vs 450 cc for ARH, operating time was 270 min vs 280 min, blood transfusion in 5 vs 4 women, and postoperative stay was 7 days for both groups. The only intraoperative complication in addition to the vein trauma was a cystotomy which occurred in 2 VRH patients. Febrile morbidity was noted in 4 VRH patients vs 9 ARH patients. There were one preperitoneal abscess and one hematoma in the VRH group vs 4 wound infections and 1 hematoma after ARH. Ileus occurred in 1 VRH vs 4 ARH patients. The current mean follow-up time is 27 months (8-52) and there has been one recurrence so far in the ARH group. Even though this is a retrospective study, our data indicate that VRH and ARH are comparable, except for the absence of an abdominal scar and less febrile morbidity with the vaginal approach. However, in our opinion, the main advantage in learning the Schauta operation is that the experience gained allows one to offer radical trachelectomy to selected young patients who wish to preserve their fertility.

Adult↗
PubMed1996

Supplementation with selenium augments the functions of natural killer and lymphokine-activated killer cells.

This study examined the effects of dietary (2.0 ppm for 8 wk) and in vitro (1 x 10(-7)M) supplementation with selenium (Se, as sodium selenite) on the activity of spleen natural killer (NK) cells and plastic-adherent lymphokine-activated killer (A-LAK) cells from C57B1/6J male mice. Dietary supplementation with Se resulted in a significant increase in the lytic activity of activated NK cells, and cells from these highly lytic effector cell populations expressed significantly higher numbers of intermediate affinity interleukin-2 receptors (II-2R)/cell. In the presence of high concentrations of II-2 and 1 x 10(-7)M Se, resting populations of spleen NK cells developed into A-LAK cells that had a significantly enhanced ability to proliferate, as indicated by the significantly higher amounts of nuclear 3H-thymidine incorporation, and a significantly augmented cytolytic activity against both NK-sensitive and NK-resistant target cells. Se appears to enhance the lytic activity of activated NK cells and to augment the proliferation, expansion, and lytic activity of A-LAK cells in the presence of high concentrations of II-2 through its ability to enhance the expression of intermediate affinity II-2R on these cells.

Adjuvants, Immunologic↗
PubMed1996

Measurement of heparin concentration in whole blood with the Hepcon/HMS device does not agree with laboratory determination of plasma heparin concentration using a chromogenic substrate for activated factor X.

UNLABELLED: Measurement of circulating heparin concentration has been suggested to optimize anticoagulation during cardiopulmonary bypass. The Hepcon/HMS device (Medtronic HemoTec, Inc., Parker, Colo.) uses heparin/protamine titration to quantitatively determine heparin concentration. Extensive validation of this instrument is still lacking. METHODS: Agreement between heparin concentrations measured by the Hepcon/HMS system and by laboratory determination was evaluated in 16 patients undergoing cardiac operations. For laboratory determinations, plasma heparin concentration was derived from the measure of anti-Xa activity by means of chromogenic substrate technique. The Hepcon/HMS instrument and cartridges measured whole blood heparin concentration. Samples were analyzed 5 minutes after administration of heparin, 15 and 30 minutes after the start of cardiopulmonary bypass, 5 minutes after aortic unclamping, at the end of cardiopulmonary bypass, and after administration of protamine. Data were plotted and interpreted according to the method of Bland and Altman: First, a difference less than 1.4 U/ml (i.e., +/- 0.7 U/ml) was chosen as acceptable, because it would not cause major difficulties in clinical interpretation; second, the difference between the two measurement techniques was plotted against the mean of the two measures. RESULTS: The mean difference (bias) between heparin concentrations derived by the Hepcon/HMS device and those obtained by laboratory determination was as expected for measures performed on whole blood versus plasma (1.45 U/ml). Nevertheless, heparin concentrations derived by the Hepcon/HMS device may be as much as 2.76 U/ml above or 6.17 U/ml below the concentrations measured in the laboratory, differences well outside the predetermined limits of agreement and clearly unacceptable for clinical purposes. CONCLUSION: We conclude that heparin concentrations determined with the Hepcon/HMS instrument do not agree with laboratory determination of heparin concentration. Monitoring of heparin concentrations during bypass with the Hepcon/HMS device cannot be recommended.

Blood Chemical Analysis↗
PubMed1996

Pituitary adenylate-cyclase activating polypeptide (PACAP) evokes long-lasting secretion and de novo biosynthesis of bovine adrenal medullary neuropeptides.

