Inclusion volume solid-phase synthesis

Solid-phase synthesis of peptides was carried out using only the volume of the solvent included in the swollen solid-phase resin beads [inclusion volume synthesis]. This approach enables (i) the use of higher concentrations of activated amino acids, resulting in increased coupling rates, (ii) drastically decreased consumption of solvents, and (iii) the construction of multiple peptide synthesizers having virtually no reaction vessels.     

Pathological changes of myocardial cytoskeleton in cardiomyopathic hamster

Immunocytochemical investigation was performed on the cytoskeletal proteins in cardiac tissue of the cardiomyopathic hamster. Male cardiomyopathic UM-X7.1 hamsters at 180 days of age (n=8) and age- and sex-matched normal BIO-RB hamsters (n=8) were used in this study. Immunofluorescence microscopy using monoclonal antibodies against desmin, -actinin, titin, and vincullin was employed. The heart weight to body weight ratio was significantly increased in the heart of cardiomyopathic hamster compared with that of normal hamster. In cardiomyopathic hamster, the left ventricular cavity was markedly dilated. Light microscopically, hypertrophy and atrophy of myocytes and myocardial fibrosis were prominently observed in cardiomyopathic myocardium. Immunocytochemically, desmin, -actinin and titin showed the cross striations along the myofibers in normal myocardium. In contrast, in cardiomyopathic myocardium, desmin was irregularly distributed in myocytes and the amount of desmin was increased. Loss of cross striations of -actinin and titin were frequently observed. Immunofluorescence against vinculin was not significantly altered. We conclude that the alterations of cytoskeletal proteins in myocardial cells may relate to decreased myocardial function in cardiomyopathic hamster failing heart.     

Biochemical variation of Cryptococcus neoformans

Ninety-seven strains of Cryptococcus neoformans and C. bacillisporus were examined for 44 biochemical characters and the results were analyzed numerically. One phenon emerged at the 86% level of similarity when strains were clustered according to their M-similarity values. All strains grew in ten carbon sources (D-glucose, D-galactose, arbutin, maltose, sucrose, D-melezitose, D-xylose, D-mannitol, D-glucitol, and meso-inositol), and also grew at 37 ° C and produced urease and phenoloxidase. None of them grew in melibiose, lactose, nor valine, and none reduced nitrate to nitrite. Comparison of selected biochemical characters, creatinine utilization, and serotypes of 49 aberrant strains is presented. Forty-eight of the 97 strains produced the Filobasidiella state either alone or when paired with a strain of compatible mating-type. Filobasidiella neoformans serotypes A and D were interfertile with compatible mating-types of F. bacillispora serotypes B and C. The 44 biochemical characters and 4 serotypes did not predict barriers to mating competence. The present study further substantiates that Filobasidiella neoformans and F. bacillispora are one species.     

Responsiveness of the lamb ductus arteriosus to prostaglandins and their metabolites

The relative potencies of the prostaglandins A₁, A₂, E₁, E₂, F_2α and their 15-keto-, 15-keto-13,14-dihydro-, and 13,14-dihydro-metabolites were investigated on isolated lamb ductus arteriosus preparations contracted by exposure to elevated PO₂. All the prostaglandins (except PGF_2α and its 15-keto-metabolites) relaxed the tissue. However, only PGE₁, E₂, and their 13,14-dihydro-metabolites, were effective at concentrations below 10⁻⁸ M. Therefore, events that alter metabolism of circulating PGs in the perinatal period may have significant effects on the relative patency or closure of the ductus arteriosus.     

A new sensitive radial diffusion method for microdetermination of α-amylase

A sensitive agarose diffusion method for the determination of α-amylase has been developed, using Reactone Red 2 B-amylopectin as the substrate. The logarithm of enzyme activity is linearly correlated with the diameters of the diffusion zones over a very extended range from 1 mU/ml to at least 1100 U/ml. The α-amylase activity in biological samples may be determined without dilution or pretreatment, and the test can be performed at any desired temperature between 4 and 45°C. The clear radial diffusion zones may be fixed, further enhancing the contrast to the bright red surrounding.     

Production of human plasminogen activators by cell culture

Plasminogen activators are a group of enzymes which play a crucial role in the breakdown of blood clots. The plasminogen activators currently used in medicine to remove clots from veins and arteries suffer from several disadvantages, but new cell culture techniques or cloned genes could make available safer and cheaper enzymes.     

