Effect of chromosome loss on the leavening ability of Saccharomyces cerevisiae in dough

Summary To investigate the leavening ability of yeast in dough, chromosome loss was induced by benomyl treatment in YOY1037, a diploid between a baking strain and a laboratory strain, and its effect on the leavening ability was studied. When benomyl-treated cells were spread on plates with a dye indicator for ploidy, about 20% of the visible colonies were stained dark blue or dark purple; the rest stained pale blue, similar to the diploid YOY1037. Strains showing the MAT phenotype, and non-galactose fermenting strains, apparently having lost particular chromosomes, were observed only in those with darkcoloured colonies. Strains with dark-coloured colonies showed a wider range of leavening ability than did those with pale-coloured colonies.     

Experimental antitumor activity of BMY-28175 a new fermentation derived antitumor agent

Summary BMY-28175 is a novel antitumor antibiotic produced in fermentation by Actinomadura verrucosospora. The cytotoxic effects of BMY-28175 were determined using murine and human tumor cell lines in vitro. Following 72 hour exposure, the drug had IC50 values 1.5 to 13.5 ng/ml in a microtiter assay. BMY-28175 was evaluated for antitumor activity against several experimental murine and human tumor models. The drug administered ip was active against ip implanted P388 leukemia, L1210 leukemia, B16 melanoma, M109 lung carcinoma, C26 colon carcinoma, M5076 sarcoma and Lewis lung carcinoma. In addition, BMY-28175 administered iv was active against iv implanted P388 and L1210 leukemias. BMY-28175 was active against sc implanted B16 melanoma (increased lifespan and/or inhibition of primary tumor growth) in about 60% of the tests. The growth of sc implanted M109 was inhibited by BMY-28175 in a single experiment. BMY-28175 was also active against the MX-1 human mammary xenograft implanted in the subrenal capsule of nude mice. The optimal dose for BMY-28175 in these various studies ranged from 0.16 g/kg per injection with consecutive daily (qd1-9) administration, to 51.2 g/kg with single dose administration. The results of these studies indicate that BMY-28175 is one of the most potent antitumor agents yet observed, with a broad spectrum of activity against tumors of murine and human origin and activity against tumors located distal to the site of drug administration.     

Risk factors for hepatocellular carcinoma at baseline and 1 year after initiation of nucleos(t)ide analog therapy for chronic hepatitis B

Nucleos(t)ide analogs (NAs) cannot completely suppress the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). This study aimed to identify the risk factors for HCC development in naïve CHB patients treated with current NA. Patients receiving NA (n = 905) were recruited retrospectively from the 17 hospitals of the Japanese Red Cross Liver Study Group. All treatment-naïve patients had been receiving current NA continuously for more than 1 year until the end of the follow-up. We analyzed the accuracy of predictive risk score using the area under receiver operating characteristic curve. The albumin–bilirubin (ALBI) score was significantly improved by NA therapy (−0.171 ± 0.396; p < 0.001 at Week 48). A total of 72 (8.0%) patients developed HCC over a median follow-up of 6.2 (1.03–15.7) years. An independent predictive factor of HCC development was older age, cirrhosis, lower platelet counts at baseline and ALBI score, and alpha-fetoprotein (AFP) at 1 year after NA therapy according to multivariate analysis. The accuracy was assessed using the PAGE-B, mPAGE-B, aMAP, APA-B, and REAL-B scores that included these factors. Discrimination was generally acceptable for these models. aMAP and REAL-B demonstrated high discrimination with 0.866/0.862 and 0.833/0.859 for 3- and 5-year prediction from the status of 1 year after NA therapy, respectively. Baseline age and platelet count, as well as ALBI and AFP one year after NA, were useful for stratifying carcinogenesis risk. The aMAP and REAL-B scores were validated with high accuracy in Japanese CHB patients.     

Clinical application of18F-FUdR in glioma patients — PET study of nucleic acid metabolism

Summary Positron emission tomography was used to investigate the metabolism of nucleic acids by¹⁸F-fluoro-2-deoxyuridine (¹⁸F-FUdR) in 22 patients with gliomas. Sixteen cases of high grade glioma clearly demonstrated a region of high activity with a differential absorption rate (DAR) of 0.64 ± 0.34. Six cases of low grade glioma failed to reveal a positive image of the tumor and the DAR in tumor was 0.21 ± 0.042 (p < 0.01). This PET-¹⁸F-FUdR study succeeded in differentiating high and low grade gliomas from the view point of nucleic acid metabolism.     

