Biological Assessment of Stevioside and Sucralose as Sucrose Substitutes for Diabetics on STZ-Induced Diabetes in Rats.

Numerous food organizations have identified excessive calorie consumption and accompanying ailments as significant health risks associated with high sugar consumption. Administering stevioside (ST), sucralose (SU), and the two synergically (SU+ST) affected normal rats' weight gain. In the current study, SU showed the highest undesired effect. Indeed, administering the three treatments to diabetic rats (DR) did not improve the rats' weight gain. Although, insulin injection synergically with the treatments improved the weight gain, as recorded after three weeks. The best-improving rate was observed in the ST group. After the administration of ST and ST+SU to the DR, the blood glucose level (GL) was positively affected, with SU having no effects on reducing the GL. A considerable reduction in serum insulin (SIL) was noted in the DR+SU group. On the contrary, ST did not negatively affect the SIL, rather an improvement was recorded. In addition, giving SU did not significantly affect the ALT level in the DR or normal rats (NR). A significant improvement in total bilirubin (TBILI) was observed when insulin was injected with ST or SU in DR groups. Further, triglycerides (TG) after administering ST, SU, or ST+SU to NR had no significant difference compared to the control group (NR). Although, the three treatments markedly but not significantly lowered TG in the DR. For total cholesterol (CHO), both DR and NR had no significant effect after the three treatments. No histopathological alterations were recorded in the NR group. Diffuse and severe atrophy of the islands of Langerhans due to depletion of their cells and mild papillary hyperplasia of the pancreatic ducts were represented by a slightly folded ductal basement membrane and newly formed ductules in STZ-DR. Simultaneous atrophy and absence of the cells of islands of Langerhans besides ductal hyperplasia were evident in DR+SU. Hyperplastic ductal epithelium and atrophic Langerhans cells were seen in DR+SU+In. Degeneration and mild atrophy were observed in the islands of Langerhans structures. There was essentially no noticeable change after utilizing ST. A slight shrinkage of the Langerhans' islets was detected in DR+ST. In DR+ST+In, no histopathological alterations in the islands of Langerhans were recorded. Congestion in the stromal blood vessels associated with degenerative and necrotic changes in the cells of the islands of Langerhans in DR+SU+ST was observed. In NR+SU, congestion of the blood vessels associated with mild atrophy in the islands of Langerhans and dilatation in stromal blood vessels was noticed. In conclusion, ST is safe, and SU should be taken cautiously, such as mixing with ST and/or taken at a very low concentration to avoid its drastic effect on the human body.

Establishment of an Efficient In Vitro Propagation of Cnidium officinale Makino and Selection of Superior Clones through Flow Cytometric Assessment of DNA Content.

Cnidium officinale is a valuable medicinal plant cultivated in Asia for its rhizomes. This study reports the in vitro regeneration of Cnidium officinale plants and the induction of rhizomes from microshoots. The rhizomatous buds of Cnidium officinale induced multiple shoots on Murashige and Skoog (MS) medium supplemented with 0.5 mg L-1 BA, which led to the regeneration of plants within four weeks of culture. After four weeks of culture, the plants were assessed for fresh weight, the number of leaves, the number of roots, and the length of roots to compare the performance of the different clones. The clones with good growth characteristics were selected with the aid of a flow cytometric analysis of 2C nuclear DNA content. The plants bearing high DNA values showed better growth characteristics. Various factors, namely, sucrose concentration (30, 50, 70, and 90 g L-1), ABA (0, 0.5, 1.0, and 2.0 mg L-1), the synergistic effects of BA (1.0 mg L-1) + NAA (0.5 mg L-1) and BA (1.0 mg L-1) + NAA (0.5 mg L-1) + ABA (1.0 mg L-1) with or without activated charcoal (1 g L-1), and light and dark incubation were tested on rhizome formation from microshoots. The results of the above experiments suggest that MS medium supplemented with 50 g L-1 sucrose, 1.0 mg L-1 ABA, and 1 g L-1 AC is good for the induction of rhizomes from the shoots of Cnidium officinale. Plantlets with rhizomes were successfully transferred to pots, and they showed 100% survival.

