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Biomedical subjects

M Lambert

Publications and source records attributed to M Lambert.

At least 55 records · Page 3Linked to original sources
PubMed2000

Do emergency physicians save time when locating a live intrauterine pregnancy with bedside ultrasonography?

OBJECTIVE: To determine whether patients presenting to the emergency department (ED) with first-trimester pregnancy complications have a decreased length of stay (LOS) when a live intrauterine pregnancy (IUP) is diagnosed by emergency physicians (EPs). METHODS: This study was performed at an urban community ED with a residency program and an annual census of 65,000. A retrospective chart review from October 1995 to August 1998 identified 1,419 patients who received ultrasound examinations confirming live IUP in the first trimester with pain and/or bleeding. Two hundred seventy-seven of these patients received their ultrasound examinations from EPs; 1, 142 patients received a study from radiology and were not scanned by EPs. The LOSs for the two groups were compared and defined as the time from being placed into a room to discharge from the ED. Significance was determined using a two-tailed t-test. Median times with confidence intervals were calculated. RESULTS: When patients had a live IUP confirmed by an EP, the median LOS was 21% (59 min) less than those who received an ultrasound examination by radiology (p = 0.0001; 95% CI = 49 min to 1 hr 17 min). When evaluated by time of day, patients who presented after hours (6 PM to 6 AM) and were scanned by EPs spent 28% (1 hr 17 min) less time in the ED (p = 0.0001; 95% CI = 55 min to 1 hr 37 min). CONCLUSIONS: Emergency physicians identifying live IUP with bedside ultrasonography significantly decreased patients' LOSs in the ED. The decrease in LOS was most apparent for patients presenting during evening and nighttime hours.

Emergency Service, Hospital↗
PubMed2000

Paraoxonase activity is dramatically decreased in patients positive for anticardiolipin antibodies.

It has been reported that paraoxonase 1 (PON1) activity inhibits low-density lipoprotein (LDL) oxidation and modulates the risk of coronary heart disease. This study shows that autoantibodies (IgG) directed against modified LDL were increased in 71 patients positive for anticardiolipin antibodies. In a representative subgroup of these patients (n = 36) PON1 activity was dramatically decreased and the prevalence of the RR genotype of this enzyme tended to be increased in patients who had developed arterial thrombosis. This study suggests that PON1 abnormalities play a role in the antiphospholipid syndrome.

Adult↗
PubMed2000

Immobilized dimers of N-cadherin-Fc chimera mimic cadherin-mediated cell contact formation: contribution of both outside-in and inside-out signals.

Cell adhesion receptors of the cadherin family are involved in various developmental processes, affecting cell adhesion and migration, and also cell proliferation and differentiation. In order to dissect the molecular mechanisms of cadherin-based cell-cell adhesion and subsequent signal transduction to the cytoskeleton and/or cytoplasm leading to adapted cell responses, we developed an approach allowing us to mimic and control cadherin activation. We produced a dimeric N-cadherin-Fc chimera (Ncad-Fc) which retains structural and functional properties of cadherins, including glycosylation, Ca(2+)-dependent trypsin sensitivity and the ability to mediate Ca(2+)-dependent self-aggregation of covered microbeads. Beads covered with either Ncad-Fc or anti-N-cadherin antibodies specifically bound to N-cadherin expressing cells. Both types of beads induced the recruitment of N-cadherin, beta-catenin, alpha-catenin and p120, by lateral mobilization of preexisting cell membrane complexes. Furthermore, cadherin clustering elicited by Ncad-Fc beads triggered local accumulations of tyrosine phosphorylated proteins, a recruitment and redistribution of actin filaments, as well as local membrane remodeling. These results support a model where the adhesion of cadherin ectodomains is followed by clustering of cadherin/catenin complexes allowing signal transduction affecting both cytoskeletal reorganization and cytoplasmic signal mobilization (outside-in signaling). Interestingly, bead-cell binding was altered by agents promoting microfilament and microtubule depolymerization or tyrosine phosphorylation, indicating a possible regulation of the adhesive properties of the extracellular domain of N-cadherin by intracellular factors (inside-out signaling).

