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Biomedical subjects

M Neuman

Publications and source records attributed to M Neuman.

At least 91 records · Page 5Linked to original sources
PubMed1987

Comparative pharmacokinetic parameters of new systemic fluoroquinolones: a review.

The recent piperazinyl-substituted mono-fluoroquinolones represent a family with some common characteristics on one side, and variable parameters on the other side. COMMON characteristics: same mechanism of action: DNA-gyrase inhibitors of the A subunit of topoisomerase; pH dependent antibacterial activity; a rather long post-antibiotic effect for both gram-positive and gram-negative bacteria; same physiochemical properties: organic acids, high pKa, lipophilicity. Some common pharmacokinetic parameters: low protein binding (less than 50%); high volume of distribution (greater than 1.5 l/kg) with good attainable tissue concentrations in lymph, blister fluid, renal tissue, prostate, bronchial secretions, saliva, aqueous humor, CSF, bone, bile; good intracellular penetration in macrophages, polynuclear neutrophils; high peak urinary concentrations markedly exceeding the MIC for virtually all bacterial urinary tract pathogens, even accounting for the increase in MIC in the urine, especially at lower (acidic) pH; low extraction ratio dialysis; similar adverse reactions; CNS, gastro-intestinal, photosensitivity, tendo-articular and cartilage toxicity. However, most other pharmacokinetic parameters are different from one fluoroquinolone to the other; oral bioavailability, peak serum levels (C max) as a measure of bioavailability, terminal half-life of elimination (t1/2) are all variable. The extent of metabolic biotransformation varies greatly, the two extremes being ofloxacin, showing a high metabolic stability, and pefloxacin, highly metabolized. The degree of antibacterial activity of different metabolites also varies greatly. The renal clearance of most fluoroquinolones, except pefloxacin, greatly exceeds normal glomerular filtration rate, suggesting additional renal tubular secretion. Renal elimination of most fluoroquinolones - except pefloxacin, is blocked by probenecid.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗
PubMed1987

Comparative pharmacokinetic parameters of new systemic fluoroquinolones.

The recent piperazinyl-substituted mono-fluoroquinolones represent a family with some common features on the one hand, and some variable parameters on the other. Some of the common features are: same mechanism of action (DNA-gyrase inhibitors of the A subunit of topoisomerase); pH-dependent antibacterial activity; a rather long post-antibiotic effect for both Gram-positive and Gram-negative bacteria; same physicochemical properties (organic acids, high pKa, lipophilicity). Common pharmacokinetic parameters include low protein binding (less than 50%); high volume of distribution (greater than 1 l/kg) with good tissue concentrations attainable in lymph, blister fluid, renal tissue prostate, bronchial secretions, saliva, aqueous humour, CSF, bone and bile; good intracellular penetration in macrophages and polynuclear neutrophils; high peak urinary concentrations, markedly exceeding the MIC for virtually all bacterial urinary tract pathogens, even accounting for the increase in MIC in the urine, especially at lower (acidic) pH; low extraction ratio dialysis; similar adverse reactions (CNS, gastrointestinal, photosensitivity, tendo-articular and cartilage toxicity). However, most other pharmacokinetic parameters are different from one fluoroquinolone to the other: oral bioavailability, peak serum levels (Cmax) as a measure of bioavailability, terminal half-life of elimination (t1/2) are all variable. The extent of metabolic biotransformation varies greatly, the two extremes being ofloxacin, showing a high metabolic stability and pefloxacin, highly metabolized. The degree of antibacterial activity of different metabolites also varies widely.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗
PubMed1987

Relationship between chemical structure of antibiotics and pharmacokinetics.

Modifications to the chemical structure of antibiotics can modify nearly all pharmacokinetic parameters: digestive absorption, half-life, protein binding, tissue distribution, metabolic biotransformation, biliary and renal elimination. Examples of increased oral bioavailability are given for beta-lactams, macrolides, tetracyclines, fosfomycin, quinolones and acyclovir. The structural modifications responsible for prolonged or shortened half-life, increased or decreased biliary excretion, increased or decreased renal clearance for the different families of antibiotics are reviewed.

Anti-Bacterial Agents↗
PubMed1987

[Campylobacter pyloridis and gastroduodenal pathology].

After the first report by Marshall and Warren of the presence of gastritis associated Campylobacter pyloridis in antral mucosa, many groups have found the same association in many countries of Europe, USA, Japan. In France, too C.P. is found in antral mucosa. We have studied 119 dyspeptic patients; during endoscopy 3 biopsy specimens were taken, one for microaerophilic culture and 2 for pathologic examination. We found the germ in 27 p. 100 of 22 normal subjects but no culture was positive. In chronic interstitial gastritis it is found in 90 p. 100 of cases and in 98 p. 100 if a duodenal ulcer is associated. Ten patients with healed duodenal ulcer have been treated by V Penicillin: 3 millions unit/day during 2 weeks. In five cases C.P. disappeared but 2 of them relapse 2 months later.

Adult↗
PubMed1987

Relationships between chemical structure and adverse effects of antibacterial and antifungal agents.

Chemical structure and adverse effects are presented, including the side chains responsible for platelet inhibitory effects, hypoprothrombinemic effects, the disulfiram effect of some betalactams as well as the structures responsible for the hemotoxic effects of chloramphenicol, the digestive intolerance and hepatotoxic effect of some macrolides, the neurotoxic effects of quinolones, the nephrotoxicity of amphotericin, aminoglycosides, and polymyxin B - colistin. The conclusions to be derived by the prescribing physician are discussed in relation with these aspects.

Anti-Bacterial Agents↗
PubMed1986

Serum beta-N-acetyl hexosaminidase levels in chronic renal failure.

Serum beta-N-acetyl hexosaminidase (beta-NAH) levels, the indirect indicators of hepatic endothelial and Kupffer cell function, were examined in 16 anuric chronic hemodialysis patients, and in 11 patients in different stages of chronic renal failure (serum creatinine 2-8.8 mg/dl). They were found to be lower than those of the healthy controls, contrary to expectation. It might be concluded that nonparenchymal liver cells are functioning well in chronic renal failure. However, the possibility that production of beta-NAH in these patients is abnormally reduced cannot be excluded.

Adult↗
PubMed1986

Prevention of migraine attacks through the use of dihydroergotamine.

A strictly controlled clinical trial on a group of 20 patients treated with a time-release preparation of dihydroergotamine compared with 20 on a placebo for the prevention of migraine attacks confirmed that dihydroergotamine was very effective and considered satisfactory by 65% of the patients treated.

Adolescent↗