Recently, the pituitary adenylate-cyclase activating polypeptide (PACAP) has emerged as a potential noncholinergic neuromodulator of adrenal medullary function. In support of this hypothesis, we documented PACAP's effects on the secretion and biosynthesis of neuropeptides by cultured bovine chromaffin cells. Data presented in this study indicate that PACAP is a potent and efficacious secretagogue of leucine-enkephalin which was coreleased with catecholamines with identical profiles. In comparison to nicotinic activation, however, rates of PACAP-induced secretion were substantially slower but persisted for several hours causing a prolonged increase in the tonic release of both transmitters and peptides. Interestingly, renewal of intracellular pools of neuropeptides was also stimulated by PACAP but not the vasoactive intestinal peptide (VIP). Indeed, the higher incorporation of [35S]-labeled amino acids into atrial and brain natriuretic peptides (ANP, BNP) provided strong evidence that PACAP directly activated de novo biosynthesis. Of particular importance was PACAP's net preferential stimulation of the biosynthesis of BNP, similar to the differential regulation by protein kinase A (PK-A) and protein kinase C (PK-C) activators we have previously the differential regulation by protein kinase A (PK-A) and protein kinase C (PK-C) activators we have previously reported. PACAP-induced secretion and biosynthesis appeared to be mediated by the PACAP-specific type I receptors known to activate adenylate cyclase and phospholipase C. We verified that PACAP did indeed stimulate the production of cyclic AMP and inositol phosphates in our cell system. These findings suggest that the dual signaling properties of type I receptors may be important for PACAP's differential effect on the biosynthesis of natriuretic peptides. We conclude that PACAP might assume important noncholinergic trans-synaptic regulation of the adrenal medulla by releasing and modifying intragranular catecholamine and neuropeptide contents.

Adrenal Medulla↗
PubMed1996

Determinants of persistent detection of human papillomavirus DNA in the uterine cervix.

To identify factors associated with persistence of human papillomavirus (HPV) DNA in the uterine cervix, 179 women who were 18-49 years old and who had normal cytologies and positive cervical HPV DNA test at a routine periodic examination were analyzed. Among them, 91 (50.8%) remained HPV-positive a few months (mean, 11 weeks) later. Persistence was higher in women who had used oral contraceptives for > or = 2 years (odds ratio, 3.9; 95% confidence interval, 1.5-10.3) compared with those who never used oral contraceptives or used them for <2 years. HPV types 16, 18, and 31/33/35 appeared more persistent (odds ratio, 2.5; 95% confidence interval, 1.0-6.2) than other types. Persistence seemed to increase with virus load and decrease with increasing interval between examinations.

Chronic Disease↗
PubMed1996

Spontaneous and induced mutations in a single open reading frame alter both virulence and avirulence in Xanthomonas campestris pv. vesicatoria avrBs2.

Molecular characterization of the avrBs2 locus from Xanthomonas campestris pv. vesicatoria has revealed that expression of this gene triggers disease resistance in Bs2 pepper (Capsicum annuum) plants and contributes to virulence of the pathogen. Deletion analysis and site-directed mutagenesis established the avrBs2 gene as a 2,190-bp open reading frame encoding a putative 80.1-kDa protein. Two classes of Xanthomonas pathogens evading Bs2 host resistance and displaying reduced fitness were found to be specifically mutated in avrBs2. Members of one class contained a 5-bp insertion, while the second class was distinguished by a divergent 3' region of avrBs2; both mutant classes were complemented in trans by a plasmid-borne copy of avrBs2. A divergent avrBs2 homolog was cloned from the Brassica pathogen X. campestris pv. campestris. The predicted AvrBs2 proteins from the two Xanthomonas pathovars were strongly conserved and had predicted sequence similarity with both Agrobacterium tumefaciens agrocinopine synthase and Escherichia coli UgpQ, two enzymes involved in the synthesis or hydrolysis of phosphodiester linkages. On the basis of homology with agrocinopine synthase and UgpQ and the dual phenotype of avirulence and virulence, several models for the function of AvrBs2 are proposed.

Alleles↗
PubMed1996

Lp(a) levels and atherosclerotic vascular disease in a sample of patients with familial hypercholesterolemia sharing the same gene defect.

