The absence of DNA from the blood serum of Bufo arenarum

The absence of DNA from the blood serum of the toad Bufo arenarum was confirmed by classical colorimetric techniques and by a new method which allows differentiation between DNA and the glycosaminoglycans (GAG). A component of serum which had some of the properties of DNA was identified as a GAG. This component gave positive reactions in colorimetric assays for DNA, but the absorption spectra were completely different from those of authentic DNA. The compound was also not hydrolyzed at all by treatment with deoxyribonuclease.     

Continuous production of thienamycin in immobilized cell systems

A novel 2-L bubble column was used to study the continuous, immobilized cell production of thienamycin. Cells of Streptomyces cattleya were immobilized by culturing them in an appropriate growth medium containing 60/80 mesh celite particles. The dilution rate used during the continuous growth phase was 0.2 h(-1). This growth phase was terminated upon the development of heavy cell films (100-500 mum thickness), and the medium was replaced with an appropriate thienamycin production medium. The system was then operated in a batch mode until thienamycin production began. At that time, continuous feeding of the production medium was initiated and the influence of medium composition and dilution rate on CO(2), NH(4), biomass, and thienamycin production investigated. With synthetic production medium, a doubling of the dilution rate from 0.05 to 0.10 h(-1) resulted in a doubling of the thienamycin volumetric productivity. Rates of CO(2) and NH(4) production increased by ca. factors of three and two, respectively. The rate of PO(4) utilization also doubled. When the dilution rate was decreased to 0.05 h(-1), the rates of CO(2) production and PO(4) utilization quickly decreased (i.e., within 3 h). The rates of NH(4) and thienamycin production also decreased but more slowly (i.e., ca. 100 h after the decrease in dilution rate). With complex production medium, the rates of CO(2) production and PO(4) utilization appeared to be a direct function of dilution rate at the dilution rates tested. Thienamycin production in this case was not a function of dilution rate. Comparing the synthetic medium with the complex medium at either dilution rate, the volumetric rate of thienamycin production was higher in the system being fed complex medium. However, the specific activity (units thienamycin/g cell/h) observed with complex medium was lower than that observed with synthetic medium. The higher volumetric productivity observed with complex medium was the result of a high cell loading. The above observations will be discussed in terms of control of thienamycin synthesis and film thickness effects.     

Ethanol production by immobilized cells of Zymomonas mobilis

Summary Columnar reactors containing immobilized cells of Zymomonas mobilis were utilized for the continuous production of ethanol from glucose. Two different immobilization strategies were investigated. In one case, cells were entrapped in borosilicate glass fiber pads, while in the other, cells were immobilized via flocculation. The reactors were operated in both the fixed-bed and expanded-bed manner. Ethanol productivities as high as 132 g/l·h were achieved. Data obtained from studies employing 5.0 and 10.0% glucose concentrations are presented. Problems encountered during the operation of the continuous, immobilized cell reactors are discussed.Operated by Union Carbide Corporation under contract W-7405-eng-26 with the U.S. Department of Energy.     

Evaluation of domestic wastewater treatment using microalgal-bacterial processes: effect of CO<Subscript>2</Subscript> addition on pathogen removal

Microalgal-bacterial processes represent a sustainable and cost-effective biotechnology able to promote efficient wastewater treatment, including natural pathogen removal (disinfection), as well as being able to perform CO₂ uptake and biogas upgrading. In this context, the influence of CO₂ supply from a synthetic gas mixture (30% v/v CO₂) on the removal of pathogens (Pseudomonas, enterococci, and Escherichia coli) and total coliforms during secondary domestic wastewater treatment by a microalgal-bacterial symbiosis in a 180-L high-rate algal pond (HRAP) was investigated. The supply of CO₂ in the HRAP positively influenced the Pseudomonas aeruginosa removal, with the removal efficiency increasing from 97.4% (1.6 log) to 99.6% (2.5 log) without and with CO₂ supply, respectively. Likewise, the total coliform removal efficiency rose from 88.7% (1.1 log) to 99.4% (2.8 log). On the other hand, the effect of CO₂ supply on enterococci (99.7% and 2.6 log) and Escherichia coli (98.6% and 2.2 log) removal was negligible.     

Differential regulation of colony stimulating factor 1 and macrophage migration inhibitory factor expression by inflammatory cytokines in term human decidua: implications for macrophage trafficking at the fetal-maternal interface

Macrophages are a major component of the leukocyte population of human pregnant endometrium. Although several crucial functions have been ascribed to these cells, the mechanisms underlying macrophage trafficking in the placental bed are poorly understood. The aim of this study was to evaluate the in vivo expression of two potentially antagonistic macrophage-targeting chemokines, colony stimulating factor 1 (CSF1, also known as M-CSF) and macrophage migration inhibitory factor (MIF), in term decidua, and to examine the effects of the inflammatory cytokines tumor necrosis factor (TNF, also known as TNF alpha) and interleukin 1beta (IL1B) on CSF1 and MIF expression in cultured decidual cells. The expression of CSF1 and MIF in term decidua was evaluated by immunohistochemistry. Cultured decidual cells were primed with estradiol (E2) or with E2+medroxyprogesterone acetate (MPA), and then incubated with corresponding steroid(s) with or without TNF or IL1B. The levels of CSF1 and MIF protein and mRNA were assessed by ELISA and quantitative RT-PCR, respectively. Immunostaining for CSF1 and MIF was observed in term decidua. The levels of secreted CSF1 and MIF were similarly unchanged whether the decidual cells were incubated with E2 or with E2+MPA. The CSF1 levels significantly increased in cultures exposed to E2 or E2+MPA plus TNF or IL1B. In contrast, the MIF levels in TNF- and IL1B-treated cells were not changed significantly from the control cultures. The ELISA data were confirmed by quantitative RT-PCR analysis. These results indicate that CSF1 and MIF are involved in regulating macrophage trafficking at the fetal-maternal interface, and suggest a mechanism by which inflammatory cytokines influence pregnancy by regulating decidual macrophage infiltration.     

