Characteristics of apoptosis in HCT116 colon cancer cells induced by deoxycholic acid

Hydrophobic bile acids induce apoptosis in both colon cancer cells and hepatocytes. The mechanism by which colon cancer cells respond to bile acids is thought to be different from that of hepatocytes. Therefore, we investigated the characteristics of apoptosis in colon cancer cell line HCT116. Hydrophobic bile acids, i.e., deoxycholic acid (DCA), and chenodeoxycholic acid, induced apoptosis in HCT116 cells. Apoptotic indications were detectable at as early as 30 min and the extent increased in time- and concentration-dependent manners. SDS and a hydrophilic bile acid, cholic acid, did not induce apoptosis even at cytotoxic concentrations. Pretreatment with cycloheximide failed to inhibit apoptosis, suggesting that protein synthesis is not involved in the apoptotic response. Release of cytochrome c from mitochondria and activation of caspase-9 were detectable after 5 and 10 min, respectively, whereas remarkable activation of Bid was not detected. Ursodeoxycholic acid (UDCA) protected HCT116 cells from DCA-induced apoptosis but a preincubation period of > or =5 h was required. Nevertheless, UDCA did not inhibit cytochrome c release from mitochondria. Our results indicate that hydrophobic bile acids induce apoptosis in HCT116 cells by releasing cytochrome c from mitochondria via an undefined but specific mechanism, and that UDCA protects HCT116 cells by acting downstream of cytochrome c release.     

Forms of Aspartic Acid in Human Urine

It was found by amino acid analysis before and after acid hydrolysis of human urine that most glutamic and aspartic acid was in bound form, while glycine, glutamic and aspartic acids accounted for about 70% of bound amino acids. Fractions rich in peptides containing aspartic acid were obtained by chromatography on various columns, and 7 peptides containing aspartic acid were isolated from these fractions. It may be inferred from these results and from the literatures that there are numerous oligopeptides containing aspartic acid in human urine.     

Absence of Red Light-Induced Stimulation of Growth in the Hook of Etiolated Dwarf-Pea Seedlings

Red light inhibited the growth of the apical part of the hookin dark-grown seedlings of a dwarf variety (cv. Progress No.9) of pea (Pisum sativum L.), whereas it promoted such growthin a tall variety (cv. Alaska). In the elongation zone of theepicotyl of the dwarf variety the extent of inhibition of growthwas similar to or even smaller than that in the tall variety.Local irradiation of the apical part of the hook also causedinhibition of growth in the hook of the dwarf variety and promotionof growth in the tall variety. The inhibition of growth in theapical part of the hook of cv. Progress may be involved in thedwarfism induced by irradiation with red light of this cultivar. (Received May 15, 1989; Accepted April 27, 1990)     

Ontogenetic variations in C17 hydrocarbon composition in root oil of Cirsium japonicum

Large decreases occur in the amounts of four unsaturated hydrocarbons present in the root oil of Cirsium japonicum during the months of February and March. These decreases are correlated with the onset of flowering.     

Spontaneous recovery of the anoxic diminution in the action potential plateau of the late embryonic and neonatal chicken hearts

The action potential plateau of the embryonic chick hearts at the latest stage of development (19- to 20-day-old) was depressed initially by anoxia but recovered spontaneously under the sustained anoxic condition. A similar spontaneous recovery of the action potential plateau was observed in hearts from neonatal chicks. Propranolol (3 × 10^?6M) did not affect the spontaneous recovery of the action potential plateau, excluding the possible involvement of the release of endogenous catecholamines. Since tissue adenosine triphosphate content continued to decrease during anoxia in these hearts, it is unlikely that the anoxia-resistant metabolic pathway appeared or was enhanced to supply the energy for the rebuilding of the plateau. In a Ca²⁺-free solution the action potential plateau rapidly disappeared and did not recover spontaneously during anoxia; at this time, however, the addition of Ca²⁺ (2 mM) prolonged the plateau. An inward calcium current may play an important role in spontaneous recovery of the action potential plateau during anoxia. The duration of the action potential decreased after hatching. From these results it is suggested that the mechanism underlying the action potential plateau may somehow differ in the hearts at the stages around the time of hatching.     

Experimental study on convective heat transfer coefficient of the human body

1. 1. The convective heat transfer coefficient of the human body is essential to predict convective heat loss from the body.

2. 2. The object of this paper is to calculate the convective heat transfer coefficient of the human body using heat flow meters and to estimate the thermally equivalent sphere and cylinder to the human body.

