One-year chronic oral toxicity with combined reproduction toxicity study of a novel probiotic, Bacillus coagulans, as a food ingredient.

Some strains of Bacillus coagulans can survive extremes of heat, stomach acid and bile acids, to which commonly consumed probiotics are susceptible. A toxicological safety assessment was published in 2009 on a proprietary preparation of B. coagulans - GanedenBC(30)™ - a novel probiotic. It was concluded that GanedenBC(30)™ is safe for chronic human consumption based upon scientific procedures, supported by a safe history of use (Endres et al., 2009). A one-year chronic oral toxicity study combined with a one-generation reproduction study was conducted to further investigate safety of long-term consumption. The one-year study of GanedenBC(30)™ administered to male and female HsdBrlHan: Wistar rats in their diet showed no signs of toxicity at the highest dose tested. The conclusion from the reproduction toxicity study is that administration of GanedenBC(30)™ in the diet caused no signs of toxicity in the parental generation (male or female) nor the F1 offspring. Using the lowest NOEL of 1948 mg/kg concluded at the end of the 1-year feeding study, a 100-fold safety factor, a test article concentration of 6.88×10(10) CFU (colony forming units) per gram, and an average 70 kg human, it is determined that GanedenBC(30)™ is safe for chronic consumption at up to 9.38×10(10) CFUs per day.

Evaluation of a Hungarian acaricide original molecule based on its environmental toxicological studies.

The results of the environmental toxicological investigations and their results of a new hungarian acaricide molecule (SZI-121) developed by the CHINOIN were summarized. The toxicological effects of the test item on different ecotoxicological test systems were investigated in the following tests: Bacterium, alga, and plant growth inhibition tests, acute immobilization and 21 days reproduction tests on Daphnia magna, acute fish test, closed bottle test, mobility, aerob degradation and adsorption/desorption tests on three different soils. No toxic effect was found in the bacterium, alga, plant growth inhibition and acute fish tests in the highest concentrations used. In the Daphnia immobilization test 0.14 mg/l LC50 value was established in the concentration range of 0.0128-40 mg/l applied. The test item showed similar characteristics as the reference item during the mobility test in soils, the adsorption/desorption study and the degradation investigations. In order to determine the environmental degradation rate further degradation investigations, as well as the nitrogen mineralization test and the model of concentration change in natural waters were performed.

Results of the general toxicity and genetic studies of an insecticide intermediate.

Methyl-chrysanthemate is one of the intermediates of pyrethroid type insecticides. The acute toxicity of the test item was investigated in rats after single oral, dermal and inhalation applications. The irritation effect was determined by Draize method. Buehler method was applied to evaluate the sensitization potential of the test item. The mutagenic effect was assessed on Salmonella typhimurium strains. Furthermore metaphase chromosome aberration assay was performed on CHO cell line to check the structural chromosome aberrations.

DNA-binding proteins that interact with the 19-base pair (CRE-like) element from the HCMV major immediate early promoter in differentiating human embryonal carcinoma cells.

The pluripotent human embryonal carcinoma (EC) cell line NTERA-2 provides a useful tool for investigating cell differentiation in a way that is pertinent to the development of the early human embryo. The major immediate early (MIE) gene of human cytomegalovirus (HCMV), which is not transcribed in undifferentiated NTERA-2 EC cells but is transcribed in their differentiated derivatives, offers a model with which to study the developmental regulation of gene activity during the differentiation of these cells. We have investigated the regulatory activity of the cAMP response elements (CRE) and the activation protein (AP1) site found within several repeated 19-base-pair (bp) elements from the HCMV MIE promoter, and the developmental regulation of nuclear DNA-binding factors that interact with these sites. The 19-bp CRE but not the AP1 site is responsive to cAMP in undifferentiated NTERA-2 EC and its activity is enhanced upon differentiation. Nuclear proteins of the CREB, Fos, and Jun families bind to these sites, but, surprisingly, their levels only show limited regulation during NTERA-2 differentiation. This contrasts with results obtained with murine EC cells. However, additional and apparently novel proteins with molecular weights between 80,000 and 90,000, and binding specificities for both CRE and AP1 sites, were detected in undifferentiated EC cells. The activity of these proteins decreased markedly after differentiation, indicating their involvement in negative regulation of the CRE/AP1-like site in undifferentiated EC cells. This suggests novel members able to interact via leucine zippers with other members of the Jun-Fos-CREB family of DNA binding proteins that are also involved in this regulation.