Antimicrobial activity of Brazilian propolis extracts against rumen bacteria in vitro

The antimicrobial activity of three Brazilian propolis extracts was evaluated on bacterial strains representing major rumen functional groups. The extracts were prepared using different concentrations of propolis and alcohol, resulting in different phenolic compositions. The propolis extracts inhibited the growth of Fibrobacter succinogenes S85, Ruminococcus flavefaciens FD-1, Ruminococcus albus 7, Butyrivibrio fibrisolvens D1, Prevotella albensis M384, Peptostreptococcus sp. D1, Clostridium aminophilum F and Streptococcus bovis Pearl11, while R. albus 20, Prevotella bryantii B₁4 and Ruminobacter amylophilus H18 were resistant to all the extracts. The inhibited strains showed also different sensitivity to propolis; the hyper-ammonia-producing bacteria (C. aminophilum F and Peptostreptococcus sp. D1) being the most sensitive. Inhibition of hyper-ammonia-producing bacteria by propolis would be beneficial to the animal. The extract containing the lowest amount of phenolic compounds (LLOS C3) showed the lowest antimicrobial activity against all the bacteria. The major phenolic compounds identified in the propolis extracts (naringenin, chrysin, caffeic acid, p-coumaric acid and Artepillin C) were also evaluated on four sensitive strains. Only naringenin showed inhibitory effect against all strains, suggesting that naringenin is one of the components participating to the antibacterial activity of propolis.     

An extremal criterion for epimorphic regeneration

Many developing systems obey the principle of continuity: a morphogenetic field, when perturbed, tends to restore the normal local pattern of structures in its organ district. We have investigated physical field theories for a morphogenetic field, seeking constraints which would make a field theory produce the principle of continuity. We assume that during embryonic (ontogenetic) development a leg develops a pattern of positional values and a length which extremize a time-independent functional—the integral, over the length of the leg, of a function of positional values and position. For a single state variable which represents positional value, if a unique extremizing solution for the ontogenetically generated pattern and the length exists, and if no position-dependent functions other than the state variable appear in the integrand, then the principle of continuity is valid: in any regenerated leg the state variable is continuous and each region is locally identical to a region of the ontogenetically generated leg. This proposition is applied to three simple examples. For an exponential gradient and a Jacobi elliptic function there is a set of parameter values and boundary values for which a functional is minimized and the ontogenetically generated leg has an optimal length. Thus a leg which meets these constraints will obey the principle of continuity. However, a functional which when extremized gives a sinusoidal pattern does not in general provide a unique extremal length. Mathematical conditions are discussed under which an ontogenetically generated limb or a regenerated limb represents an asymptotically stable steady state. For a specific model of the transient dynamics in the exponential gradient case, the steady state gradient is asymptotically stable.     

Grape skin extract protects against programmed changes in the adult rat offspring caused by maternal high-fat diet during lactation

Maternal overnutrition during suckling period is associated with increased risk of metabolic disorders in the offspring. We aimed to assess the effect of Vitis vinifera L. grape skin extract (ACH09) on cardiovascular and metabolic disorders in adult male offspring of rats fed a high-fat (HF) diet during lactation. Four groups of female rats were fed: control diet (7% fat), ACH09 (7% fat plus 200 mg kg^?1 d^?1 ACH09 orally), HF (24% fat), and HF+ACH09 (24% fat plus 200 mg kg^?1 d^?1 ACH09 orally) during lactation. After weaning, all male offspring were fed a control diet and sacrificed at 90 or 180 days old. Systolic blood pressure was increased in adult offspring of HF-fed dams and ACH09 prevented the hypertension. Increased adiposity, plasma triglyceride, glucose levels and insulin resistance were observed in offspring from both ages, and those changes were reversed by ACH09. Expression of insulin cascade proteins IRS-1, AKT and GLUT4 in the soleus muscle was reduced in the HF group of both ages and increased by ACH09. The plasma oxidative damage assessed by malondialdehyde levels was increased, and nitrite levels decreased in the HF group of both ages, which were reversed by ACH09. In addition, ACH09 restored the decreased plasma and mesenteric arteries antioxidant activities of superoxide dismutase, catalase and glutathione peroxidase in the HF group. In conclusion, the treatment of HF-fed dams during lactation with ACH09 provides protection from later-life hypertension, body weight gain, insulin resistance and oxidative stress. The protective effect ACH09 may involve NO synthesis, antioxidant action and activation of insulin-signaling pathways.