[Neuroendocrine Carcinoma of the Non-Ampullary Duodenum-A Case Report]

A 69-year-old woman was admitted to a territory hospital because of severe right hypochondoralgia after 2 weeks of internal medicine for persistent epigastralgia. Gastroduodenal endoscopy revealed a large tumor with a fistula in the duodenal bulb that expanded to the stomach. Histopathologically, the biopsy specimen indicated a poorly differentiated adenocarcinoma and HER2 negative. Computed tomography revealed that the tumor invaded the left lobe of the liver. The patient was referred to our hospital for cancer treatment. After 1 course of chemotherapy with S-1 and CDDP, laparoscopic gastroenterostomy bypass was performed because of tumor hemorrhage and poor food intake. However, the tumor hemorrhage and poor food intake continued, and the tumor enlarged. Therefore, left hemihepatectomy and distal gastrectomy with resection of the duodenal bulb were performed 1 month after bypass surgery. Histological testing confirmed the diagnosis of duodenal large-cell neuroendocrine carcinoma invading the liver without lymph node metastasis. Adjuvant chemotherapy was not administered, and the patient has been alive without recurrence for 7 years and 3 months. Neuroendocrine carcinoma of the non-ampullary duodenum is very rare; however, a large cell type without lymph node metastasis may be a factor in the long-term prognosis.

[Laparoscopic Splenectomy for Metachronous Splenic Metastasis of Fallopian Tube Cancer with Synchronous Rectal Metastasis-A Case Report]

A 59-year-old woman underwent simple abdominal total hysterectomy with bilateral salpingo-oophorectomy, partial omentectomy, and extirpation of intrapelvic disseminated nodules for right fallopian tube cancer with rectal metastasis and peritoneal dissemination as primary debulking surgery(PDS). The histopathological diagnosis was high grade serous carcinoma( HGSC)of the right fallopian tube. After adjuvant chemotherapy with 4 courses of paclitaxel-carboplatin(TC), low anterior resection of the rectum for rectal metastasis and pelvic and para-aortic lymph node dissection were performed as interval debulking surgery(IDS). Histopathologically, lymph node metastasis was detected only in the right obturator lymph node. After adjuvant chemotherapy with 4 courses of TC, bevacizumab maintenance monotherapy was administered. Three years after PDS, laparoscopic splenectomy for splenic metastasis and extirpation of the solitary peritoneal metastases were performed as secondary debulking surgery(SDS). After adjuvant chemotherapy with 4 courses of TC, olaparib maintenance monotherapy was administered. The patient has remained alive without recurrence for 4 years after SDS and for 7 years after PDS. No case of metachronous splenic metastasis from fallopian tube cancer with synchronous rectal metastasis has been reported; however, long-term prognosis may be expected with PDS, IDS and SDS for platinum-sensitive HGSC.

[Surgical Resection of Pulmonary Oligometastases of Ampullary Cancer-A Case Report and Review of Seven Cases]

A 62-year-old woman underwent a subtotal stomach-preserving pancreatoduodenectomy for ampullary carcinoma (T3bN0M0, Stage Ⅱb). Histopathologically, the tumor was a tubular adenocarcinoma with mixed features, predominantly the intestinal type, following which adjuvant chemotherapy was not performed. Computed tomography performed 32 months after surgery showed a tumor measuring 6.7 mm in diameter at the apex of the right lung. The tumor had gradually increased in size and measured 10 mm in diameter, 47 months postoperatively. Since other metastatic lesions were absent, partial resection of the right lung under video-assisted thoracic surgery was performed 48 months postoperatively. Histopathological testing confirmed a diagnosis of lung metastasis from the resected specimen of ampullary carcinoma without mediastinal lymph node metastasis. Adjuvant chemotherapy was not performed, and recurrence was not observed even after 53 months following the partial lung resection. Previously, 7 resected cases of solitary lung metastasis from ampullary cancer have been reported. The histopathological sub-type of these 7 cases were intestinal type in 5 and pancreatobiliary type in 2 cases, respectively. No mortality or recurrence was observed for 8-119 months in any of the 7 cases(median, 19 months). In conclusion, owing to the good prognosis, solitary lung metastasis from an ampullary cancer can be classified as an oligometastatic disease, based on the concept proposed by Hellman and Weichselbaum.