There is considerable variation in the severity of cardiovascular disease among patients with familial hypercholesterolemia (FH). Some reports have suggested that plasma lipoprotein(a) [Lp(a)] levels may explain such variation and that FH subjects deficient in LDL receptors, especially those with coronary heart disease, tend to have elevated Lp(a) levels. We have investigated the possible role of the LDL receptor in determining plasma Lp(a) levels in genetically homogeneous FH population and the contribution of Lp(a) to cardiovascular risk. A total of 98 FH subjects and 66 healthy first- and second-degree relatives from 30 families with FH due to the French-Canadian > 10-kilobase deletion of the LDL receptor gene were studied. A reference group of 392 normolipidemic French-Canadian participants in a Heart Health Survey was used for comparison. FH subjects were subdivided into subsets of 63 individuals free from atherosclerotic vascular disease (AVD) and 35 individuals with AVD. A complete cardiovascular evaluation was performed, and plasma lipid, lipoprotein, and Lp(a) levels were measured in all subjects in the absence of medication. Apolipoprotein (a) [apo(a)] phenotype was determined in 112 of FH and non-FH subjects. The log-transformed values for plasma Lp(a) were not significantly different among the three groups: 0.98 +/- 0.54 (mean +/- SD) in FH subjects with AVD, 0.89 +/- 0.51 in FH subjects without AVD, and 0.82 +/- 0.64 in their relatives. The distribution of the apo(a) phenotypes did not differ between the FH and non-FH groups. Comparison of two age- and sex-matched subgroups of FH subjects, with and without AVD, failed to show any differences in Lp(a) level. However, mean Lp(a) log values in the reference group (n = 392) were significantly lower than values obtained for the total FH group (0.79 +/- 0.57 versus 0.92 +/- 0.52, respectively; P < .05) but were not different from those of the unaffected family members. Thus, in our sample, the LDL receptor appears not to influence plasma Lp(a) levels; rather, these levels reflect shared apo(a) genes. The cardiovascular risk in this group of subjects with FH was related to age, male sex, total and LDL cholesterol, and higher apoB but not Lp(a) levels.

Adolescent↗
PubMed1996

Plasma concentration of apolipoprotein E in intermediate-sized remnant-like lipoproteins in normolipidemic and hyperlipidemic subjects.

Triglyceride-rich lipoprotein (TRL) remnants have been strongly implicated in the pathogenesis of atherosclerosis. To further investigate plasma remnant lipoprotein metabolism, we have determined the plasma concentration of apolipoprotein (apo) E (by polyclonal enzyme-linked immunoassay) in remnant-like lipoproteins, isolated by automated gel filtration chromatography as a fraction intermediate in size between VLDL and HDL. In normolipidemic subjects (n = 12), 1.2 +/- 0.11 mg/dL (33 +/- 2%, mean +/- SE) of total plasma apoE was associated with this fraction (termed ISL apoE). In hypercholesterolemic (type IIa, n = 12), hypertriglyceridemic (type IV, n = 12), and mixed hyperlipidemic (type IIb, n = 12) subjects, mean ISL apoE concentrations were 2.1 +/- 0.2, 2.5 +/- 0.2, and 3.8 +/- 0.4 mg/dL, respectively (P < .001 versus normal values) (45 +/- 2%, 32 +/- 2%, and 44 +/- 2% of total). ISL apoE was 8.7 +/- 1.4 mg/dL (42 +/- 3%) in type III dyslipidemic subjects (apoE2/2, n = 8). ISL apoE was positively correlated with plasma triglyceride (r = .41, P < .01), and at any given level of plasma triglyceride, subjects with an apoE2/2 or apoE3/2 phenotype tended to have a higher concentration of ISL apoE (P < .01) than apoE3/3 or E4/3 individuals. ISL apoE was also correlated (P < .001) with total plasma cholesterol (r = .66), TRL cholesterol (r = .49), TRL apoE (r = .47), LDL apoB (r = .42), and LDL+HDL triglyceride (r = .74). These results suggest that (1) a significant proportion of plasma apoE resides within an intermediate-sized remnant-like lipoprotein fraction in both normolipidemic and hyperlipidemic subjects; (2) plasma remnant lipoprotein accumulation is associated with an elevation in ISL apoE concentration; and (3) ISL apoE concentration is significantly correlated with various proatherogenic lipid parameters and may itself be a potentially important atherogenic index.

Adult↗
PubMed1996

Abnormal electroretinogram in cocaine-dependent patients. Relationship to craving.

BACKGROUND: The retina contains high concentrations of dopamine. We previously reported that recently withdrawn cocaine-dependent patients had significantly reduced blue cone b wave amplitude responses on the electroretinogram (ERG). In this study we wished to examine if there was a relationship between cocaine craving and reduced blue cone b wave ERG responses. METHODS: A series of 14 recently withdrawn cocaine-dependent patients completed a 45-item cocaine craving questionnaire shortly before the ERG. RESULTS: Cocaine dependent patients who had a reduced ( < 0.5 microvolts) blue cone b wave ERG response had significantly higher cocaine craving scores than patients without a reduced blue cone ERG response. There was also a significant negative correlation between blue cone b wave amplitude responses and scores on the cocaine craving questionnaire. CONCLUSIONS: A reduced blue cone b wave ERG response may identify recently withdrawn cocaine-dependent patients with biological dysregulation and increased cocaine craving.