Animals↗
PubMed2000

Antimony excretion in a patient with renal impairment during meglumine antimoniate therapy.

Meglumine antimoniate was administered to a patient with visceral leishmaniasis with normal renal function. Soon after the first intramuscular administration of meglumine antimoniate 20 mg/kg, equivalent to 510 mg antimony (Sb), the patient developed septic shock with oliguria. Creatinine clearance decreased to 23 ml/minute. Treatment was discontinued, and Sb urinary excretion was measured. After the initial dose, 500.25 mg Sb was recovered in urine over 8 days, corresponding to 98% of the amount of Sb given intramuscularly (66% eliminated within first 48 hrs). Nine days after the dose, meglumine antimoniate was reintroduced at a dosage of 11.7 mg/kg (equivalent to 300 mg Sb) every 48 hours with good tolerance. At that time creatinine clearance had returned to 87.8 ml/minute. By day 14 of therapy the interval was reduced to daily administration of the same dose; the dosage was increased to 16.6 mg/kg/day (equivalent to 425 mg Sb) from day 17 to day 31. The patient eventually completely recovered and was discharged with normal renal function. Although no specific guidelines exist for dosage adjustment in renal failure, monitoring of Sb urinary excretion indicates that the kidneys are the almost exclusive route of elimination.

Antimony↗
PubMed2000

Hypothenar hammer syndrome followed by systemic sclerosis.

We describe the first case of bilateral hypothenar hammer syndrome (HHS) followed by systemic sclerosis (SSc) that was associated with silica exposure (Erasmus syndrome). The patient was a woman smoothing tiles in an earthenware factory who presented with bilateral digital ischemia associated with Raynaud's phenomenon. HHS was diagnosed, based on an angiographic study showing aneurysm of the ulnar arteries and occlusions of multiple digital arteries. Pulmonary silicosis was also diagnosed on pulmonary tomodensitometry. Two years later digital swelling with acroosteolysis developed. The FANA test was positive (titer 1:640) and anticentromere antibody tests were also positive. Esophageal manometry showed dysmotility of the lower esophagus. These findings were consistent with a diagnosis of SSc.

Adult↗
PubMed1999

Identification and confirmation of 3-hydroxy metabolite of ketoprofen in camels by gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy.

The metabolites of ketoprofen were investigated in five camels following intravenous administration of a dose of 2.0 mg/kg body weight. Two metabolites were identified. The first one was purified with thin-layer chromatography. It was identified by gas chromatography-mass spectrometry (GC-MS) in comparison with authenticated reference standard and was found to be hydroxyketoprofen due to reduction of the ketone group of ketoprofen. The second metabolite was purified by high-performance liquid chromatography. It was identified with GC-MS and nuclear magnetic resonance spectroscopy as 3-hydroxybenzolketoprofen resulting from oxidation of the aromatic ring.

Animals↗
PubMed1999

Pyruvate carboxylase deficiency: prenatal onset of ischemia-like brain lesions in two sibs with the acute neonatal form.

Pyruvate carboxylase (PC) is a key enzyme in the gluconeogenesis and anaplerotic metabolic pathways. PC deficiency is a rare autosomal recessive disorder with three clinical presentations: an infantile form, a severe neonatal form, and a benign form. We report brother and sister sibs with the severe form of PC deficiency. Both had macrocephaly and severe ischemia-like brain lesions at birth and died in the first week of life with intractable lactic acidemia. In the girl, increased head circumference and periventricular leukomalacia (PVL) were detected on fetal ultrasonography at 29.4 weeks of gestation. PC activity in cultured skin fibroblasts was <2% of control. This is the first reported case of ischemia-like brain lesions documented prenatally in PC deficiency. The lesions were detected at a time of maximal periventricular metabolic demand. We postulate that energy deprivation induced by PC deficiency impairs astrocytic buffering capacity against excitotoxic insult and compromises normal microvascular morphogenesis and autoregulation, both mechanisms leading to cystic degeneration of the periventricular white matter. Discovery of cystic PVL on cerebral ultrasound at birth in a newborn infant presenting with primary lactic acidemia is highly suggestive of PC deficiency. Moreover, PC deficiency should also be considered when ischemia-like brain lesions are documented by fetal ultrasonography.

