Biphasic Response Research Articles

Experimental arena size alters larval zebrafish photolocomotor behaviors and influences bioactivity responses to a model neurostimulant

Zebrafish behavior is increasingly common in biomedical and environmental studies of chemical bioactivity. Multiple experimental arena sizes have been used to measure photolocomotion in zebrafish depending on age, endpoints observed, and instrumentation, among other factors. However, the extent to which methodological parameters may influence naïve behavioral performance and detection of behavioral changes is poorly understood. Here we measured photolocomotion and behavioral profiles of naïve larval zebrafish across arena sizes. We then performed concentration response studies with the model neurostimulant caffeine, again across various arena dimensions. We found total swimming distance of unexposed fish to increase logarithmically with arena size, which as related to circumference, area, and volume. Photomotor response during light/dark transitions also increased with arena size. Following caffeine exposure, total distance travelled was significantly (p < 0.001) affected by well size, caffeine treatment (p < 0.001), and the interaction of these two experimental factors (p < 0.001). In addition, behavioral response profiles showed differences between 96 well plates and larger well sizes. Biphasic response, with stimulation at lower concentrations and refraction at the highest concentration, was observed in dark conditions for the 96 well size only, though almost no effects were identified in the light. However, swimming behavior was significantly (p < 0.1) altered in the highest studied caffeine treatment level in larger well sizes during both light and dark periods. Our results indicate zebrafish swim more in larger arenas and arena size influences behavioral response profiles to caffeine, though differences were mostly observed between very small and large arenas. Further, careful consideration should be given when choosing arena size, because small wells may lead to restriction, while larger wells may differentially reflect biologically relevant effects. These findings can improve comparability among experimental designs and demonstrates the importance of understanding confounding methodological variables.

Mechanisms of biphasic surges of testosterone in response to human chorionic gonadotrophin (hCG) in stallions

Human chorionic gonadotrophin (hCG) is included in stimulation tests for diagnosis of cryptorchidism and endocrine function of testes in stallions. Although the exact mechanisms are unknown, circulating testosterone (T) concentration shows a clear biphasic increase in response to a single administration of hCG (Tsunoda. et. al. Animal Reproduction Science. 2010; 121S: S165-S167). In the first experiment, concentrations of circulating T and estradiol-17β (E) in response to intravenous administration of 10,000IU hCG were measured. Concentrations of circulating testosterone were also measured in adult Thoroughbred stallions (n=4). In the second experiment, the same experiment was done using adult male golden hamsters (n=45) to figure out mechanisms of biphasic response of T. Adult male golden hamsters were used as a model of stallions, because golden hamsters are typical long day seasonal breeders same as stallions. In the first experiment, blood samples were taken hourly for 6 hours, and daily for 7 days after administration of hCG. Circulating T concentrations in stallions showed a clear biphasic increase within 6 hours and between 2 and 4 days after administration of hCG. Circulating T concentrations at the second peak were significantly higher than those at the first peak. Circulating E concentrations after hCG administration was similar to that of T at the first peak, though the second increase was not detected. Circulating hCG concentrations sharplyincreased just after administration, then followed by an abrupt decline, and low levels were maintained until day 7. It indicated that concentrations of hCG decreased completely when the second peak of T concentrations appeared in circulation. In the second experiment, 25 male golden hamsters were administered 100IU of hCG, and 20 hamsters were administered saline. Blood samples and testes were taken from 5 golden hamsters 5 hours, 24 hours, 3, 5, and 7 days after administration, respectively. Testicular tissues were investigated by real-time PCR for cytochrome P450scc (P450scc), 3β-hydroxy-steroid dehydrogenase (3β-HSD), 17β-hydroxysteroid dehydrogenase (17β-HSD), and receptors of luteinizing hormone (LHR). Testes were also histologically evaluated by hematoxylin-eosin staining. The results of changes in circulating T and hCG concentrations in male golden hamsters were similar to those in stallions. Expression of P450cc, 3β-HSD, 17β-HSD and number of LHR in testes 3 days after administrations of hCG were significantly higher as compared with those at 0 hour. The number of Leydig cells in the histological section 3 days after administration of hCG were also higher compared to 0 hour. The present study strongly suggests that the increase in numbers of LHR and Leydig cells, together with upregulation of steroid enzymes in testes causes the second increase of T plasma concentration after hCG in stallions.

