A simplified modification of the AOAC official method for determination of total dietary fiber using newly developed enzymes: preliminary interlaboratory study

A preliminary interlaboratory study was conducted to evaluate the validity of the modified AOAC method for determination of total dietary fiber by Tada and Innami, in which the 3-step enzymatic digestion process in AOAC Method 991.43 is modified to a 2-step process without pH adjustment. Total dietary fiber contents in 8 representative foodstuffs were measured using both the original AOAC Method 991.43 and the modified method in 6 research facilities in Japan. Repeatability relative standard deviations, reproducibility relative standard deviations, and Horwitz ratio values from the modified method were equivalent to those from AOAC Method 991.43, except in the rice sample. However, this exceptional case shown in the modified method was entirely dissolved by the addition of alpha-amylase stabilizing agents. The modified method, which shortens the process of enzymatic digestion from 3 to 2 steps and in which only reaction temperature is adjusted under the same pH, was found not only to give accurate values comparable to the original method, but also to substantially reduce the labor required by the laboratory staff in the process of routine analysis. This study revealed that the validity of the modified method was further ensured by adding alpha-amylase stabilizing agents to the reaction system.

Plant residue and bacteria as bases for increased stool weight accompanying consumption of higher dietary fiber diets

OBJECTIVE

Stool diluting effects of relatively inert material, such as unfermentable dietary fiber, has been proposed as an effect of fiber beneficial to the colon. Stool dilution by increasing bacterial mass may be beneficial or deleterious, depending on bacterial metabolic products. The purpose of this study was to determine the basis for stool weight when two stepwise increases of fiber from all classes of fiber-containing foods were consumed.

METHODS

Stool from five men consuming three constant diets containing 15, 30 and 42 g/d of dietary fiber were fractionated into plant material and bacteria and analyzed for neutral and amino sugar content. Fecal nitrogen, fat and ash were measured.

RESULTS

Daily gravimetric yield and sugar content of the plant fraction from stool increased with each fiber addition. Compared to the low fiber diet, the medium fiber diet decreased the concentration of the bacterial mass in wet stool by 11% and the high fiber diet by an additional 32%. The high fiber diet decreased stool fat concentration; the medium and high fiber diets decreased stool nitrogen concentration to the same extent. Apparent digestibility of plant-derived neutral sugars decreased with each fiber addition.

CONCLUSIONS

Inherently less fermentable plant material modulates the colon environment in three beneficial ways: it is a relatively unreactive diluent of lumenal contents; it adds mass to promote distal movement of waste; it does not promote a large bacterial mass.

Regulation of the polyspermy block in the mouse egg: maturation-dependent differences in cortical granule exocytosis and zona pellucida modifications induced by inositol 1,4,5-trisphosphate and an activator of protein kinase C

Germinal vesicle (GV)-intact fully grown mouse oocytes do not undergo cortical granule (CG) exocytosis in response to A23187 treatment, whereas metaphase II (MII)-arrested eggs do. This differential response may reflect the development of the ability of the egg to undergo CG exocytosis, which is responsible for the biochemical modification of the glycoprotein ZP2 in the zona pellucida. Accordingly, we compared in these two stages the ability of 12-O-tetradecanoyl phorbol 13-acetate (TPA) or inositol 1,4,5-trisphosphate (IP3) to promote CG exocytosis and/or the ZP2 to ZP2f conversion; these agents are known to stimulate early events of mouse egg activation. TPA (10 ng/ml) treatment for 60 and 120 min resulted in a 25% and 52% CG loss in GV-intact oocytes and a 38% and 76% loss in MII eggs, respectively; fertilization resulted in a CG loss of approximately 70-80%. Although a similar extent of ZP2 to ZP2f conversion was observed in oocytes and eggs after a 120-min TPA treatment (approximately 70-80%), a greater extent of conversion was observed in oocytes after a 60-min treatment (80% for oocytes, 50% for eggs). Microinjection of IP3 (final concentration 1 microM) into MII eggs resulted in an extent of ZP2 conversion similar to that observed following fertilization, whereas little conversion occurred in GV-intact oocytes similarly injected. These results indicate that a protein kinase C sensitivity develops prior to meiotic maturation, whereas responsiveness to IP3 develops after maturation has resumed. We propose that the regulatory mechanism involving an IP3-mediated calcium release is deficient in GV-stage oocytes.