Adult↗
PubMed1996

A reference cross DNA panel for zebrafish (Danio rerio) anchored with simple sequence length polymorphisms.

The ultimate informativeness of the zebrafish mutations described in this issue will rest in part on the ability to clone these genes. However, the genetic infrastructure required for the positional cloning in zebrafish is still in its infancy. Here we report a reference cross panel of DNA, consisting of 520 F2 progeny (1040 meioses) that has been anchored to a zebrafish genetic linkage map by 102 simple sequence length polymorphisms. This reference cross DNA provides: (1) a panel of DNA from the cross that was used to construct the genetic linkage map, upon which polymorphic gene(s) and genetic markers can be mapped; (2) a fine order mapping tool, with a maximum resolution of 0.1 cM; and (3) a foundation for the development of a physical map (an ordered array of clones each containing a known portion of the genome). This reference cross DNA will serve as a resource enabling investigators to relate genes or genetic markers directly to a single genetic linkage map and avoid the problem of integrating different maps with different genetic markers, as must be currently done when using randomly amplified polymorphic DNA markers, or as has occurred with human genetic linkage maps.

Alleles↗
PubMed1996

Fine needle aspiration cytology of ophthalmic lesions.

Forty cases of ophthalmic lesions were subjected to fine needle aspiration cytology for pre-operative diagnosis which included retinoblastomas (5 cases), inflammatory and neoplastic lesions of the eyelid and lacrimal glands (29 cases) and extra-ocular orbital lesions (6 cases) inclusive of 3 cases of rhabdomyosarcomas. The lesions were distributed in both the eyes almost in equal proportions. Histological confirmation was obtained in 85% of cases; false positive in only one case with malignant neoplasm of the eyelid and false negative also in only one case with inflammatory pseudotumour which were, histologically, proved to be adenoma of tarsal gland and lymphocytic lymphoma respectively.

Biopsy, Needle↗
PubMed1996

Characterization of inherited scavenger receptor overexpression and abnormal macrophage phenotype in a normolipidemic subject with planar xanthomas.

It is proposed that, in hyperlipidemia, foam cells develop in cutaneous xanthomas from the uptake by the macrophage scavenger receptor (SR) of low density lipoproteins (LDL) that are modified due to increased residence time in plasma. We have observed extensive xanthelasmas and planar xanthomas in the absence of hyperlipidemia in two siblings. In blood monocytes from one sibling, 125I-labeled acetylated LDL (Ac-LDL) degradation and SR mRNA were 4 and 7 times higher, respectively, than in four control subjects. Among monocytes from these five individuals, variation in Ac-LDL degradation was completely accounted for by SR mRNA levels (R2 = 0.98, P < 0.001). Monocyte SR mRNA was induced upon maturation into macrophages during 7 days in culture. Mean monocyte and macrophage SR mRNA values from one sibling and six additional family members were elevated 5- and 4-fold compared to that of 16 control subjects, and elevated monocyte SR mRNA was associated with abnormally high cell-surface expression of SR epitopes. Monocytes from eight of nine family members examined displayed an unusual phenotype characterized by increased adhesion and rapid maturation into large macrophages which overaccumulated lipids. Monocyte-macrophage SR overexpression relative to control persisted even in the absence of autologous serum, consistent with a cellular abnormality. This is the first demonstration of an inherited abnormality in scavenger receptor expression and its occurrence in association with planar xanthomas.

Aged↗
PubMed1995

Reaction of peripheral-blood lymphocytes to the human chorionic gonadotropin beta sub-unit in patients with productive tumors.

Human chorionic gonadotropin (hCG) and its beta sub-unit (hCG beta) are secreted by trophoblast cells during pregnancy, and by tumoral cells of trophoblastic and non-trophoblastic origin. In contrast to hCG, the free hCG beta sub-unit is consistently undetectable in healthy non-pregnant subjects. With this in mind, we sought to determine whether an immune response to hCG beta can be detected in patients with bladder or germ-cell testis cancers. Peripheral-blood mononuclear cells (PBMC) from 31% of patients with hCG beta-productive bladder cancers and 33% of testis-tumor-bearing patients displayed an hCG beta-specific proliferative response, whereas no patients with non-hCG beta-productive cancers had a proliferative response. PBMC from pregnant women and healthy controls did not elicit significant reactivity. By the use of overlapping synthetic peptides, the immunogenic regions of hCG beta were delineated within the central 20-65 portion. Moreover, in 2 bladder-cancer patients with the HLA DR7, DQ2 haplotype, the T-cell response to hCG beta was focused on the hCG beta (20-47) peptide. Taken together, these results indicate that hCG beta is a tumor-associated antigen capable of inducing a cell-mediated immune response in patients with productive tumors.

