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Biomedical subjects

M Lambert

Publications and source records attributed to M Lambert.

At least 199 records · Page 11Linked to original sources
PubMed1996

Case report: thoracic aorta thrombus with systemic embolization: a rare paraneoplastic antiphospholipid syndrome?

Antiphospholipid syndrome (APS) is characterized by venous and/or arterial thromboses in the presence of the lupus anticoagulant, anticardiolipin antibodies, or both. Antiphospholipid syndrome may occur as a primary disease or in patients with systemic lupus erythematosus or other autoimmune, infectious, or neoplastic disorders. This is a case of APS associated with chronic myelomonocytic leukemia and complicated by a large descending thoracic aorta thrombus responsible for lower limb and visceral emboli. The intraaortic clot was discovered by transesophageal echography (TEE). The association of APS with chronic leukemias has only rarely been described and, as far as can be ascertained, the location of a thrombus in the descending thoracic aorta has never been reported for this syndrome. This case illustrates the crucial role of TEE in the assessment of patients with systemic embolizations.

Aged↗
PubMed1996

A systematic review of the effectiveness of health service interventions aimed at reducing inequalities in health.

OBJECTIVE: To review the available evidence in order to identify effective interventions which health services alone or in collaboration with other agencies could use to reduce inequalities in health. METHODS: A search of the literature was undertaken using a number of databases including Medline (from 1990), Applied Social Science Index and Abstracts (1987-1994), and the System for Information on Grey Literature in Europe (1984-1994), on a large range of key words. Studies were included if they assessed interventions designed to reduce inequalities in health or improve the health of a population group relevant to the review, and could be carried out by a health service alone or in collaboration with other agencies. Only studies evaluating interventions using an experimental design were included. Papers in any language were considered. In addition, systematic reviews of the research on the effectiveness of health promotion and the treatment of conditions where there are significant health inequalities were identified in order to illustrate the potential for reducing inequalities in health. RESULTS: 94 studies were identified which satisfied all the inclusion criteria and 21 reviews were included. A number of interventions have been shown to improve the health of groups who are disadvantaged by socio-economic class, ethnicity or age and, if properly targeted, could be expected to reduce health inequalities. If a health intervention is being used, there should be evidence that it has an impact on health status. Attention should then be given to the way in which the intervention is delivered and the characteristics of a programme to promote implementation. Characteristics of successful interventions specifically aimed at reducing health differentials include: systematic and intensive approaches to delivering effective health care; improvement in access and prompts to encourage the use of services; strategies employing a combination of interventions and those involving a multi-disciplinary approach; ensuring interventions address the expressed or identified needs of the target population; and the involvement of peers in the delivery of interventions. However, these characteristics alone are not sufficient for success, nor are they universally necessary. CONCLUSIONS: Although it is likely that the most significant contributions to reducing health inequalities will be in improving economic and social conditions and the physical environment, there are interventions which health services, either alone or in collaboration with other agencies, can use to reduce inequalities in health.

Age Factors↗
PubMed1996

Functional and growth properties of a myometrial cell line derived from transgenic mice: effects of estradiol and antiestrogens.

This study describes the properties of a myometrial cell line, m-M116, that was derived from a leiomyoma developed in an adult female transgenic mouse harboring the simian virus 40 large T antigen (Tag) under the control of the 5'-regulatory sequence of the calbindin D9k (CaBP9k) gene. As the expression of this transgene is governed by the CaBP9k estrogen-responsive element, m-M116 cells were grown in medium supplemented with 17 beta-estradiol. The cells were long lived, had Tag-positive nuclei, and were nontumorigenic when injected into nude mice. They formed irregular layers of elongated cells with typical features of uterine, smooth muscle cells, as assessed by the presence of alpha-smooth muscle actin and desmin filaments, estradiol and progesterone receptors, and expression of the CaBP9k gene. The rate of cell doublings and the expression of the Tag gene in early passaged cells depended on the presence of 17 beta-estradiol. Tamoxifen, a mixed estrogen agonist-antagonist, also stimulated the growth of m-M116 cells, whereas ICI 182 780, a pure antiestrogen, blocked cell growth. Later passages of m-M116 cells still had a smooth muscle phenotype, but proliferated even in the absence of 17 beta-estradiol. These mouse uterine smooth muscle cells obtained by targeted oncogenesis provide a useful model for studies of the progression of steroid-independent carcinomas.

