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Biomedical subjects

M Lambert

Publications and source records attributed to M Lambert.

At least 163 records · Page 9Linked to original sources
PubMed1998

[Differential diagnosis of psychotic disorders in immigrants].

Several studies [5,6] on the prevalence of psychiatric disorders among migrants describe a higher rate of schizophrenic disorders. Other studies [2,3] as well as DSM-IV [1] point out that affective disorders with psychotic symptoms can be misdiagnosed as schizophrenic or schizoaffective disorders. We report on a patient admitted with the diagnosis of paranoid schizophrenia (ICD-10: F20.0), discussing differential diagnostic criteria and the problems of diagnosing along ICD-10 criteria.

Adult↗
PubMed1998

[Cadherins, the development and regeneration of the neuromuscular axis].

Various cell adhesion molecules of the cadherin family characterize the neuromuscular system. During development, cadherins N and M are sequentially expressed by myogenic cells during the two waves of myoblast fusion. Two other cadherins, called 6 and 11, are also expressed during the embryonic musculature development. In adult muscle, cadherins N and M, whose expression is suppressed by muscle activity, persist only at the neuromuscular junction and are reexpressed at the surface of denervated fibers. Cadherins N, M and E are also expressed in adult peripheral nerves. Their differential localization at Schmidt-Lanterman clefts, Ranvier nodes and neuromuscular junctions suggest that these molecules contribute to the stabilization of specialized intercellular contacts. In conclusion, a combination of cadherins, the expression of which is spatially and temporally regulated, participates in the differentiation and maintenance of the organization of the various cellular and tissular components of the neuromuscular system.

Adult↗
PubMed1997

Identification of two novel LDL receptor gene defects in French-Canadian pediatric population: mutational analysis and biochemical studies.

Familial hypercholesterolemia (FH) is at least twofold more prevalent in French Canadians from Québec than in most Western populations. Although our recent data confirmed this high frequency of heterozygous FH in our pediatric population with hypercholesterolemia, none of the five established molecular defects for the French-Canadian population was detected in 29% of the unrelated French-Canadian children characterized by a persistent increase in LDL (low density lipoprotein receptor) cholesterol and a positive parental history of hyperlipidemia (Assouline et al., 1995). To probe for new mutations, six of these molecularly undiagnosed children were investigated as index patients. By using single-strand conformation polymorphism analysis and DNA sequencing, two novel mutations were identified in two of these subjects: (1) 7-base pair (bp) duplication following nucleotide 681 (according to the cDNA sequence) in exon 4 (681ins7), which causes a frameshift, the introduction of a stop at codon 208, and premature chain termination, and (2) A to G change in exon 8 substituting a tyrosine for a cysteine at amino acid 354 (Y354C). A third subject carried the recently reported exon 10 mutation (Y468X), whereas the remaining three patients demonstrated various known polymorphisms with no effect on gene product. Rapid molecular assays were developed to detect the two new mutations as well as the Y468X mutation. Screening of our cohort showed heterozygosity in 1/88, in 2/88, and in 2/88 of patients for the 681ins7, the Y354C, and the Y468X mutations, respectively.

Amino Acid Sequence↗
PubMed1997

Hematological changes in anorexia nervosa are correlated with total body fat mass depletion.

OBJECTIVE: To assess the relationships between total body fat mass (FM) and hematological abnormalities in anorexia nervosa (AN). METHOD: Peripheral blood parameters and body composition were determined in 10 anorectic patients and 19 age- and sex-matched healthy subjects. In patients with AN, magnetic resonance imaging (MRI) studies of bone marrow were also performed. RESULTS: Compared with controls, patients with AN had -41% body weight, -81% FM, -18.8% lean tissue mass (LTM), and -22.6% bone mineral content; they also had lower mean total leukocyte (4.52 +/- 0.47 vs. 6.28 +/- 0.33 x 10(3)/microliter, p < .005), neutrophil (2.45 +/- 0.34 vs. 3.46 +/- 0.20 x 10(3)/microliter, p < .005), monocyte (0.24 +/- 0.03 vs. 0.37 +/- 0.03 x 10(3)/microliter, p < .05), and platelet counts (184 +/- 17 vs. 238 +/- 9 x 10(3)/microliter, p < .005). Hemoglobin level was normal and comparable in both groups. In patients with AN, but not in controls, total leukocyte, neutrophil, eosinophil, and monocyte counts as well as hemoglobin level were highly correlated with FM expressed in absolute values or in percentage of body weight, but not with LTM. Moreover, AN patients with signal intensity patterns suggestive of serous atrophy of bone marrow at MRI had not only lower erythrocyte, leukocyte, neutrophil, and platelet counts, but they also had lower FM than AN patients with normal MRI patterns. DISCUSSION: Hematological changes in AN, as assessed by peripheral blood parameters and MRI patterns of bone marrow, are correlated with total body FM depletion, suggesting that the reduction of adipose tissue adversely affects hematopoiesis.

