Postoperative residual paralysis and respiratory status: a comparative study of pancuronium and vecuronium

The objective of this prospective double-blind study was to determine whether postoperative residual paralysis (PORP) after pancuronium or vecuronium results in hypoxemia and hypercapnia in the immediate admission period to the recovery ward. Eighty-three consecutive surgical patients received balanced or intravenous anesthesia with pancuronium for operations lasting longer than one hour or vecuronium for those lasting less than 60 min, both combined with neostigmine at the end of anesthesia. Standard clinical criteria assessed neuromuscular function intraoperatively. Postoperatively, we determined neuromuscular function (acceleromyography with supramaximal train-of-four (TOF) stimulation of the ulnar nerve, and a 5-s head lift) and pulmonary function (pulse oximetry: SpO2, and blood gas analysis: SaO2, PaCO2). We defined PORP as a TOF-ratio <70%, hypoxemia as a postoperative SpO2 > or =5% below the pre-anesthestic level together with a postoperative SaO2 <93%, and hypercapnia as a PaCO2 > or =46 mm Hg. Among the 49 pancuronium and 27 vecuronium patients studied, the PORP rates were 20% in the pancuronium group and 7% in the vecuronium group (p>0.05). Hypoxemia and hypercapnia occurred more often in pancuronium patients with PORP than in those without PORP namely 60% vs. 10% (p<0.05) and 30% vs. 8% (p>0.05), respectively. We conclude that PORP after pancuronium is a significant risk factor for hypoxemia.     

Antibacterial activity of extract, fractions and four compounds extracted from Piper solmsianum C. DC. VAR. solmsianum (Piperaceae)

Piper solmsianum C. DC. var. solmsianum (Piperaceae) is a shrub commonly found in areas with wet tropical soils. Other Piper species have been used in folk medicine as antitumoral and antiseptic agents. We studied the crude methanolic extract, some organic fractions and compounds isolated from this plant for possible antimicrobial activity against Gram-positive and Gram-negative bacteria. The bioautographic assays disclosed three inhibition zones. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined showing excellent activity, particularly against the Gram-positive bacteria (Bacillus cereus, Staphylococcus aureus, Staphylococcus saprophyticus and Streptococcus agalactiae). It appears that the antimicrobial activity of Piper solmsianum is related mainly to the presence of conocarpan and eupomatenoid-5 (neolignans). However another, as yet unidentified, active compound could also be extracted from the plant.     

Effects of some S-blocked glutathione derivatives on the prevalent glyoxalase II (a form) of rat liver

The prevalent glyoxalase II (S-2-hydroxyacylglutathione hydrolase, EC 3.1.2.6, a form) of rat liver cytosol has been studied with a series of seven S-blocked glutathione derivatives. At pH 7.4 and 20 degrees C, only p-nitrobenzyl-S-glutathione was found completely inactive. All the other derivatives are linear competitive inhibitors of the enzyme. Ki values using S-D-lactoylglutathione as substrate are reported. Alkyl-S-glutathiones are weak inhibitors and their inhibition increases with the decrease of the length of the alkyl chain. The best inhibitors are those glutathione derivatives which contain a thioester bond (carbobenzoxy- and p-nitrocarbobenzoxy-S-glutathione) or a carbonyl group (p-chlorophenacyl-S-glutathione). Inhibition by carbobenzoxy-S-glutathione seems to be more complex since the double reciprocal plot shows deviation from linearity at low substrate concentration.     

Methodological specifications on the Todd method and preliminary results

In order to measure the potentiality and kinetics tissue fibrinolysis we have modified Todd's histochemical method preparing at least six sections taken from same sample tissue, by infraoperatory biopsy, esponing them to a fibrin film at a constant concentration; we have also chosen to incubate the section at 10, 20, 30, 45, 60 min. The measurement of the areas of fibrin, of tissue and fibrinolysis, at the above mentioned times, has been effected at standard magnification (15 X) by an image analyser (Videoplan) scale 1:8. For each sample we suggest to elaborate an Index of the Potentiality of Fibrinolysis (formula; see text) and an Index of the Kinetics of the Fibrinolysis (formula; see text). Applying this method to two different groups of thyroid disease (struma and adenoma) we have not pointed out any statistically significant difference.     

Kinetics and mechanism of the substitution reactions of [PtCl(bpma)]<Superscript>+</Superscript>, [PtCl(gly-met-<Emphasis Type="Italic">S,N,N</Emphasis>)] and their aqua analogues with <Emphasis Type="SmallCaps">l</Emphasis>-methionine,glutathione and 5′-GMP

The substitution reactions of [PtCl(bpma)]+, [PtCl(gly-met-S,N,N)], [Pt(bpma)(H(2)O)](2+) and [Pt(gly-met-S,N,N)(H(2)O)](+) [where bpma is bis(2-pyridylmethyl)amine and gly-met-S,N,N is glycylmethionine] with L-methionine, glutathione and guanosine 5'-monophosphate (5'-GMP) were studied in aqueous solutions in 0.10 M NaClO(4) under pseudo-first-order conditions as a function of concentration and temperature using UV-vis spectrophotometry. The reactions of the chloro complexes were followed in the presence of 10 mM NaCl and at pH approximately 5, whereas the reactions of the aqua complexes were studied at pH 2.5. The [PtCl(bpma)]+ complex is more reactive towards the chosen nucleophiles than [PtCl(gly-met-S,N,N)]. Also, the aqua complexes are more reactive than the corresponding chloro complexes. The activation parameters for all the reactions studied suggest an associative substitution mechanism. The reactions of [PtCl(bpma)]+ and [PtCl(gly-met-S,N,N)] with 5'-GMP were studied by using (1)H NMR spectroscopy at 298 K. The pK (a) value of the [Pt(gly-met-S,N,N)(H(2)O)]+ complex is 5.95. Density functional theory calculations (B3LYP/LANL2DZp) show that in all cases guanine coordination to the L(3)Pt fragment (L(3) is terpyridine, bpma, diethylenetriamine, gly-met-S,N,N) is much more favorable than the thioether-coordinated form. The calculations collectively support the experimentally observed substitution of thioethers from Pt(II) complexes by N7-GMP. This study throws more light on the mechanistic behavior of platinum antitumor complexes.     

Insect peptide hormones, an overview of the present literature.

A comprehensive overview of the recent state of the art of insect peptide hormones with chemical structures is presented. An increased interest in insect neuropeptides and dynamic development of that research area has been influenced by a rapid improvement of instrumentation necessary for isolation and structural characterization. Several research teams have studied the relationships between biological properties of insect and vertebrate peptide hormones. Thus hormones from the AKH family can be considered glucagon counterparts, whereas the myotropic hormones such as proctolin and Lem-PK (LPK) are a substance P equivalent. Insect melanization hormones Bom-MRCH in their structural characteristics and properties resemble those of mammal MSH, and leucosulfakinins Lem-SK-I and -II show some similarities with gastrin II and cholecystokinin. Bombyxin-II (Bom-PTTH-II) reveals a structural homology with human insulin and similar biological properties to adenocorticotropic mammal hormone. Allatostatin (Dip-JHS-I) may be compared to somatostatin as it can be inferred from the observations that this peptide modulates JH secretion in cockroach, Blattella germanica. Determination of the primary structure of eclosion hormones Mas-EH and Bom-EH-II as well as the amino acid sequence of allatotropin and allatostatin is a significant contribution to the understanding of the molecular mechanisms of metamorphosis and insect development.