One-step preparation of photoclick method for embolic microsphere synthesis and assessment for transcatheter arterial embolization.

Vascular embolization is a well-known therapeutic treatment against hepatocellular carcinoma. However, existing embolic agents require complex synthesis, toxic organic solvents and sometimes produce only low yields. In this study, a novel photopolymerization technique, which addresses these issues, was used to prepare embolic microspheres successfully from the sucrose multi-allyl ether monomer in one step. Compared to the preparation of such microspheres always involved in multiple steps or complicated conditions, we obtained the microspheres used photoclick method in a soft template with simple, economic and feasible procedure. This work focuses on the synthesis of new materials by conducting a photopolymerzation in the presence of the sucrose monomer and the photoinitiator. Then, the embolic microspheres obtained were characterized by morphology assay, degradation, and swelling test. Cell experiments showed that the microspheres had good biocompatibility. Rabbit embolizations showed that the microspheres had long-term embolic effects. It is manifested that one-step preparation of photoclick method hold great potential and competitiveness of being used in preparation embolic microspheres in clinic.

Varenicline rescues nicotine-induced decrease in motivation for sucrose reinforcement.

Varenicline is one of the top medications used for smoking cessation and is often prescribed before termination of nicotine use. The effect of this combined nicotine and varenicline use on the reward system and motivation for primary reinforcement is underexplored. The goal of this study was to assess the effects of nicotine and varenicline on motivation for a food reinforcer. In Experiment 1, we first assessed the responding for sucrose after pretreatment with nicotine (0, 0.1, or 0.4 mg/kg) and varenicline (0.0, 0.1, 1.0 mg/kg) using a behavioral economics approach. The responding for sucrose was then assessed using a progressive ratio schedule of reinforcement after pretreatment with all possible combinations of nicotine and varenicline doses. In Experiment 2, rats were assessed for the consumption of sucrose in home cages after pretreatment with nicotine and varenicline. We found that (a) nicotine decreased economic demand for sucrose, (b) varenicline rescued nicotine-induced reduction in economic demand for sucrose, and (c) history of varenicline treatment predicted responding for sucrose on a progressive ratio schedule of reinforcement where rats with a history of varenicline treatment responded significantly lower for sucrose across nicotine doses than rats that had not been exposed to varenicline. The results of Experiment 2 largely confirmed that nicotine decreases motivation for sucrose using a passive consumption protocol and that varenicline rescues this effect. Overall, these findings suggest that varenicline interacts with the effects of nicotine by restoring nicotine-induced reduction in motivation for appetitive rewards.

Toward isolating reward changes in diet-induced obesity: A demand analysis.

Although hormonal and metabolic factors are well known to influence obesity, recent evidence suggests that obesity may be influenced also by changes in reward sensitivity akin to that seen in other 'reward pathologies', like substance use disorders. The current study sought to isolate changes in reward that may occur after the onset of diet-induced obesity by characterizing the economic demand for caloric (sucrose) and non-caloric (saccharin) reinforcers in a preclinical model of diet-induced obesity (DIO). We utilized economic demand analysis to measure baseline demand intensity (Q0) and demand elasticity (α) for sucrose and saccharin reinforcers in rats. After baseline measures were collected, rats were assigned randomly to a high-fat (HF) diet or low-fat (LF) control diet. After 8-weeks of diet exposure, HF rats were divided into obesity-resistant (OR) or obesity-prone (OP) groups based on weight after the 8-week HF diet exposure. Post-DIO demand data for each reinforcer were reassessed. At baseline, rats had higher demand intensity and lower elasticity for sucrose compared to saccharin. After 8-weeks of the high-fat diet, OP rats had significantly greater weight gain and lower demand elasticity for sucrose and saccharin and higher demand intensity for saccharin. The changes in sucrose and saccharin elasticity suggest that DIO-induced changes in food-related behavior are associated with changes in reward processes. The changes in demand intensity for saccharin suggest that demand intensity, as a measure of 'set point', is not directly linked to metabolic processes. The current study shows that microeconomic theory and demand analysis is able to isolate independent aspects of diet-induced reward changes related to caloric and non-caloric reinforcers.

