Ionomycin and 2,5'-di(tertbutyl)-1,4,-benzohydroquinone elicit Ca2+-induced Ca2+ release from intracellular pools in Physarum polycephalum.

Calcium level in organelles of the slime mold Physarum polycephalum was monitored by chlortetracycline, a low-affinity calcium indicator. It was found that 2,5'-di(tertbutyl)-1,4,-benzohydroquinone (BHQ) at a concentration of 100 microM, but not the highly specific inhibitor of sarco-endoplasmic reticulum Ca2+-ATPase (SERCA), thapsigargin (1-10 microM), elicited calcium release from the CTC-stained intracellular calcium pool. Ionomycin also caused a calcium release (23.7+/-5.1%), which was less than that induced by BHQ (30.1+/-6.0%). Procaine (10 mM), a blocker of ryanodine receptor, completely abolished the responses to BHQ and ionomycin. Another blocker, ryanodine (100 microM), only slightly diminished the responses to ionomycin and BHQ. Apparently, BHQ and ionomycin acting as a Ca2+-ATPase inhibitor and an ionophore, respectively, elicit an increase in [Ca2+]i, which in turn triggers a calcium-induced calcium release (CICR) via the ryanodine receptor. Caffeine, an activator of ryanodine receptor, at a concentration of 25-50 mM produced a Ca2+-release (5.6-16.0%), which was not similar in magnitude to CICR. The response to 25 mM caffeine was only moderately inhibited by 25 mM procaine, and almost completely abolished by 50 mM procaine and 100 microM ryanodine.

Effects of Ca2+-ATPase inhibitors, ionomycin, and pharmacological modulators of ryanodine receptor on calcium release from intracellular pools and on oscillatory contractile behavior in Physarum polycephalum.

Changes in calcium levels in organelles of the plasmodium of the myxomycete Physarum polycephalum were analyzed using the fluorescent calcium indicator chlortetracycline (CTC). Both the Ca2+-ATPase inhibitor 2,5;-di(tert-butyl)-1,4-benzohydroquinone (BHQ) (100 microM) and the calcium ionophore ionomycin (1 microM) induce a significant decrease in fluorescence level (by 30%) in CTC-stained microplasmodia; this is caused by release of calcium from intracellular storage compartments. An activator of ryanodine receptors, caffeine (10-50 mM), is less effective on Ca2+ release than BHQ or ionomycin, and their inhibitor, ryanodine (100 microM), almost completely blocks the response to caffeine, but only slightly decreases the effects of BHQ or ionomycin. Procaine, another inhibitor of ryanodine receptors, at 10 mM concentration completely abolishes both the BHQ and the ionomycin responses, but 50 mM is necessary to block the effect of 25 mM caffeine. These results suggest that both the BHQ- and the ionomycin-dependent Ca2+ releases occur through the ryanodine receptor and are to be considered as calcium-induced Ca2+ release (CICR). Both the ionomycin and the BHQ responses persist in the presence of Cd2+, which blocks Ca2+ channels of the plasmalemma. In most cases, Cd2+ itself induces release of Ca2+ from the CTC-stained calcium pool; the more effective Cd2+ is, the less the following ionomycin or BHQ responses occur. This indicates that Ca2+ entry through plasmalemma plays no significant role in the ionomycin- or BHQ-evoked initiation of CICR, and that the Cd2+- and BHQ/ionomycin-depleted Ca2+ stores overlap.

[The role of laparoscopy in assessing the resectability of cancer of the esophagus and proximal stomach]. / Rol' laparoskopii v otsenke rezektabel'nosti raka pishchevoda i proksimal'nogo otdela zheludka.

Laparoscopic findings obtained in patients with cancer of the thoracic part of the esophagus (321) and proximal part of the stomach (383) were analysed. As a result of laparoscopy, unjustified surgery was withheld in 14.9 and 19.3% of cases, respectively. Tumor resectability in the laparoscopy negative group was 92.8 and 84.5% for cancer of the lower and mid-third of the esophagus, respectively, and 76.2% for cancer of the proximal part of the stomach. Laparoscopy yielded false-negative results in 1.9% of cases and failed to be instrumental in diagnosis-in 4.5%.

[Experience in the diagnosis and treatment of malignant and benign tumors of the chest]. / Opyt diagnostiki i lecheniia zlokachestvennykh i dobrokachestvennykh opukholei grudnoi kletki.

