Tze-Fun Lee

Identification and Determination of Geniposide, Genipin, Gardenoside, and Geniposidic Acid from Herbs by HPLC/Photodiode-Array Detection

Abstract An improved high-performance liquid chromatographic technique with photodiode-array detection was developed for the identification and determination of the active components geniposide, genipin, gardenoside and geniposidic acid from Gardenia jasminoides Ellis and Gardenia jasminoides Ellis var. grandiflora Nakai. An isocratic system consisting of a reverse-phase phenyl column with a mobile phase of acetonitrile-water-perchloric acid (6:94:0.1. v/v/v, pH 4.0) was used to elute the active ingredients. Variations in extraction methods found that 0.1 M HCl is the best extraction solvent for geniposide and genipin, 0.1 M NaOH for geniposidic acid and water for gardenoside. It was found that water extracts of Gardenia jasminoides Ellis contained 56.03 ± 0.62, 1.72 ± 0.01, 2.16 ± 0.04 and 1.79 ± 0.01 mg/g of geniposide, genipin, gardenoside and geniposidic acid respectively. Gardenia jasminoides Ellis var. grandiflora Nakai, however contained 79.76 ± 0.62. 1.88 ± 0.04, 3.37 ± 0.21 and 6.38 ± 0.13 mg/g.

Cardiopulmonary resuscitation with chest compressions during sustained inflations: a new technique of neonatal resuscitation that improves recovery and survival in a neonatal porcine model.

Background— Guidelines on neonatal resuscitation recommend 90 chest compressions (CCs) and 30 manual inflations (3:1) per minute in newborns. The study aimed to determine whether CC s during sustained inflations (SIs) improves the recovery of asphyxiated newborn piglets in comparison with coordinated 3:1 resuscitation. Methods and Results— Term newborn piglets (n=8/group) were anesthetized, intubated, instrumented, and exposed to 45-minute normocapnic hypoxia followed by asphyxia. Piglets were randomly assigned to receive either 3:1 resuscitation (3:1 group) or CCs during SIs (SI group) when the heart rate decreased to 25% of baseline. Piglets randomly assigned to the SI group received SIs with a pressure of 30 cm H2O for 30 s. During the SI, CCs at a rate of 120/min were provided. SI was interrupted after 30 s for 1 s before a further 30-s SI was provided. CCs were continued throughout SIs. CCs and SI were continued until the return of spontaneous circulation. Continuous respiratory parameters, cardiac output, mean systemic and pulmonary artery pressures, and regional blood flows were measured. Mean (standard deviation) time for return of spontaneous circulation was significantly reduced in SI group versus 3:1 group (32 [11] s versus 205 [113] s, respectively). In the SI group, administration of oxygen and epinephrine was significantly lower, whereas minute ventilation and exhaled CO2 were significantly increased. The SI group had significantly higher mean systemic and pulmonary arterial pressures during resuscitation in comparison with the 3:1 group (51 [10] versus 31 [5] mm Hg; 41[7] versus 31 [7] mm Hg, respectively; all P<0.05), with improved cardiac output and carotid blood flow. Conclusions— Combining CCs and SIs significantly improved the return of spontaneous circulation with better hemodynamic recovery in asphyxiated newborn piglets in comparison with standard coordinated 3:1 resuscitation.

Thermoregulatory effects of alkaloids isolated from Wu-chu-yu in afebrile and febrile rats

Dehydroevodiamine (DeHE) and evodiamine (EVO), alkaloids isolated from a Chinese medicinal herb, Wu-chu-yu, exhibit calcium antagonistic activity. Intraperitoneal injections of DeHE (5-20 mg/kg) and EVO (2.5-10 mg/kg) caused a dose-related hypothermia in afebrile rats at an ambient temperature (Ta) of 20 degrees C. Because the heat production of alkaloid-injected rats did not differ from that of the controls, the hypothermic effect likely resulted from increased peripheral heat loss. This suggestion is supported by the finding that both DeHE and EVO did not affect the thermoregulatory response of rats exposed to a Ta of 35 degrees C, at which heat loss was maximized. Injection of the same doses of DeHE and EVO attenuated the febrile response in a dose-related manner, induced by intrahypothalamic injection of exogenous pyrogen. The attenuation of the febrile response was associated with a reduction in heat production. Because DeHE and EVO did not affect HP in afebrile rats at a Ta of either 20 or 35 degrees C, but suppressed the metabolic rate of febrile rats at 20 degrees C, the thermoregulatory effect of DeHE and EVO could involve both a calcium-dependent increase in heat loss and a suppression in heat production; the latter may only be manifested when the set point for thermoregulation is elevated.

