Search PubMed⌕ Search

Biomedical subjects

I Lambert

Publications and source records attributed to I Lambert.

At least 19 recordsLinked to original sources
PubMed1994

Prenatal diagnosis and post-mortem study of a fetus with mosaic trisomy 14 due to a dic(14)(p11).

Amniocentesis at 17 weeks' gestation revealed a mosaic karyotype--46,XX/46,XX,-14,+dic(14)(p11). No abnormalities were detected on ultrasound. Growth and placentation were normal. The fetus was examined after termination of pregnancy and micrognathia and pulmonary hyperlobation were the only abnormalities detected. Several tissues were set up for cytogenetics, including fetal skin, kidney, ovary, and placenta. The diagnosis was confirmed by these studies. The level of mosaicism varied between tissues, with the trisomy 14 cell line highest in amniotic fluid.

Adult↗
PubMed1992

Juvenile distal cerebral ischemia: angiographic features. A study of 55 cases.

This study of juvenile distal cerebral ischaemia is based on 55 patients aged from 18 to 30 years. The authors describe the circumstances of discovery, as well as the clinical features and the course of the disease which may be severe and lead to non-resolutive neurological accidents and sometimes dementia. Paraclinical evaluation includes capillaroscopy, finger and toe pads biopsy (which clearly shows a pathological process with fibrocellular promontories narrowing the lumen of arterioles), and above all angiography which displays two typical signs: arterial narrowness and bands of peripheral ischaemia. In advanced forms of the disease angiography reveals classical signs of ischaemic lesions, but charateritically these are very distal. Associated abnormalities of the carotid siphon can also be found. Finally, positive CT scans show an isolated widening of the sulci which is fairly suggestive of the disease.

Adolescent↗
PubMed1991

Bronchopulmonary dysplasia: a longitudinal study of 23 cases.

Bronchopulmonary dysplasia (B.P.D.) is a condition reflecting the reaction of the immature lung to the intensive support (barotrauma from mechanical ventilation and oxygen toxicity) required for survival in critically ill newborn infants. This study examines all infants who developed B.P.D. over a 2 year period in the Rotunda Hospital. Between 1st January 1986-31st December 1987 there were 1,360 N.I.C.U. admissions, 198 with respiratory problems and 76 requiring assisted ventilation (I.P.P.V.); 23 infants developed B.P.D. with a mean gestational age of 28.7 weeks (SD 2.5), mean birth weight 1,243 g. (SD 523 g.). One infant died at 4 months from S.I.D.S. and one was lost to follow-up (both had been clinically normal). At one year post term the weight was 7,843 g. (SD 1,134) (normal population mean 9.75 Kg. third percentile 8 Kg.) and head circumference 46 cm. (SD 2.5) (normal population mean 47 cm., third percentile 45 cm). During the 1st year of life 11 infants required re-hospitalisation (5 bronchiolitis, 2 urinary tract infections, 2 failure to thrive, 2 myringotomies/grommets) and a further 8 attended hospital with respiratory infections. Only 6/21 received 3 in 1 vaccine (all in hospital O.P.D.) and 14/21 received 2 in 1 vaccine. At one year 15 infants were normal, 2 had cerebral palsy, 2 mild motor delay (one with arrested hydrocephalus), 1 sensorineural deafness and 1 arrested hydrocephalus with mild motor delay. Five infants developed retinopathy of prematurity but none required treatment.

Bronchopulmonary Dysplasia↗
PubMed1990

Multiple abnormalities in a child with partial duplications of 10p and 13q from a 3:1 segregation of a maternal t(10;13) translocation.

Partial duplications of 10p and 13q in association with partial deletions of other chromosome segments have been variously reported. We describe here a female child with multiple congenital abnormalities and combined partial duplications of 10p and 13q resulting from a 3:1 segregation of a maternal t(10;13)(p13;q22). In comparing the phenotypic features of the two chromosome imbalances, the expression of features typical of partial duplication 10p appeared more pronounced.

Abnormalities, Multiple↗
PubMed1989

[Value of magnetic resonance imaging in cancer of the endometrium. Apropos of 3 cases].

Magnetic nuclear resonance imaging offers a new approach for assessing the spread of endometrial cancer. Clinical and histopathological data correlated well in two cases; in the third patient, the degree of vesicovaginal wall involvement was more difficult to appreciate. RMN accurately characterizes the tumor and provides information on how deeply the myometrial lesion extends, as well as on isthmic and cervical involvement. Such evaluation is conducive to more precise prognostic conclusions and may be strategically influencial on therapeutic behavior.

Adenocarcinoma, Papillary↗
PubMed1987

[The Whitaker test. Apropos of an obstacle not to be ignored].

