Polysaccharide-protein interaction: a rheological study of the gel-sol transition of a gelatin-methylcellulose-water system.

Viscoelastic parameters for mixtures of gelatin and methylcellulose were measured as a function of temperature, in order to study the gel-sol transition of the system in which biopolymers forming thermo-setting and thermo-melting gels coexist. At higher temperatures than 45 degrees C, the gel network is mainly formed by methylcellulose while at lower temperatures around 5 degrees C, it is mainly formed by gelatin. At higher temperatures than 45 degrees C, gelatin inhibits the gelation of methylcellulose. A small amount of methylcellulose helps gelatin to form a network at lower temperatures. However, excessive amounts of methylcellulose inhibit the growth of network structure. Therefore, this mixture forms a phase separated gel at higher temperatures while it is not completely phase separated at lower temperatures, probably by some interaction between non-substituted hydroxyl groups in methylcellulose with carboxylic groups in gelatin.

Changes in endogenous cytokinin levels in partially synchronized cultured tobacco cells.

During the course of partially synchronized cell divisions in cultured tobacco (Xanthi) cells the amount of endogenous cytokinins in the butanol-soluble fraction increased 5 to 10 times in 3 hours and paralleled the increase in frequency of mitosis. Among three cytokinins detected in tobacco cells, the activity corresponding to the R(F) of authentic zeatin in thin layer chromatography changed in parallel with the mitotic index.

Fundic patch operation in the treatment of esophageal stricture with Barrett's esophagus--a case report.

A 66-year-old woman, who had a stricture of the distal esophagus with Barrett's epithelium caused by gastroesophageal reflux, was operated upon by means of the fundic patch method. Preoperative manometric and pH studies revealed that the patient had a cardiac incompetence and a delayed acid clearance of the esophagus. Endoscopic biopsies between 33-35 cm from the incisors, above the gastroesophageal junction, showed columnar metaplasia with a villiform surface, mucous glands, intestinal goblet cells, moderate inflammatory changes and focal mild dysplasia. After the operation, relief of the dysphagia and reflux symptoms were obtained successfully, and an endoscopy done 7 months later demonstrated that the esophageal lumen was adequate enough for passage, and that there was improvement of the esophagitis, though persistent Barrett's esophagus without malignancy still existed. These results indicate that the fundic patch operation with the formation of a mucosal valve and 270 degrees fundoplication is a useful method of choice for benign strictures of the lower esophagus.

Long esophageal myotomy with a fundic patch procedure for treating diffuse esophageal spasm: report of a case.

A diagnosis of diffuse esophageal spasm (DES) based on radiological and manometric studies was made in a 70-year-old man who presented with severe dysphagia, vomiting, and spontaneous chest pain. The manometric studies revealed a simultaneous onset of high amplitude contractions and a hypertensive lower esophageal sphincter (LES) that was well relaxed in response to deglutition, in contrast to the incomplete relaxation seen in achalasia. Because his dysphagia was so severe and did not respond to pneumatic dilatation, the patient was treated by a long esophageal myotomy with a full thickness incision through the LES and mucosa, adding a Thal-Hatafuku procedure. The patient made a good postoperative recovery and has since been eating normally without any further dysphagia or chest pain. Good manometric and radiological results have been obtained in this patient during 5 years of follow-up.