3. 3. The experimental formulae of the convective heat transfer coefficient for the whole body were obtained by regression analysis for natural, forced and mixed convection.

4. 4. Diameters of the thermally equivalent sphere and cylinder of the human body were calculated as 12.9 and 12.2 cm, respectively.

Purification and properties of two truncated endoglucanases produced in Escherichia coli harbouring Clostridium cellulolyticum endoglucanase gene celCCD

The endoglucanase gene, celCCD, of Clostridium cellulolyticum has been expressed in Escherichia coli. Multiple active polypeptides were detected in the E. coli cells. The relative molecular mass (M_r) of two major active polypeptides were 56 000 (D56) and 38 000 (D38), which were smaller than the deduced M_r of the mature protein (63 401). D56 and D38 were purified from the periplasmic fraction. The N-terminal sequences of the two purified polypeptides were identical to that of the mature endoglucanase (Ala-Ile-Asn-Ser-Gln-Asp-Met-Val---) deduced from the nucleotide sequence. These data indicated that these polypeptides were produced by processing the original mature protein in the C-terminal region. The enzymatic properties of these two polypeptides were very similar, except that the specific activity of D38 was 2–3.5-fold higher than that of D56, and D38 was more heat stable than D56. Correspondence to: T. Kodama     

Effects of abscisic acid on flowering in Pharbitis nil

Under continuous light, flowering of Pharbitis seedlings wasnot induced by abscisic acid (ABA) treatment. Under short daytreatment, flowering was slightly enhanced by ABA at 0.2 and0.4 mg/liter. Stem elongation was considerably inhibited by25 and 50 mg/liter of ABA irrespective of day length. (Received October 21, 1972; )     

The Utility of a Flexible Fluorescence-Cystoscope with a Twin Mode Monitor for the 5-Aminolevulinic Acid-Mediated Photodynamic Diagnosis of Bladder Cancer

Objectives

To evaluate the diagnostic value of a new photodynamic diagnosis (PDD) system using 5-aminolevulinic acid (ALA) for the diagnosis of bladder tumors. To validate whether false-positive findings caused by tangent effects in PDD can be resolved, we compared diagnostic accuracies between the new PDD system and a conventional PDD system.

Patients and Methods

Among 30 transurethral bladder biopsies, 15 cases received ALA-PDD using rigid fluorescence cystoscopy (conventional PDD system), and flexible fluorescence cystoscopy with a twin mode monitor (new PDD system) was used in a separate set of 15 cases. To evaluated the usefulness of ALA-PDD, diagnostic accuracies were retrospectively compared between the conventional PDD system and the new PDD system.

Results

Of 207 specimens from 30 cases, we obtained 110 specimens using the conventional PDD system and 97 specimens using the new PDD system. Of these samples, we selected 30 distal bladder specimens each from both the conventional PDD system and the new PDD system. The overall sensitivity, specificity and false-positive rate for the new PDD system were 100%, 82.6%, and 17.4%, respectively. Those of the conventional PDD system were 83.3%, 66.2% and 33.8%, respectively. The overall false-positive rate of the new PDD system improved to 16.4% when compared with the conventional PDD system. Furthermore, the false-positive rate of the new PDD system in distal bladder samples improved to 11.8%. The overall AUC of the new PDD system was significantly greater compared with that of the conventional PDD system (P<0.05). We obtained similar significant results in the distal bladder samples (P<0.05). All procedures were well tolerated by all patients without any severe adverse events.

Conclusion

Flexible cystoscopy had a significantly higher specificity and improved incidence of tangent effects when compared with conventional methods. This preliminary study suggests that the new PDD system using 5-aminolevulinic acid may be more useful than the conventional PDD system.     

Nucleosides and Nucleotides. 98. Synthesis and Antitumor Activities of 5-Ethynylimidazole-4-carboxamide and -carbonitrile Derivatives

Abstract

5-Ethynyl-1-(2-deoxy-β-D-ribofuranosyl)imidazole-4-carbonitrile (4) and -carboxamide (5) and 5-ethynyl-1-(5-deoxy-β-D-ribofuranosyl)imidazole-4-carbonitrile (11) and -carboxamide (12) have been synthesized from the corresponding 5-iodo derivatives 2 and 7 by a palladium-catalyzed cross-coupling reaction with (tri-methylsilyl)acetylene. The aglycons, 5-ethynylimidazole derivatives 14 and 15 were synthesized by the hydrolytic cleavage of the corresponding nucleosides. The antileukemic activity of these nucleosides and base analogues are also described.