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Biomedical subjects

M Lambert

Publications and source records attributed to M Lambert.

At least 19 recordsLinked to original sources
PubMed2000

Vasopressin V1a receptor signaling in a rat choroid plexus cell line.

A new cell line was derived from primary culture of rat choroid plexus (RCP) by immortalization with the TSOri minus adenovirus. The selected clone expressed vasopressin V1a receptors at a density of 64,000 sites per cell, and a K(d) of 7.2 nM. Addition of vasopressin to the RCP cells induced a transient calcium peak comparable to V1a receptor signalling in different expression systems. This [Ca(2+)](i) increase was dose-dependent with an EC(50) of 22 nM vasopressin. Similar [Ca(2+)](i) increase was elicited by addition of serotonin, angiotensin II, endothelin-1, and bradykinin. Heterologous desensitization of V1a receptor was observed in RCP cells exposed to the phorbol ester PMA or following stimulation of other receptors coupled to the phosphoinositide pathway. Positive immunolabelling with Factor VIII, Flt1 and CD 34 antibodies suggests that this new RCP cell line originated from endothelial cells of rat choroid plexus.

Animals↗
PubMed2000

Markers of tissue hypoperfusion in pediatric septic shock.

OBJECTIVE: To describe measurements of global oxygenation parameters, markers of splanchnic hypoperfusion and those of metabolic activity related to cellular energy production among critically ill children with septic shock. DESIGN: Clinical study of a series of cases. PATIENTS AND PARTICIPANTS: 11 previously healthy children with septic shock admitted to the pediatric intensive care unit (ICU) of a university hospital. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Oxygen consumption, oxygen delivery (DO(2)), serum bicarbonate, arterial pH, gastric intramucosal pH (pHi), gastroarterial carbon dioxide tension gradient, serum lactate, pyruvate, lactate to pyruvate ratio (L/P), ketone body ratio, and the esterified to free carnitine ratio were measured serially at 0, 6, 12, 24, 36, and 48 h after admission to the pediatric ICU. All children survived. One patient failed to show supranormal DO(2) ( > 570 ml/min per m(2)). Normalization of serum bicarbonate and lactate were associated with patient recovery. One patient presented an increasingly abnormal L/P ratio with normal lactate levels, suggesting an increased utilization of pyruvate rather than an increased cytosolic redox potential. Although values of gastric pHi < 7.30 were observed in 43 % of samples, serial measurements in individuals showed significant variability and unpredictable trends. Free fatty acid concentrations, ketone body production, and carnitine levels remained within the normal range. CONCLUSIONS: In this study, trends in serum bicarbonate and lactate somewhat characterized the recovery of children with septic shock. Based on our data, it is unclear how other markers may have been used to modify therapy.

Adolescent↗
PubMed2000

Ambient pH signalling in ascomycetous yeasts involves homologues of the Aspergillus nidulans genes palF and paIH.

In Yarrowia lipolytica, the transcription factor Rim101p mediates both pH regulation and control of mating and sporulation. Like its homologues PacC of Aspergillus nidulans and Rim101p of Saccharomyces cerevisiae, Y1Rim101p is activated by proteolytic C-terminal processing, which occurs in response to a signal transduced by a pathway involving several PAL gene products. We report here the cloning and sequencing of two of these genes, PAL2 and PAL3. PAL2 encodes a putative 632-residue protein with six possible transmembrane segments, which differs from the transmembrane proteins Rim9p of S. cerevisiae and Pall of A. nidulans, but is homologous to A. nidulans Pa1H and to the product of the ORF YNL294c, a predicted polypeptide of unknown function in S. cerevisiae. PAL3 encodes an 881-residue polypeptide that is homologous to PalF of A. nidulans and to a newly identified putative polypeptide of S. cerevisiae. Both PAL2 and PAL3 are expressed constitutively, regardless of ambient pH. Mutations in these genes affect growth at alkaline pH and sporulation in both Y. lipolytica and in S. cerevisiae. They affect invasiveness of haploid strains in S. cerevisiae only, and conjugation in Y. lipolytica only. These results highlight the conservation of the Pal pathway initially described in A. nidulans.

Amino Acid Sequence↗
PubMed2000

[Bronchiolitis obliterans with organized pneumonia: a rare complication of primary Gougerot-Sjögren syndrome].

INTRODUCTION: Bronchiolitis obliterans organizing pneumonia (BOOP) is characterized by plugs of granulation tissue in bronchioles, alveolar ducts and alveoli. This pulmonary disorder has been reported in some cases in relation to drug consumption (D-penicillamine, amiodarone), with bacterial or viral infections (Mycoplasma pneumoniae, HIV), and with systemic diseases, such as rheumatoid arthritis. To our knowledge, only three cases of association BOOP-Sjögren's syndrome have been reported. EXEGESIS: We report three new cases of BOOP. These patients presented a primary Sjögren's syndrome without clinical or biological abnormalities suggestive of other autoimmune diseases. Initial presentation was an acute pulmonary disorder mimicking a bacterial pneumonia. Two patients had cutaneous vasculitis and the third vasculitic neuropathy. Corticosteroid therapy was begun and was quickly successful. None of the patients presented a relapse of BOOP. CONCLUSION: The incidence of BOOP is probably underestimated in patients with primary Sjögren's syndrome without cutaneous vasculitis. In case of pneumonia with antibiotic resistance, an immunological mechanism should be considered.