Brain↗
PubMed1999

Clinical spectrum of infantile free sialic acid storage disease.

Infantile free sialic acid storage disease (ISSD) is a rare autosomal recessive metabolic disorder caused by a lysosomal membrane transport defect, resulting in accumulation of free sialic acid within lysosomes. Only a few cases have been described. We report on three new cases of ISSD with different modes of presentation: an infant with nephrotic syndrome, a case of fetal and neonatal ascites with heart failure, and a case of fetal ascites with esophageal atresia type III. From these patients and a review of the literature (27 cases total) we draw the following conclusions. 1) "Coarse facies," fair complexion, hepatosplenomegaly, and severe psychomotor retardation are constant findings in this disorder. 2) Nephrotic syndrome occurred in most cases (four in seven) in which renal evaluation was performed. Therefore, ISSD is an important cause of nephrosis in infants with a storage disorder phenotype. 3) Fetal/neonatal ascites or hydrops was the mode of presentation in 13 (60%) of 21 cases. Thus, ISSD enters in the differential diagnosis of hydrops fetalis with a storage disease phenotype. 4) Cardiomegaly was evident in nine cases. 5) Corneae were always clear, and albinoid fundi were reported in five cases. 6) Dysostosis multiplex was not prominent. 7) Bone marrow aspiration could be negative. 8) Death ensued in early infancy with a mean age of 13.1 months. All reported deaths were caused by respiratory infections.

Ascites↗
PubMed1999

Efficacy of iodine-131 6beta-methyl-iodo-19-norcholesterol scintigraphy and computed tomography in patients with primary aldosteronism.

In order to define the role of scintigraphy in determining the aetiology of primary aldosteronism, 41 patients were examined by computed tomography (CT) scan and adrenal scintigraphy using iodine-131 6beta-methyl-iodo-19-norcholesterol with the dexamethasone suppression test. Hormonal and scintigraphic examinations were conducted while avoiding interference by medical treatment. The aetiological diagnosis was established by taking account of the clinical context, the endocrine profile, and CT scan and scintigraphic data, as well as possible hormone assays after catheterization of the adrenal veins (12 cases) and postoperative pathology data (14 cases). The aetiological diagnoses established were Conn's adenoma (insensitive to angiotensin II) in 12 cases, idiopathic hyperplasia in 11 and macronodular hyperplasia (with functional autonomy of the nodules) in 18. Unilateral and bilateral lesions were correctly distinguished by scintigraphy in 92% of cases as compared with only 58% using CT scan alone; this was because the CT scan appearance was normal in 3/12 cases of adenoma and because a single nodule was visible in 2/11 cases of idiopathic hyperplasia and in 12/18 cases of macronodular hyperplasia. It is concluded that scintigraphy using noriodocholesterol with the dexamethasone suppression test should be performed systematically in conjunction with hormonal tests and adrenal CT scan in all cases of primary aldosteronism, as part of a strategy aimed not only at detecting adenoma but also at determining whether the hyperfunctional lesions are bilateral.

19-Iodocholesterol↗
PubMed1999

[Quality of life. Construct validation and the development of a modular system].