Adipose Tissue↗
PubMed1997

Effect size of efficacy measures comparing divalproex, lithium and placebo in acute mania.

Effect size (ES) is a statistical concept that can be used to improve the interpretation of results from psychopharmacological studies. ES may aid interpretation of results when sample size is unbalanced or small or when units or levels of baseline measures differ across items. Usually, an investigator can define a threshold value for a clinically meaningful ES based on published data and clinical judgment or by resorting to conventions, e.g., a medium ES = 0.5 S.D., which can usually be discerned by the trained clinician. In the present study, we apply ES analysis to results from a study comparing the effectiveness of divalproex (DIVAL), lithium (LI), and placebo (PLA) in hospitalized, acutely manic patients. One hundred seventy-six patients were randomly assigned to DIVAL, LI, or PLA in a 2:1:2 ratio, with drug administered in a double-blind, parallel group design for 21 days. The primary efficacy measure was the Mania Rating Scale from the Schedule for Affective Disorders and Schizophrenia, composed of the Manic Syndrome Score (MSS) from items that are relatively specific to the manic state, and the Behavior and Ideation Score (BIS), which reflects severe but nonspecific psychopathology. Improvement of the MSS after 5 days of treatment was difficult to interpret based on percentage change (DIVAL = 19%, LI = 13.5%, PLA = 8.5%). However, the corresponding effect sizes of 0.79, 0.55, and 0.35 indicated a medium to marked ES for DIVAL, a medium ES for LI, and a small ES for PLA at this early point in treatment. Similarly, the ES for change on the MSS at the end of treatment indicated a large, readily observable improvement with both DIVAL (ES = 1.01) and LI (ES = 0.79) vs. an ES of 0.37 for PLA. ES analysis also indicated that the BIS is a less robust indicator of change to either drug. The ES at the end of treatment for the BIS was 0.67 for DIVAL-, 0.62 for LI-, and 0.25 for PLA-treated patients.

Adolescent↗
PubMed1997

Association of an exon 3 mutation (Trp66-->Gly) of the LDL receptor with variable expression of familial hypercholesterolemia in a French Canadian family.

The ligand-binding domain of low-density lipo-protein (LDL) is composed of seven 40-amino-acid repeats encoded by exons 2-6. Previous studies identified a missense mutation in codon 66 of exon 3, which resulted in the production of LDL receptor protein that is not processed to its mature form. In the current investigation, we documented the presence of two identical mutant LDL receptor alleles (Trp66-->Gly) in two familial hypercholesterolemia (FH) probands, II-1 and II-2, associated with markedly elevated plasma LDL cholesterol (17.22 +/- 0.78 and 11.95 +/- 0.24 mmol/liter, respectively). Functional assays of their fibroblast LDL receptor showed inefficient binding (39 and 50%), internalization (33 and 37%), and degradation (32 and 37%) compared with controls. The contribution of the apo B gene to variation in LDL levels was virtually eliminated given the normal ligand interaction with cell surface receptors and the absence of the mutation occurring in codon 3500 of the apo B gene. Similarly, the homozygous apo E3/E3 wildtype phenotype excluded any genetic contribution of apo E to the lipoprotein abnormalities. Furthermore, the LPL mutations commonly observed in French Canadians could not account for the observed lipid alterations. Several alterations in lipoprotein composition characterized VLDL, IDL, LDL, HDL2, and HDL3 fractions. Moreover, defective intestinal fat transport was observed in both probands (II-1 and II-2). Thus, the disturbance of lipoprotein concentration, composition, size, and metabolism may in part be related to the exon 3 mutation (Trp66-->Gly) of the LDL receptor gene. The biochemical phenotype was more severe in the father (I-1) than in the mother (I-2), and in the younger homozygous proband (II-1) than in the older (II-2). The greater severity was associated with a higher LDL cholesterol/HDL cholesterol ratio. Whether the differences between the two probands are due to polygenic factors or to a metabolic consequence of a major nonallelic trait is unknown. Nevertheless, the present biochemical findings stress the extent of the lipid abnormalities associated with homozygous FH and the importance of the phenotypic variability encountered even among subjects carrying the same mutation.

