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J W Slot

Publications and source records attributed to J W Slot.

115 records · Page 7Linked to original sources
PubMed1976

Synthesis and intracellular transport of proteins in the exocrine pancreas of the frog (Rana esculenta). II. An in vitro study of the transport process and the influence of temperature.

Frog pancreatic tissue was pulse-labelled in vitro with 3H-leucine and protein transport was studied in exocrine cells by electron microscope autoradiography. The proteins appeared to be synthesized in the RER and transported to the secretory granules along a similar route and with the same velocity as previously described under in vitro conditions. Evidence was obtained for the involvement of the vesicular and tubular elements at the periphery of the Golgi system in transferring protein from the RER to the Golgi cisternae. Kinetics of the release of newly synthesized proteins from the RER and their appearance in the condensing vacuoles are discussed and related to results reported from other tissues. The transport velocity in this poikilothermic system was studied in relation to the incubation temperature and compared with results reported from its mammalian counterpart. At temperatures between 20 and 30 degrees C intracellular protein transport occurs faster in the frog than in the Guinea pig pancreas. At higher temperature the transport process was severely disturbed in the frog.

Animals↗
PubMed1975

Rapid regeneration of the dermal-epidermal junction after partial separation by vacuum: an electron microscopic study.

A process of rapid repair of dermal-epidermal adherence, as found in experiments with interrupted suction, was investigated electron microscopically. Biopsies in different stages of the process of suction blister formation and of the repair process were studied. Results show that suction blister formation occurs by successive detachment of hemidesmosomes from the basement membrane, and that, after partial separation of the epidermis from the dermis, a rapid regeneration of the dermal-epidermal junction takes place. This regeneration process apparently consists of two steps: realignment of basal cells to the basement membrane accompanied by autophagocytosis of detached hemidesmosomes, and de novo formation of hemidesmosomes. The time required for this structural regeneration corresponds well with the speed of the functional repair of dermal-epidermal adherence measured with the technique of interrupted suction.

Adult↗
PubMedDate not supplied

Quantitative aspects of immunogold labeling in embedded and in nonembedded sections.

We tried to control immunolabeling conditions so that information about antigen concentration could be achieved by quantifying labeling patterns. Working with immunogold labeling procedures in ultrathin cryosections, we observed that differential penetration of immunoreagents causes considerable differences in labeling efficiency between various cell structures. Therefore, in these nonembedded sections, labeling densities can only be used to measure variations in antigen concentration within one cell structure. After embedding the tissue in 30% polyacrylamide (PAA), differences in penetration were negated. The equalizing effect of PAA on the labeling efficiency enabled us to design a simple immunocytochemical method by which concentrations of a protein can be measured in situ at subcellular levels, provided that no variations in the protein's structural conformation occur that would affect its immunoreactivity. In spite of a higher sensitivity observed for Ig-gold, we preferred to use protein A-gold in our system because of the low nonspecific labeling and the more precise antigen detection by the latter immunomarker.

Amylases↗