Animal models in micromanipulation

Micromanipulation is a useful technique for various studies of reproductive biology. Using this technique, we investigated the role of cAMP in the regulation of oocyte maturation. Anti cAMP serum was microinjected into oocyte cytoplasma. Immature oocytes resumed meiosis after microinjection and this result shows oocyte cAMP to be important for the intrafollicular meiotic arrest of oocyte and its decrease to cause resumption of meiosis. We also determined maturation promotion factor (MPF) activity in the mouse egg. Microinjection of cytoplasma from mature egg induced geminal vesicle break down of immature oocyte in the presence of dbcAMP. In addition, we detected MPF activity in cytoplasma of metaphase II oocyte. Some of the initial events of sperm-induced egg activation are accompanied by hydrolysis of phosphatidyl inositol which generates inositol trisphosphate (IP3). Mouse eggs microinjected with increasing concentration of IP3 revealed concentration dependent increase in conversion of the zona glycoprotein ZP2 to ZP2f. Modification of zona pellucida elicited by microinjection of IP3 are similar to those that occur following fertilisation. We also microinjected some cytoplasma of morula or 2 cell mouse embryo into 1 cell embryo of ICR mouse. After microinjection and culture, most of the embryo that reached 4 cells stage and 2 cell block of ICR mouse embryo was released significantly. These results suggest that some cytoplasmic factor(s) is a requisite for the development of embryo after fertilisation.

Precocious loss of cortical granules during mouse oocyte meiotic maturation and correlation with an egg-induced modification of the zona pellucida

Fertilization results in cortical granule exocytosis, which is thought to be involved in modifications of the zona pellucida that constitute the zona pellucida block to polyspermy. A previous report demonstrated that a decrease in the number of Lens culinaris agglutinin-staining granules, which are likely to be cortical granules, occurred during in vivo mouse oocyte maturation with arrest at metaphase II, as well as the formation of a cortical granule-free domain in the area of the metaphase II spindle (T. Ducibella, E. Anderson, D.F. Albertini, J. Aalberg, and S. Rangarajan, 1988, Dev. Biol. 130, 184-197). We extend these observations by reporting here that germinal vesicle-intact oocytes matured in vitro to metaphase II in either the absence or the presence of serum develop a cortical granule-free domain and have reduced numbers of cortical granules when compared to germinal vesicle-intact oocytes; these changes are similar to those of oocytes matured in vivo. The reduction in the number of cortical granules requires germinal vesicle breakdown, since it is prevented by dibutyryl cAMP, which inhibits germinal vesicle breakdown in vitro. The ability of oocytes to respond to the calcium ionophore A23187 with a reduction in the number of cortical granules is also associated with meiotic maturation and develops between 7 and 12 hr after initiation of maturation. The maturation-associated reduction in the number of cortical granules is likely to represent cortical granule exocytosis, since this reduction is accompanied by the formation of a cortical granule-free domain and a conversion of ZP2 to ZP2f when the oocytes are matured in vitro in serum-free medium; this zona pellucida modification occurs following fertilization and is thought to be due to cortical granule exocytosis. In contrast, the loss of cortical granules and development of the cortical granule-free domain of oocytes matured in vitro in the presence of serum is not accompanied by the modification of ZP2. The inhibitory effect of serum on the ZP2 modification may afford in vivo a physiological mechanism to prevent a precocious modification of the zona pellucida that could result in a premature block to polyspermy and hence inhibit fertilization.

Altemicidin, a new acaricidal and antitumor substance. I. Taxonomy, fermentation, isolation and physico-chemical and biological properties

Screening of new insecticidal and acaricidal antibiotics was carried out with reference to anti-brine shrimp activity from actinomycete strains isolated from marine environments. Of 200 actinomycete isolates, one isolate was found to produce a new substance, altemicidin. The strain was isolated from sea mud collected at Gamo, Miyagi Prefecture, Japan, and identified as Streptomyces sioyaensis SA-1758. Altemicidin was purified by Diaion CHP-20P and Sephadex LH-20 column chromatographies. The molecular formula was determined as C13H20N4O7S by elemental analysis, MS and 13C NMR spectrum. Altemicidin showed not only acaricidal activity but also antitumor activity. The compound showed no antimicrobial activity except the inhibitory activity to Xanthomonas strains.

Altemicidin, a new acaricidal and antitumor substance. II. Structure determination

The structure of altemicidin, a new acaricidal and antitumor agent, was determined to be (1R,2S,3aR,7aS)-4-carbamoyl-2-hydroxy-6-methyl-1-(sulfamo ylacetamido)-2,3,3a,6, 7,7a-hexahydro-6-azaindene-1-carboxylic acid by a combination of spectroscopic and X-ray crystallographic analysis of its derivatives. Altemicidin is a monoterpene alkaloid.