The article analyses the follow-up of 155 patients among whom 63 had malignant tumors, 65 had benign tumors, while in 27 patients the tumor-like lesions were recognized as posttraumatic and post-inflammatory processes. Among 61 patients with sarcomatous lesions of the thoracic wall 21 had a resectable tumor. Operation was undertaken as a component of combined treatment in 21 patients. In a group of 19 patients 10 (16.4% of those admitted for treatment) have a survival period of 6 months to 18 years without signs of tumor growth. The other patients died in periods of 3 to 18 months. In a group of 65 patients with benign tumors 51 were treated by operation. Complications were not encountered. Among 27 patients with "false" tumors 5 underwent operation. The results of the study allow combined treatment of malignant tumors of the thoracic wall to be recommended for wider application.

[20 years' experience in the use of local hyperthermia in the treatment of inoperable cancer of the esophagus]. / Dvadtsatiletnii opyt primeneniia mestnoi gipertermii v lechenii neoperabel'nykh bol'nykh rakom pishchevoda.

The paper discusses the results of treatment of 280 patients with inoperable esophageal cancer which included local hyperthermia, radiotherapy, hyperglycemia and chemotherapy. 122 patients receiving radiotherapy alone served as controls. The complete remission rate obtained with local hyperthermia and radiotherapy was 2.5 times that observed for radiotherapy alone. Hospital lethality was 1.4% in the study group and 2.4% in controls whereas 5-year survival rates were 13.1% and 0, respectively.

[Endoscopic laser coagulation of the tumor in patients with cancer of the esophagus and proximal portion of the stomach]. / Endoskopicheskaia lazerkoaguliatsiia opukholi u bol'nykh rakom pishchevoda i proksimal'nogo otdela zheludka.

The paper discusses the results of treatment of 152 cases of cancer of the esophagus and proximal part of the stomach presenting with grade III-IV dysphagia. In 107 patients, treatment included endoscopic laser coagulation of tumor: in 52 the procedure was combined with radiation and in 18 cases-with chemotherapy, whereas in 37 patients the method was used alone for palliation only attempting at return to enteral nutrition. Histories of 45 patients with esophageal cancer who had received standard treatment served as control. Laser coagulation-associated lethality was 1.9%. Normal food passage was restored in 97.6% of esophageal cancer patients and in 96% of those with cancer of the proximal part of the stomach. The mean overall survival was 8.7, 8.4 and 7.3 months for the study groups and 3.2 months only for controls. The mean dysphagia-free survival was 48.5 days.

[Comparative evaluation of various surgical and combined methods of treatment of patients with esophageal cancer]. / Sravnitel'naia otsenka riada khirurgicheskikh i kombinirovannogo metodov lecheniia bol'nykh rakom pishchevoda.

The work gives a comparative analysis of the results of treatment of 267 patients with carcinoma of the thoracic esophagus by different variants of surgical intervention and preoperative irradiation. The results show that separation of surgical treatment into two or more stages fails to reduce postoperative lethality. Preoperative irradiation does not lead to increase of postoperative lethality and increases 5-year survival of patients as compared to the survival of patients treated by surgery alone. Five-year survival after radical operations was 12.3 +/- 1.2 per cent and after combined treatment it was 24.5 +/- 2.8 per cent. None of the patients who were subjected to palliative operations lived for more than 5 years.

[Endoscopic electrothermocoagulation of tumors in inoperable cancer of the esophagus and proximal part of the stomach]. / Endoskopicheskaia élektrotermokoagulatsiia opukholi pri neoperabel'nom rake pishchevoda i proksimal'nogo otdela zheludka.

The paper discusses application of endoscopic electrothermocoagulation in complex treatment of inoperable cancer of the esophagus and the proximal part of the stomach presenting with severe dysphagia. The study included 247 such patients, with 77.3% having stage IV tumor. 202 cases underwent electrothermocoagulation as a component of the treatment modality whereas 45 received standard therapy (controls). The newly-developed procedure assured enteral nutrition in 95.4% of cases and a drop in treatment--related complication rate from 33 to 9.3%. Survival ranged 8.4-11.2 months in different study groups and was as low as 3.1 months in controls.

[Diagnosis and treatment of neoplastic and cystic formations of the mediastinum]. / Diagnostika i lechenie opukholevykh i kistoznykh obrazovanii sredosteniia.

