Synthesis and biological activity profile of new analogues of the cyclic opioid peptide H-Tyr-c[D-Cys-Gly-Phe(pNO2)-D-Cys]-NH2 containing (S)-alpha-hydroxymethylcysteine in place of cysteine.

To examine the effect on biological activity of replacing D-Cys in the opioid peptide H-Tyr-c[D-Cys-Gly-Phe(pNO(2))-D-Cys]-NH(2) in position 2 or/and 5 with alpha-hydroxymethylcysteine (alpha-Hmc), three analogues were synthesized. These compounds exhibit agonist activity at both mu and delta receptors. However, the most active analogue, with (S)-alpha-Hmc residue in position 5, was 3360- and 2190-fold less active than the parent peptide in the GPI and MVD assays, respectively.

New analogue of cyclolinopeptide B modified by amphiphilic residue of alpha-hydroxymethylmethionine.

In order to evaluate the role and influence of the methionine residue on the biological activity of cyclolinopeptide B, an analogue with methionine residue in position 7 replaced by the amphiphilic (S)-alpha-hydroxymethylmethionine residue was synthesized. This peptide exhibits high immunosuppressive activity in the cellular, and to a lesser degree in the humoral immune response, comparable to that of CsA. In addition, the peptide was devoid of toxicity, even at high doses.

Synthetic formyl tripeptide chemoattractants: a C(alpha,alpha)-dialkylated, amphiphilic glycyl residue at position 1.

The two diastereomeric tripeptides f-(S)-HmMet-Leu-Phe-OMe and f-(R)-HmMet-Leu-Phe-OMe, analogues of the prototypical chemoattractant f-Met-Leu-Phe-OH, were synthesized in solution by classical methods and fully characterized. A conformational study was performed in solution by 1H-NMR. Concomitantly, the two peptides were tested for their ability to induce chemotaxis, superoxide anion production and lysozyme secretion from human neutrophils.

[Effect of general anesthesia induction on cerebral circulation in subacute and chronic subdural hematoma assesssed by computerized rheo-encephalography].

Cerebral circulation in 21 patients with subacute (SSH) and chronic subdural hematoma (CSH) were studied by computerized rheoencephalography before and after induction of general anesthesia. ECG and REG courses were sampled with a frequency of 62.5 Hz during a period of 15 minutes, and both sets of data points were fitted by an cubic polynomials.

[Experiments in evaluation of brain oxygenation and metabolism based on continuous bilateral SjO2 monitoring and metabolic glucose transformations in patients after severe cranio-cerebral injuries].

The study group consisted of 17 patients after severe cranio-cerebral injuries-in GCS below 8. Saturation in both jugular bulbs was measured by using fiberoptic catheters, the concentration of lactate taken from jugular bulbs was measured too. These values were compared to concentration in peripheral arteries.

[Procedures for patients with brain injuries and GCS <8].

Epidemiologic date concerned to multiple injuries with concomitant brain injuries are presented. The basic mechanisms developing brain damage are pointed out and principles managing with patients for protection against secondary injuries. The necessity of treatment this kind of patients in intensive care centers with broad possibilities in monitoring and diagnostic equipment is defined.

C(alpha)-hydroxymethyl methionine: synthesis, optical resolution and crystal structure of its (+)-N(alpha)-benzoyl derivative.

(R, S)-Methionine was transformed into C(alpha)-hydroxymethyl methionine by a route involving C(alpha)-hydroxymethylation of 2-phenyl-4-methylthioethyl-5-oxo-4,5-dihydro-1,3-oxazole. The absolute configuration of (-)-C(alpha)-hydroxymethyl methionine was elucidated to be (S) by chemical correlation with (S) (-)-C(alpha)-ethyl serine. Absolute structure determination (by single crystal X-ray diffraction) on N(alpha)-benzoyl-C(alpha)-hydroxymethyl methionine confirmed the (R)-configuration for the (+)-enantiomer.

Amino acid auxotrophy increases sensitivity of Saccharomyces cerevisiae to a quaternary ammonium salt IM.

Relationships between amino acid auxotrophy and N-dodecyloxy-carboxy-methyl-N-N-N-trimethyl ammonium chloride (IM) sensitivity have been investigated in isogenic yeast strains Saccharomyces cerevisiae and their meiotic segregants. It has been found, that auxotrophy increases the level of sensitivity to this salt markedly. A gene conferring resistance to that drug cancels the auxotrophy-dependent sensitivity.

Effect of some quaternary benzylammonium salts on physiology of yeast.

In order to determine the biological activity of eight compounds belonging to a group of quaternary ammonium salts, their influence on the active methionine transport, the integrity of cell membranes, respiration, and viability of Saccharomyces cerevisiae and some other yeast species has been investigated. The earliest effect observed during ammonium salts action on yeast cells is an immediate methionine transport abolishment followed by its fast leakage, which indicates increasing cell membrane degradation. Gradual decline of other biological functions such as respiration and viability is thus a result of disintegration and lack of tightness of the cell membranes.

N, N' (p-Xylylidene)-bis-aminoguanidine (2HCI) resistant mutants in Saccharomyces cerevisiae and their relation to the amino acid transport system.

N,N'-(p-Xylylidene)-bis-aminoguanidine 2HCl proved to be an efficient inducer of non-chromosomal petite mutation in Saccharomyces cerevisiae in either growing or non-growing conditions. A mutant Agr-7 resistant to this compound was obtained. Resistance proved to dominate over its XBAG-sensitive allele in the diploid formed in cross.

Blood cyanide and thiocyanate concentrations after administration of sodium nitroprusside as hypotensive agent in neurosurgery.

In a group of 50 neurosurgical patients receiving sodium nitroprusside as a hypotensive agent, in doses of 50--2131 microgram/kg body weight, whole blood cyanide was estimated before infusion of drug, during infusion, immediately after infusion, and 1 and 3 h later. Cyanide values increased significantly, reaching the maximum in a sample taken immediately after infusion (mean value, 333; highest value, 1800 microgram/liter). Values correlated closely with both dose and rate of infusion.