Blood interactions with novel polyurethaneurea hydrogels

The influence on blood of polyurethaneurea hydrogels in vitro was investigated based on poly(ethylene oxide). A hydrogel was compared with the regenerated cellulose membrane Cuprophan in terms of complement activation, as determined by measurement of C3a concentration. The hydrogel induced less complement activation and the presence of poly(ethylene oxide) is likely to be beneficial to platelet reactivity. The ability to vary the polymer composition and the solubility of the polymers in organic solvents makes the polyurethaneurea hydrogels strong candidates for composite biomaterials.

The Lec4A CHO glycosylation mutant arises from miscompartmentalization of a Golgi glycosyltransferase

Two CHO glycosylation mutants that were previously shown to lack N-linked carbohydrates with GlcNAc beta 1,6Man alpha 1,6 branches, and to belong to the same genetic complementation group, are shown here to differ in the activity of N-acetylglucosaminyltransferase V (GlcNAc-TV) (UDP-GlcNA: alpha 1,6mannose beta-N-acetylglucosaminyltransferase V). One mutant, Lec4, has no detectable GlcNAc-TV activity whereas the other, now termed Lec4A, has activity equivalent to that of parental CHO in detergent cell extracts. However, Lec4A GlcNAc-TV can be distinguished from CHO GlcNAc-TV on the basis of its increased sensitivity to heat inactivation and its altered subcellular compartmentalization. Sucrose density gradient fractionation shows that the major portion of GlcNAc-TV from Lec4A cells cofractionates with membranes of the ER instead of Golgi membranes where GlcNAc-TV is localized in parental CHO cells. Other experiments show that Lec4A GlcNAc-TV is not concentrated in lysosomes, or in a post-Golgi compartment, or at the cell surface. The altered localization in Lec4A cells is specific for GlcNAc-TV because two other Lec4A Golgi transferases cofractionate at the density of Golgi membranes. The combined data suggest that both lec4 and lec4A mutations affect the structural gene for GlcNAc-TV, causing either the loss of GlcNAc-TV activity (lec4) or its miscompartmentalization (lec4A). The identification of the Lec4A defect indicates that appropriate screening of different glycosylation-defective mutants should enable the isolation of other mammalian cell trafficking mutants.

Population data on the forensic genetic markers: phosphoglucomutase-1, esterase D, erythrocyte acid phosphatase and glyoxylase I

Blood specimens from white and black sample populations from Baltimore, Maryland, were analyzed for the four most forensically important, polymorphic red cell enzyme systems-phosphoglucomutase-1, esterase D, erythrocyte acid phosphatase and glyoxalase I. The distributions of the phenotypes for each marker in each racial group were in Hardy-Weinberg equilibrium. The population data were similar to previously reported data for Whites and Blacks from different geographical locations within the United States.

Transferable plasmid-mediated drug resistance among non-O1 Vibrio cholerae and rough strains of Vibrio cholerae from Tamilnadu, India

A total of 289 non-O1 Vibrio cholerae (NVC) strains and 20 rough V. cholerae (RVC) strains isolated in an endemic area were tested for antibiotic resistance and for transferable R-plasmids. Twenty three per cent of NVC and 40% of the RVC isolates were found to be resistant to one or more drugs. Eight NVC and four RVC strains possessed multiple drug resistance, varying from four to eight drugs. The common spectrum found in NVC isolates were chloramphenicol and streptomycin (CS) or chloramphenicol, streptomycin, tetracycline and ampicillin (CSTA). Resistance to sulphamethoxazole (Su) and to trimethoprim (Tm) was encountered infrequently. In RVC isolates in addition CSTASuTm determinants, resistance markers to aminoglycosides kanamycin, gentamicin and neomycin were also found. Eighteen of the 27 V. cholerae strains with two or more resistance determinants transferred them en bloc to Escherichia coli K12. The level of resistance in the recipient strain was equal to or greater than that of the donor vibrio strains. Most of the strains possessing solitary resistance markers were unable to transfer them. beta-lactamase production could be demonstrated in 92.8% of the ampicillin resistant strains. None of the strains was resistant to nalidixic acid or furazolidone. The results emphasize the importance of antimicrobic susceptibility determination of V. cholerae isolates, regardless of the serotypes, before commencing chemotherapy.