[Synchronous Double Primary Non-B, and Non-C Intrahepatic Cholangiocarcinoma and Hepatocellular Carcinoma-A Case Report]

A 78-year-old man without hepatitis virus B or C underwent right hemi-hepatectomy and lymph node dissection for a tumor 5 cm in diameter located in the hepatic hilum of the posterior segment of the liver with portal vein thrombi extending into the main portal trunk and a tumor 1.5 cm in diameter in the peripheral side of segment 5 of the liver. Histopathologically, the former was diagnosed as intrahepatic cholangiocarcinoma and the latter as hepatocellular carcinoma(HCC). Five months after the surgery, intrahepatic and lymph node metastases were diagnosed based on computed tomography(CT); therefore, chemotherapy with S-1 for 3 months and gemcitabine and cisplatin(GC)for 5 months was administered, after which the metastatic lesions were not detected. Nineteen months after the surgery, partial resection of segment 2 of the liver was performed for a tumor 3 cm in diameter, which was diagnosed as HCC histopathologically. Two years after the second surgery, 2 recurrent nodules in the liver in segments 3 and 4 were detected on CT. Platinum-based hepatic arterial infusion chemotherapy(HAIC)and transcatheter arterial chemoembolization(TACE)were performed, and chemotherapy with GC was then administered for 7 months. For a new tumor detected in segment 1 in the liver, TACE was performed 17 months after initial HAIC. Seventy-four months after the initial surgery, 5 new nodules less than 1 cm in diameter were detected, and chemotherapy with sorafenib was administered for 5 months, after which the patient died of coronavirus disease 2019.

Laparoscopic lithotripsy and lithotomy of impacted stone at the terminal end of the common bile duct using a laparotomy biliary lithotomy spoon: A case report

Introduction and importance

Endoscopic intervention is considered first-line therapy for common bile duct (CBD) stones, in recent times. However, surgically altered anatomy and consequent inaccessibility of the duodenal papilla necessitate surgery in some patients.

Case presentation

A 61-year-old woman presented with fever and right subcostal pain. She underwent total gastrectomy and Roux-en-Y reconstruction for gastric ulcer, 4 years prior to presentation. Based on the clinical findings, she was diagnosed with acute obstructive cholangitis secondary to a CBD stone. Endoscopic retrograde biliary drainage was attempted; however, the duodenal papilla was endoscopically inaccessible owing to the previous Roux-en-Y reconstruction, and we performed percutaneous transhepatic gallbladder drainage (PTGBD). She underwent laparoscopic cholecystectomy and choledocholithotomy, 6 days after the PTGBD. Choledocholithotomy was attempted using basket forceps under choledochoscopic guidance; however, this procedure was unsuccessful, and we performed laparoscopic choledocholithotomy using a laparotomy biliary lithotomy spoon.

Clinical discussion

Usually, laparoscopic cholecystectomy concomitant with CBD exploration is performed in patients with an endoscopically inaccessible duodenal papilla. However, an inadequately opened basket may not capture large impacted stones at the duodenal end of the CBD. Intraductal shock wave lithotripsy (electrohydraulic or laser lithotripsy) is considered in such cases; however, the specialized instruments required for this procedure are unavailable at all centers. Laparoscopic choledocholithotomy using a laparotomy biliary lithotomy spoon may be useful to overcome this surgically challenging situation.

Conclusion

A laparotomy biliary lithotomy spoon is a simple, user-friendly, and economical device that may be useful for laparoscopic lithotripsy and lithotomy of impacted stones.

•

Endoscopy did not show the duodenal papilla owing to surgically altered anatomy.

•

Stone impaction was observed at the terminal portion of the common bile duct.

•

Choledochoscopic basket lithotomy could not be performed.

•

Laparoscopic lithotomy was performed using a laparotomy biliary lithotomy spoon.

[Laparoscopic Liver Resection for Liver Metastasis from Unresectable Pancreatic Ductal Adenocarcinoma Well-Controlled by Chemotherapy-A Case Report]

A 45-year-old man with unresectable locally advanced pancreas head cancer with multiple synchronous liver metastases was treated with gemcitabine plus nab-paclitaxel therapy as a first-line chemotherapy. During 24 months of 30 courses of this therapy, the primary lesion remained stable and liver metastases were completely disappeared on CT. Three months later, however, solitary relapse of liver metastasis occurred in segment 2. Therefore, we changed the chemotherapy regimen to the second-line treatment, FOLFIRINOX. After 3 courses of FOLFIRINOX, the primary lesion was kept well-controlled, but the solitary metastatic liver lesion was enlarged. An interdisciplinary team suggested surgical resection of the liver metastasis to control disease progress. We performed laparoscopic lateral segmentectomy of the liver. The postoperative course was uneventful, and the patient was discharged on postoperative day 8. The patient underwent another round of gemcitabine therapy owing to the good response of the primary pancreatic lesion to this drug. Three years after starting the first-line chemotherapy, the patient is still alive with well-controlled PDAC without distant metastasis. Surgical intervention for liver metastases may be a promising treatment option when unresectable primary PDAC is well controlled by chemotherapy.