Undifferentiated keratinocytes control growth, morphology, and antigen expression of normal melanocytes through cell-cell contact.

BACKGROUND: Melanocytes in the normal human epidermis are generally dendritic and neither proliferate nor express melanoma-associated antigens. In culture, on the other hand, melanocytes are bi- to tripolar, proliferate with 2 to 4 day doubling times, and express melanoma-associated antigens. This observation prompted us to investigate the regulatory role of keratinocytes for growth, morphology, and antigen expression of melanocytes. EXPERIMENTAL DESIGN: Melanocytes and keratinocytes were cultured under three different co-culture conditions: (a) separated by a semiporous membrane, (b) in monolayer cultures allowing direct contact between cells, and (c) in three-dimensional epidermal reconstructs. RESULTS: Melanocytes separated from keratinocytes by semiporous membranes remained di- and tripolar and could not proliferate in medium optimal for keratinocytes. When cell-cell contact was established between melanocytes and undifferentiated, but not differentiated, keratinocytes, melanocytes proliferated at a rate similar to keratinocytes and they developed multiple dendrites. In co-cultures allowing the multi-layered growth of keratinocytes, melanocytes were nonproliferative when juxtaposed to undifferentiated keratinocytes in the basal layer, but proliferated when surrounded by differentiated keratinocytes in the intermediate and upper layers. Expression of melanoma-associated antigens on melanocytes decreased to similar levels as in normal skin when melanocytes were in direct contact with undifferentiated, but not differentiated, keratinocytes. CONCLUSIONS: Undifferentiated, but not differentiated, keratinocytes control growth, morphology, and antigen expression of melanocytes through direct cell-cell contact. These results suggest that the phenotypic characteristics of nevus and melanoma cells in the dermis, i.e., proliferation and expression of tumor-associated antigens, may be due to their loss of contact with undifferentiation keratinocytes.

Differentiation-dependent human immunodeficiency virus long terminal repeat regulatory elements active in human teratocarcinoma cells.

We have examined the transcriptional utilization of the human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) under differentiating conditions by using the embryonal carcinoma cell line NTERA-2. NTERA-2 cells undergo two distinct pathways of terminal differentiation, to a neuronal phenotype in response to retinoic acid and to a nonneuronal phenotype in response to hexamethylene bisacetamide. To identify LTR regulatory elements active in each cell type we used a set of HIV LTR linker substitution mutants, which contain mutations that progressively replace adjacent 18-bp segments across the U3 region and into the R region (between nucleotides -453 and +15 relative to the transcription start site). Although each differentiating cell type showed utilization of expected key elements (e.g., NF-kappa B, SP1, TATA) in the 3' portion of the LTR (+1 to -112), the data indicated differentiation-dependent differences in the utilization of these elements. In addition, regions showing dramatic differentiation-dependent effects were detected in the 5' portion of the LTR (-112 to -453), in positions where transcription control elements have not been described previously. The marked differences in the sets of LTR regulatory elements required by each cell type indicate that the LTR can function under a variety of differentiation conditions. Together with previous findings, the data suggest that the complexity of the HIV LTR for transcriptional control is much greater than was previously thought and that the LTR maintains elements which facilitate transcription in many cell types.

High expression of human cytomegalovirus (HCMV)-gB protein in cells infected with a vaccinia-gB recombinant: the importance of the gB protein in HCMV immunity.