Hormesis Responses of Photosystem II in Arabidopsis thaliana under Water Deficit Stress.

Since drought stress is one of the key risks for the future of agriculture, exploring the molecular mechanisms of photosynthetic responses to water deficit stress is, therefore, fundamental. By using chlorophyll fluorescence imaging analysis, we evaluated the responses of photosystem II (PSII) photochemistry in young and mature leaves of Arabidopsis thaliana Col-0 (cv Columbia-0) at the onset of water deficit stress (OnWDS) and under mild water deficit stress (MiWDS) and moderate water deficit stress (MoWDS). Moreover, we tried to illuminate the underlying mechanisms in the differential response of PSII in young and mature leaves to water deficit stress in the model plant A. thaliana. Water deficit stress induced a hormetic dose response of PSII function in both leaf types. A U-shaped biphasic response curve of the effective quantum yield of PSII photochemistry (ΦPSII) in A. thaliana young and mature leaves was observed, with an inhibition at MiWDS that was followed by an increase in ΦPSII at MoWDS. Young leaves exhibited lower oxidative stress, evaluated by malondialdehyde (MDA), and higher levels of anthocyanin content compared to mature leaves under both MiWDS (+16%) and MoWDS (+20%). The higher ΦPSII of young leaves resulted in a decreased quantum yield of non-regulated energy loss in PSII (ΦNO), under both MiWDS (-13%) and MoWDS (-19%), compared to mature leaves. Since ΦNO represents singlet-excited oxygen (1O2) generation, this decrease resulted in lower excess excitation energy at PSII, in young leaves under both MiWDS (-10%) and MoWDS (-23%), compared to mature leaves. The hormetic response of PSII function in both young and mature leaves is suggested to be triggered, under MiWDS, by the intensified reactive oxygen species (ROS) generation, which is considered to be beneficial for activating stress defense responses. This stress defense response that was induced at MiWDS triggered an acclimation response in A. thaliana young leaves and provided tolerance to PSII when water deficit stress became more severe (MoWDS). We concluded that the hormesis responses of PSII in A. thaliana under water deficit stress are regulated by the leaf developmental stage that modulates anthocyanin accumulation in a stress-dependent dose.

Expected and Unexpected Effects of Pharmacological Antioxidants.

In this review, we have collected the existing data on the bioactivity of antioxidants (N-acetylcysteine, polyphenols, vitamin C) which are traditionally used in experimental biology and, in some cases, in the clinic. Presented data show that, despite the capacity of these substances to scavenge peroxides and free radicals in cell-free systems, their ability to exhibit these properties in vivo, upon pharmacological supplementation, has not been confirmed so far. Their cytoprotective activity is explained mainly by the ability not to suppress, but to activate multiple redox pathways, which causes biphasic hormetic responses and highly pleiotropic effects in cells. N-acetylcysteine, polyphenols, and vitamin C affect redox homeostasis by generating low-molecular-weight redox-active compounds (H2O2 or H2S), known for their ability to stimulate cellular endogenous antioxidant defense and promote cytoprotection at low concentrations but exert deleterious effects at high concentrations. Moreover, the activity of antioxidants strongly depends on the biological context and mode of their application. We show here that considering the biphasic and context-dependent response of cells on the pleiotropic action of antioxidants can help explain many of the conflicting results obtained in basic and applied research and build a more logical strategy for their use.

The hemodynamic initial-dip consists of both volumetric and oxymetric changes reflecting localized spiking activity.