[A Case of Disturbance of Consciousness Due to Hyperammonemia during Chemotherapy for Metastasis of Sigmoid Colon Cancer]

A 76-year-old woman had underwent 5-fluorouracil(5-FU), oxaliplatin(L-OHP)combination therapy(mFOLFOX6)as first-line chemotherapy for peritoneal recurrence after resection of sigmoid colon cancer. She showed severe general fatigue and disturbance of consciousness on the second day of the 12th course of chemotherapy. Computed tomography of the head detected no abnormal findings in the central nervous system. The laboratory results revealed a marked hyperammonemia. She was diagnosed as a disturbance of consciousness due to hyperammonemia and treated her with branched- chain amino acid solution. Then the disturbance of consciousness resolved on the following day. After changing the regimen of chemotherapy, the disturbance of consciousness was not found. Recently, it has been reported that high-dose 5-FU regimen such as mFOLFOX6 causes hyperammonemia as a rare adverse event. We should take hyperammonemia into account when disturbance of consciousness occurs during high-dose 5-FU chemotherapy.

[Laparoscopic Resection of Solitary Lymph Node Metastasis of Hepatocellular Carcinoma after Transcatheter Arterial Chemoembolization and Percutaneous Locoregional Therapies]

A 75-year-old woman underwent transcatheter chemoembolization(TACE)for 2 small hepatocellular carcinoma(HCC) lesions associated with severe alcoholic liver cirrhosis that necessitated management for ascites. Over 5 years after the initial TACE, she received multidisciplinary therapies with TACE, transcatheter arterial infusion of anticancer agents, percutaneous ethanol injections, or percutaneous radiofrequency ablation performed on 5 occasions for small recurrent HCC lesions. Computed tomography performed after the last therapy for HCC revealed a solitary lymph node swelling(39 mm in diameter) around the common hepatic artery. Magnetic resonance imaging performed 3 months later revealed that the lymph node had enlarged to 45 mm, without recurrence of the primary HCC, and after 4 months, to 60 mm; she then underwent laparoscopic lymph node resection. Histopathological examination of the resected specimen showed HCC metastasis. A recurrent metastatic lymph node(30 mm in diameter)was detected around the common hepatic artery and was resected laparoscopically 17 months postoperatively. Pancreatic head cancer was diagnosed 22 months after the second surgery; however, the patient refused cancer therapy and died 16 months after this diagnosis. No recurrence of the primary HCC or lymph node metastasis was observed over the 38 months after the second surgery.

Stent-graft placement for delayed extrahepatic portal hemorrhage after surgical treatment for perihilar cholangiocarcinoma: A case report

•

Stent-graft placement is a viable option for treatment of portal vein hemorrhage.

•

Postoperative hemorrhage was caused by extrahepatic portal vein pseudoaneurysm formation.

•

Portal vein pseudoaneurysm occurred at the reconstructed portion.

Introduction

Potential curative therapy for perihilar cholangiocarcinoma requires extensive surgical treatment, which can still be associated with significant morbidity and mortality. Postoperative hemorrhage from the portal vein is a rare but life-threatening complication. We herein report postoperative hemorrhage from an extrahepatic portal vein pseudoaneurysm successfully treated by stent graft placement late after surgical treatment for perihilar cholangiocarcinoma.

Presentation of case

An 83-year-old man was referred to our hospital with a chief complaint of jaundice. Based on radiological findings, we diagnosed the patient with hilar cholangiocarcinoma. After endoscopic retrograde biliary drainage, resection of the extrahepatic bile duct combined with extended left hemi-hepatectomy, including the caudate lobe, lymphadenectomy of the hepatoduodenal ligament, partial resection and reconstruction of the portal vein, and right hepaticojejunostomy was performed. Fourteen days postoperatively, bleeding through the abdominal drain around the portal vein was observed. Twenty days postoperatively, abdominal computed tomography revealed a portal vein pseudoaneurysm that had formed at the portion of reconstruction. Therefore, 24 days postoperatively, a stent graft placement of the pseudoaneurysm through the ileocolic vein was performed. Subsequently, the portal vein hemorrhage ceased.