Since 1980, 35 pyelomanometric procedures have been performed in the Department of Clinical Urology for dilatations of the upper urinary tract of uncertain etiology. During two recent procedures, pressure measurements were modified by an extra-urinary obstacle caused by the patient's position. Our experience confirms the value of the Whittaker test as well as the need for a faultless technique.

Adult↗
PubMed1985

1,4-Bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP) and related compounds as inducers of hepatic monooxygenases. Structure-activity effects.

1,4-Bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP) resembles phenobarbital (PB) in its mode of induction of the hepatic drug-metabolizing enzymes in mice. The structural features of this molecule include: a linear tricyclic aromatic ether ring system, an internal 1,4-disubstituted benzene ring and two 3,5-dichloropyridyloxy substituents. Ten analogs of TCPOBOP have been synthesized and their activities as microsomal enzyme inducers evaluated. Dose-response induction of mice hepatic microsomal cytochrome P-450, aldrin epoxidase and dimethylaminoantipyrine N-demethylase gave ED50 values for TCPOBOP and five homologs. The results illustrate that changes in the structure of the pyridyloxy ring markedly affect enzyme induction activity. The order of activity for the substituents was 3,5-dibromopyridyloxy approximately 3,5-dichloropyridyloxy greater than 5-bromopyridyloxy approximately 5-chloropyridyloxy greater than 3-chloropyridyloxy greater than pyridyloxy. In addition, the effects of altered substitution pattern of the benzene ring and structural alterations of the internal ring moiety were evaluated by measuring hepatic microsomal coumarin hydroxylase activity. The results confirm the microsomal monooxygenase enzyme induction activity of TCPOBOP, and the observed structure-dependent potencies of several related homologs support a receptor-mediated mechanism of action for the process.

Animals↗
PubMed1984

PCBs and PBBs: biologic and toxic effects on C57BL/6J and DBA/2J inbred mice.

Treatment of genetically inbred "responsive" C57BL/6J and "non-responsive" DBA/2J mice with Aroclor 1254 or fireMaster BP-6 resulted in the induction of hepatic microsomal benzo[a]pyrene hydroxylase only in the former mouse strain and aminopyrine N-demethylase in both strains of mice. In contrast, 3,3',4,4',5-pentachlorobiphenyl and 3,3',4,4'-tetrabromobiphenyl, induced benzo[a]pyrene hydroxylase in both C57BL/6J and DBA/2J but did not enhance aminopyrine N-demethylase in either strain of mouse. Both these coplanar halogenated biphenyls also caused thymic atrophy in the responsive and non-responsive mice and their effects resembled those of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Treatment of the inbred mice with several mono-ortho substituted analogs of the coplanar halogenated biphenyls, including 2,3,3',4,4'-pentachloro-, 2,3',4,4',5-pentabromo-, 2,3,3',4,4',5-hexachloro- and 3',4'-dibromo-2,3,4,5-tetrachlorobiphenyl, gave hepatic enzyme-induction results similar to those observed for the commercial halogenated biphenyls. At dose levels of 1500 mumol/kg, most of these compounds caused thymic atrophy in C57BL/6J mice but not in DBA/2J mice. The structure-activity correlations in the mice complement similar studies with the halogenated biphenyls in rats and support the proposed receptor-mediated mechanism for the toxic halogenated aromatics.

Aminopyrine N-Demethylase↗
PubMed1983

Polychlorinated biphenyls as phenobarbitone-type inducers of microsomal enzymes. Structure-activity relationships for a series of 2,4-dichloro-substituted congeners.

Several polychlorinated biphenyl (PCB) isomers and congeners resemble phenobarbitone (PB) in their mode of induction of the hepatic drug-metabolizing enzymes; however, unlike PCBs which induce aryl hydrocarbon hydroxylase, no apparent structure-activity correlations have been reported. This study examines the effects of structure on the activity of a series of 2,4-dichloro-substituted biphenyls as inducers of several microsomal enzyme activities including dimethylaminoantipyrine N-demethylase, benzo[a]pyrene hydroxylase, aldrin epoxidase, and ethoxyresorufin O-deethylase. The results clearly illustrate a marked effect of structure on activity: all of the 2,4-dichloro-substituted PCBs resembled PB in their mode of induction. However, the potency of the induction response was dependent on the substitution pattern of the second phenyl ring (i.e. 2,3,4,5-tetrachloro greater than or equal to 2,3,4,5,6-pentachloro greater than 2,3,4,6-tetrachloro greater than 2,3,5,6-tetrachloro greater than 2,4,6-trichloro); the structure of the lower chlorinated ring also determined induction potency since the 2,4-dichloro-substituted PCBs were generally more active than their 4-chloro-substituted analogs, whereas the 2-substituted PCB homologs were inactive. The structural factors which typify the most active PB-type inducer, 2,2',3,4,4',5-hexachlorobiphenyl, include the presence of two para-, at least two meta- and two ortho-chloro substituents. In addition to the structure-activity correlations noted for PCBs, the 2,2',3,4,4',5-hexachlorobiphenyl congener also elicited a dose-response induction of two PB-inducible enzymes, aldrin epoxidase and dimethylaminoantipyrine N-demethylase.