Apolipoproteins B↗
PubMed1997

Acquired carnitine abnormalities in critically ill children.

UNLABELLED: In order to characterize the role of carnitine during metabolic stress, we prospectively determined carnitine profiles in plasma and urine on admission, days 2, 5, 10 and 15, among 28 critically ill children free of any known conditions associated with secondary carnitine deficiency. More than 25% of plasma and 50% of urinary carnitine measurements were abnormal; 96% (27/28) of patients displayed on at least one occasion an abnormal [< -2 SD or > +2 SD] carnitine value in plasma. Three children had extremely low [< 10 micromol/l] free carnitine (FC) levels in plasma. Plasma esterified and FC levels on admission were not related to the risk of mortality [PRISM score], to muscle lysis [CK values], and to the caloric intake. Levels of FC and esterified carnitine in plasma were unrelated to those measured in urine. CONCLUSION: Abnormal plasma and urine carnitine measurements are frequently found in critically ill children; the biological significance of these perturbations remains unclear. Caution must be exercised before concluding that an abnormal carnitine value is indicative of an underlying hereditary metabolic disorder in this population.

Adolescent↗
PubMed1997

Energy expenditure of a noncontact boxing training session compared with submaximal treadmill running.

The aim of this study was to determine the energy expenditure of a 1-h noncontact boxing training session and to compare these results with the energy expenditure of a more conventional recreational activity such as running. Eight healthy males, accustomed to noncontact boxing training, were recruited for the study. Subjects underwent three tests: (i) a boxing training session in the laboratory during which energy expenditure was measured continuously using indirect calorimetry (BOXL), (ii) a boxing training session in a boxing studio during which heart rate was measured continuously (BOXS), and (iii) an incremental running test on the treadmill during which energy expenditure was measured continuously. The energy expenditure during 60 min of BOXL ranged between 2519 and 3079 kJ (2821 +/- 190 kJ). Seven of the 8 subjects had higher heart rates during BOXL compared with those during BOXS, suggesting that the subjects exercised at a slightly higher intensity during BOXL, possibly because of the "one on one" supervision. A typical boxing training session lasting 60 min causes a person to expend 2821 +/- 190 kJ x h(-1), the same amount of energy as someone running about 9 km in 60 min on the treadmill.

Adult↗
PubMed1997

Geographic distribution of French-Canadian low-density lipoprotein receptor gene mutations in the Province of Quebec.

A total of 35 homozygous and 1320 heterozygous patients with familial hypercholesterolemia (FH) was screened for the presence of six low-density lipoprotein receptor (LDLR) gene mutations previously reported among French-Canadians. The geographic distribution of patients' birthplaces and the relative prevalence of these six mutations in the LDLR gene in the province of Quebec were compared. For this purpose, the 16 administrative regions of the province of Quebec were grouped into seven geographic regions. The relative frequency of the six mutations differed in the seven regions: the > 15 kb deletion (delta > 15 kb) had the highest relative frequency in the Bas St-Laurent/Gaspésie region, and the point mutation in exon 3 had the highest relative frequency in the Saguenay-Lac-St-Jean/Côte-Nord region. In the Montreal area, the delta > 15 kb and the mutation in exon 3 had prevalence rates of 71.2% and 13.0%, respectively, whereas the relative frequencies of the delta > 15 kb and the point mutation in exon 3 in the Quebec city region were 57.5 and 21.8%, respectively. Finally, in Saguenay-Lac-St-Jean/Côte-Nord, the relative frequency of the delta > 15 kb only reached 31.5% and the point mutation in exon 3, 59.2%. Thus, on the north shore of the St. Lawrence River, the prevalence of the delta > 15 kb decreases from west to north-east, whereas the relative frequency of the mutation in exon 3 appears to increase. These observations provide a better characterization of FH among French-Canadians of Quebec, a Canadian province with a high prevalence of this inherited disease.

