Collective cell migration during human mammary gland organoid morphogenesis.

Organ morphogenesis is driven by cellular migration patterns, which become accessible for observation in organoid cultures. We demonstrate here that mammary gland organoids cultured from human primary cells, exhibit oscillatory and collective migration patterns during their development into highly branched structures, as well as persistent rotational motion within the developed alveoli. Using high-resolution live-cell imaging, we observed cellular movement over the course of several days and subsequently characterized the underlying migration pattern by means of optical flow algorithms.

Mechanical plasticity of collagen directs branch elongation in human mammary gland organoids.

Epithelial branch elongation is a central developmental process during branching morphogenesis in diverse organs. This fundamental growth process into large arborized epithelial networks is accompanied by structural reorganization of the surrounding extracellular matrix (ECM), well beyond its mechanical linear response regime. Here, we report that epithelial ductal elongation within human mammary organoid branches relies on the non-linear and plastic mechanical response of the surrounding collagen.

[A method for measuring the function of the organ of continence].

For preoperative assessment of anal continence we developed a simple device to measure both anal sphincter function and sensitivity of the rectal ampulla. With this instrument anorectal function was studied in 19 males and 26 females without anorectal disorders. Anal resting tone and voluntary squeeze was higher in the males than in the females.

[Significance of the colon contrast enema in evaluating the importance of rectosigmoid polyps].

The radiological appearance of mostly broad-based polyps in the rectosigmoid was studied in 35 patients. In all patients the diagnosis was histologically confirmed after surgical treatment. Conclusions on the histological tumour status could not be drawn either from surface structure, broadness of base and retraction of base, or from the base/height ratio.

[Transanal endoscopic microsurgery].

A new endoscopic surgical method was developed for removal of large sessile adenomas of the rectum and lower sigmoid. Stereoscopic sight and magnifying glasses do allow precise surgery of these tumors. If adenomas are present they can be removed using the technique of mucosa excision; if on the other hand rectum carcinomas have to be removed the complete wall of the rectum in an appropriate extension can be excised.

Endoscopic surgery in the rectum.

A new transanal endoscopic operative technique permits microsurgery in the rectal cavity and the placing of surgical sutures. Compared with other procedures this one is non-aggressive, and there were not postoperative complications in twelve cases. A stereoscopic optical system, a new operating rectoscope and special surgical instruments, as well as a modification to an insufflation device are necessary for the endoscopic operation.

The endoscopic multiple-diameter bougie--clinical results are after one year of application.

A new technique for dilation of the upper gastrointestinal tract permits complete endoscopic control of the whole procedure for the first time. 113 dilations have been carried out in 37 patients within a period of 15 months. The endoscopic guidance of the multiple diameter bougie positively excludes perforation resulting from the bougie's going the wrong way.

A multiple-diameter bougie fitted over a small-caliber fiberscope.

New instruments for dilatation of the upper gastrointestinal tract are described: 1. A hollow plastic bougie with an inside diameter of approximately 10 mm to allow a 9 mm endoscope to pass. The diameter of this tube-like bougie increases in four steps up to 16 mm.

[Transanal endoscopic surgery of the rectum - testing a new method in animal experiments].

Surgery of the lower third of the rectum can be done without difficulty through the anus using an endoscopical approach. Polyps or tumors located in the upper two thirds of the rectum can be removed using the Mason or Kraske procedure, or by the transabdominal approach. A new endoscopic technique has been developed with the aim, to allow surgery in the whole rectum through the anus.

A form of rabbit liver cytochrome P-450 that catalyzes the 7 alpha-hydroxylation of cholesterol.

A form of cytochrome P-450 which comigrates with cytochrome P-450LM4 (molecular weight, 55 000) on SDS-polyacrylamide gel was purified from liver microsomes of cholestyramine-treated rabbits. This form of cytochrome P-450 catalyzed the 7 alpha-hydroxylation of cholesterol with an activity of 37.5 pmol/min per nmol cytochrome P-450 in the reconstituted enzyme system containing cytochrome P-450 and NADPH-cytochrome P-450 reductase.

The identification of cytochrome P-450-LM2 synthesized in vitro from a rabbit liver polysomal mRNA template.

We demonstrate the in vitro synthesis of cytochrome P-450-LM2 (phenobarbital-inducible form of liver microsomal cytochrome P-450) from a rabbit liver polysomal mRNA template by specific immunoprecipitation of the product. The in vitro synthesized cytochrome P-450-LM2 comigrates with authentic cytochrome P-450-LM2 on sodium dodecyl sulphate-polyacrylamide gels, and is also selectively competed by authentic purified cytochrome P-450-LM2. In addition, we demonstrate that phenobarbital increases the amount of translatable mRNA for cytochrome P-450-LM2 but not for albumin, suggesting that phenobarbital has selective effects on the amount of available translatable mRNA or on mRNA biosynthesis.

Effects of cytochrome p-448 and p-450 inducers on microsomal dimethylnitrosamine demethylase activity and the capacity of isolated microsomes to activate dimethylnitrosamine to a mutagen.

The relationship between microsomal dimethylnitrosamine (DMN) demethylase activity and the capacity of isolated hepatic microsomes to activate DMN to a mutagen was examined using microsomes from C57 and DBA/2 mice which had been exposed to three different types of microsomal enzyme inducers: phenobarbital, which induces cytochrome P-450, 3-methylcholanthrene, which induces cytochrome P-448, and the polychlorinated biphenyl, Aroclor 1254 which appears to induce both types of cytochromes. DNM induced mutagenesis was assayed by a Salmonella auxotroph reversion test. With the C57 mice all three inducers increased both the activity of microsomal DMN demethylase and the capacity of the microsomes to activate DMN mutagenicity.

Cytochrome P-450 in the activation and inactivation of carcinogens.

The capacity of isolate mouse liver microsomes to alter the mutagenicity for bacteria of the primary carcinogen N-methyl-N'-nitro-N-nitrosoguanisine (MNNG) and the secondary one dimethylnitrosamine (DMN) was studied. Microsomal activation of DMN and inactivation of MNNG were decreased by protein- and protein-cholinedeficient diets and were increased by pretreatment with microsomal enzyme inducers. The decrease and increase paralleled the content of cytochrome P-450 present in the different microsomal preparations.