The initial-dip is a transient decrease frequently observed in functional neuroimaging signals, immediately after stimulus onset, believed to originate from a rise in deoxy-hemoglobin (HbR) caused by local neural activity. It has been shown to be more spatially specific than the hemodynamic response, and is believed to represent focal neuronal activity. However, despite being observed in various neuroimaging modalities (such as fMRI, fNIRS, etc), its origins are disputed, and its precise neuronal correlates are unknown. Here we show that the initial-dip is dominated by a decrease in total-hemoglobin (HbT). We also find a biphasic response in deoxy-Hb (HbR), with an early decrease and later rebound. Both the HbT-dip and HbR-rebound were strongly correlated to highly localized spiking activity. However, HbT decreases were always large enough to counter the spiking-induced increase in HbR. We find that the HbT-dip counters spiking induced HbR increases, imposing an upper-limit to HbR concentration in the capillaries. Building on our results, we explore the possibility of active venule dilation (purging) as a possible mechanism for the HbT dip.

A challenging-to-manage biphasic response following pituitary surgery for acromegaly

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

A Case Report of Acute Onset and Rapid Resolution of Atrioventricular Block After Sugammadex: Is the Autonomic System Involved?

Administering sugammadex to reverse neuromuscular blockade can cause marked bradycardia and rarely asystole. In this case, a rapid onset, biphasic heart rate response; slowing then speeding, after administering sugammadex was noted while at steady state, 1.3% end-tidal sevoflurane. On review of the electrocardiogram (ECG), the heart rate slowing coincided with the onset of a second-degree, Mobitz type I block that lasted 45 seconds. No other events, drugs, or stimuli coincided with the event. The acute onset and transient nature of the atrioventricular block without evidence of ischemia implies a brief parasympathetic effect on the atrioventricular node after sugammadex administration.

A network-based model of dynamic cerebral autoregulation.

Cerebrovascular diseases continue to be one of the leading causes of morbidity and mortality in humans. Abnormalities in dynamic cerebral autoregulation (dCA) have been implicated in many of these disease conditions. Accurate models are therefore needed to better understand the complex pathophysiology behind impaired dCA. We thus present here a simple framework for modelling a vessel-driven network model of dCA in the microvasculature, as opposed to the conventional compartmental modelling approach. Network models incorporate the actual connectivity and anatomy of the vasculature, thereby allowing us to include and trace changes in the calibre and morphology of individual vessels, investigate the spatial specificity and heterogeneity of the various control mechanisms to help disentangle their contributions, and link the model parameters to the actual network physiology. The proposed control feedback mechanisms are incorporated at the level of the individual vessel, and the dynamic pressure and flow fields are solved for here within a simple vessel network. In response to an upstream pressure drop, the network is found to be able to recover cerebral blood flow (CBF) while exhibiting the characteristic autoregulatory behaviour in terms of changes in vessel calibre and the biphasic flow response. We assess the feasibility of our formulation in larger networks by comparing the simulation results to those obtained using a one-dimensional (1D) model of CBF applied to the same microvasculature network and find that our model results are in very good agreement with the 1D solution, while significantly reducing the computational cost, thus enabling more detailed models of network behaviour to be adopted in the future. Accurate and computationally feasible models of dCA that are more representative of the vasculature can help increase the translatability of haemodynamic models into the clinical environment, which would help develop more informed treatment guidelines for patients with cerebrovascular diseases.

IgE-mediated cow’s milk allergy in Brazilian children: Outcomes of oral food challenge

BackgroundOral food challenge (OFC) is useful for diagnosing food allergies and assessing tolerance, but severe reactions may occur during the procedure. ObjectiveTo characterize the frequency and severity of reactions during cow's milk (CM) OFCs. MethodsA cross-sectional study was conducted to analyze the outcome of cow's milk oral food challenges (CMOFCs) performed to confirm IgE-mediated CM allergy or to assess food tolerance. CM was given first as baked milk (BM), followed by whole CM if there was no prior reaction to BM. An OFC was considered positive if IgE-mediated symptoms developed up to 2 h after ingestion. Symptoms were described and variables including age at OFC, prior anaphylaxis, other atopic diseases, and skin test results were compared according to the OFC outcomes. ResultsA total of 266 CMOFCs were performed, including 159 patients with a median age of 6.3 years old. One hundred thirty-six tests were positive and 62 resulted in anaphylaxis. Thirty-nine anaphylactic reactions were observed up to 30 min after the first dose. Severe anaphylaxis (cardiovascular and/or neurological involvement) was reported in 5 tests. A second dose of epinephrine was required in 3 tests, and 1 presented a biphasic response. Younger patients had a higher risk of anaphylaxis during baked milk oral food challenge (BMOFC) (p = 0.009). The frequency of anaphylaxis was higher in patients submitted to BM (p = 0.009). ConclusionsAnaphylaxis is a known complication of CMOFCs even when there is no prior anaphylaxis or when conducted with baked products. This study reinforces the importance of conducting OFC in appropriate settings with a well-trained team.