Animals↗
PubMed1983

The comparative biologic and toxic potencies of polychlorinated biphenyls and polybrominated biphenyls.

Aroclor 1254 and fireMaster BP-6, two commercial polychlorinated biphenyl (PCB) and polybrominated biphenyl (PBB) preparations, exhibit comparable biologic and toxic effects. In the present study the commercial PBB was more active than Aroclor 1254 in causing thymic atrophy in male Wistar rats. However, a direct comparison of the relative effects of bromine vs chlorine substituents is not possible with the commercial PBB and PCB mixtures due to their complex congeneric composition. This study reports the synthesis and biologic and toxic effects of a series of laterally substituted 3,3',4,4'-tetrahalobiphenyls which contain the following variable molecular Cl/Br ratios; Br4, Br3Cl, Br2Cl2 (two isomers), BrCl3, and Cl4. 3,3',4,4'-Tetrabromobiphenyl and 3,4,4'-tribromo-3'-chlorobiphenyl (150 mumol/kg)-pretreated animals significantly inhibited the growth rate of and caused thymic atrophy in immature male Wistar rats whereas those isostereomers with reduced Br (and increased Cl) content were either less active or inactive. Pretreatment of male Wistar rats with 10 mumol/kg of the 3,3',4,4'-tetrahalobiphenyls and determination of their effects as inducers of the hepatic microsomal drug-metabolizing enzymes also illustrated the effects of the relative Cl/Br ratios on induction potencies. Both 3,3',4,4'-tetrabromo- and 3,4,4'-tribromo-3'-chlorobiphenyl maximally induced the cytochrome P-448-dependent monooxygenases, benzo[a]pyrene and 4-chlorobiphenyl hydroxylase; the order of potency of the other isostereomers was 4,4'-dibromo-3,3'-dichloro- congruent to 3,4-dibromo-3',4'-dichlorobiphenyl greater than 4-bromo-3,3',4'-trichloro- greater than 3,3',4,4'-tetrachlorobiphenyl. With few exceptions this order of potency was observed for the induction of benzo[a]pyrene hydroxylase and ethoxyresorufin O-deethylase in rat hepatoma cells in culture and for their relative binding affinities to the rat cytosolic receptor protein. The data clearly demonstrate that the biologic activities of this group of isosteric halogenated biphenyls are enhanced with increasing bromine substitution and also support the hypothesis that the activities of this class of chemicals are mediated through the receptor.

Animals↗
PubMed1983

Effects of hypo and hyperosmotic media on rabbit renal cortical slices.

Rabbit kidney cortex slices behave as osmometers when withstanding either hyperosmotic shocks or hypo-osmotic shocks of amplitude up to P1/P2 = 1.25. For hypo-osmotic shocks of amplitude larger or equal to P1/P2 = 1.5 a volume regulation process occurs. Na+ is the main osmotic effector implicated in volume control.

Animals↗
PubMed1983

Effect of osmotic shocks on rabbit kidney cortex slices.

Rabbit kidney cortex slices behave an osmometers when withstanding hyperosmotic or hyposmotic shocks of amplitude up to pi 1/pi 2 = 1.25. For hyposmotic shocks of amplitude larger than or equal to pi 1/pi 2 = 1.50, the maximum swelling achieved is less than what can be expected on the basis of the van't Hoff relation, thereby indicating that a volume regulation process is taking place. Volume regulation in kidney slices can be dissociated into two distinct phases. The first one, of swelling limitation, is very rapid and keeps maximum cell volume at values lower than expected when the tissue is considered as an osmometer. This phase is followed by a slow volume readjustment process during which volume progressively decreases towards control values. The major intracellular osmotic effector loss during both swelling limitation and volume readjustment is Na+. The overall volume regulation process is insensitive to furosemide, vanadate, and bumetanide. Swelling limitation is blocked by addition of ouabain. Contrary to what has been believed previously, there is, however, no need to implicate control of the activity of a ouabain-sensitive, Na+/K+ pump in the Na-dependent volume regulation mechanism.

Amino Acids↗