Tumor scintigraphy by the method for subtracting the initial image with technetium-99m labeled antibody

The method for subtracting the initial image from the localization image was evaluated for radioimmunoscintigraphy of tumors with technetium-99m (Tc-99m) labeled antibodies. Monoclonal antibodies were parental mouse and mouse-human chimeric antibodies to carcinoembryonic antigen (CEA), designated F11-39 and ChF11-39, respectively, both of which have been found to discriminate CEA in tumor tissues from the CEA-related antigens. After reduction of the intrinsic disulfide bonds, these antibodies were labeled with Tc-99m. In vivo studies were performed on athymic nude mice bearing the human CEA-producing gastric carcinoma xenografts. Though biodistribution results showed selective and progressive accumulation of Tc-99m labeled antibodies at the tumor site, high radioactivity in blood was inappropriate for scintigraphic visualization of the tumors within a few hours. We examined the subtraction of the initial Tc-99m image from the Tc-99m localization image after a few hours. Subtracted images of the same count reflected the in vivo behavior of the Tc-99m radioactivity. The subtracted scintigrams revealed excellent tumor images with no significant extrarenal background. Visualization of the tumor site was dependent on antigen-specific binding and nonspecific exudation. These results demonstrate that a method of subtraction of the initial image may serve as a potentially useful diagnostic method for an abnormal site for agents with a low pharmacokinetic value.     

Scintigraphic demonstration of renal cell carcinoma with I-131-6β-iodomethyl-19-norcholesterol: A case report

Extraadrenal abnormal uptake on adrenocortical scintigraphy has been reported rarely in the normal gallbladder, lipid cell tumor of the ovary, or in clear cell type renal cell carcinoma. Clear cell type renal cell carcinoma contains glycogen and cholesterol like the adrenal gland, but the uptake of the radionuclide I-131 cholesterol has been reported to be low and not sufficient to image it. Right renal and adrenal masses were incidentally discovered on abdominal CT scan in a patient with chronic renal failure resulting in bilateral acquired cystic kidney disease. Adrenocortical scintigraphy done to know the nature of the adrenal mass showed high uptake corresponding to the right renal mass and the right adrenal mass. Clear cell type renal cell carcinoma and adrenal adenoma with prominent clear cells were histologically confirmed on hematoxylin-eosin stain and in an immunohistochemical study with renal cell antibody. Not only low-density lipoprotein receptors mediated uptake but also overall replacement of the right non-tumorous renal parenchyma by acquired cysts may have played a role in imaging the renal cell carcinoma on adrenocortical scintigraphy.     

Mediastinal lymph node metastasis of colon cancer: Report of a case

We herein describe a patient with mediastinal lymph node metastases which occurred after both a primary sigmoid colon cancer and metachronous ovarian metastasis had been resected. The most likely route of metastases to the mediastinum in this case is the paravertebral venous plexus probably connected to the ovarian metastasis, or so-called remetastasis. This case illustrates that the mediastinum is thus a possible metastatic site in patients with colon cancer. Surgeons should therefore pay attention to the mediastinum as well as the lung fields when checking chest X-ray films during a follow-up of patients after a resection of colon cancer.     

Inhibition of cardiac inward-rectifier K current by terodiline

The antispasmodic agent terodiline has cardiotoxic effects that include QT lengthening. To determine whether inhibition of inwardly-rectifying K⁺ current (I_K1) might be a factor in the cardiotoxicity, we measured I_K1 in guinea pig ventricular myocytes. Terodiline reduced outward I_K1 with an IC₅₀ of 7 μM; maximal reduction was 60% with 100–300 μM concentration. Inhibition was independent of current direction, and persisted after removal of the drug. Terodiline (3–5 μM) lengthened action potentials in guinea pig papillary muscles by ca. 10%, primarily by slowing phase 3 repolarization; higher concentrations abbreviated the plateau and markedly slowed late repolarization. Terodiline washout provoked an extra lengthening, consistent with persistent inhibition of I_K1 and rapid recovery of net inward plateau current. The results suggest that inhibition of I_K1 is a likely factor in the cardiotoxicity of the drug.