Parvalbumin interneuron activity drives fast inhibition-induced vasoconstriction followed by slow substance P-mediated vasodilation

The role of parvalbumin (PV) interneurons in vascular control is poorly understood. Here, we investigated the hemodynamic responses elicited by optogenetic stimulation of PV interneurons using electrophysiology, functional magnetic resonance imaging (fMRI), wide-field optical imaging (OIS), and pharmacological applications. As a control, forepaw stimulation was used. Stimulation of PV interneurons in the somatosensory cortex evoked a biphasic fMRI response in the photostimulation site and negative fMRI signals in projection regions. Activation of PV neurons engaged two separable neurovascular mechanisms in the stimulation site. First, an early vasoconstrictive response caused by the PV-driven inhibition is sensitive to the brain state affected by anesthesia or wakefulness. Second, a later ultraslow vasodilation lasting a minute is closely dependent on the sum of interneuron multiunit activities, but is not due to increased metabolism, neural or vascular rebound, or increased glial activity. The ultraslow response is mediated by neuropeptide substance P (SP) released from PV neurons under anesthesia, but disappears during wakefulness, suggesting that SP signaling is important for vascular regulation during sleep. Our findings provide a comprehensive perspective about the role of PV neurons in controlling the vascular response.

Four class A AUXIN RESPONSE FACTORs promote tomato fruit growth despite suppressing fruit set.

In flowering plants, auxin produced in seeds after fertilization promotes fruit initiation. The application of auxin to unpollinated ovaries can also induce parthenocarpy (seedless fruit production). Previous studies have shown that auxin signalling components SlIAA9 and SlARF7 (a class A AUXIN RESPONSE FACTOR (ARF)) are key repressors of fruit initiation in tomato (Solanum lycopersicum). A similar repressive role of class A ARFs in fruit set has also been observed in other plant species. However, evidence is lacking for a role of any class A ARF in promoting fruit development as predicted in the current auxin signalling model. Here we generated higher-order tomato mutants of four class A SlARFs (SlARF5, SlARF7, SlARF8A and SlARF8B) and uncovered their precise combinatorial roles that lead to suppressing and promoting fruit development. All four class A SlARFs together with SlIAA9 inhibited fruit initiation but promoted subsequent fruit growth. Transgenic tomato lines expressing truncated SlARF8A/8B lacking the IAA9-interacting PB1 domain displayed strong parthenocarpy, further confirming the promoting role of SlARF8A/8B in fruit growth. Altering the doses of these four SlARFs led to biphasic fruit growth responses, showing their versatile dual roles as both negative and positive regulators. RNA-seq and chromatin immunoprecipitation-quantitative PCR analyses further identified SlARF8A/8B target genes, including those encoding MADS-BOX transcription factors (AG1, MADS2 and AGL6) that are key repressors of fruit set. These results support the idea that SlIAA9/SlARFs directly regulate the transcription of these MADS-BOX genes to inhibit fruit set. Our study reveals the previously unknown dual function of four class A SlARFs in tomato fruit development and illuminates the complex combinatorial effects of multiple ARFs in controlling auxin-mediated fruit set and fruit growth.