Aged↗
PubMed1995

Simultaneous determination of terbinafine (Lamisil) and five metabolites in human plasma and urine by high-performance liquid chromatography using on-line solid-phase extraction.

The antimycotic agent terbinafine (Lamisil) and five of its main metabolites were determined simultaneously in human plasma and urine samples by an isocratic HPLC method. The compounds were separated on a phenyl column following on-line solid-phase sample clean-up with a column-switching device. Terbinafine and its metabolites were detected by monitoring the column effluent with UV light at a wavelength of 224 nm. The linear range in plasma was assessed between 0 and 2500 ng/ml for the parent drug and metabolites V, IV and I. The linear response of metabolites III and II was assessed between 0 and 1250 ng/ml. In urine, linearity was assessed between 0 and 10,000 ng/ml for metabolites V, IV, III, II and between 0 and 1000 ng/ml for the parent drug and metabolite I. Quantification limits based on a C.V. < or = 20% and a bias < or = +/- 20% ranged from 20 to 500 ng/ml depending on the compound and the matrix. Inter-day and intra-day variations were similar indicating the ruggedness of the two methods. Due to the considerable differences in hydrophobicity between the compounds, extraction efficiencies ranged from 55 to 100%. Both methods were found to be reproducible and sufficiently sensitive for the evaluation of metabolite pharmacokinetics.

Autoanalysis↗
PubMed1995

Studies on the interdependence of gp39 and B7 expression and function during antigen-specific immune responses.

Interactions between T and B cells are dynamic and regulated by interacting receptor: co-receptors. Interactions between CD40 and its ligand, gp39, and the CD28/CTLA-4 and B7 family members play a decisive role in regulating the progression of cognate interactions. The interdependence of gp39-CD40 and CD28/CTLA-B7 expression and function was studied in vitro during an antigen-induced immune response using T cells from mice expressing a transgenic T cell receptor (TCR). gp39 was induced on pigeon cytochrome c (PCC)-transgenic T cells in the presence of antigen and antigen-presenting cells. The antigen-induced expression of gp39 on transgenic T cells was inhibited by antibodies to class II major histocompatibility complex, CD4 and LFA-1, but not by CTLA-4 Ig, anti-B7-1 or anti-B7-2. These data established that the antigen-induced expression of gp39 was not dependent on co-stimulation via CD28/CTLA-4. The addition of PCC also resulted in the modest expression of B7-1 and a more robust expression of B7-2 on the cognate B cells. The addition of anti-gp39 blocked the up-regulated expression of B7-1 and partially blocked the up-regulated expression of B7-2. The addition of anti-gp39 and anti-interleukin-4 inhibited antigen-induced expression of B7-2 on B cells to near background levels. Studies on the up-regulation of B7-1 and B7-2 on resting B cells showed that soluble gp39 up-regulated B7-1 and B7-2 expression on B cells. In addition, interleukin-4 and interferon-gamma up-regulated B7-2 expression on B cells. Taken together, these data demonstrate that the antigen-induced expression of gp39 is dependent on TCR-derived signals, yet independent of CD28/CTLA-4 co-stimulatory signals. Cognate interactions also resulted in the modest enhancement of B7-1 expression and a more profound expression of B7-2 which were completely or partially dependent on gp39-CD40 interactions.

Abatacept↗
PubMed1995

Primary proliferative T cell response to wild-type p53 protein in patients with breast cancer.

Mutations in the p53 tumor suppressor gene are the most frequent genetic alterations found in human tumors. There are mainly point mutations that lead to single amino acid substitutions. The mutated proteins have a longer half-life than wild-type p53 and accumulate in the nucleus of tumor cells. Anti-p53 antibodies have been found in sera of patients with several types of cancers including breast cancer. This report describes a T cell immune response in three patients with breast tumors who had mutated p53 gene and accumulated p53 protein. All showed a humoral response to p53 protein and the T cells of these patients recognized the wild-type p53 protein and proliferated in response to it. The data reported here are relevant to the immune processes leading to autoimmunity and have a bearing on anti-p53 vaccine development in tumor immunology.

Antibodies↗