WOMEN IN NINETEENTH CENTURY AMERICAN BOTANY; A GENERALLY UNRECOGNIZED CONSTITUENCY

Botany was thought to be a suitable study for young women in schools and an amateur avocation in the Nineteenth Century. A surprisingly large number of American women identified themselves as being seriously interested in botany. For example, in the first published directory of American botanists in 1873, 13 percent of the 599 names are women's and that increased to 16 percent of the 982 names in 1878. In this paper, 1,185 women have been identified as a sample of those actively interested in botany during the century. Less than 2% of them were active before 1870, and most of them, 67%, resided in New England and the Middle Atlantic States. Almost three quarters of them were unmarried, and only 10% had higher educational degrees although 15% had some identifiable profession. Some particular individuals are noted for their contributions to science, their activity as plant collectors, and their support of botanical societies. Though few American women became professional botanists in the Nineteenth Century, they constitute an important overlooked constituency for the developing profession of botany.     

Protective effects of soluble CR1 in complement- and neutrophil-mediated tissue injury.

Complement activation is an important step for triggering of acute inflammatory reactions. Soluble human recombinant complement receptor type 1 (sCR1) blocks complement activation by both classical and alternative pathways. In addition to glycogen-induced peritonitis, three models of complement-dependent acute inflammatory injury have been used to assess the protective effects of sCR1: lung and dermal injury after intraalveolar or intradermal deposition of IgG immune complexes; acute lung injury resulting from intravascular activation of complement after the i.v. injection of cobra venom factor; and acute skin and lung injury (at 4 h) after thermal trauma involving 25 to 30% total body surface area. Vascular injury was quantified by increases in vascular permeability, hemorrhage, neutrophil infiltration, and, as indicated, tissue water content. Intravenous infusion of sCR1 reduced lung and dermal vascular injury in all models studied. In glycogen-induced peritoneal exudates sCR1-reduced neutrophil accumulation by 79%. In animals undergoing IgG immune complex-induced alveolitis, sCR1 treatment reduced vascular permeability and hemorrhage by 72 and 71%, respectively, and tissue accumulation of neutrophils was reduced by 68%. After cobra venom factor injection, sCR1 reduced increases in lung vascular permeability by 67%, hemorrhage by 73%, and lung myeloperoxidase content by 55%. Four hours after thermal injury of skin, sCR1-treated animals demonstrated significant protection against lung injury; increases in vascular permeability and hemorrhage were reduced by 45 and 46%, respectively, and myeloperoxidase content was lowered by 39%. In thermal injury of the skin, sCR1 injection reduced dermal vascular permeability by 25% at 1 h (p = NS) and 44% at 4 h. Water content in skin biopsies was also decreased. There was a dose-response relationship between the amount of sCR1 infused and the extent of protection in each of the injury models. These data demonstrate that sCR1 offers significant protection against complement-dependent tissue injury in the animal models studied and that the protective effects are related to reduced neutrophil content.     

Alternatively folded states of an immunoglobulin

Well-defined, non-native protein structures of low stability have been increasingly observed as intermediates in protein folding or as equilibrium structures populated under specific solvent conditions. These intermediate structures, frequently referred to as molten globule states, are characterized by the presence of secondary structure, a lack of significant tertiary contacts, increased hydrophobicity and partial specific volume as compared to native structures, and low cooperativity in thermal unfolding. The present study demonstrates that under acidic conditions (pH less than 3) the antibody MAK33 can assume a folded stable conformation. This A-state is characterized by a high degree of secondary structure, increased hydrophobicity, a native-like maximum wavelength of fluorescence emission, and a tendency toward slow aggregation. A prominent feature of this low-pH conformation is the stability against denaturant and thermal unfolding that is manifested in highly cooperative reversible phase transitions indicative of the existence of well-defined tertiary contacts. These thermodynamic results are corroborated by the kinetics of folding from the completely unfolded chain to the alternatively folded state at pH 2. The given data suggest that MAK33 at pH 2 adopts a cooperative structure that differs from the native immunoglobulin fold at pH 7. This alternatively folded state exhibits certain characteristics of the molten globule but differs distinctly from it by its extraordinary structural stability that is characteristic for native protein structures.