Multi-Region Microdialysis Imaging Platform Revealed Dorsal Raphe Nucleus Calcium Signaling and Serotonin Dynamics during Nociceptive Pain

In this research, we combined our ultralight micro-imaging device for calcium imaging with microdialysis to simultaneously visualize neural activity in the dorsal raphe nucleus (DRN) and measure serotonin release in the central nucleus of the amygdala (CeA) and the anterior cingulate cortex (ACC). Using this platform, we observed brain activity following nociception induced by formalin injection in the mouse's hind paw. Our device showed that DRN fluorescence intensity increased after formalin injection, and the increase was highly correlated with the elevation in serotonin release in both the CeA and ACC. The increase in calcium fluorescence intensity occurred during the acute and inflammatory phases, which suggests the biphasic response of nociceptive pain. Furthermore, we found that the increase in fluorescence intensity was positively correlated with mouse licking behavior. Lastly, we compared the laterality of pain stimulation and found that DRN fluorescence activity was higher for contralateral stimulation. Microdialysis showed that CeA serotonin concentration increased only after contralateral stimulation, while ACC serotonin release responded bilaterally. In conclusion, our study not only revealed the inter-regional serotonergic connection among the DRN, the CeA, and the ACC, but also demonstrated that our device is feasible for multi-site implantation in conjunction with a microdialysis system, allowing the simultaneous multi-modal observation of different regions in the brain.

The pattern of brain oxygen response induced by intravenous fentanyl limits the time window of therapeutic efficacy of naloxone

Opioids induce respiratory depression resulting in coma or even death during overdose. Naloxone, an opioid antagonist, is the gold standard reversal agent for opioid intoxication, but this treatment is often less successful for fentanyl. While low dosing is thought to be a factor limiting naloxone's efficacy, the timing between fentanyl exposure and initiation of naloxone treatment may be another important factor. Here, we used oxygen sensors coupled with amperometry to examine the pattern of oxygen responses in the brain and periphery induced by intravenous fentanyl in freely moving rats. At both doses (20 and 60 μg/kg), fentanyl induced a biphasic brain oxygen response—a rapid, strong, and relatively transient decrease (8–12 min) followed by a weaker and prolonged increase. In contrast, fentanyl induced stronger and more prolonged monophasic oxygen decreases in the periphery. When administered before fentanyl, intravenous naloxone (0.2 mg/kg) fully blocked the hypoxic effects of moderate-dose fentanyl in both the brain and periphery. However, when injected 10 min after fentanyl, when most of hypoxia had already ceased, naloxone had minimal effect on central and peripheral oxygen levels, but at a higher dose, it strongly attenuated hypoxic effects in the periphery with only a transient brain oxygen increase associated with behavioral awakening. Therefore, due to the rapid, strong but transient nature of fentanyl-induced brain hypoxia, the time window when naloxone can attenuate this effect is relatively short. This timing limitation is critical, making naloxone most effective when used quickly and less effective when used during the post-hypoxic comatose state after brain hypoxia has already ceased and harm for neural cells already done.

TRPV6 Calcium Channel Targeting by Antibodies Raised against Extracellular Epitopes Induces Prostate Cancer Cell Apoptosis

The TRPV6 calcium channel is known to be up-regulated in various tumors. The efforts to target the TRPV6 channel in vivo are still ongoing to propose an effective therapy against cancer. Here, we report the generation of two antibodies raised against extracellular epitopes corresponding to the extracellular loop between S1 and S2 (rb79) and the pore region (rb82). These antibodies generated a complex biphasic response with the transient activation of the TRPV6 channel. Store-operated calcium entry was consequently potentiated in the prostate cancer cell line LNCaP upon the treatment. Both rb79 and rb82 antibodies significantly decreased cell survival rate in a dose-dependent manner as compared to the control antibodies of the same isotype. This decrease was due to the enhanced cell death via apoptosis revealed using a sub-G1 peak in a cell cycle assay, TUNEL assay, and a Hoechst staining, having no effects in the PC3Mtrpv6-/- cell line. Moreover, all TUNEL-positive cells had TRPV6 membrane staining as compared to the control antibody treatment where TRPV6-positive cells were all TUNEL negative. These data clearly demonstrate that TRPV6 channel targeting using rb79 and rb82 antibodies is fatal and may be successfully used in the anticancer therapies.