Exploring the mucoadhesive behavior of sucrose acetate isobutyrate: a novel excipient for oral delivery of biopharmaceuticals.

Oral drug delivery is an attractive noninvasive alternative to injectables. However, oral delivery of biopharmaceuticals is highly challenging due to low stability during transit in the gastrointestinal tract (GIT), resulting in low systemic bioavailability. Thus, novel formulation strategies are essential to overcome this challenge. An interesting approach is increasing retention in the GIT by utilizing mucoadhesive biomaterials as excipients. Here, we explored the potential of the GRAS excipient sucrose acetate isobutyrate (SAIB) to obtain mucoadhesion in vivo. Mucoadhesive properties of a 90% SAIB/10% EtOH (w/w) drug delivery system (DDS) were assessed using a biosimilar mucus model and evaluation of rheological behavior after immersion in biosimilar intestinal fluid. To ease readability of this manuscript, we will refer to this as SAIB DDS. The effect of SAIB DDS on cell viability and epithelial membrane integrity was tested in vitro prior to in vivo studies that were conducted using SPECT/CT imaging in rats. When combining SAIB DDS with biosimilar mucus, increased viscosity was observed due to secondary interactions between biosimilar mucus and sucrose ester predicting considerable mucoadhesion. Mucoadhesion was confirmed in vivo, as radiolabeled insulin entrapped in SAIB DDS, remained in the small intestine for up to 22 h after administration. Moreover, the integrity of the system was investigated using the dynamic gastric model under conditions simulating the chemical composition of stomach fluid and physical shear stress in the antrum under fasted conditions. In conclusion, SAIB is an interesting and safe biomaterial to promote high mucoadhesion in the GIT after oral administration.

Social reinforcement as alternative to sucrose reinforcement is increased by nicotine and methylphenidate in male Fischer-344 rats.

BACKGROUND: Stimulant drugs such as nicotine (NIC) and methylphenidate (MPH) are hypothesized to increase the reinforcing value of sensory stimuli, thus increasing the effectiveness of such reinforcers as alternatives to sucrose reinforcers. METHODS: Inbred Fischer-344 rats (n = 30) were assigned to three groups: saline (SAL; n = 10), nicotine (NIC; n = 10), or methylphenidate (MPH; n = 10). Testing was done in three phases: sucrose only, (SUC), sucrose and drug (SUC/DRUG), and sucrose, drug, and social reinforcement (SUC/DRUG/SOC). During the SUC phase, rats were trained on a progressive ratio 5 (PR5) reinforcement schedule for sucrose (20% solution). In the SUC/DRUG phase, animals were treated with SAL, NIC (0.4 mg/kg, n = 10 SC), or MPH (2.0 mg/kg, n = 10 IP) 30 min prior to testing. In the SUC/DRUG/SOC phase, animals continued receiving drug treatment, and social reinforcement was introduced concurrently with the sucrose reinforcer. The progressive ratio for each reinforcer ran independently of the others. Reinforcing value was measured as break point (BP), the highest number of responses resulting in a reinforcer. RESULTS: SAL-treated animals showed no significant change in sucrose BP. MPH-treated animals showed decreased sucrose BP in the SUC/DRUG phase, with a further reduction in the SUC/DRUG/SOC phase. NIC-treated animals decreased sucrose BP only when a social alternative was offered. CONCLUSION: Both NIC and MPH reduce the sucrose BP in the presence of a social alternative. The decrease in sucrose responding, coupled with increased social responding, suggests that the social alternative acted as an effective alternative reinforcer to sucrose. From a translational perspective, these results suggest that stimulant drugs such as NIC and MPH may increase the effectiveness of treatments that use alternative social reinforcers to decrease eating.