The construct Quality of Life (QoL) is investigated by metaanalysis of eight (inter)nationally validated questionnaires in a multicenter study. Data have been collected in a mentally healthy (n = 479), a depressed (n = 171) and a schizophrenic (n = 139) sample. Conventional psychometric criteria and a facet analytical methodology have been applied. The resulting questionnaire "Modular System for Quality of Life" (MSQoL) consists of a core module with 47 items (one "G-factor" and six subdimensions), which is sufficiently valid for all three samples. Additionally, there are four specific modules (demography, family, partnership, profession). No specific modules can be identified for the psychopathological subgroups. The validated radex structure for subjective QoL offers the opportunity for a cumulative research design and for adaptations to the actual setting.

Adolescent↗
PubMed1999

Cerebral vascular complication and hyperhomocysteinemia in a cystinotic uremic child.

We report a 13-year-old girl with nephropathic cystinosis on chronic peritoneal dialysis who presented with two episodes of stroke. Laboratory evaluation showed severe hyperhomocysteinemia (108 mumol/l). Further testing revealed that she was homozygous for the thermolabile variant of the methylenetetrahydrofolate reductase (MTHFR) gene. Treatment with folic acid and vitamin B12 lowered plasma homocysteine to less than 20 mumol/l. No further episodes of stroke occurred over a follow-up of 12 months. Homocysteine levels should be measured in patients with chronic renal failure, since simple and safe treatment with folic acid and vitamin B12 is effective in lowering the plasma homocysteine level in patients with the thermolabile MTHFR allele.

Adolescent↗
PubMed1999

Outcome of individuals with low-moderate methylmalonic aciduria detected through a neonatal screening program.

BACKGROUND: The clinical spectrum of methylmalonic aciduria (MMAuria) ranges from severe, neonatal acidosis to benign asymptomatic organic aciduria. In 1975, screening for MMAuria was established in the province of Quebec. Although newborn screening programs facilitate presymptomatic detection and treatment and also detect asymptomatic variants, uncertainties about potential long-term hazards of mild to moderate elevations of MMA create concern. The objective of this study was to examine the outcome of individuals excreting low to intermediate quantities of MMA, ascertained by a newborn screening program. RESULTS AND STUDY DESIGN: One hundred and thirty-six individuals with elevations of urinary MMA were initially identified by the screening program; 122 individuals were noted to have excretion of urinary MMA <1400 micromol/mmol creatinine. At follow-up assessment at 1 year of age, in 65 of these 122 individuals, the MMA excretion had resolved. Of the remaining individuals, 9 were lost to follow-up, 13 had symptoms, and the remaining 35 were free of symptoms. Among the 35 individuals with asymptomatic persistent MMAuria, MMA excretion has resolved in 13 over 1 year; 22 individuals exhibit persistent low-moderate MMAuria (range, 210 to 1133 micromol/mmol creatinine). CONCLUSION: Follow-up examination of individuals in the latter asymptomatic cohort with persistent low-moderate MMAuria indicates normal somatic and cognitive outcomes.

Adolescent↗
PubMed1999

[Low prevalence of anti-annexin V antibodies in antiphospholipid syndrome with fetal loss].

PURPOSE: Annexin V, a protein with potent anticoagulant activity has a calcium-dependent binding affinity for phospholipids. Annexin V is distributed in many organs, especially in the placenta and endothelium. Various studies have shown that placental annexin V is decreased in women with anti-phospholipid syndrome. It has been suggested that annexin V might be a target of anti-phospholipid antibodies and that the subsequent decrease in annexin V might be associated with obstetrical complications. We investigated the presence of anti-annexin V antibodies in the plasma of women with anti-phospholipid syndrome and obstetrical complications. METHODS: Twenty-three patients with at least one spontaneous abortion were included in the study. Anti-cardiolipin antibodies and lupus anticoagulant were present in 87% and 30% of the patients, respectively. A group of 40 healthy women were included in the control group. Anti-annexin V IgG and IgM antibodies were measured by ELISA. RESULTS: The IgG mean OD was 0.07 +/- 0.013 in patients and 0.042 +/- 0.06 in the control group. There was no significant difference between the two groups (P = NS). Only two out of the 23 patients and two out of the 40 healthy women were positive for IgG (OD > 0.25). The sensitivity of the assay was poor (8.7%). Even when the threshold was adjusted according to the mean OD in control subjects +2 SD, the sensitivity was still poor, reaching only 13%. CONCLUSION: The prevalence of anti-annexin V was low in patients with anti-phospholipid syndrome and repetitive spontaneous abortions. Anti-annexin V assay does not appear to be sensitive enough for the identification of anti-phospholipid antibodies that might be involved in the decrease in annexin V leading subsequently to thrombosis risk.

