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Biomedical subjects

D Dive

Publications and source records attributed to D Dive.

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

Synthetic ferrocenic mefloquine and quinine analoguesas potential antimalarial agents.

A few years ago we proposed a strategy for the synthesis of new ferrocene-chloroquine analogues replacing the carbon chain of chloroquine by hydrophobic ferrocenyl moieties. Now, this strategy has been applied to the antimalarial amino-alcohols class to afford new potentially active analogues of mefloquine and quinine bearing a substituted ferrocenic group. The pathway used for the synthesis of the mefloquine analogues includes the coupling of an aminomethyl substituted ferrocene carboxaldehyde with a lithio quinoline compound. On the other hand, the synthesis of quinine analogues was ensured by the 'inverse' reaction of a lithio aminomethyl ferrocene with a quinoline carboxaldehyde. The configurations of each diastereoisomer were unambiguously determined by spectroscopic data. The mechanistic interpretations were fully discussed. Ferrocenyl analogues of mefloquine and quinine exhibited a lower antimalarial activity than mefloquine and quinine themselves. Comparing optical isomers, those isomers dissimilar to ferrocenyl derivatives presented better antimalarial activities than those similar to ferrocenyl.

Animals↗
PubMedDate not supplied

Cerebral glucose utilization during sleep in Landau-Kleffner syndrome: a PET study.

Three right-handed male children (aged 5, 6, and 11 years) with signs, symptoms and/or history of the syndrome of acquired aphasia-epilepsy (Landau-Kleffner syndrome) were studied during drug-induced, electroencephalographically (EEG)-monitored sleep by positron-emission tomography (PET) and the [18F]fluorodeoxyglucose (FDG) method. Our data demonstrate that in Landau-Kleffner syndrome, cerebral glucose utilization is not normal during sleep. The metabolic pattern varied between the children but the metabolic disturbances always predominated over the temporal lobes. They were right-sided, left-sided, or bilateral. In the two first patients, EEG recordings showed continuous spike-and-wave discharges during sleep and a right-greater-than-left asymmetry was observed in temporal areas. In patient 1, the asymmetry was associated with a relative increase of glucose utilization of the right posterior temporal region. In patient 2, the glucose utilization was relatively decreased in the left anterotemporal and left perisylvian regions. In patient 3, the sleep EEG showed no discharge and no significant asymmetry was observed; however, glucose utilization of both temporal lobes was decreased. Lower metabolic rates in subcortical structures than in cortex were also noted in the three children. This metabolic pattern may be related to the maturation of the central nervous system (CNS).

Aphasia↗
PubMedDate not supplied

Molecular cloning and characterization of a superoxide dismutase (sod) gene in Pneumocystis carinii.

This work reports the isolation and characterization of a gene encoding a superoxide dismutase (SOD, EC.1.15.1.1.) from Pneumocystis carinii derived from rat. Sense and antisense oligonucleotides, deduced from SOD amino acid sequences from a wide variety of organisms, allowed amplification of a 669 bp genomic DNA fragment specific to this P. carinii. RACE-PCR was used to obtain the major part of the complementary DNA; the 5'- and 3'-genomic regions were obtained respectively from a Mbol subgenomic library and from an amplified fragment using oligonucleotides designed from the cDNA sequence. Comparison of genomic and cDNA sequences showed an open reading frame of 660 bp interrupted by seven small introns. The deduced amino acid sequence contained 220 residues. Protein sequence alignment demonstrated the highest homology (50.5% identity; 70.3% similarity) with Saccharomyces cerevisiae manganese-SOD (MnSOD) suggesting that P. carinii SOD belongs to the mitochondrial MnSOD group. A putative targeting peptide found at the 5'-end of the P. carinii SOD sequence also suggested its mitochondrial localization.

Amino Acid Sequence↗
PubMedDate not supplied

[Diabetic peripheral neuropathy].

Peripheral neuropathy is a very frequent consequence of diabetes mellitus. Its clinical expression is quite variable. A specific therapy is sometimes necessary. Early diagnosis of diabetic neuropathy is a cornerstone of patient's follow-up. Differential diagnosis of diabetic neuropathy is sometimes difficult from another type of neuropathy or a focal, even systemic, disease. It is mandatory to know how a diabetic neuropathy may express. Pathophysiological mechanisms involved in diabetic neuropathy are complex and interrelated. Hyperglycaemia alone, even mild or moderate, vascular disorders and dysimmune factors may be combined to induce axonal injury. Glycaemic control is the cornerstone of effective treatment for neuropathy associated with diabetes. Specific pain control and therapies of autonomic disturbances are regularly required.

Diabetes Complications↗
PubMedDate not supplied

[Amoebae in the water supply: an epidemiological study (author's transl)].

Drinking water samples (836) of various origins have been examined for amoebae. For collector water, half of the samples are contamined without influence of the origin. So, occurrence of amoeba in underground waters is discussed. Filtration and disinfection are generally inefficient. Bottles of drinking water are very often polluted during bottling. International mineral waters of french origin are not so damaged during conditioning operation. Bacteria and amoebae populations are quite independant and can't be indicators one for another. Thermophilic amoebae strains are very rare and any pathogenic amoeba has been found during the study.

Amoeba↗
PubMedDate not supplied

[Amoebae in swimming-pools: microbiological and epidemiological aspects (author's transl)].

An inquiry was held to determine the occurrence and quantitative importance of "Limax" amoebae in 8 swimming-pools of the North of France. The influence of water flow system, filters and water disinfectants was studied. The connections with the bacterial flora growing at 37 degrees C and the presence of strains able to grow at 41 degrees were analyzed. The significance of their presence in the swimming-pools is discussed from the obtained results.

Amebiasis↗
PubMedDate not supplied

[Toxicity and bioaccumulation of isomers of polychlorobiphenyls by the ciliated protozoan Colpidium campylum (Stokes)].

A toxicity and bioaccumulation study was carried out in Colpidium campylum with sixteen pure isomers of mono-, di-, tri-, tetra-, penta-, hexa- and heptachlorobiphenyls and a commercial product: Pyralene 3010, dissolved in alcohol, after factorial study of the summation of effects between PCB and solvent. The position of chlorine atoms on the aromatic rings and their number influence toxicity, probably in relationship to the possibilities of hydroxylation of these molecules. The experimental conditions must be very carefully respected to obtain reproducible results.

Animals↗