Viability assessment of primary growth oocytes following ovarian tissue vitrification of neotropical teleost pacu (Piaractus mesopotamicus).

Vitrification of ovarian tissue containing immature oocytes provides an important tool for protecting the endangered species and genetic diversity in aquatic species. Therefore, the main objective was to assess primary growth (PG) oocytes viability following ovarian tissue vitrification using histological analysis, two staining protocols (trypan blue or fluorescein diacetate combined with propidium iodide) and mitochondrial activity assay (MTT assay). In addition, oocyte histomorphometry was performed to evaluate the morphometric parameters after vitrification and the relationship with the occurrence of damage (nucleus and/or membrane) in PG oocytes. There was no significant difference among the vitrified oocytes using trypan blue dye or FDA + IP staining. Oocyte viability assessed using histological analysis showed that vitrification solution 2.0 M Me2SO + 2.5 M etilenoglycol +0.5 M sucrose (VS3; 66.43 ± 4.68%) and 1.5 M methanol + 5.5 M Me2SO + 0.5 M sucrose (VS5; 74.14 ± 3.71%) had the lowest viability rate. Similar results were observed in MTT assay where VS3 (1.63 ± 0.12) and VS5 (1.58 ± 0.09) had the lowest averages when compare with VS1 (2.39 ± 0.14), VS2 (1.78 ± 0.06) and VS4 (2.34 ± 0.19) (P = 0.0002). In membrane damage evaluation by histology, there was no difference among vitrified oocytes and control. However, the highest percentages of nucleus damage were observed in treatments VS3 (26.00 ± 5.55) and VS5 (26.00 ± 5.55). Oocyte diameter did not change after vitrification; however, nucleus diameter was significantly higher in control group (49.03 ± 1.07). Oocyte viability by histological analysis was positive-correlated to the occurrence of nucleus (r2 = 0.78) and membrane (r2 = 0.45) damage after vitrification/warming. The high viability of PG oocytes obtained after ovarian tissue vitrification of Piaractus mesopotamicus suggests that the protocol applied here might be used successfully in other teleost species for food production.

An in vitro assessment of the value of sucrose supplementation to warming media for the vitrification of bovine embryos.

　　BACKGROUND: In order to thaw slow-cooled bovine embryos it is standard practice to draw out permeating cryoprotectants by passing embryos through successively decreasing osmotic solutions. However, recently it has been suggested that sucrose may not be needed in the warming media. OBJECTIVE: The aim of this experiment was to compare the effect of warming media prepared with or without the inclusion of sucrose on the survival and hatching capacity of vitrified in vitro-derived bovine embryos. MATERIALS AND METHODS: Expanded blastocysts were produced in vitro and vitrified. Vitrified embryos were warmed either successively through 0.5, 0.3 and 0.2 M sucrose solutions ('stepwise'), or by placing directly into the blastocyst solution without the addition of sucrose ('direct'). A total of 93 expanded blastocysts were assigned randomly to two treatment groups, respectively. RESULTS: The re-expansion rates of vitrified embryos warmed after 24h in vitro culture were similar between the two groups (46/46, 100%; 46/47, 97.9%). From those vitrified embryos that expanded at 24 h there was also no significant difference in hatching rates after 48 h in vitro culture (42/46, 91.3%; 40/46, 87.0%). CONCLUSION: The findings indicate that stepwise warming through sucrose solutions is not required for continued embryo development. Hence, a more time-efficient warming method for vitrified embryos may be followed when conducting cattle embryo transfers.

Assessment of four experimental models of hyperlipidemia.

Various animal models of hyperlipidemia are used in research. Four rodent hyperlipidemia experimental models are examined in this study: three chronic hyperlipidemia models based on dietary supplementation with lipid or sucrose for 3 months and one acute hyperlipidemia model based on administration of the nonionic surfactant poloxamer. Neither lipid supplementation nor sucrose supplementation in Wistar rats was effective for establishing hyperlipidemia. Combining both lipid and sucrose supplementation in BALB/c mice induced hypercholesterolemia, as reflected in a considerable increase in blood cholesterol concentration, but did not produce an increase in blood triglyceride concentration. Poloxamer administration in C57BL/J6 mice produced increases in blood cholesterol and triglyceride concentrations. The authors conclude that supplementation of both lipid and sucrose in BALB/c mice was the most effective method for developing chronic hypercholesterolemia.