Discussion

Our present postoperative extrahepatic portal vein hemorrhage case was caused by an extrahepatic portal vein pseudoaneurysm that had formed at the reconstructed portion by erosion due to the chemical effect of the leaking bile and mechanical irritation of the surgical drain adjacent to the portal vein.

Conclusion

Stent-graft placement is a minimally-invasive, safe, and effective treatment option for hemorrhage from postoperative portal vein pseudoaneurysm.

Pressure-induced nano-crystallization of silicate garnets from glass

Transparent ceramics are important for scientific and industrial applications because of the superior optical and mechanical properties. It has been suggested that optical transparency and mechanical strength are substantially enhanced if transparent ceramics with nano-crystals are available. However, synthesis of the highly transparent nano-crystalline ceramics has been difficult using conventional sintering techniques at relatively low pressures. Here we show direct conversion from bulk glass starting material in mutianvil high-pressure apparatus leads to pore-free nano-polycrystalline silicate garnet at pressures above ∼10 GPa in a limited temperature range around 1,400 °C. The synthesized nano-polycrystalline garnet is optically as transparent as the single crystal for almost the entire visible light range and harder than the single crystal by ∼30%. The ultrahigh-pressure conversion technique should provide novel functional ceramics having various crystal structures, including those of high-pressure phases, as well as ideal specimens for some mineral physics applications.

It is suggested that the optical and mechanical properties of transparent ceramics become very favourable if they can be synthesized as nanocrystals. Here, the authors report direct conversion of bulk glass starting material to pore-free nano-polycrystalline silicate garnet at high pressure and temperature.

In vitro thermo- and thermochemo-sensitivity of retinoblastoma cells from surgical specimens

The sensitivity to heat and chemical modification of human retinoblastoma cells obtained from patients with primary retinoblastoma was studied in vitro by the human tumour colony assay established by Hamburger and Salmon in 1977. Retinoblastoma cells showed moderate sensitivity to 1 h of hyperthermia at 42 degrees C; the median T/C% (ratio of the colony number in treated vs. control dishes, x 100) under hyperthermia was 47.0% for 46 tumours studied. When tumours were treated with melphalan, cis-diamminedichloroplatinum (II), adriamycin, etoposide and teniposide at 37 degrees C and 42 degrees C, the median T/C% for each chemical agent was decreased significantly by concomitant hyperthermia. One-hour exposure of 38 tumours to melphalan, cis-diamminedichloroplatinum (II) (30 tumours), adriamycin (27 tumours), teniposide (22 tumours) and etoposide (20 tumours) at 37 degrees C gave median T/C%s of 9.5, 33.5, 16.0, 3.8 and 38.0%, respectively, while exposure at 42 degrees C gave values of 2.4, 8.2, 5.6, 1.0 and 6.6%, respectively. Combination of heat and chemical treatment with melphalan, cis-diamminedichloroplatinum (II) and etoposide appeared to be synergistic with median T/C%s that were significantly lower than the median T/C%s expected from a simple sum of their individual effects. These in vitro results suggest that combining the treatment modalities of hyperthermia and chemotherapy for primary retinoblastoma would be advantageous.

Cross-country comparisons suggest shared risk factors for carcinomas, including male lung adenocarcinoma and colon cancer development

Smoking is clearly the major risk factor for both squamous cell carcinomas (SCCs) and adenocarcinomas (ACs) of the lung, although less so for the latter, where other influences appear to be important. In order to determine whether cross-country comparisons might provide evidence of shared risk factors with cancers in other organs of males, an examination of IARC/WHO data for cancer incidence was made for countries/registries in Europe, North America, Australia and Asia. Significant simple correlations, which persisted on partial analysis, were observed between lung SCCs and tumors of the larynx (P < 0.001), but not the buccal cavity or oesophagus, along with a link to rectal ACs (P < 0.001). Incidences of lung ACs also correlated with those for colon ACs (P < 0.001) but not lung SCCs. Oesophageal ACs were only related to colon cancers at the simple correlation level, this not persisting on partial analysis or separation into Asian and Western groups. The results suggest that blood borne factors, like hormones, may be important as determinants for the increasingly prevalent lung AC.