Exons↗
PubMed1997

Genetic analysis of regulatory mutants affecting synthesis of extracellular proteinases in the yeast Yarrowia lipolytica: identification of a RIM101/pacC homolog.

Depending on the pH of the growth medium, the yeast Yarrowia lipolytica secretes both an acidic proteinase and an alkaline proteinase, the synthesis of which is also controlled by carbon, nitrogen, and sulfur availability, as well as by the presence of extracellular proteins. Recessive mutations at four unlinked loci, named PAL1 to PAL4, were isolated which prevent alkaline proteinase derepression under conditions of carbon and nitrogen limitation at pH 6.8. These mutations markedly affect mating and sporulation. A dominant suppressor of all four PAL mutations was isolated from a wild-type genomic library, which turned out to be a C-terminally truncated form of a 585-residue transcriptional factor of the His2Cys2 zinc finger family, which we propose to call YlRim101p. Another C-terminally truncated version of YlRim101p (419 residues) is encoded by the dominant RPH2 mutation previously isolated as expressing alkaline protease independently of the pH. YlRim101p is homologous to the transcriptional activators Rim101p of Saccharomyces cerevisiae, required for entry into meiosis, and PacC of Aspergillus nidulans and Penicillium chrysogenum, which were recently shown to mediate regulation by ambient pH. YlRim101p appears essential for mating and sporulation and for alkaline proteinase derepression. YlRIM101 expression is autoregulated, maximal at alkaline pH, and strongly impaired by PAL mutations.

Amino Acid Sequence↗
PubMed1997

Administration of medicines by emergency nurse practitioners according to protocols in an accident and emergency department.

OBJECTIVE: To present the legal and professional issues related to nurse administration of drugs according to protocols, and describe the implementation and initial audit findings of such a scheme. SETTING: Accident and emergency (A&E) department of a district general hospital. METHODS: Analysis of legal and professional opinion. Protocols acceptable to the medical, nursing, and pharmacy professions were developed across a wide range of drugs appropriate for administration by accident and emergency nurse practitioners (ENPs). The first six months of the scheme were audited. Audit initially addressed general compliance with protocols and later the specific areas of tetanus immunisation and emergency contraception. RESULTS: ENPs assessed 2925 patients in six months (10.9% of all new patients); 455 patients (15.5% of the ENP patients) were given drugs according to protocols. There were no breaches of the protocols. Subsequent audit of tetanus immunisation showed 94-100% compliance with protocol standards and 71-100% compliance for emergency contraception. CONCLUSIONS: There are no legal or professional obstacles to the development of protocols for the administration of drugs to patients by nurses without reference to a doctor, providing the protocols meet all the requirements of the UKCC and have the support of consultant medical staff. Such a system must be subject to regular audit to promote a dynamic approach to protocols and training. The system safely enhanced the quality of care of patients treated by ENPs in A&E.

Clinical Protocols↗
PubMed1997

Kaposi's sarcoma during immunosuppressive therapy for atopic dermatitis.

We describe an HIV-negative homosexual man who developed Kaposi's sarcoma (KS). He had CD4 lymphocytopenia during azathioprine and topical corticosteroid therapy for atopic dermatitits (AD). KS was observed after only 2 months of immunosuppressive therapy. No regression was observed despite discontinuation of immunosuppressive therapy and normalization of the CD4+ cell count. This patient appears to be the first case of KS associated with AD. Moreover, as our patient had been sexually inactive for 15 years, this case raises the questions about the latency and about the sexual transmission of a novel herpes-like virus (KHSHV) recently detected in all forms of KS.