A re-assessment of sucrose signaling involved in cluster-root formation and function in phosphate-deficient white lupin (Lupinus albus).

Apart from substrate functions, a signaling role of sucrose in root growth regulation is well established. This raised the question whether sucrose signals might also be involved in formation of cluster-roots (CRs) under phosphate (Pi) limitation, mediating exudation of phosphorus (P)-mobilizing root exudates, e.g. in Lupinus albus and members of the Proteaceae. Earlier studies demonstrated that CR formation in L. albus was mimicked to some extent by external application of high sucrose concentrations (25 mM) in the presence of extremely high P supply (1-10 mM), usually suppressing CR formation. In this study, we re-addressed this question using an axenic hydroponic culture system with normal P supply (0.1 mM) and a range of sucrose applications (0.25-25 mM). The 2.5 mM sucrose concentration was comparable with internal sucrose levels in the zone of CR initiation in first-order laterals of P-deficient plants (3.4 mM) and induced the same CR morphology. Similar to earlier studies, high sucrose concentrations (25 mM) resulted in root thickening and inhibition of root elongation, associated with a 10-fold increase of the internal sucrose level. The sucrose analog palatinose and a combination of glucose/fructose failed to stimulate CR formation under P-sufficient conditions, demonstrating a signal function of sucrose and excluding osmotic or carbon source effects. In contrast to earlier findings, sucrose was able to induce CR formation but had no effect on CR functioning with respect to citrate exudation, in vitro activity and expression of genes encoding phosphoenolpyruvate carboxylase, secretory acid phosphatase and MATE transporters, mediating P-mobilizing functions of CRs.

Silver sucrose octasulfate (IASOS™) as a valid active ingredient into a novel vaginal gel against human vaginal pathogens: in vitro antimicrobial activity assessment.

This in vitro study assessed the antimicrobial properties of a novel octasilver salt of Sucrose Octasulfate (IASOS) as well as of an innovative vaginal gel containing IASOS (SilSOS Femme), against bacterial and yeast pathogens isolated from human clinical cases of symptomatic vaginal infections. In BHI and LAPT culture media, different ionic silver concentrations and different pHs were tested. IASOS exerted a strong antimicrobial activity towards all the pathogens tested in both culture media. The results demonstrated that salts and organic compounds present in the culture media influenced IASOS efficacy only to a moderate extent. Whereas comparable MBCs (Minimal Bactericidal Concentrations) were observed for G. vaginalis (10 mg/L Ag+), E. coli and E. aerogenes (25 mg/L Ag+) in both media, higher MBCs were found for S. aureus and S. agalactiae in LAPT cultures (50 mg/L Ag+ versus 25 mg/L Ag+). No minimal concentration totally inhibiting the growth of C. albicans was found. Nevertheless, in both media at the highest ionic silver concentrations (50-200 mg/L Ag+), a significant 34-52% drop in Candida growth was observed. pH differently affected the antimicrobial properties of IASOS against bacteria or yeasts; however, a stronger antimicrobial activity at pH higher than the physiological pH was generally observed. It can be therefore concluded that IASOS exerts a bactericidal action against all the tested bacteria and a clear fungistatic action against C. albicans. The antimicrobial activity of the whole vaginal gel SilSOS Femme further confirmed the antimicrobial activity of IASOS. Overall, our findings support IASOS as a valid active ingredient into a vaginal gel.

Cryopreservation of Thymus lotocephalus shoot tips and assessment of genetic stability.