Cross-country comparisons of colon and rectal cancer mortality suggest the existence of differences in risk factors in eastern and western Europe

A comparison of relative mortality rates from colon and rectal cancers in World Health Organization data for various countries in Europe was undertaken to determine whether the two sites demonstrate a direct link. A significant correlation between figures for colon and rectal cancers was found throughout Europe but limited to males and only at the p < 0.05 level. Cluster analysis revealed marked differences between countries of the former west and east European blocks, the latter having much higher values for rectal cancers. Separation of countries on this basis gave rise to significant correlation between the two sites for both sexes (p < 0.05 and p < 0.001, respectively, for western and eastern males; and p < 0.05 and p < 0.001 for females). In order to assess the possible contribution of factors associated with squamous cell cancers (SCCs), data for buccal and cervical cancers, both more prevalent in eastern than in western Europe, were also compared. Whereas a significant correlation was evident between female rectal and cervical cancers overall and in the western countries (p < 0.05) this was not the case for the eastern countries. The results suggest that the observed excess of rectal cancer mortality in eastern European countries may not be simply due to factors contributing to SCCs, but that country level comparisons of individual harmful and beneficial influences, alone and in combination, might allow the underlying reasons to be explained.

European country comparisons provide evidence of a link between colon cancer and adenocarcinoma development in the lung but not the oesophagus

Relative incidence rates of lung cancers demonstrate marked international variation in values for the different histological sub-types. In order to determine whether adenocarcinomas (ACs) in this site might share risk factors with other ACs, for example, in the breast, prostate, oesophagus and colon, a comparison of data in the IARC/WHO Cancer Incidence in Five Continents (Volume VII) was made for selected registries in Europe. Significant correlations were found between lung AC incidences/100,000 population and prostate and colon cancers in males (P < 0.005 and P < 0.05, respectively) and for breast and colon in females (P < 0.05 for both). Partial correlation coefficients were significant for lung and colon (P < 0.001) and prostate and colon (P < 0.005) in men, and for breast and colon in women (P < 0.005). A significant negative correlation with prostate cancer was noted for lung ACs in men. The results provide support for shared risk factors between lung Acs and colon cancers but do not indicate any link with AC development in the oesophagus. Data from registries in the UK and Italy were remarkable for high incidences of oesophageal and lung ACs, respectively, pointing to major differences in environmental risk factor or beneficial influence acting on these sites between the two countries.

Inhibitory effects of oleic and docosahexaenoic acids on lung metastasis by colon-carcinoma-26 cells are associated with reduced matrix metalloproteinase-2 and -9 activities

In order to determine the effects of single unsaturated fatty acids (UFAs) or combinations on establishment of lung metastatic colonies, UFAs were administered orally to CDF1 mice bearing s.c. implants of the highly metastatic colon carcinoma 26. Oleic acid (OA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) demonstrated significant inhibition. In the case of DHA, this inhibitory potential was markedly reduced by co-administration of linoleic acid (LA) or EPA. Furthermore, while tumor cells treated with DHA showed a very low potential for lung colony formation when injected i.v., this again being partially reversed by co-administration of EPA. UFAs were found to be well absorbed into tumor tissues after oral administration, causing marked changes in relative levels, the arachidonic acid (AA) content, in particular, being markedly decreased by treatment with DHA or EPA, but not with DHA plus EPA or with DHA plus LA. Investigation of the gelatinolytic activity of the 57-kDa and 92-kDa isoforms of type-IV collagenase (MMP-2 and MMP-9, respectively) showed a clear reduction in the former by treatment with OA, while DHA, but not DHA plus LA or EPA, caused a decrease in the 92-kDa isoform, which was well correlated with AA content in tumor tissues (r = 0.900, p < 0.001). These results suggest that inhibition of metastasis due to treatment with OA and DHA might be due to depressed type-IV collagenase activity.

Evaluation of synergism by a novel three-dimensional model for the combined action of cisplatin and etoposide on the growth of a human small-cell lung-cancer cell line, SBC-3

Although the combination of cisplatin and etoposide has been used as standard therapy for small-cell lung cancer, it is difficult to demonstrate combination effects between cisplatin and etoposide in vitro. We therefore adopted a 3-dimensional (3-D) model to analyze the combination effects of anticancer drugs, and compared the results of analysis by the new 3-D model with those obtained from traditional 2-D models for the cisplatin-etoposide combination. In this study, using a human small-cell lung-cancer cell line (SBC-3), 3-D model analysis clearly identified a relationship depending on the concentrations of both drugs, and demonstrated that peak synergy occurred at the higher concentrations of cisplatin and etoposide. Antagonistic interactions were noted with a nadir at low concentrations of etoposide and cisplatin. In contrast, 2-D models such as combination index and isobologam analysis fail to characterize the complex interactions between cisplatin and etoposide, since their joint effects are concentration-dependent. Combination index (CI) plots show that synergy is evident only for molar ratios of cisplatin: etoposide of 2:1 to 1:5. On isobologram analysis, synergy could be detected when great inhibitory effects on cell growth were present (high endpoint), but not with small inhibitory effects (lower endpoints). Thus, either synergy or antagonism may occur, but depend on the selection of variables, such as the molar ratios or the endpoints chosen for the experiments. This could explain the inconsistency in the in vitro combination effects reported to date. The 3-D model, which compensates for the above deficiencies of 2-D models, can facilitate rigorous analysis of drug interactions over the entire clinical dose range, using microcomputers and sophisticated graphics programs. This direct and pragmatic method offers investigators a practical new tool with which to analyze drug combinations for cancer chemotherapy.

