Monoclonal antibodies to human cytokeratins: application to various epithelial and mesothelial cells

Immunohistological analysis of human tissue using monoclonal antibodies against cytokeratins, which are confined to cells of epithelial origin, is a valuable technique. Using human epidermal keratins as antigen, we prepared monoclonal antibodies against cytokeratins (ZK1, ZK7, ZK61 and ZK99) and against a desmosomal protein (ZK31). Immunohistochemical staining of human skin sections using these antibodies showed a specific reaction with the epidermis: ZK1 stained the entire epidermis, ZK7 only the basal layer, ZK61 and ZK99 the suprabasal layers, and ZK31 the cellular interfaces. In order to test for antibody specificity, immunoblots with human epidermal and amnion epithelial cytokeratin polypeptides, as well as immunofluorescence microscopy of simple epithelia (glandular and simple columnar epithelia) were performed. ZK1, ZK61 and ZK99 reacted preferentially with cytokeratin polypeptides of stratified squamous epithelia and ZK7 recognized cytokeratins of stratified and simple epithelia. When the ZK antibodies were tested on mesothelial cells in pleural effusions, only ZK7 reacted with these cells. Biochemical analysis of cytokeratin accumulation in cells of primary and long-term cultures indicated that the cytokeratin pattern of mesothelial cells was quite unstable, while that of amnion epithelial cells showed only minor quantitative changes. The use of these antibodies to determine the epithelial origin of cells present in pleural effusions is proposed.     

A collection of programs for nucleic acid and protein analysis, written in FORTRAN 77 for IBM-PC compatible microcomputers.

We have developed a collection of programs for manipulation and analysis of nucleotide and protein sequences. The package was written in Fortran 77 on a Sirius1/Victor microcomputer which can be easily implemented on a large variety of other computers. Some of the programs have already been adapted for use on a Vax 11. Our aim was to develop programs consisting of small, comprehensible and well documented units that have very fast execution times and are comfortably interactive. The package is therefore suitable for individual modifications, even with little understanding of computer languages.     

Isolation and characterization of prolyl hydroxylase from Chlamydomonas reinhardii

Prolyl hydroxylase, which is responsible for the hydroxylation of peptidyl proline residues, has been isolated and purified from the green alga Chlamydomonas reinhardii. The enzyme, which appears to be loosely associated with microsomal membranes, was released into solution by sonication in the presence of detergent. Purification was achieved by ion-exchange chromatography followed by affinity chromatography using the immobilized substrate poly-L-proline. Apart from its differing substrate specificity the enzyme appears to possess similar molecular characteristics to prolyl hydroxylase isolated from animal tissues: the active enzyme is a tetramer of about 240–250 kDa and nonidentical monomers of 65 and 60 kDa. The monomers are capsule shaped having a dimension of 12×7 nm.Abbreviations Da dalton - DEAE diethylaminoethyl - DTT dithiothreitol - Hepes 4-(2-hydroxymethyl)-1-piperazine ethanesulfonic acid - -KGA -ketoglutarate - PAGE polyacrylamide gel electrophoresis - SDS sodium dodecyl sulfate     

Continuous production of L-tryptophan from indole and L-serine by immobilized Escherichia coli cells

Escherichia coli B 10, which has high activity of tryptophan synthetase, was grown in a 50-L batch culture in order to determine in which growth phase the cells have the highest specific tryptophan productivity. Accordingly, whole cells of the stationary phase were used for immobilization in polyacrylamide beads. After immobilization, these immobilized cells had 56% activity of tryptophan synthetase compared with that of free cells. First, the properties of immobilized cells were investigated. Next, discontinuous productions of L-tryptophan were carried out by using immobilized cells. In discontinuous production of L-tryptophan by the batch, the activity remaining of immobilized cells was 76-79% after 30 times batchwise use. In continuous production of L-tryptophan with a continuous stirred tank reactor (CSTR), the activity remaining of the immobilized cells was 80% after continuous use for 50 days. The maximum productivity of L-tryptophan in this CSTR system was 0.12 g tryptophan L(-1) h(-1).     

COMPARATIVE ULTRASTRUCTURE OF CULTURED SPECIES OF TREBOUXIA1,2

Five species of cultured Trebouxia—T. anticipata, T. decolorans, T. erici, T. gelatinosa, and T. impressa—were examined with the electron microscope. A comparative examination of their pyrenoids revealed pyrenoglobuli associated with single pyrenoid thylakoids. The pyrenoids of T. decolorans, T. erici, and T. gelatinosa possess single thylakoids that cross or deeply penetrate the pyrenoid matrix and are often disposed in parallel arrays. T. anticipata possesses both single and double pyrenoid thylakoids within the matrix. T. impressa possesses vesiculate invaginations of thylakoid membranes into the pyrenoid matrix. The phycobiont. T. erici was examined in detail at the light and electron microscopic levels for pyrenoid alterations associated, with varied environmental regimes and with cell division. A greater amount of starch is present in cells grown in organic culture at 215 lux light intensity than in cells of similar size grown at 1075 or 3600 lux. Pyrenoglobuli are present throughout the life cycle and occur both in aplanospores and in zoospores.     

Ultrasonic absorption studies of poly-benzyl-L-aspartate in mixed solvents, in relation to the helix-cell transition

Ultrasonic absorption measurements were carried out on solutions of polybenzyl-L -aspartate (PBLA) in chloroform–dichloroacetic acid (DCA) and in 1,2-dichloroethane (DCE)–DCA, in the range 3.9–155 MHZ . The helix–coil transition of PBLA produces an increase of absorption which is larger in CHCl₃–DCA than in DCE–DCA solutions. The influence of the solvent on the excess ultrasonic absorption suggests that solvation processes may be involved in these changes of absorption. The plots of the absorption vs. the volume fraction of DCA do not show any absorption maximum. This indicates that the ultrasonic absorption is not sensitive to the helix–coil equilibrium of PBLA in the frequency range investigated. A maximum value of 10⁹ S ^?1 has been obtained for the rate constant of growth of a helix region.     

Leaf water balance during oscillation of stomatal aperture

Continuous transpiration and β-guage measurements were made on cotton plants, the stomatal apertures of which had been induced to oscillate, thus allowing a water balance to be made, and leaf potential to be measured as functions of time.