BACKGROUND: Thymus lotocephalus is a rare endemic species from the Algarve, Portugal, and is legally protected by Portuguese and European legislation. OBJECTIVE: The aim is to develop a cryopreservation protocol for T. lotocephalus shoot tips, as an alternative approach for the long-term conservation of this species. METHODS: Several methods (droplet-vitrification, vitrification and encapsulation-dehydration) were tested. Conditions regarding the subculture period, cold-hardening and preculture were optimized. Cryopreserved shoot tips were also assessed for their genetic stability using RAPD markers. RESULTS: Droplet-vitrification presented the best results. The best regrowth of cryopreserved shoot tips obtained eight weeks after rewarming was 67%. This was accomplished with four weeks subculture period of in vitro-donor plants at 25 degree C, preculture of excised shoot tips for one day on MS medium containing 0.3 M sucrose, treatment in PVS2 for 60 min, and MS supplemented with 0.2 mg per L zeatin as recovery medium. The assessment using RAPD markers observed variation at a low frequency and shoots regenerated from cryopreserved apices showed normal development compared to the regular in vitro-grown shoots. CONCLUSION: Droplet-vitrification is thus a viable method for the cryopreservation of T. lotocephalus shoot tips.

Biotechnological valorization of low-cost sugar-based media for bacteriocin production by Leuconostoc mesenteroides E131.

The aim of the present study was to evaluate the suitability of low-cost carbon sources for bacteriocin production by Leuconostoc mesenteroides strain E131. For this purpose, inexpensive sugars derived from a sugar refinery plant (glucose, fructose and sucrose) as well as waste molasses were utilized as carbon sources in submerged shake-flask experiments and the kinetic response of the microorganism was evaluated. Interestingly, in the case of molasses, non-negligible decolorization-detoxification (up to ∼27%) of the residue was performed together with the production of bacteriocin. In all instances the initial concentration of sugars employed was adjusted at 20 and 30 g/L, therefore the effect of both the nature and the initial quantity of sugar upon the growth of the microorganism was assessed. All media proved to be suitable for both biomass and bacteriocin production by L. mesenteroides, whereas variable quantities of lactate, acetate and ethanol were detected into the medium. Employment of fructose, sucrose or molasses as carbon sources resulted in the accumulation of mannitol (in some cases in significant quantities) into the medium; remarkable portion thus of the available or released fructose acted as electron acceptor instead of carbon source by the microorganism. The highest bacteriocin production achieved (=640 AU/mL) was obtained when initial glucose at 30 g/L was used as substrate. Finally, utilization of waste molasses as carbon source by L. mesenteroides resulted in satisfactory bacteriocin production (up to 320 AU/mL) besides the decolorization of the residue.

Multimodal cues drive host-plant assessment in Asian citrus psyllid (Diaphorina citri).

Asian citrus psyllid (Diaphorina citri) transmits the causal agent of Huanglongbing, a devastating disease of citrus trees. In this study we measured behavioral responses of D. citri to combinations of visual, olfactory, and gustatory stimuli in test arenas. Stimuli were presented to the psyllids in droplets or lines of an emulsified wax formulation in two different arena types in no-choice tests. First, when placed on a colored ring situated halfway between the center and perimeter of a petri dish, D. citri spent more time on yellow versus gray rings; however, this response disappeared when either gray or yellow wax droplets were applied. When the psyllids were presented with droplets scented with terpenes, the response to both scent and color was increased. The addition of a dilute (≍0.1 M) sucrose solution to the wax droplets increased the magnitude of D. citri responses. Next, groups of D. citri were placed on plastic laboratory film covering a sucrose solution, to mimic a leaf surface. Test stimuli were presented via two 'midribs' made from lines of emulsified wax formulation. Probing levels were measured as a function of color saturation and scent composition, and concentration. The test scents were based on qualitatively major volatiles emitted by Murraya paniculata (L.) Jack, Citrus aurantifolia (Christm.) Swingle, and C. sinensis (L.) Osbeck. The highest probing response was observed on the middle concentration (20-µl scent/10 ml wax formulation) of the C. aurantifolia-scented wax lines. Results indicate that there are interactive effects between the different sensory modalities in directing host-plant assessment behavior.