The human cytomegalovirus (HCMV), Towne strain, glycoprotein B (gB) gene was cloned into a vaccinia vector (Copenhagen strain) under the control of the H6 early and late vaccinia promoters (Vac-gB recombinant). The gB protein was expressed in a high percentage of the Vac-gB-infected cells throughout the virus replication cycle. Cytosine-arabinoside (ara-C) did not influence the expression of the gB protein early after infection (5 h), but did inhibit it later in viral replication (7-29 h). The Vac-gB recombinant induced HCMV neutralizing antibodies in guinea-pigs. Cells infected with the Vac-gB recombinant absorbed 50-88% of neutralizing activity of human sera obtained from volunteers previously inoculated with the Towne or Toledo strains and from naturally seropositive individuals.

Differentiation of human embryonal carcinoma cells induces human immunodeficiency virus permissiveness which is stimulated by human cytomegalovirus coinfection.

Human immunodeficiency virus (HIV) replicates in differentiated but not undifferentiated NTERA-2 human embryonal carcinoma cells; neither cell type expresses CD4. Susceptibility of the differentiated cells is enhanced by coinfection with cytomegalovirus. HIV infection induces lactoseries glycolipids, suggesting a mechanism whereby HIV might interfere with normal embryogenesis.

Changes of lactic dehydrogenase activity and combination of its subunits in rat anterior pituitary during puberty and in maturity, as well as during estrous cycle on the actue effect of estradiol and after castration.

LDH activity in the female rat anterior pituitary increases substantially at the opening of the vagina, after the gradual increase up to the 90st day no important change occurs. During the estrous cycle activity reaches its peak during the estrus, and lowest in ghe proestrus. Molecular organization of the enzyme shows a change only at the opening of the vagina, i. e. a sudden decrease of H/M ratio occurs, value of which does not change during the estrous cycle. Pituitary LDH activity and subunit ratio in males remains constant during life. LDH activity excess in mature female rat pituitary, being about the double as compared to males, develops at the age of about three months, the difference in H/M ratio however is manifest already during puberty. Anterior pituitary LDH activity and structure of the enzyme are affected by sexual hormones, primarily by estradiol, under physiological conditions, too. After ovariectomy LDH activity decreases gradually. The value before the opening of the vagina to be considered as basal level, develops in the 4th postoperative week. H/M ratio decreases by 20 per cent one week after the operation and shows no change thereafter. Orchidectomy involves but a minor activity and H/M ratio decrease. Experimental findings on activity and subunit ratio are related presumably to prolactin cells and suggest that sexual hormone feedback effects in addition to polypeptide production pituitary metabolism.

The role of estrogens in the regulation of lactate dehydrogenase activity and its submolecular organization in rat anterior pituitary.

Estrogens increase LDH activity and decrease H/M subunit ratio in rat anterior pituitary in both the experimental circumstances and the physiological conditions. The cellular messengers mediating estrogenic effect are structure- and stereospecific. The activity increasing and subunit ratio decreasing potency of the three tested estrogens was of following decreasing order: 17 beta-estradiol, estrone, and estriol. 17 alpha-estradiol did not affect activity parameters and submolecular organisation of the enzyme. The estrogen induced activity increase is consequence of the enhanced de novo enzyme protein synthesis which could be inhibited by Actinomycin-D. The lack of adrenocorticoids did not involve the alteration of LDH activity and H/M ratio in female rat anterior pituitary. Accordingly, these steroids do not mediate estrogenic action. 17 beta-estradiol had a substantial increasing effect on LDH activity in the subrenal implanted pituitary homografts and decreased H/M subunit ratio. Pituitary LDH activity in androgenized female rats decreased only after the removal of the polycystic ovaries. The two latter observations suggest that hypothalamic hormones are not involved in the regulation of pituitary LDH activity and its submolecular organization. De novo synthesis of LDH enzyme protein and the regulation its submolecular organization is induced by the direct action on anterior pituitary cells of the estrogens.