Characterization of an Etoposide-resistant Human K562 Cell Line, K/eto

An etoposide-resistant K562 cell line (K/eto) was obtained by stepwise exposure, in culture, to increasing concentrations of etoposide, without the use of mutagens. This cell line was resistant to etoposide, and slightly resistant to adriamycin, but sensitive to anti-cancer drugs such as camptothecin, vincristine, actinomycin D and so on. P-GIycoprotein, the mdr 1 gene product, was not detected in this cell line, as assessed by immunocytochemistry, itnmunoprecipitation and flow cytometry. Overexpression of mdr 1 mRNA was also not found. Interestingly, expression of 85 kD protein recognized by MRK 20 monoclonal antibody was noted. The level of DNA topoisomerase II protein, detected by antibody staining, decreased concomitantly with a general decrease in DNA topoisomerase II unknotting activity, while DNA topoisomerase I activity was not affected. Cellular accumulation of [³H]etoposide was reduced by 75% in the resistant line compared with parental K562. Karyotype analysis showed that the number of chromosomes in K/eto was 55 and neither a homogeneous staining region nor double-minute chromosomes were detected. These results indicate that this resistance is not due to an altered interaction between the drug and cellular transport machinery, i.e. MDR1, associated with the "classic" multiple drug resistance phenotype, but rather is due to the existence of other mechanism(s) of resistance, decreased transport of the drug and decreased target enzyme, DNA topoisomerase II.     

Clinical phase III study on TAP-144-SR, an LH-RH agonist depot formulation, in patients with prostatic cancer

A randomized controlled phase III clinical trial comparing TAP-144-SR (TAP) and diethylstilbestrol diphosphate was conducted for patients with prostatic cancer. Patients with Stage B, C, or D disease, who were previously untreated, were enrolled. TAP-144-SR 3.75 mg was administered subcutaneously at 4-week intervals for 12 weeks (a total of 3 injections) in the TAP-144-SR group, while 100 mg of diethylstilbestrol diphosphate was administered orally three times a day (before meals) for 12 weeks in the control group. A total of 141 patients were enrolled using a centralized telephone registration system. Four of these patients were ineligible, and there were 3 drop-outs who never received drugs because they withdrew their consents to participate in the trial. These 7 were excluded from the evaluation, and as a result, 134 patients (66 in the TAP group and 68 in the control group) were evaluable in safety and efficacy. Between the two groups, there were no significant differences in patient characteristics, except the age distribution. Clinical response rates (CR+PR) in evaluable patients according to the criteria of Japanese Prostatic Cancer Study Group were 54.5% in the TAP group and 47.1% in the control group. In addition, the rates according to the criteria for Evaluating the Direct Response to Chemotherapy in Solid Carcinomas and NPCP criteria were 7.6% in the TAP group and 8.8% in the control group and 18.2% in the TAP group and 20.6% in the control group, respectively. Using any of the three criteria, there were no significant differences in response rate between the two groups. The incidence of side effects was 64.1% in the TAP group and 95.4% in the control group; the incidence being significantly higher in the control group (p less than 0.001; chi 2-test). Therefore, the overall safety was significantly greater in the TAP group than in the control group (p less than 0.001; chi 2-test). On the basis of the efficacy and safety the clinical usefulness rate of TAP-144-SR was significantly higher than that of diethylstilbestrol diphosphate (p = 0.038; U-test). In conclusion, TAP-144-SR was confirmed to be more useful than diethylstilbestrol diphosphate as a standard drug for hormonal therapy of prostatic cancer.     

Modulation of carbachol-induced [Ca2+]i oscillations by Ca2+ influx in single intestinal smooth muscle cells.

1. Oscillations of cytosolic Ca2+ concentration ([Ca2+]i) evoked by carbachol (CCh; 2 microM), a muscarinic agonist, were detected as oscillatory changes of muscarinic receptor-coupled cationic current (Icat) in guinea-pig ileal smooth muscle cells by the whole cell patch-clamp technique. 2. Reduction of extracellular Ca2+ from 2 mM to 0.2 or 0.05 mM, during CCh-induced Icat oscillations, caused them to disappear or to decrease markedly in frequency. A return to 2 mM Ca2+ concentration restored the initial Icat oscillations. 3. Application of nifedipine (1-3 microM) or D600 (2-5 microM) to block the voltage-gated Ca2+ channel (VGCC) decreased the frequency of the ongoing Icat oscillations in the cells held at -20 mV, but it was without effect in cells held at -60 mV. 4. Displacement of the holding potential of -20 mV to -60 mV to deactivate VGCC produced a decrease, an increase or no noticeable change in the frequency of the Icat oscillations in different cells. Displacement to 20 mV to inactivate VGCC invariably produced a decrease in the frequency. In nifedipine-treated cells, the Icat oscillations varied in frequency voltage-dependently in a reverse and linear way within the range -80 to 40 mV. 5. Application of thapsigargin (1 or 2 microM), an inhibitor of Ca(2+)-ATPase in the membrane of internal Ca2+ stores, caused CCh-induced Icat oscillations to disappear with a progressing phase during which their amplitude, but not frequency, declined. 6. The results suggest that membrane Ca2+ entry has a crucial role to play in regulation of the frequency of CCh-induced [Ca2+]i oscillations in addition to persistence of their generation, and that the effect is brought about by a potential mechanism independent of Ca2+ store replenishment. They also provide evidence that two types of Ca2+ permeant channels, VGCC and an as yet unidentified channel, are involved in the Ca2+ entry responsible for modulation of [Ca2+]i oscillations.     