Sensory response system of social behavior tied to female reproductive traits.

BACKGROUND: Honey bees display a complex set of anatomical, physiological, and behavioral traits that correlate with the colony storage of surplus pollen (pollen hoarding). We hypothesize that the association of these traits is a result of pleiotropy in a gene signaling network that was co-opted by natural selection to function in worker division of labor and foraging specialization. By acting on the gene network, selection can change a suite of traits, including stimulus/response relationships that affect individual foraging behavior and alter the colony level trait of pollen hoarding. The 'pollen-hoarding syndrome' of honey bees is the best documented syndrome of insect social organization. It can be exemplified as a link between reproductive anatomy (ovary size), physiology (yolk protein level), and foraging behavior in honey bee strains selected for pollen hoarding, a colony level trait. The syndrome gave rise to the forager-Reproductive Ground Plan Hypothesis (RGPH), which proposes that the regulatory control of foraging onset and foraging preference toward nectar or pollen was derived from a reproductive signaling network. This view was recently challenged. To resolve the controversy, we tested the associations between reproductive anatomy, physiology, and stimulus/response relationships of behavior in wild-type honey bees. METHODOLOGY/PRINCIPAL FINDINGS: Central to the stimulus/response relationships of honey bee foraging behavior and pollen hoarding is the behavioral trait of sensory sensitivity to sucrose (an important sugar in nectar). To test the linkage of reproductive traits and sensory response systems of social behavior, we measured sucrose responsiveness with the proboscis extension response (PER) assay and quantified ovary size and vitellogenin (yolk precursor) gene expression in 6-7-day-old bees by counting ovarioles (ovary filaments) and by using semiquantitative real time RT-PCR. We show that bees with larger ovaries (more ovarioles) are characterized by higher levels of vitellogenin mRNA expression and are more responsive to sucrose solutions, a trait that is central to division of labor and foraging specialization. CONCLUSIONS/SIGNIFICANCE: Our results establish that in wild-type honey bees, ovary size and vitellogenin mRNA level covary with the sucrose sensory response system, an important component of foraging behavior. This finding validates links between reproductive physiology and behavioral-trait associations of the pollen-hoarding syndrome of honey bees, and supports the forager-RGPH. Our data address a current evolutionary debate, and represent the first direct demonstration of the links between reproductive anatomy, physiology, and behavioral response systems that are central to the control of complex social behavior in insects.

Intravenous iron in chronic kidney disease: haemoglobin change shortly after treatment of patients neither on dialysis nor on erythropoietin.

Anaemia is a common in chronic kidney disease. Although erythropoietin and iron supplementation are established treatments, knowledge on the use of IV iron alone in patients not on dialysis or erythropoietin is incomplete. The responses of 82 patients referred to the renal anaemia service with haemoglobin of 11.5 g/dl or less were assessed 1 week after completing four once weekly doses of 200 mg of venofer. No patients were on dialysis or erythropoietin. The haemoglobin rise 1 week after treatment was 0.53 g/dl. Ferritin levels improved from 110.8 to 410.2 ng/l and transferrin saturation from 17.7 to 27.3%. Ferritin levels remained below our target range (200-500 ng/l) in 7.7% while 25.6% had levels above this. Ferritin levels remained less than 800 ng/l in nearly all patients. Intravenous iron is cost effective and should be considered for use in patients with renal anaemia. Patients with CKD stage 5 appeared to respond less well.

Mcl1p is a polymerase alpha replication accessory factor important for S-phase DNA damage survival.