Naringin promotes positive inotropism in atrial tissue through β-AR/PKA-dependent pathway

Naringin is a flavonoid glycoside found in citrus fruits and grapes with a wide range of therapeutic actions. We aimed to study the inotropic effect of naringin on rat-isolated atria, dissecting intracellular mechanisms involved in this response. Concentration-response curves of naringin (0.003-6 mM) were obtained before and after pre-incubation with selective antagonists. Our results showed that naringin presented a biphasic inotropic response, with a positive inotropic effect at low and middle concentrations (0.003-2.0 mM), and a negative inotropic effect at high concentrations (above 3 mM). Pre-incubation with propranolol or atenolol (β-adrenergic receptors antagonists, β-AR), H89 (protein kinase-A inhibitor, PKA), nifedipine (L-type Ca2+ channel blocker), or ryanodine (ryanodine receptor inhibitor) fully abolished the positive inotropic effect induced by naringin. Pre-treatment of animals with reserpine, catecholamine-depleting drug, also prevented the increase of atrial contractility evoked by naringin. Altogether, we show that naringin causes a positive inotropic effect in isolated atria through β-AR/PKA-dependent pathway.

Coupling of Zinc Dose to Frequency in a Regularly Recurrent Pattern Shows a Limited Capacity of Excessive Dietary Zinc to Compensate for a Previously Deficient Intake

The impact of feeding a proportional dose of zinc in a regularly recurrent pattern (idiorrhythmic feeding) on body growth of weanling rats was studied to assess the extent to which an intake exceeding the requirement could compensate for a previously deficient intake. The idiorrhythmic regimen (I) was designed so that the overall dose-time equivalent (modulo; Mx) was kept constant over a selected period of time (epoch; E), whereas the actual dose and frequency varied regularly according to a predetermined pattern; that is, I = dnth(Mx)/dnth, where Mx and dnth are the selected dose-time equivalent and the sequential number of zinc-dosing days, respectively. For example, 3 mg Zn·kg-1 diet fed every day (I = 3/1) and 24 mg Zn·kg-1 diet fed 1 d in an 8-d period (7 d of feeding a zinc-deficient diet) (I = 24/8) are dose-time equivalents because they both provide 72 mg Zn·kg-1 over a 24-d E. Modulos of M3, M6, M12 and M24 were used, which provided 3, 6, 12 and 24 mg Zn·kg-1·d-1 dose-time equivalents during a 24-d E. Each modulo had seven analogous idiorrhythms: I = Mx/1, 2Mx/2, 3Mx/3, 4Mx/4, 5Mx/5, 6Mx/6 and 8Mx/8; for example, with 8 Mx/8, 24, 48, 96 or 192 mg Zn·kg-1 diet was fed every 8th d; on the other 7 d a diet without a zinc supplement was fed for M3, M6, M12 and M24, respectively. Zinc dose-rate idiorrhythm generated a complex, gestalt-like, biphasic growth response pattern where an intake of dietary zinc exceeding requirements had either no effect (M3 or average of 3 mg kg-1 diet) or fully compensated for only 1 (M6 and M12 or average of 6 and 12 mg Zn·kg-1 diet) or 2 (M24 or average of 24 mg Zn·kg-1 diet) d.

Differences in the Basal Flow and Occlusion-induced Reactive Hyperemia of the Apical and Non-apical Cutaneous Microcirculation. Effect of Botulinum Toxin

Introduction: In general, two types of skin are distinguished: apical (glabrous, A) and non-apical (hairy, NA), but less is known regarding the differences in their microcirculation. Thus we aimed to measure changes in subcutaneous microcirculation in these two skin types and its modulation by botulinum toxin (BT). Materials and Methods: Perimed 5000 Laser Doppler flowmetry was used to measure the perfusion (perfusion unit, PU) of skin in the temporal (A) and lower arm (NA) regions. The temporal artery or the upper arm was occluded for 2 min, then released, which was followed by reactive hyperemia. Also the effects of 25 IU BT injected under the forehead skin on PU were observed. Results: In the skin of temporal region PU changed from control PU: 73,01±15,4 to occlusion: 51,64±7,16, then after release to 110,76±22,56. In the skin of upper arm, PU changed from control PU: 10,4±1,2, to occlusion: 1.9±05, then after release to 48,8±25,5. In the forehead skin BT elicited a biphasic response then PU returned close to control, whereas BT inhibited reactive hyperemia; PU changed from 70,63 ±16,08 to occlusion 55,73 ± 6,75 and after release to 71,37±29,22. Conclusion: Thus there is 1) a higher level of microcirculation in the temporal region of the forehead skin than that of the forearm, 2) ischemia/reperfusion elicited greater reactive hyperemia (RH) in the forearm skin then in the temporal skin 3) BT interferes with the mechanisms eliciting reactive hyperemia.