Serological diagnosis of pulmonary aspergillosis

Methods for the preparation of antigens from clinically isolated cultures of Aspergillus were standardized. Sera from 25 suspected cases of pulmonary aspergillosis were tested against antigens prepared by us, from 4 strains of A. fumigatus and one strain of A. flavus, using the Ouchterlony double diffusion and immunoelectrophoretic techniques. Of the 25 sera, 18 reacted positively with antigens of A. fumigatus, one with A. flavus and 2 with both these species. Antigens of two non-pathogenic Aspergilli included in the study failed to react with any of the sera. Our antigen preparations gave more numerous as well as sharper precipitin lines than the commercial Bencard antigens which were used for comparison. Moreover, mycelial antigens from 48 to 96 h old cultures revealed precipitin lines comparable to that of the routine, 4 week old culture filtrate antigens, thus suggesting that the incubation period for obtaining antigens could be cut down considerably.

Chromic acid oxidation of benzhydrols-kinetics and mechanism

The kinetics of the oxidation of benzhydrol (diphenylmethanol) and several of its substituents by chromium(VI) oxide in aqueous acetic acid have been studied in detail. The rate of oxidation is expressed as ��������������������� v = k3[ArAr'CHOH][CrVI][H+]2 The effect of ring substituents on the rate gives a p+ value of -0.546 (r = 0.959) pointing to the development of an electron-deficient centre in the transition state. The oxidation of benzhydrol[α-D] proceeds 6.5 times slower than that of its protio analogue at 55°C. From the Arrhenius plots, activation parameters have beep evaluated and the isokinetic relationship has been analysed. The results are discussed in terms of a mechanism involving a rate-determining loss of hydride ion from the α-carbon of benzhydroxy chromate ester.

SUBSTITUTED METHANES: PART XXXVI. CALCULATED WAVE NUMBERS, ASSIGNMENTS, AND THERMODYNAMIC PROPERTIES FOR CH2DI AND CD2HI, AND CALCULATED ROTATIONAL DISTORTION CONSTANTS AND MEAN AMPLITUDES FOR CH3I AND CD3I

A set of potential energy constants has been obtained for CH3I and CD3I from their vibrational spectral data. From these constants, the rotational distortion constants and the mean amplitudes have been calculated for these two molecules. The rotational distortion constants DJ, DJK, and DK were, respectively, CH3I, 6.34, 59.36, and 3 542.30; CD3I, 3.90, 33.08, and 866.43 kc/s. The principal mean amplitudes of vibration in pm (pm = picometer = 10−12 meter = 10−2 Å) at 298.16°K are CH3I, 5.25 (C—I), 7.71 (C—H), 12.37 [Formula: see text], and 12.00 [Formula: see text]; CD3I, 5.14 (C—I), 6.63 (C—D), 10.85 [Formula: see text], and 10.65 [Formula: see text]. The potential energy constants were used to obtain the wave numbers of CH2DI and CD2HI. A complete assignment of the observed wave numbers for the molecules CH2DI and CD2HI has been made. The fundamental wave numbers for the gaseous state of CH2DI are a′, 2 980, 2 235, 1 418, 1 170, 723, and 519; a″, 3 091, 1 266, and 871 cycles/cm. For CD2HI, the corresponding values are a′, 3 017, 2 174, 1 185, 1 009, 757, and 508; a″, 2 273, 1 279, and 676. With these wave numbers, the thermodynamic functions have been calculated for the two molecules for 12 temperatures from 100 to 1 000°K for 1 atm pressure. The values of (H0−E00)/T, −(F0−E00)/T, S0, and Cp0 at 298.16°K are, respectively, CH2DI, 8.82, 54.66, 63.48, and 10.98; CD2HI, 9.00, 55.20, 64.19, and 11.53 cal deg−1 mole−1.

MOLECULAR INTERACTIONS: I. INFRARED SPECTRA OF SOME CARBOXYLIC ACIDS IN CARBON TETRACHLORIDE AND BENZENE SOLUTIONS

Infrared spectra of benzoic, o-chlorobenzoic, and salicylic acids in the range 700 to 3800 cm−1 have been studied. Measurements have been made on the three acids in carbon tetrachloride and benzene solutions, at a number of concentrations in each case. The results are interpreted in terms of the molecular species present in each solution and the effect of the solvents on these species. Assignments have been made of the observed bands to the various vibrational modes characteristic of the COOH group.