Animals↗
PubMed1996

Distribution of serouslike bone marrow changes in the lower limbs of patients with anorexia nervosa: predominant involvement of the distal extremities.

OBJECTIVE: To assess the distribution of marrow changes in the bones of the lower limbs of patients with anorexia nervosa (AN) and to correlate the importance of the extent of marrow changes with clinical and hematologic data. MATERIALS AND METHODS: The frequency of serouslike marrow (low signal intensity on T1-weighted images and very high signal intensity on T2-weighted images) was determined with MR imaging in the bones of the feet, distal tibias, and proximal femurs in 19 patients with AN. RESULTS: Serouslike marrow was found with an increasing frequency from proximal to distal in the lower-limb bones (femur, 31%; distal phalanx of the first toe, 79%). The patients with abnormal femoral marrow (n = 6) were more severely emaciated and had lower leukocyte and neutrophil counts than the patients with normal femoral marrow (n = 13). Among these patients, the six patients with at least two involved bones in the feet had lower blood cell counts than the seven patients with fewer than two involved bones. CONCLUSION: In the lower limbs of patients with AN, marrow changes predominate in the distal aspects. This distribution pattern is the reverse of that seen in most bone marrow disorders but is similar to the normal conversion of hematopoietic to fatty marrow. The importance of the blood cell count changes is correlated with the extent of marrow changes in the limbs.

Adolescent↗
PubMed1996

Treatment of familial hypercholesterolemia in children and adolescents: effect of lovastatin. Canadian Lovastatin in Children Study Group.

OBJECTIVE: Familial hypercholesterolemia (FH), an inherited autosomal dominant disorder of lipoprotein metabolism, is associated with premature atherosclerosis. The recommended pediatric therapy consists of dietary intervention and, when necessary, treatment with bile acid-binding resins. However, compliance has been poor in many children. Therefore, our objectives were to determine the efficacy, safety, and tolerance of the short-term use of lovastatin, a 3-hydroxy 3-methylglutaryl coenzyme A reductase inhibitor, in the control of severe FH in a male pediatric population and to evaluate the dose-response relationship. METHODS: Sixty-nine male patients with FH 12.9 +/- 2.4 years of age (mean +/- SD) participated in this multicenter, randomized, double-blind trial. After a 4-week placebo period, the patients were allocated to four treatment groups (lovastatin 10, 20, 30, 40 mg/d) for 8 weeks. Plasma lipid and apolipoprotein (Apo) concentrations were measured every 2 weeks. Clinical and laboratory evidence of adverse events was monitored periodically throughout the study. RESULTS: All lovastatin doses reduced total cholesterol (-17% to -29%), low density lipoprotein cholesterol (-21% to -36%), and ApoB (-19% to -28%) concentrations. A dose-response relationship was seen, and between-group comparisons showed that results were significantly improved up to a dose of 30 mg/d. We observed a 7% increase in high-density lipoprotein cholesterol and a 4% increase in ApoA1 concentrations. The medication was well tolerated by all patients. No serious clinical adverse experience was reported. Lovastatin increased aspartate aminotransferase concentrations, but there was no evidence of a dose-response relationship, and no value exceeded two times the upper limit of normal. No significant change in alanine aminotransferase was observed. Three patients had marked (more than three times the upper limit of normal) asymptomatic elevations in their creatine kinase values, which returned spontaneously to normal, and no action was required regarding the drug.

Adolescent↗
PubMed1996

[Contribution of Doppler sonography in inflammatory pathology of the large bowels].