Abortion, Spontaneous↗
PubMed1999

Neuroleptic-induced extrapyramidal symptoms are accompanied by cognitive dysfunction in schizophrenia.

Cognitive impairments in schizophrenics have been found to precede tardive dyskinesia and to co-exist with other motor deficits. However, little is yet known about the prevalence of cognitive disturbances in patients with neuroleptic-induced parkinsonism. From the literature on idiopathic parkinson, it was inferred that extrapyramidal symptoms (EPS) are accompanied by cognitive dysfunction. 85 schizophrenic in-patients were divided into EPS high and low scorers according to an established criterion (Simpson Angus Scale, cut-off score: 0.4). Cognitive impairments were assessed using a self-rating instrument measuring disturbances of information processing. Patients with high EPS exhibited significantly elevated scores in six of ten cognitive and perceptual subscales (t = 2.1-3.1) as compared to low EPS patients. It is concluded that high EPS patients suffer from cognitive disturbances which are assumed to possess high relevance for both psycho-social and medical treatment. Cognitive problems may, when not considered, disturb compliance, insight of illness and transfer of learnt skills into everyday life.

Adult↗
PubMed1999

Dexamethasone-induced decrease in HMG-CoA reductase and protein-farnesyl transferase activities does not impair ras processing in AR 4-2J cells.

Rat pancreatic acinar cells AR 4-2J respond to dexamethasone by differentiation and a decreased proliferation rate. Protein labelling by [3H]-mevalonolactone, used as a precursor of farnesyl and geranylgeranyl isoprenoid groups, was increased in the presence of dexamethasone. In these same conditions, dexamethasone decreased HMG-CoA reductase activity, leading to a diminished isotopic dilution of the mevalonate precursor. As ras proteins, known to be involved in the regulation of proliferation and differentiation, need to be farnesylated for full biological function, we also measured the level of farnesyl transferase activity and found a dose-dependent decrease in dexamethasone treated cells. Despite these negative effects of dexamethasone on mevalonate pathway, there was no appearance of non-isoprenylated forms of ras, indicating that the level of isoprenoid precursors and farnesyl transferase activity were not limiting in this model.

Alkyl and Aryl Transferases↗
PubMed1999

Hyperornithinaemia-hyperammonaemia-homocitrullinuria syndrome is caused by mutations in a gene encoding a mitochondrial ornithine transporter.

Neurospora crassa ARG13 and Saccharomyces cerevisiae ARG11 encode mitochondrial carrier family (MCF) proteins that transport ornithine across the mitochondrial inner membrane. We used their sequences to identify EST candidates that partially encode orthologous mammalian transporters. We thereby identified such a gene (ORNT1) that maps to 13q14 and whose expression, similar to that of other urea cycle (UC) components, was high in liver and varied with changes in dietary protein. ORNT1 expression restores ornithine metabolism in fibroblasts from patients with hyperammonaemia-hyperornithinaemia-homocitrullinuria (HHH) syndrome. In a survey of 11 HHH probands, we identified 3 ORNT1 mutant alleles that account for 21 of 22 possible mutant ORNT1 genes in our patients: F188delta, which is common in French-Canadian HHH patients and encodes an unstable protein; E180K, which encodes a stable, properly targeted protein that is inactive; and a 13q14 microdeletion. Our results show that ORNT1 encodes the mitochondrial ornithine transporter involved in UC function and is defective in HHH syndrome.

Amino Acid Metabolism, Inborn Errors↗