Antitumor activity of polymorphonuclear leukocytes activated by a beta-1,3-D-glucan

The antitumor activity of mouse polymorphonuclear leukocyte (PMN) treated with a beta-1,3-D-glucan from Alcaligenes faecalis var. myxogenes IFO 13140 (TAK-N) and its carboxymethylated derivative (CM-TAK) was investigated in vitro and in vivo. ICR mouse PMN showed strong cytotoxicity against sarcoma 180 cells and inhibition of the growth of the tumor cells in vitro in the presence of TAK-N but not in the presence of CM-TAK. Since the cytotoxicity induced by TAK-N was almost completely inhibited by catalase, it seems to be mediated by H2O2 production by PMN. On the other hand, TAK-N induced no cytotoxicity in macrophages and neither did CM-TAK in PMN or in macrophage. Intraperitoneal injection of TAK-N into ICR mice induced a large number of PMN and macrophages in the peritoneal cavity. The peritoneal exudate PMN which were harvested at 10 to 72 h after TAK-N injection showed cytotoxicity against sarcoma 180 cells, but the peritoneal exudate macrophages did not. Treatment of sarcoma 180 ascites tumor-bearing ICR mice with TAK-N at a dose of 100 mg/kg prolonged significantly the survival time over that of the control. These results indicate that TAK-N induces PMN cytotoxicity against sarcoma 180 cells not only in vitro but also in vivo. The antitumor effect of TAK-N on sarcoma 180 ascites tumor seems to be derived from PMN stimulated with TAK-N.

[Tumor-regressing factor induced by antitumor polysaccharide in the serum of tumor-bearing mice]

A potent tumor-regressing activity was found in the serum of mice with S180 tumor undergoing rapid regression caused by antitumor polysaccharides. Beta (1-3) glucan including CM-TAK and lentinan and mannoglucan MGA induced such activity. It causes a rapid decrease in the number of tumor cells accompanied with a marked increase in neutrophiles in solid tumors. The entity of the activity was named as tumor-regressing factor (TRF) and was partially purified revealing a proteinaceous nature with an approximate molecular weight of 250,000. The factor was induced in a serum of tumor-bearing mice in various host-tumor combinations after the tumor growth had been established but only weakly in normal mice. The sensitivity of tumors to the factor was also dependent on the stage of tumor growth. The serum of normal mice or tumor-bearing mice without polysaccharide treatment exhibited similar activity as TRF after definite chromatographic step. The chromatographic behavior of the revealed activity was closely similar to that of the induced factor. It was postulated that a TRF-like activity exists in normal serum in a inactivated form being bound by antagonist(s) and the appropriate chromatography might remove the antagonist resulting in the active form of the factor. The concept was confirmed by reconstituting the chromatographic fractions, the revealed activity was again obscured after mixing with a certain fraction.

Antitumor activity of 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy-camptothec in, a novel water-soluble derivative of camptothecin, against murine tumors

The search for new water-soluble analogues of camptothecin (CPT) with higher activity and less toxicity has led to the development of a novel compound, 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy-camptothecin (CPT-11), which showed significant antitumor activity against a broad spectrum of experimental tumor models by i.p., i.v., or oral administration. When its activity against L1210 was compared with that of CPT and known derivatives, CPT-11 was most effective, giving the highest maximum increase in life span (ILS) and showing good activity over a wide dose range. The antitumor activity of CPT-11 was shown against tumors not only in the ascites form but also in the solid form. Included among the more susceptible murine tumors are S180, Meth A fibrosarcoma, Lewis lung carcinoma, Ehrlich carcinoma, MH134 hepatoma, mammary carcinoma of C3H/HeN mice, L1210, and P388 leukemia. Probable cures of these tumors were induced frequently by CPT-11. The antitumor activity of CPT-11 against i.p.-implanted L1210 was superior to that of Adriamycin in maximum ILS, the number of cured mice, and the therapeutic ratio. CPT-11 at a dose of 100 mg/kg produced an ILS in excess of 300% with five of six mice surviving tumor free, and effected 100% tumor regression at 200 mg/kg, whereas the optimum dose of Adriamycin, 12.5-25 mg/kg, brought about 114-129% ILS with one of six mice surviving. The acute toxicity of CPT-11 was extremely low, particularly in the case of oral administration. CPT-11 is expected to be clinically useful.

