Effect of airway anaesthesia on the ventilatory and heart rate responses to isocapnic progressive hypoxia

The effect of airway anaesthesia by lidocaine inhalation on the hypoxic ventilatory response was examined together with the heart rate response by the isocapnic progressive hypoxia test in human subjects. During the test, end-tidal PCO2 (PETCO2) was maintained at the resting level. However, because resting PETCO2 tends to decrease by airway anaesthesia, we conducted the test at the resting PETCO2 determined both before (normocapnic) and after lidocaine (hypocapnic). Ventilatory and heart rate response were evaluated as a linear function of oxygen saturation of the arterial blood (SaO2). In the "hypocapnic" runs, ventilatory responses tended to be depressed, while the slope of heart rate response-PETCO2 relationship increased after lidocaine. However, when PETCO2 was restored to the normocapnic level, ventilation apparently increased from the control, and the augmented slope in the heart rate response disappeared. Although the elevated ventilation in normocapnic hypoxia might be due simply to the increased ventilatory response to CO2, we suggested that the augmented slope in the heart rate response in hypocapnic hypoxia might be related not only to PETCO2 level itself but also to the direct effect of airway anaesthesia.

Identification of the 21 monosomic lines in Avena byzantina C. Koch cv. 'Kanota'

All of the 21 possible monosomic lines have been screened and confirmed from 33 monosomic stocks of Avena byzantina C. Koch cv. 'Kanota'. All of them, except Mono-21 which was a progeny of monosomic 'Cherokee' (A. sativa) repeatedly backcrossed with 'Kanota', were obtained in the progenies of haploid (2n = 3x), aneuploid (2n = 6X±) and autotriploid (2n = 9X) partners of twins. Identification of the monosomics was carried out by means of the double monosomic method, monosomic analysis on marker genes, leaf peroxidase isozyme analysis, karyotype analysis and nullisomic analysis. The monosomic lines were numbered from Mono-1 through to Mono-21, mainly in the order of monosome length from the longest to the shortest. Most monosomic lines were hardly distinguishable by morphological characteristics from each other or from normal disomics. In the selfed progenies of four monosomic lines, Mono-8, -9, -17 and-19, segregation of nulli-, mono- and disomics was observed, but no nullisomics were found in the other lines. In most cases the frequency of monosomics ranging from 35.5 to 97.8% was, compared to those of nulli- and disomics, highest in the selfed progeny of monosomics. The monosomic lines were easily maintained and can be used for genetic analysis because of their good seed fertility and high monosome transmission rate. They have the near isogenic background of 'Kanota'.

Novel peptides with orally active and long-lasting antihypertensive activity

A series of N-(P-substituted phosphinoyl)peptides were synthesized and their antihypertensive activities were tested in spontaneously hypertensive rats (SHR). Among them, N-(dibenzyloxyphosphinoyl)-L-Ala-L-Pro-L-Pro-OH showed the most potent and long-lasting antihypertensive activity in SHR when administered orally. Although the inhibitory activity of this peptide against the angiotensin-converting enzyme was about one-hundredth of that of Captopril, the antihypertensive activity in SHR was significantly higher and longer-lasting than that of Enalapril which has been reported to be the most potent agent among similar converting enzyme inhibitors.

Graded-index sphere lens with hemispherical rod cladding

When a radially inhomogeneous sphere whose refractive-index profile decreases from center to periphery in a nearly parabolic manner is cladded with an additional hemispherical rod, the spherical aberration of the resultant lens (having a diameter of several millimeters) can be minimized to the diffraction limit for N.A. 0.45.

A new class of nitrosoureas. 4. Synthesis and antitumor activity of disaccharide derivatives of 3,3-disubstituted 1-(2-chloroethyl)-1-nitrosoureas

A series of 33 N-(2-chloroethyl)-N-nitrosocarbamoyl derivatives of N-substituted glycosylamines has been prepared and tested for antitumor activities. The compounds were obtained by reaction of glycosylamines with isocyanate, followed by nitrosation with N2O4. Structure-activity relationships of these trisubstituted nitrosoureas were investigated by varying the N-substituents and disaccharide groups and by comparing them with the corresponding disubstituted analogues. A large number of the nitrosoureas bearing a maltosyl group exhibited strong antitumor activities against leukemia L1210 and Ehrlich ascites carcinoma, and 60-day survivors against leukemia L1210 were found at the optimal dose for these derivatives. In contrast, the lactosyl and the melibiosyl derivatives were almost inactive. The most interesting compound in this series, the 3-isobutyl-3-maltosyl derivative (37), was tested against leukemia L1210 by single and multiple treatment. Its therapeutic ratio (96.3) obtained by multiple treatment is 3 times larger than that (31.5) obtained by single treatment, suggesting a possible clinical utility of 37 by multiple treatment. The favorable effect of a maltosyl moiety in this class of compounds is discussed.

Partial purification of a procollagen C-proteinase. Inhibition by synthetic peptides and sequential cleavage of type I procollagen

A procollagen C-proteinase which cleaves the C-propeptides from type I procollagen was purified about 125-fold from membranous bones of chick embryos. As estimated by gel filtration, the enzyme was about 80 000 daltons. When a reaction with modified procollagen was carried out, the enzyme preferentially cleaved the C-propeptides from the pro alpha chains in the order pro alpha 1, pro alpha 1, and then pro alpha 2. The enzyme was inhibited by several metal chelators and high concentrations of dithiothreitol. It was also inhibited by 5% fetal calf serum. A series of inhibitors of serine proteinases and sulfhydryl-containing proteinases were not inhibitory. Four oligopeptides were synthesized with amino acid sequences similar to the amino acid sequences around the sites at which the C-propeptides are cleaved during the conversion of procollagen top collagen in vivo. The peptide Tyr-Tyr-Arg-Ala-Asp-Asp-Ala inhibited the enzyme 35--60% in concentrations of 6--12 mM. Shorter peptides containing the Ala-Asp bond cleaved by the enzyme were less effective. The partially purified enzyme was also found to cleave the C-propeptides from type II and type III procollagens.

KRS-5 optical fibers capable of transmitting high-power CO(2) laser beam

Polycrystalline KRS-5 optical fibers were experimentally demonstrated to have high-power transmission capabilities for a cw CO(2) laser beam. A typical sample of fibers provided by extrusion, 1 mm in diameter and 0.87 m in length, carried a laser power of 68 W to its output end and was found to remain free from damage at an incoming laser intensity up to 30 kW/cm(2).

Preferential hydration of bovine serum albumin in polyhydric alcohol-water mixtures

The preferential solvent interaction with bovine serum albumin in aqueous solution of polyhydric alcohols (ethylene glycol, glycerol, xylitol, sorbitol, mannitol, and inositol) was investigated by a densimetric method with the application of multicomponent theory. This proteins was preferentially hydrated in all solvent systems examined: the extent depended on the number and the steric configuration of the hydroxyl groups of alcohols. The absolute interactions of these alcohols with the protein were estimated by assuming that the amount of hydration of protein at every solvent composition used is identical with that in pure water. The preferential hydration of the protein in 30% aqueous solutions of glycerol and sorbitol was found to decrease as the temperature was increased, indicating that the increase in chemical potential of protein on transferring it from water to both aqueous solvents is generated by a large positive enthalpy change, sufficient to compensate for the positive entropy change in the transfer process. On the basis of these results, and mechanism of stabilization of protein structure by these alcohols was discussed from the viewpoint of the solvation of protein.