The article analyses problems of the diagnosis and surgical and complex treatment of 56 patients with neoplastic and cystic structures in the mediastinum. In the group of 56 patients 28 had neoplastic diseases of the mediastinum, in 11 of them the tumors were malignant. According to the data presented, postoperative mortality in mediastinal cysts was zero. In mediastinal tumors the preoperative diagnosis was authentically established in 11 of 28 patients (39.3%), postoperative mortality was 7%. An original method for hemostasis in bleeding from the seat of the mediastinal tumor is described. The survival of patients with malignant mediastinal structures treated by partial resection of the tumor, radiotherapy and polychemotherapy varies from 6 months to 4 years, which allows the conclusion that wider application of complex treatment is expedient.

[Experience in the surgical treatment of patients with cancer of the proximal stomach]. / Opyt khirurgicheskogo lecheniia bol'nykh rakom proksimal'nogo zheludka.

The results of surgical treatment of 116 patients with cancer of the proximal part of the stomach are analysed; in 63 of the patients the tumor had spread to the esophagus. Combined gastrectomy was performed in 87 patients, combined proximal resection of the stomach--in 2 patients. In 73 patients the operation was carried out through a transperitoneal approach. The authors describe an original method of compression esophago-intestinal anastomosis established through a transperitoneal approach with a suturing apparatus of their design. The operation was performed on 14 patients. Comparative analysis of the results of surgical treatment with the use of different methods for creating the anastomosis allows the suggested method to be recommended when a transpleural approach is contraindicated.

[Experience in esophagogastroplasty in surgical and combined treatment of patients with cancer of the thoracic esophagus]. / Opyt ézofagogastroplastiki pri khirurgicheskom i kombinirovannom lechenii bol'nykh rakom grudnogo otdela pishchevoda.

The results of surgical and combined treatment of 79 patients with cancer of the thoracic esophagus are discussed. All underwent resection of the esophagus. One-stage esophagogastroplasty was carried out in 44 patients, in 35 patients resection of the esophagus was the first stage of treatment, esophagogastroplasty was undertaken 6-8 weeks later. The authors describe their techniques of separating the upper part of the esophagus, forming the gastric tube and inserting it through the posterior mediastinum. Postoperative mortality was 15.9% in one-stage and 22.8% in postponed esophagogastroplasty. Completeness of treatment in both groups in relation to the total number of patients subjected to resection of the esophagus was 86.5 and 48.1%, respectively. Preoperative radiotherapy influenced neither the incidence of complications nor the mortality.

[Approaches to improving the methods of treating esophageal cancer]. / Puti uluchsheniia metodov lecheniia bol'nykh rakom pishchevoda.

The paper deals with an analysis of the results of treatment of 344 patients with cancer of the thoracic part of the esophagus. Out of those, 104 received surgical and combined treatment and 240 (inoperable cancer) were given radiotherapy alone or in combination with local hyperthermia, general chemotherapy or intratumoral iontophoresis of chemotherapeutic agents. The procedure after Dobromyslov-Torek proved to be insufficient in most of surgical cases because there were metastatic lesions below the diaphragm. A surgical procedure which takes care of metastases is suggested. Local hyperthermia potentiated the effect of radiation treatment. The immediate results of treatment improved after intratumoral sarcolysin iontophoresis was used in conjunction with radiation therapy.

[Intraneoplastic iontophoresis of cytostatics in the overall treatment of esophageal cancer]. / Vnutriopukholevyi ionoforez tsitostatikov v kompleksnom lechenii raka pishchevoda.

The authors report the results of clinical elaboration and testing of the technic of intraesophageal intratumor sarcolysin iontophoresis associated with radiotherapy in 40 inoperable patients with cancer of the thoracic esophagus. A total focal dose of irradiation was on the average 1/3 less compared with the routine one. Iontophoresis was performed by a specially designed electrode with 5-10 mA during 60 minutes. The iontophoresis procedure was followed by irradiation. The immediate good results of the treatment were twice as frequent as in control groups. The treatment proceeded with less pronounced radiation response. An average survival of patients while using chemical drugs intophoresis proved to be equal to control data that is likely to be due to the far-advanced stage of the disease in most patients. An average survival in patients with less tumor proliferation was found to be longer than in analogous control series.