Mcl1p is an essential fission yeast chromatin-binding protein that belongs to a family of highly conserved eukaryotic proteins important for sister chromatid cohesion. The essential function is believed to result from its role as a Pol1p (polymerase alpha) accessory protein, a conclusion based primarily on analogy to Ctf4p's interaction with Pol1p. In this study, we show that Mcl1p also binds to Pol1p with high affinity for the N terminus of Pol1p during S phase and DNA damage. Characterization of an inducible allele of mcl1+, (nmt41)mcl1-MH, shows that altered expression levels of Mcl1p lead to sensitivity to DNA-damaging agents and synthetic lethality with the replication checkpoint mutations rad3Delta, rqh1Delta, and hsk1-1312. Further, we find that the overexpression of the S-phase checkpoint kinase, Cds1, or the loss of Hsk1 kinase activity can disrupt Mcl1p's interaction with chromatin and Pol1p during replication arrest with hydroxyurea. We take these data to mean that Mcl1p is a dynamic component of the polymerase alpha complex during replication and is important for the replication stress response in fission yeast.

Barley anther culture: assessment of carbohydrate effects on embryo yield, green plant production and differential plastid development in relation with albinism.

Sugars and polyols were tested at different steps of anther culture in barley (Hordeum vulgare L.) to elucidate their influence on both the overall yield of androgenesis and the structure of plastids in relation to albinism. During the pretreatment period, the osmotic regulation in the medium was beneficial to microspore embryogenesis regardless of the type and concentration of the tested osmoticum. The use of mannitol (300 mOsm/kg), sorbitol (180 mOsm/kg), PEG (240 mOsm/kg) and sucrose (180 mOsm/kg) gave the best results in terms of green plant production, although the influence of each substance differed according to the studied parameter. Similarly, during anther culture the regulation of the osmotic pressure in the medium had various effects, according to the osmoticum used. The best results were obtained using mannitol (364 mOsm/kg), providing 139.7 green plants per 100 plated anthers. Plastids were examined by electron microscopy following both pretreatment and culture. In the presence of mannitol and PEG, plastids did not accumulate starch at any stage of the protocol but they started to differentiate into chloroplasts in the microspore-derived embryos. Using sorbitol and sucrose, plastids differentiated poorly but accumulated large amounts of starch, suggesting that these sugars are metabolized by micropores and microspore derived structures. However, the accumulation of starch was not correlated with the occurrence of albinism. These results indicated that, in barley, the osmotic regulation was favourable to switch the microspore gametophytic program toward a sporophytic program regardless of the nature of the osmoticum. In addition, during the pretreatment period, mannito was found to be the most suitable osmoticum for subsequent embryo development.

Assessment of sucrose and ethanol reinforcement: the across-session breakpoint procedure.

We have demonstrated previously that the use of an across-session progressive ratio procedure yields breakpoint values for 10% ethanol (10E) that are stable and comparable to those measured for other drugs of abuse [Alcohol. Clin. Exp. Res. 23 (1999) 1580]. The aims of the present experiment were twofold: (1). to determine whether this procedure is sensitive to changes in reinforcer magnitude using a reinforcer previously demonstrated to affect operant responding in a predictable fashion and (2). to determine whether ethanol reinforcement produced similar changes in behavior. Male, Long-Evans rats were trained to respond for either 3% sucrose (3S) or 10E using the sipper tube appetitive/consummatory procedure where the completion of a single response requirement results in access to a liquid solution for 20 min. Three successive breakpoints were determined for this "baseline" solution by increasing the response requirement each day until it was not completed. The concentration of the solutions was then manipulated such that breakpoints for the Sucrose Group were assessed for 1%, 3%, 5% and 10% sucrose, and breakpoints for the Ethanol Group were assessed for 2%, 5%, 10% and 20% ethanol. The concentration manipulation showed that sucrose concentration had a greater impact on seeking and consumption than did ethanol concentration. Breakpoints in the Sucrose Group were highly correlated with sucrose concentration, whereas in the Ethanol Group, breakpoint was unrelated to ethanol concentration. Ethanol intake patterns suggested that pharmacological factors might have been regulating intake, and that when physiologically detectable amounts of ethanol were consumed, there was a dissociation between seeking and intake with slightly elevated ethanol seeking. Overall, the across-session breakpoint procedure confirmed that sweet taste was highly related to seeking and consumption, whereas ethanol-motivated responding may be controlled by different regulatory mechanisms that are distinct to seeking and consumption.