Antitumor activity of a new camptothecin derivative, SN-22, against various murine tumors

The antitumor activity of a new camptothecin derivative, SN-22, was evaluated by using various murine tumors. SN-22 showed strong activity against the ascites tumors Ehrlich carcinoma, MM46, CCM, L1210, L5178Y, P388, Meth A, and B16 melanoma. In particular, the maximum increase in life span values for Ehrlich, MM46 and CCM were as high as 253-606% and many mice were cured of these tumors. The effect of SN-22 against solid tumors was also determined. The inhibition ratios were higher than 70% for MM46 and L5178Y. The LD50 of SN-22 in ICR mice was about 1.5 times that of the parent camptothecin.

[Antitumor activity of new derivatives of camptothecin]

With the purpose of obtaining more potent and less toxic camptothecin (CPT) analogs, we prepared many derivatives of CPT. Among them, 7-ethyl-CPT (SN 22) and 7-ethyl-10-hydroxy-CPT (SN 38) showed strong antitumor activity with less toxicity. They were, however, insoluble and when they were made soluble, their activity was markedly diminished, as a result of cleavage of the delta-lactone ring. We therefore attempted to make soluble derivatives without breaking the delta-lactone ring and obtained 7-ethyl-10-[4-(1-piperidino)-1-piperidino]-carbonyloxy-CPT (CPT-11), which showed very strong antitumor activity by i.p., i.v. or p.o. administration against the ascites type of L1210 leukemia, P388 leukemia, sarcoma 180, Meth A fibrosarcoma, B16 melanoma, Ehrlich carcinoma and MH134 hepatoma and the solid type of sarcoma 180, Meth A fibrosarcoma, Lewis lung carcinoma, C3H/HeN mammary carcinoma, Ehrlich carcinoma and MH134 hepatoma. The antileukemic activity of CPT-11 against L1210 was much higher than that of adriamycin. The acute toxicity of CPT-11 was extremely low, particularly in the case of oral administration, the LD50 being 765.3 mg/kg, 22 times greater than that of CPT-Na.

Antitumor polysaccharide-induced tumor-regressing factor in the serum of tumor-bearing mice: purification and characterization

Marked tumor-regressing activity was induced in the serum of S180 tumor-bearing mice by injection of an antitumor polysaccharide, CM-TAK [carboxymethylated beta(1-3)glucan]. Maximal activity was induced 7-14 days after the tumor transplantation and 10-12 h after CM-TAK treatment. A quantitative assay for the activity was established on the basis of the initial decrease in the number of the tumor cells within 24 h. The factor with tumor-regressing activity was purified 10,000-fold by the series of hydroxylapatite chromatography, ammonium sulfate precipitation, anion-exchange chromatography, gel filtration, and boronate-mediated affinity chromatography. The molecular weight was estimated to be 250,000 by gel filtration. The activity was proteinase K sensitive, but relatively resistant to trypsin. Neuraminidase did not affect the activity. It is believed that the tumor-regressing factor is different from the tumor necrosis factor.

Rapid tumor regression caused by antitumor polysaccharide and induction of tumor-regressing factor in the serum of tumor-bearing mice

The antitumor polysaccharide CM-TAK [carboxymethylated beta(1-3)glucan] caused immediate and rapid loss of viable tumor cells from S180 solid tumors in ICR mice if it was given after a week of tumor growth. We found marked tumor-regressing activity in the serum of mice with S180 tumors undergoing CM-TAK-induced regression. When injected intravenously into S180-bearing mice, 0.1 ml of serum/mouse induced complete regression of day-14 tumors. However, in vitro cytotoxic activity against L929 and S180 cells was not detected. After the injection of CM-TAK or serum, along with the rapid decrease in tumor cells there was a marked increase in polymorphonuclear leukocytes. The serum was also active against fibrosarcoma Meth A in BALB/c mice, inducing partial regression or significant decrease in growth of the tumor. The properties of the factor in the serum seem to be different from those reported for tumor-necrotizing factor and other endogenous cytotoxic substances.