At the end of the eighties, Doppler equipment added to conventional ultrasonography a new dynamic dimension. On the basis of radiological (US, CT, barium studies), clinical, biological, surgical and/or pathological correlations in 30 cases, the following considerations were emphasized. In case of intestinal obstruction, viability of the obstructed segment is compromised when Doppler parietal flow remains undetectable. In Crohn's disease or ulcerative colitis, as well as in acute appendicitis, presence of Doppler parietal flow throughout the affected thickened segment indicates an acute condition; similarly, abnormally high mean portal velocity (30-48 cm/sec; normal: 15 +/- 7 cm/sec), and abnormally low resistive index in the superior mesenteric artery (0.58-0.78; normal: 0.908 = 0.026) are detected. In colonic diverticulitis, similar characteristics can be observed, but are subtle and usually predominant at the mesenteric side of the affected segment in moderate diverticulitis. These abnormal Doppler findings disappear with successful therapy.

Appendicitis↗
PubMed1995

Identification of DNA sequences that bind retinoid X receptor-1,25(OH)2D3-receptor heterodimers with high affinity.

Vitamin D3 receptors (VDR) bind as heterodimers with retinoid X receptors (RXR) to vitamin D response elements (VDRE) and transactivate gene expression in a 1,25(OH)2D3-dependent manner. These elements are tandem direct repeats (DRs) of the hexamer RGGTCA separated by three nucleotides (DR3). We determined whether this DR3 was the optimal and/or only recognition sequence, by PCR-mediated binding site selection with reticulocyte lysate-expressed hVDR and mRXRalpha, and a pool of random sequences. We derived a consensus binding site for RXR-VDR heterodimers, RGGTCANN RRGTTCAB, and analyzed 10 of the 45 sequences slected by EMSA, methylation interference and transfection experiments: all the sequences were specific and acted as positive VDREs; the underlined purine of the spacer interacted with the heterodimer; the mutation of the third T in the second motif to a G did not influence VDRE activity. Thus, the selectivity of vitamin D pathway involving heterodimerization rather than VDR-homodimerization is not due to internal sequence variations. Except for mouse osteopontin VDRE, the natural VDREs would be efficient, only when helped by adjacent sequences and/or transactivators other than VDR and RXR.

Amino Acid Sequence↗
PubMed1995

[Leishmaniasis and human immunodeficiency virus infections].

The epidemiological, clinical and biological features of associated visceral leishmaniasis/human immunodeficiency virus infection are examined on the basis of a literature review of 239 published cases. The co-infection is principally located in Southern Europe, mainly in Spain, France and Italy. The study of restricted cohorts of patients showed that co-infection occurs in about 2 to 7% of AIDS patients. A part from the classical symptoms of visceral leishmaniasis, atypical or unusual symptoms (cutaneous, digestive or pulmonary) are described in about 10% of the cases. The parasite is occasionally found in blood and normal skin. Visceral leishmaniasis is frequently associated with other opportunistic diseases. Nine different zymodemes of Leishmania infantum, including two new ones, have been isolated from co-infected patients. There have also been a few cases of tegumentary leishmaniasis associated with AIDS.

AIDS-Related Opportunistic Infections↗
PubMed1995

New autosomal recessive form of amelia.

Amelia is a rare, usually sporadic malformation. We report on a family in which three fetuses had amelia of the upper limbs and variable deficiency of the lower limbs. The fetuses also had minor facial anomalies. Recurrence of the condition in sibs of both sexes suggests autosomal recessive inheritance. Recurrent amelia has been documented in only a few families most often associated with a different set of malformations. Possibly, mutations in more than one gene with different modes of transmission can lead to this severe limb deficiency. We speculate that the mutation found in our cases interferes with formation of the apical ectodermal ridge in the upper limbs and results in its premature degeneration in the lower limbs.

Abnormalities, Multiple↗
PubMed1995

Molecular, biochemical, and clinical characterization of mitochondrial acetoacetyl-coenzyme A thiolase deficiency in two further patients.