Egg-induced modifications of the zona pellucida of mouse eggs: effects of microinjected inositol 1,4,5-trisphosphate

Mouse eggs microinjected with physiological concentrations of inositol 1,4,5-trisphosphate (IP3) do not emit the second polar body, form a pronucleus, or display a fertilization-associated set of changes in the pattern of protein synthesis. IP3-injected eggs, however, display a conversion of the zona pellucida glycoprotein ZP2 to ZP2f. The effect is concentration-dependent with an EC50 (effective concentration, 50%) of 5-10 nM and also occurs in the presence of reduced levels of extracellular calcium. The egg-induced zona pellucida modification is not elicited by several other inositol phosphates that are not able to release calcium from intracellular stores in other systems. Analysis of individual eggs microinjected with IP3 reveals a strong correlation between a reduced binding of sperm to the zona pellucida and the ZP2 to ZP2f conversion. In addition, solubilized zonae pellucidae isolated from IP3-injected eggs possess reduced levels of acrosome reaction-inducing activity. These egg-induced modifications of the zona pellucida--reduced sperm receptor and acrosome reaction-inducing activities and the ZP2 to ZP2f conversion--elicited by microinjected-IP3 are similar to those that occur following fertilization. Results of these experiments suggest that IP3 generated in response to fertilization may play a role in the egg-induced modifications of the zona pellucida that result in the polyspermy block.

Thrazarine, a new antitumor antibiotic. I. Taxonomy, fermentation, isolation and biological properties

Thrazarine, O-[(3R)-2-diazo-3-hydroxybutyryl)]-L-serine, is a new antitumor antibiotic produced by Streptomyces coerulescens MH802-fF5. Thrazarine was isolated from culture filtrate by Sephadex LH-20 column chromatography and reversed phase HPLC. Thrazarine induced cytolysis of tumor cell lines co-cultured with nonactivated macrophages. This effect was tumor specific because the nontumorigenic cells were not lysed by macrophages in the presence of thrazarine. Thrazarine inhibited DNA synthesis and growth of tumor cells directly. It showed neither antimicrobial activity nor the inhibition of transamidation reactions in contrast to azaserine. Toxicities of thrazarine were much weaker than those of azaserine.

Thrazarine, a new antitumor antibiotic. II. Physico-chemical properties and structure determination

A new antitumor antibiotic thrazarine was soluble in water and positive to anisaldehyde-sulfuric acid and ninhydrin color reactions. The absolute structure of thrazarine was determined to be O-[3R)-2-diazo-3-hydroxybutyryl)-L-serine by acid hydrolysis, spectroscopic analysis and X-ray crystallographic analysis. Structurally, thrazarine was a new member of azaserine group antibiotics.

Inhibition of cellular phosphatidylinositol turnover by psi-tectorigenin

Psi-tectorigenin, an isoflavonoid, was isolated from a culture filtrate of actinomycetes as an inhibitor of epidermal growth factor-induced phosphatidylinositol turnover in cultured A431 cells. It inhibited phosphatidylinositol turnover with an IC50 of about 1 microgram/ml; thus, its inhibitory activity was 6-times stronger than that of genistein or orobol. When added to cultured A431 cells psi-tectorigenin inhibited phosphatidylinositol turnover without inhibiting epidermal growth factor receptor tyrosine protein kinase. Thus, psi-tectorigenin is a specific inhibitor of phosphatidylinositol turnover and may be a useful tool for the functional analysis of phosphatidylinositol turnover.

Bisucaberin, a new siderophore, sensitizing tumor cells to macrophage-mediated cytolysis. II. Physico-chemical properties and structure determination

The structure of bisucaberin, a new siderophore, was determined to be 1,12-dihydroxy-1,6,12,17-tetraazacyclodocosane-2,5,13,16-tetron e by spectroscopic analysis and X-ray crystallographic analysis. The molecule of bisucaberin consists of a cyclic dimer of 1-hydroxy-1,6-diazaundecane-2,5-dione moiety and is closely related to nocardamine, the trimer of the same moiety.

Bisucaberin, a new siderophore, sensitizing tumor cells to macrophage-mediated cytolysis. I. Taxonomy of the producing organism, isolation and biological properties

Alteromonas haloplanktis strain SB-1123 isolated from deep-sea mud produced a new siderophore, bisucaberin. Bisucaberin rendered tumor cells susceptible to cytolysis mediated by murine peritoneal macrophages which were elicited by Proteose peptone and not yet activated by lymphokine. Bisucaberin exerted its sensitizing activity by both the preincubation with tumor cells and the addition to co-culture of macrophages and tumor cells. The activity of bisucaberin was specifically inhibited by ferric ion. Bisucaberin showed direct cytostasis for tumor cells but did not cause cytolysis in the absence of macrophages. Cytostasis by bisucaberin was attributable to the specific inhibition of DNA synthesis in tumor cells.