Administration, Topical↗
PubMed1997

Analysis of phenylalanine hydroxylase genotypes and hyperphenylalaninemia phenotypes using L-[1-13C]phenylalanine oxidation rates in vivo: a pilot study.

Hyperphenylalaninemia (HPA) resulting from deficient activity of phenylalanine hydroxylase (PAH) is caused by mutations in the human PAH gene (McKusick 261600). Herein, we report a noninvasive method to: 1) estimate whole-body phenylalanine oxidation in patients with HPA and 2) compare effects of mutant genotypes on phenotypes. We used oral L-[1-13C]phenylalanine as a substrate and measured 13CO2 formation in the first hour as an index of phenylalanine oxidation rates in: 1) patients with PKU (n = 6), variant phenylketonuria (PKU) (n = 7) and non-PKU HPA (n = 4); 2) obligate heterozygotes (n = 18); and 3) controls (n = 8). PAH mutations were identified by PCR, denaturing gradient gel electrophoresis, and DNA sequencing. Phenylalanine oxidation rates demonstrated a gene dosage effect; oxidation in heterozygotes was intermediate between probands and controls. The three classes of HPA had different mean oxidation rates (PKU < variant PKU < non-PKU HPA). The in vivo phenotype (HPA class or whole-body oxidation rate) did not always correspond to prediction from in vitro expression analysis of the mutation effect on enzyme activity. The findings indicate that the in vivo metrical trait (phenylalanine oxidation rate) is not a simple equivalent of phenylalanine hydroxylation activity (unit of protein phenotype) and, as expected, is an emergent property under the control of more than the PAH locus.

Adolescent↗
PubMed1997

[Consumption patterns and motivation for use of addictive drugs in schizophrenic patients].

In particular studies conducted in the U.S. display a tendency for schizophrenics to combine hallucinogens and amphetamines, whereas other studies report on a combination of psychotropic substances with a similar range of action. Influencing negative symptoms is reported to be the motivation for consumption. A total of 222 patients with a schizophrenic disorder (F2) and addiction (F1) were examined. The main substance was alcohol (F10.1 or F10.2; 52.2%), followed by cannabis (F12; 25%), opiates (F11; 4.1%), sedatives or hypnotics (F13; 2.7%) and cocaine (F16; 0.5%). A multiple drug use (F19) is reported by 14% of them. The most frequent combination was alcohol and cannabis, whereas hallucinogens and amphetamines were only rarely combined. Actual multiple consumption was reported by 55% of the patients, while lifetime multiple consumption applied to 72%. The motivation seems to be an unspecified sedation of unpleasant affective symptoms of schizophrenia. The most frequently seen combinations do not correlate with the reports published in the literature. The great variations in motivation seem to mainly reflect the importance of the availability of the substance.

Adult↗
PubMed1997

Age-specific distribution of plasma amino acid concentrations in a healthy pediatric population.

Reference values were determined for 23 plasma free amino acids from measurements done in 148 healthy children ranging from 0 to 18 years of age. Amino acid analysis was performed by ion-exchange chromatography. We propose a graphic form of presenting the age-specific distribution of plasma amino acid concentrations where the 10th, 50th, and 90th quantiles are illustrated. Although each amino acid possesses its own pattern of distribution, we can identify five different profiles. Nine amino acids (alanine, arginine, asparagine, methionine, ornithine, phenylalanine, proline, threonine, and tyrosine) demonstrate a decrease in their concentrations during the first year of life; their concentrations then tend to increase throughout childhood and adolescence. Nine others (cystine, glutamine, glycine, histidine, isoleucine, leucine, lysine, tryptophan, and valine) show a steady increase throughout infancy, childhood, and adolescence. Five amino acids (aspartic acid, citrulline, glutamic acid, serine, and taurine) do not follow these two common profiles. For the first time, quantile curves are produced to illustrate the age-dependent variation of amino acid concentrations from infancy to adulthood. This alternative way of presenting amino acid concentrations may facilitate the follow-up of patients with inborn errors of amino acid metabolism.

Adolescent↗