Search PubMed⌕ Search

Biomedical subjects

P Geoffroy

Publications and source records attributed to P Geoffroy.

42 records · Page 3Linked to original sources
PubMedDate not supplied

Isoniazid poisonings in New York City.

We identified 41 New York City residents who had been hospitalized at least overnight between January 1992 and September 1993 because of a toxic isoniazid (INH) exposure. Review of the available medical charts of 33 patients revealed that median age was 19 years, 27 (82%) were females, and 24 (83%) were taking INH chemoprophylaxis for tuberculosis infection. Twenty-two patients had seizures. Twenty-seven (82%) patients had attempted suicide using INH, and another three patients had intentionally misused INH by making up missed doses at one time. All patients survived. Physicians should be aware of the potential for INH toxicity and should assess their patients' current mental and psychosocial status when prescribing it. INH toxicity should be considered when young patients, particularly females, present with unexplained intractable seizures, and treatment with pyridoxine should be given.

Adolescent↗
PubMedDate not supplied

Isolation and characterization of a proteinaceous inhibitor of microbial proteinases induced during the hypersensitive reaction of tobacco to tobacco mosaic virus.

A proteinase inhibitor is strongly induced in tobacco leaves reacting hypersensitively to tobacco mosaic virus. The tobacco inhibitor is highly active against four different serine endoproteinases of fungal and bacterial origin (EC 3.4.21.14) but inhibits poorly two serine endoproteinases of animal origin, trypsin (EC 3.4.21.4) and chymotrypsin (EC 3.4.21.1). The inhibitor has been purified to homogeneity by successive steps of conventional and high-performance liquid chromatography. When electrophoresed under denaturing conditions, it behaves as a small polypeptide with a molecular weight of about 6,000. From its amino acid composition and NH2-terminal amino acid sequence analysis, it appears that the inhibitor belongs to the potato inhibitor I family. A polyclonal antiserum was raised against the purified tobacco inhibitor and was used in immunoblotting experiments to follow inhibitor accumulation during the hypersensitive reaction of tobacco to tobacco mosaic virus. The inhibitor is highly efficient and might represent a potent fungicide and/or bactericide to be used in plant biotechnology.

Amino Acid Sequence↗
PubMedDate not supplied

Regulation of enzymes involved in lignin biosynthesis: induction of O-methyltransferase mRNAs during the hypersensitive reaction of tobacco to tobacco mosaic virus.

The mRNAs encoding orthodiphenol-O-methyltransferases (OMTs; EC 2.1.1.6), which are involved in the biosynthesis of lignin precursors, are highly induced in tobacco leaves during the hypersensitive reaction to tobacco mosaic virus (TMV). OMT messengers were fractionated on a sucrose gradient and translated in vitro. Protein A-Sepharose columns adsorbed with specific antisera raised against purified OMTs were used to select translation products, and the translatable activity of OMT mRNA was measured at different stages of infection. Oligonucleotides derived from peptide sequences of purified OMT I were used to prime polymerase chain reactions; total RNA was used as template to allow the isolation of an OMT I clone. RNA blots, hybridized with the OMT I probe, revealed a unique messenger of 1.7 kb. The kinetics of accumulation of OMT I mRNAs during the hypersensitive reaction to TMV parallels the kinetics of translation and suggests that an increase in mRNA controls the increase in the rate of enzyme synthesis. In healthy plants, RNA blot hybridization showed that the steady-state level of OMT I mRNA is very high in vascular tissue compared to the level measured in leaves.

Amino Acid Sequence↗
PubMedDate not supplied

Expression of angiotensin II type-I receptor and phospholipase C-linked G alpha q/11 protein in the human placenta.

OBJECTIVE: A recent study on the distribution of angiotensin II (ANG II), ANG II (AT) receptors, and human placental lactogen in human placental tissues from term pregnancies showed positive correlations among these indices, suggesting an important role for ANG II in placental endocrinology. However, nothing is known about the ontogenesis of this functional role for ANG II during pregnancy. Therefore, the aim of this study was to investigate the placental AT receptor expression at various trimesters of pregnancy. We also studied the ontogenesis of phospholipase C-linked G alpha q/11 protein, which is known to transduce ANG II type-1 (AT1) receptor signal. METHODS: Western blot analysis of placental membrane proteins was performed using a chemiluminescence kit and specific antibodies against AT1 receptor and G alpha q/11 protein. Northern blot analyses of AT1 receptor and G alpha q/11 mRNA expression were accomplished using random primed [32P]dCTP-labeled specific probes. RESULTS: The autoradiographs of AT1 receptor mRNAs (2.4 kb) and proteins (83 kDa) showed a progressive 4.8-fold and 2.6-fold increase, respectively, during pregnancy, with maximal levels at term. We also observed progressive 1.8-fold and 4.5-fold increases of G alpha q/11 protein (43 kDa) and mRNAs (4.5, 6.0, and 7.1 kb), respectively, during pregnancy, with maximal levels observed at term. CONCLUSION: Our results demonstrate that both the human placental AT1 receptor content and the G alpha q/11 protein level increase during pregnancy, and suggest that the AT1 receptor pathway may play a role in human placental physiology.

Animals↗