Cooperative inhibitory effect of follicular fluid and cAMP on hamster oocyte maturation

Porcine or human follicular fluid inhibited the spontaneous maturation of isolated hamster oocytes in vitro during the first 1.5 h of culture. Moreover, the presence of 50% follicular fluid combined with 100 microM dbcAMP cooperatively reduced the incidence of germinal vesicle breakdown. The addition of FSH also inhibited the resumption of meiosis, and the presence of LH did not overcome the inhibitory effects of follicular fluid and tended to impede isolated hamster oocyte maturation in vitro.

New antibiotic-producing streptomycetes, selected by antibiotic resistance as a marker. I. New antibiotic production generated by protoplast fusion treatment between Streptomyces griseus and S. tenjimariensis

A novel antibiotic was found after performing an interspecific fusion treatment between Streptomyces griseus and S. tenjimariensis by the selection of clones with a unique antibiotic resistance. Nonantibiotic-producing mutants of streptomycin (SM)-producing S. griseus SS-1198 with resistance to SM and istamycin (IS)-producing S. tenjimariensis SS-939 with resistance to kanamycin (KM) were protoplasted, mixed with polyethyleneglycol and regenerated. Resistant clones to both SM and KM were found among spores of the regenerated culture at a frequency of 10(-6). Their growth appearance was identical with that of S. griseus. Antibiotic productivity was found only in clones resistant to both 20 approximately 50 micrograms/ml of KM and 400 micrograms/ml of SM. The antibiotic produced by a selected strain, SK2-52, proved to be different from SM and IS.

[Effects of estrogen, progesterone and androgen on autoradiograms of the immature rat uterus]

Endometrial cancer is more frequent in patients at a postmenopausal age, when the ovarian secretion of androgens instead of estrogens seems to be relatively increased. In clinical or experimental medicine, progesterones are widely used for the treatment of endometrial cancer, probably because they have an antiestrogenic action and cause differentiation of cancer cells from the proliferative phase. The effects of testosterone(T), progesterone(P), and/or 17 beta-estradiol(E) on the incorporation of 3H-thymidine in autoradiograms were investigated in immature rats. The autoradiogram revealed many grains due to 3H-thymidine in the endometrial epithelium, stroma, and the myometrium in the immature rat 30 hours after E-injection. T alone markedly induced the DNA synthesis in the stroma and the myometrium, but not in the epithelium. T displayed a synergistic interaction with E in both the stroma and the myometrium with a slight increase in thymidine incorporation into the epithelium. P alone induced DNA synthesis in the stroma and the myometrium. Simultaneous injection of E and P also produced the same result as that when P alone was injected. P markedly inhibited DNA synthesis due to E in the epithelium. Autoradiograms of the immature rat uterus provide basic support for the rationality of P therapy for cancer or adenomatous hyperplasia of the endometrium.

Marinactan, antitumor polysaccharide produced by marine bacteria

Extracellular polysaccharides of marine bacteria were screened for their antitumor activity against sarcoma-180 solid tumor in mice. An active polysaccharide was purified and named marinactan. The producing microorganism has a typical marine bacterial nature requiring sea water for growth and was identified as Flavobacterium uliginosum. Marinactan is a novel heteroglycan consisting of glucose, mannose and fucose in a ratio of approximately 7:2:1. Marinactan, 10-50 mg mg/kg daily for 10 days i.p., produced 70-90% inhibition of the growth of solid sarcoma 180. Complete regression of the tumor was observed in some treated mice. Its administrations before and after tumor transplantation showed almost the same inhibitory effect. Marinactan prolonged markedly the survival period of mice bearing ascites sarcoma 180.

[Laboratory and clinical studies on latamoxef in the field of obstetrics and gynecology]

Latamoxef (LMOX) is a new antibiotic synthesized by Shionogi Research Laboratory. Chemically LMOX is especially unique with a sulfur atom replacing the oxygen atom in the 1 position of the conventional cephalosporin nucleus, and in addition, this antibiotic has a cephamycin-like structure. The antibacterial activity of LMOX shows high potency against Gram-negative bacteria, but tends to be weak against Gram-positive bacteria. The tissue levels of LMOX in humans after intravenous injection of 1 g were examined. The levels in uterine and adnexa uteri tissue at 1 hour after administration were 25.4 and 27.4 micrograms/g respectively. LMOX was administered to 147 cases in infections of obstetric and gynecological field. The clinical effect according to disease was 94.6% for intrauterine infections, 95.0% for adnexitis, 87.0% intrapelvic infections, and 100% for external genital organ infections, making a total of 92.5%. The rate of occurrence of side effects or abnormal laboratory findings was similar to or slightly less than that seen with other beta-lactam antibiotics.