11β-Hydroxysteroid dehydrogenase type 1 amplifies inflammation in LPS-induced THP-1 cells.

The role of glucocorticoids as anti-inflammatory and immune-stimulatory drugs has been widely reported. However, the role of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which catalyzes the conversion of inactive cortisone into active cortisol, in inflammation remains unclear. This study aimed to examine the mechanism of actions of 11β-HSD1 in lipopolysaccharide (LPS)-induced THP-1 cells. The gene expression of 11β-HSD1 and pro-inflammatory cytokines was detected via RT-PCR. The protein expression of IL-1β in cell supernatants was detected via ELISA. Oxidative stress and mitochondrial membrane potential were assessed using a reactive oxygen species (ROS) kit and a mitochondrial membrane potential (MMP) kit, respectively. The expression of Nuclear Factor- Kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) was detected via western blotting. Elevated levels of 11β-HSD1 contributed to the expression of inflammatory cytokines, whereas BVT.2733, a selective 11β-HSD1 inhibitor, ameliorated inflammatory responses, ROS, and mitochondrial damage in LPS-stimulated THP-1 cells. Furthermore, cortisone and cortisol, which are the substrate and product of 11β-HSD1, respectively, showed biphasic responses and induced the expression of pro-inflammatory cytokines at a low concentration in both LPS-stimulated or untreated THP-1 cells. The enhanced inflammation was attenuated by co-treatment with BVT.2733 and the glucocorticoid receptor (GR) antagonist RU486, but not in those treated with the mineralocorticoid receptor (MR) antagonist spironolactone. Overall, the results indicate that 11β-HSD1 amplifies inflammatory responses by activating the NF-κB and MAPK signaling pathways. Inhibition of 11β-HSD1 may serve as a potential therapeutic target against the excessive activation of inflammation.

Corn Oil, Palm Oil and Butterfat Fractions Affect Postprandial Lipemia and Lipoprotein Lipase in Meal-Fed Rats

Our objective was to investigate the time course of postprandial lipemia and lipolytic activity in male Sprague-Dawley rats trained to eat meals containing butterfat fractions, palm oil or corn oil. Baseline and postprandial blood samples were obtained via a carotid cannula in rats fed the experimental diets for 4 wk. Rats fed saturated fats compared with corn oil showed a significantly greater peak increase in postprandial triacylglycerol concentrations. Corn oil ingestion resulted in significantly lower concentrations of cholesterol and triacylglycerol in plasma and significantly less triacylglycerol accumulation (millimoles per liter per 24 h) compared with ingestion of saturated fats. Postheparin plasma lipoprotein lipase activity and plasma insulin concentration were generally greater with ingestion of corn oil compared with palm oil or butterfat. Palm oil ingestion resulted in a biphasic plasma triacylglycerol response curve and greater postheparin plasma lipoprotein lipase activity compared with butterfat ingestion, suggesting differential effects of saturated fats on postprandial lipemia. Our results indicate that greater postprandial lipemia with ingestion of saturated fats compared with corn oil may be due in part to slower plasma triacylglycerol clearance.

Focus on the Use of Resveratrol in Bladder Cancer.

Bladder cancer is the most common tumor of the urinary system, with a high incidence in the male population. Surgery and intravesical instillations can eradicate it, although recurrences are very common, with possible progression. For this reason, adjuvant therapy should be considered in all patients. Resveratrol displays a biphasic dose response both in vitro and in vivo (intravesical application) with an antiproliferative effect at high concentrations and antiangiogenic action in vivo (intraperitoneal application) at a low concentration, suggesting a potential role for it in clinical management as an adjuvant to conventional therapy. In this review, we examine the standard therapeutical approach to bladder cancer and the preclinical studies that have investigated resveratrol in xenotransplantation models of bladder cancer. Molecular signals are also discussed, with a particular focus on the STAT3 pathway and angiogenic growth factor modulation.