Adrenal Cortex Hormones↗
PubMed2000

Ultrasonographic diagnosis of testicular torsion by emergency physicians.

Testicular torsion has an incidence of one case per 4,000 men/boys. Most frequently affected are pubescent boys. Average testicular salvage rate is only 50%, and infertility can result Testicular torsion remains problematic for emergency physicians (EPs) as clinical diagnosis can be difficult and other testicular pathology can present similarly. In many institutions there are delays in obtaining Doppler or Scintigraphy studies during off-hours. We report two cases of testicular torsion diagnosed by the treating EPs using power Doppler in the emergency department (ED). Rapid diagnosis of torsion led to successful salvage of the affected testicle in both cases. These represent the first cases for emergency screening ultrasound examinations (ESUEs) of testicular torsion in the literature. Rapid technological advances over the last decade have brought portable equipment with high-resolution capability to the bed-side for EPs, who should consider using it more frequently to evaluate testicular torsion.

Adolescent↗
PubMed2000

Lung function study and diffusion capacity in anorexia nervosa.

STUDY OBJECTIVES: In humans, malnutrition alters the respiratory system in different ways. It impairs the ventilatory drive, decreases respiratory muscle strength and reduces immune competence. In addition, typical emphysema-like changes were demonstrated in starved animals. The presence of emphysema has never been demonstrated in starved humans. Our objective was to investigate whether pulmonary emphysema occurs in anorexia nervosa by means of a pulmonary function study. POPULATION AND METHOD: We examined 24 women aged between 14 and 38 years (nine smokers). We studied the lung function including lung volumes, ventilatory capacity, maximal respiratory pressures and transfer factor, as well as PaO2. RESULTS: All respiratory tests were within normal limits with the exception of decreased maximal inspiratory (59% of predicted values) and expiratory pressures (35%), and increased residual volume (162%). Diffusion capacity (98.1 +/- 16.2%) and transfer coefficient (98.4 +/- 16.2%) were also normal. The diffusion coefficient was lower in current smokers than in those who had never smoked (P < 0.01), a difference similar to that calculated from existing reference values for transfer factor for smokers and nonsmokers. CONCLUSION: In anorexia nervosa, pulmonary function tests are within normal limits with the exception of maximal pressures and residual volume. Diffusion capacity is not decreased. The present results within the limitations of the used method are not compatible with the hypothesis of starvation-induced pulmonary emphysema.

Adolescent↗
PubMed2000

Longitudinal analysis of bone mineral density in pre-menopausal female systemic lupus erythematosus patients: deleterious role of glucocorticoid therapy at the lumbar spine.

OBJECTIVE: To evaluate whether bone loss occurs over time in pre-menopausal systemic lupus erythematosus (SLE) patients. METHODS: We performed a longitudinal bone mineral density (BMD) analysis in a group of 35 pre-menopausal female SLE patients. Lumbar spine and hip (total and sub-regions) BMDs were measured twice 21 +/- 11 (mean +/- S.D.) months apart by dual-energy X-ray absorptiometry. RESULTS: In the whole cohort of SLE patients, significant bone loss was observed at the lumbar spine (-1.22%/yr) but not at the total hip. Further analyses indicated that lumbar spine bone loss (-2.12%/yr) occurred exclusively in the subgroup of patients who had taken a mean prednisolone daily dose >7.5 mg between the two BMD measurements. Moreover, bone loss was more important in patients who had previously received a cumulative prednisolone dose </=5 g by the time of their first BMD evaluation. CONCLUSIONS: These results, by demonstrating a loss of lumbar spine bone over time in pre-menopausal SLE patients given glucocorticoid (GC) therapy, strongly support the use of preventive treatment to minimize GC-induced osteoporosis in pre-menopausal female SLE patients given prednisolone daily doses >7.5 mg.

Adult↗
PubMed2000

Dosage of conventional neuroleptic medication and subjective cognitive functioning in schizophrenia.

Subjective cognitive and perceptual disturbances as assessed with the Frankfurt Complaint Questionnaire (FCQ) were correlated with chlorpromazine equivalents in 40 schizophrenic inpatients, who were treated with conventional neuroleptics. In line with previous research using 'objective' neuropsychological tests, both correlations and partial correlations (controlling for the effects of psychopathology, extrapyramidal symptoms and length of illness) confirmed that higher neuroleptic doses significantly worsen several cognitive and perceptual domains (r = 0.44 -0.54; P < or = 0.005 -0.05) with the possible exception of mnestic functions (r = 0.21 -0.24, n.s.) and language (r = 0.37 -0.38, P < 0.1). The clinical importance of self-report scales for evaluating both the risks and benefits of neuroleptic treatment is discussed.

Adult↗
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↗