Rapid tumor regression and induction of tumor-regressing activity in serum by various immune-modulating agents

A rapid decrease in the number of tumor cells from S180 tumors was caused by several antitumor polysaccharides including the beta (1-3)glucans lentinan and TAK-N and a mannoglucan MGA, but not by those lacking antitumor activity. MGA was demonstrated to induce potent tumor-regressing activity in the serum of tumor-bearing mice similar to that reported previously to be induced after an injection of CM-TAK, a carboxymethylated beta (1-3)glucan. It is probable that the induction of rapid regression of established tumors is a phenomenon common to antitumor polysaccharides and some microbiological products and that the tumor-regressing factor in the serum underlies a common mechanism.

The therapeutic effects of orally administered 5'-deoxy-5-fluorouridine, 1-(2-tetrahydrofuryl)-5-fluorouracil and 5-fluorouracil on experimental murine tumors

The antitumor effects of three 5-fluorouracil-related compounds, 5'-deoxy-5-fluorouridine (5'-DFUR), 1-(2-tetrahydrofuryl)-5-fluorouracil (FT-207) and 5-fluorouracil (5-FU) itself, on several experimental murine tumors were compared after oral administration. 5'-DFUR showed strong antitumor activity against the solid type of four kinds of tumors tested with a wide range of effective doses, and also showed moderate antitumor activity against three kinds of solid tumors with a narrow range of effective doses. 5'-DFUR was effective against a few kinds of ascites tumors. In general, the antitumor activity of FT-207 was not very strong, with narrow ranges of effective doses under the present conditions. 5-FU showed strong toxicity but at lower doses its antitumor effectiveness was almost the same as that of FT-207. When the doses were divided into three and the divided dose was given orally three times a day for five consecutive days to mice bearing L1210 leukemia, this modality (with any of the three drugs) enhanced the ILS of the mice by two to three times in the case of the ascites type but not the solid type of L1210. The chemotherapeutic index in oral treatment of the solid type of tumors was higher for 5'-DFUR than for FT-207 or 5-FU. The minimum lethal doses in oral administration for five consecutive days were about 3, 1.5 and 0.5 mmol/kg/day for 5'-DFUR, FT-207 and 5-FU, respectively. In conclusion, 5'-DFUR appeared to have stronger antitumor activity and less toxicity than FT-207 and 5-FU, and it is therefore expected to be clinically useful.

Separation of macrophages from mouse peritoneal exudate cells with substrata coated with chemically modified collagens

A cell-separation technique was designed on the basis of specific interaction between macrophages and chemically modified collagens in the presence of serum. When unseparated mouse peritoneal exudate cells containing approximately 50% macrophages and 50% lymphocytes were incubated in dishes coated with unmodified and chemically modified collagens, only macrophages adhered more rapidly and in greater numbers to succinylated and methylated collagen than to unmodified collagen. The adherent macrophages could be easily detached from the substrata by divalent cation chelating agents. The purity and recovery of macrophages separated by this method were approximately 92-94% and 41-48%, respectively.

Superoxide anion production from mouse peritoneal macrophages stimulated with surface-bound IgG and immune complexes: adsorption characteristics of IgG in relationship to biological activity

The bridging of IgG antibody molecules by either multivalent antigen or protein A adsorbed to a polymer surface triggers superoxide anion (O-2) generation from mouse peritoneal macrophages. Macrophages, upon stimulation with IgG adsorbed to a hydrophobic polymer, polystyrene, also significantly generated O-2. In contrast, soluble IgG did not stimulate macrophages. From these results we speculated that IgG adsorbed to polystyrene produces the same kind of a conformational change in its Fc region as seen in immune complexes, and leads to enhancement of the ability of the Fc region to bind macrophage Fc receptors, acting as a multivalent cross-linking agent to aggregate the Fc receptors. The surface charge density of the immunosorbent did not affect the antigen recognition function of antibody, but markedly affected its effector function. These findings suggest that activation of the Fc receptor-mediated function of macrophages requires, on the one hand, optimal conformational change and orientation of IgG and immune complexes adsorbed to the polymer surface and, on the other hand, the bridging of IgG molecules by multivalent agents.

Action of a new antibiotic, neo-enactin, on the cell membrane and its application to combination treatment in a cultured tumor cell system

Neo-enactin, a new antibiotic obtained from a Streptoverticillium, was found to act on the eukaryotic cell membrane and induce changes in the transport of molecules across the cell membrane. Neo-enactin markedly potentiated the action of the antitumor agents bleomycin and vincristine in vitro. The uptake of [14C]vincristine by HeLa cells was enhanced 3.4-fold in the presence of neo-enactin. It is suggested that the potentiation of a second drug by neo-enactin may result from enhanced permeation of that drug.