Effect of blood group matching on liver transplant survival rates

From the immunological standpoint,^1–5 liver allografts are more resistant to hyperacute rejection than are other solid organ grafts. Therefore, until recently, donor/recipient blood type (ABO type), human leukocyte antigen (HLA) matching, and crossmatch tests were not considered in clinical liver transplantation. In this report, we demonstrated that: (a) crossing the ABO barrier must be avoided except in extreme emergency; (b) HLA class I matching effect on liver allografts is as acceptable as in kidney transplantation, although, with regard to the effect of Class II matches, there are remarkable differences depending on the patients' original disease; and (c) anti-donor lymphocytotoxic antibodies (positive crossmatch) adversely affect liver allograft survival rates.     

Cardiopulmonary bypass established via a sutured vascular graft in the presence of extraanatomic bypass

Cardiopulmonary bypass (CPB) was established via a sutured collagen sealed knitted Dacron graft in two patients who had undergone extraanatomic bypasses for lower limb ischemia, whose ascending aorta was not suitable for cannulation. One patient, with a history of femorofemoral bypass, underwent surgery for a ruptured aortic arch aneurysm (AAA) and the other patient, with a history of axillobifemoral bypass for chronic dissection involving the aortic arch and descending aorta, had unstable angina and underwent coronary artery bypass grafting. This technique of perfusion was found to be safe and effective for patients with an impaired ascending aorta who have undergone an extraanatomic bypass for the lower limb.     

A solid and papillary (solid-cystic) tumor of the pancreas occurring in a 36-year-old man: Report of a case

A case of a solid and papillary (solid-cystic) tumor of the pancreas occurring in a 36-year-old man is herein reported. This patient was admitted with left hypochondrial pain and diagnostic imaging detected a large tumor consisting of both solid and cystic components in the tail of the pancreas. A distal pancreatectomy with splenectomy was performed. The resected tumor was diagnosed as a solid and papillary tumor of the pancreas by pathological examination. Detailed immunohistochemical studies showed that the tumor consisted of cells both exocrine and endocrine in character. Thus, this case appears interesting from the point of cellular differentiation in solid and papillary tumors, since they are generally considered to have an acinar cell origin.     

Distinction Between the Depletion of Opsonins and the Saturation of Uptake in the Dose-Dependent Hepatic Uptake of Liposomes

Opsonins play a role in the hepatic uptake of particles such as bacteria, lipid emulsion, and liposomes. The objective of this study was to distinguish between opsonin depletion and uptake saturation in the dose-dependent hepatic uptake of liposomes. The uptake of opsonized and unopsonized liposomes was determined in the isolated perfused liver. Serum (2.9 mL) was required to opsonize 1 µmol liposomes fully, indicating that a rat (250 g with 10 mL of serum) can opsonize 3.5 µmol liposomes. Next the dose effect on hepatic uptake of opsonized and unopsonized liposomes was examined. Saturation of uptake was found only for the opsonized liposomes. On the other hand, the hepatic uptake clearance decreased dose dependently from 4.31 to 0.79 (mL/min), with increasing doses from 0.075 to 17 µmol/250 g, respectively, after i.v. administration. Thus, the decrease in the hepatic uptake clearance at the medium dose was due to the saturation of uptake alone, and at the high dose it was due to opsonin depletion as well. These results show that the saturation of liposomal uptake in the liver and the depletion of opsonins occurred at different liposome dosage levels.     

Concomitant coronary bypass grafting and curative surgery for cancer

The surgical management of patients with concomitant critical coronary artery disease (CAD) and surgically resectable cancer is controversial. We evaluated 19 patients who underwent concomitant coronary artery bypass grafting (CABG) and curative operation for cancer of the stomach in 9 patients, the colon in 4, the lung in 4, and the breast in 2. Each cancer operation was performed under stable hemodynamics without any serious bleeding tendency, immediately after CABG with an average of 2.5±0.8 grafts. There were no operative deaths and no incidences of perioperative myocardial infarction. Postoperative complications developed in three of the patients with lung cancer: respiratory dysfunction caused by phrenic nerve paralysis in two and mediastinitis in one. During the mean follow-up period of 33±23 months, 5 patients died of recurrent cancer or non-cardiac disease; however, all 19 patients remained free from any postoperative cardiac events and their quality of life apparently improved. This experience suggests that such simultaneous correction would be safe and beneficial in carefully selected patients who have surgically correctable CAD and potentially curable cancer.     

Nasal allergen sensitivity and mucosal IgE antibodies

Skin tests, nasal provocation tests, nasal smear tests, and serum-radioallergosorbent tests were performed on 17 patients with perennial allergic rhinitis, who had suffered nasal congestion without receiving any antiallergic treatment. After the above tests, tissue-radioallergosorbent tests (t-RAST) were conducted to determine IgE antibody levels in inferior turbinate mucosal samples taken peroperatively. The results obtained in this study suggest that the allergen sensitivity of the nasal mucosa correlates to some extent with the mucosal IgE antibody level, and that the t-RAST can provide us with objective data about nasal allergen sensitivity.