The molecular basis of mitochondrial acetoacetyl-CoA thiolase (T2) deficiency was studied in two patients (GK11 and GK16). Fibroblasts from each patient had detectable immunoreactive T2 polypeptide (CRM). In pulse-chase experiments, fibroblasts from GK11 had two types of CRM: one (type I CRM) disappeared after a 24-hr chase and migrated more slowly than that of the normal control; the other (type II CRM) was detected with a small amount even after a 72-hr chase and had normal electrophoretic mobility. GK16's fibroblasts had a CRM (type III) which was also detectable even after a 72-hr chase and showed a slower mobility than type I CRM. By analyzing amplified cDNA and genomic fragments, we showed that both patients are genetic compounds; GK11 for the mutations N158D and T297M, and GK16 for the mutations A301P and IVS8 (+1). Expression analyses confirmed that mutant T2 subunits with N158D, T297M, and A301P correspond to type I, II, and III CRM, respectively. Among them, only the mutant T2 polypeptide with T297M appeared to have a detectable residual activity, in spite of its instability. Cotransfection of two cDNAs containing N158D and T297M suggested that heterotetramer formation reduces residual activity in GK11 cells.

Acetyl-CoA C-Acetyltransferase↗
PubMed1995

Prenatal diagnosis of Smith-Lemli-Opitz syndrome is possible by measurement of 7-dehydrocholesterol in amniotic fluid.

Amniocentesis was performed at 17.3 weeks in a pregnancy with severe intrauterine growth retardation. Cytogenetic studies on amniocytes were normal, 46,XX, and the pregnancy was continued. The diagnosis of Smith-Lemli-Opitz syndrome was suspected in the neonatal period and confirmed by the presence of 7-dehydrocholesterol (7-DHC) in the plasma (0.4 mmol/l, normal = not detectable) associated with a low total cholesterol concentration (0.4 mmol/l, normal = 2.56 +/- 0.23). Retrospective analysis of the amniotic fluid sample revealed an elevated level of 7-DHC (0.022 mmol/l; normal = undetectable). Therefore measurement of 7-DHC levels in amniotic fluid during the second trimester of pregnancy is useful for the prenatal diagnosis of Smith-Lemli-Opitz syndrome in families at risk and should be considered in cases of severe growth retardation of unknown aetiology for which amniotic fluid is available and in which a normal chromosomal pattern in amniocytes is present.

Adult↗
PubMed1995

Molecular basis of phenotypic variation in patients with argininemia.

Argininemia is an autosomal recessive disorder caused by a deficiency in the liver-type arginase enzyme. Clinical manifestations include progressive spastic diplegia and mental retardation. While the quality of life can severely deteriorate in most such patients, some do show remarkable improvement in neurological symptoms while on controlled diets. We examined the thesis that differences in clinical responses to dietary treatment are based on molecular heterogeneity in mutant arginase alleles. Genomic DNAs from 11 patients with argininemia were examined using the polymerase chain reaction, cloning, and sequencing. Nine mutations representing 21/22 mutant alleles were identified in 11 patients with argininemia, and four of these mutations were expressed in vitro to determine the severity of enzymatic defects. We found that these mutations accounted for 64% of the mutant alleles in our patients. Based on findings in vitro expression tests, the mutations can be considered either severe or moderate. Patients with at least one moderate mutant allele responded well to dietary treatment; concentrations of plasma arginine were controlled within 300 microM. In contrast, patients with two severely mutated alleles did not respond to dietary treatment and plasma arginine was over 400 microM. Argininemia is heterogeneous at the molecular level. The degree of clinical improvement during dietary treatment is reflected in the concentration of arginine in plasma, as a measure of metabolic control. Plasma arginine levels during treatment is reflected in the concentration of arginine in plasma, as a measure of metabolic control. Plasma arginine levels during treatment correlated with types of molecular defects in the arginase genes.

Alleles↗