3:1 Compression to ventilation ratio versus continuous chest compression with asynchronous ventilation in a porcine model of neonatal resuscitation

OBJECTIVE In contrast to the resuscitation guidelines of children and adults, guidelines on neonatal resuscitation recommend synchronized 90 chest compressions with 30 manual inflations (3:1) per minute in newborn infants. The study aimed to determine if chest compression with asynchronous ventilation improves the recovery of bradycardic asphyxiated newborn piglets compared to 3:1 Compression:Ventilation cardiopulmonary resuscitation (CPR). INTERVENTION AND MEASUREMENTS Term newborn piglets (n=8/group) were anesthetized, intubated, instrumented and exposed to 45-min normocapnic hypoxia followed by asphyxia. Protocolized resuscitation was initiated when heart rate decreased to 25% of baseline. Piglets were randomized to receive resuscitation with either 3:1 compressions to ventilations (3:1C:V CPR group) or chest compressions with asynchronous ventilations (CCaV) or sham. Continuous respiratory parameters (Respironics NM3(®)), cardiac output, mean systemic and pulmonary artery pressures, and regional blood flows were measured. MAIN RESULTS Piglets in 3:1C:V CPR and CCaV CPR groups had similar time to return of spontaneous circulation, survival rates, hemodynamic and respiratory parameters during CPR. The systemic and regional hemodynamic recovery in the subsequent 4h was similar in both groups and significantly lower compared to sham-operated piglets. CONCLUSION Newborn piglets resuscitated by CCaV had similar return of spontaneous circulation, survival, and hemodynamic recovery compared to those piglets resuscitated by 3:1 Compression:Ventilation ratio.

Perspectives on Metabolic Suppression during Mammalian Hibernation and Daily Torpor

During hibernation and daily torpor, metabolic rate (MR) can be maximally reduced to only 1 or 12%, respectively, of the minimum euthermic levels. The physiological mechanisms causing these metabolic reductions remain unclear and are under debate. Earlier observations based on high ratio of (MRcuthermia / MRhibernation) and high corresponding Q10 values (>3), suggest temperatureindependent mechanisms such as tissue acidification through retention of respiratory CO2 may be involved in actively inhibiting metabolism beyond the effect of low body temperature (Tb) alone. This, however, has been challenged due to inherent problems in defining the proper MRcuthermia for comparison and the proper execution of Q10 calculation. The proposition that a reduced thermoconductance during torpor could account for the reduced metabolism and that the (Tb-Ta) gradient ultimately determines the level of metabolism during torpor have also been challenged. Since the thermoregulatory set-point (Tset) is progressively lowered during entry into torpor and remains low during torpor, and hibernators and daily heterotherms are capable of strong thermogenic efforts even at low Tb the prevailing level of MR during torpor likely reflects the thermogenic magnitude (or its suppression) of the error signal (Thypo-Tset) and the Arrhenius effect on MR. To date, however, no direct evidence has been provided to argue for or against any of the above conjectures. We have proposed a different experimental approach which could allow direct comparison of minimum MR at the same Tb during hibernation and induced hypothermia. This hopefully will resolve if active inhibition of MR is indeed a state-dependent characteristic of torpor and hibernation.

Differential Apoptosis Effects of Primate Lentiviral Vpr and Vpx in Mammalian Cells

The growth inhibitory effects of Vpr and Vpx are species- and cell type-dependent. HIV-1, HIV-2 and SIV Vpr are primarily cytostatic in mammalian cells and HIV-1 Vpr has been reported to induce apoptosis in human cells. Our previous studies have shown that HIV-1, HIV-2 and SIV Vpr and Vpx have differential cytostatic and cytotoxic effects in the yeast cells [Zhang et al.: Virology, 230:103-112; 1997]. Here, we further examined the apoptosis function of HIV-1 Vpr in different species of mammalian cells and investigated if other primate lentiviral Vpr and Vpx exert similar functions. Our results show that none of the primate lentiviral Vpr or Vpx we tested induces apoptosis in nonhuman species of mammalian cells. However, HIV-1 Vpr, but not HIV-2 or SIV Vpr and/or Vpx, induced apoptosis in different types of human cell lines. Further, the apoptotic effect of HIV-1 Vpr can be distinguished from that of the human interferon-gamma, a known proapoptotic protein, that HIV-1 Vpr shows little to no paracrine and/or bystander effect. When coexpressed with Bcl-2 or Bcl-X(L), the apoptotic effect of HIV-1 Vpr became markedly attenuated. These results indicate that the apoptotic effect of HIV-1 Vpr is species-dependent and is intracellularly modulated by the Bcl-2 family of proteins. Our study also suggests that the proapoptotic function of HIV-1 Vpr is developmentally associated with human but not nonhuman primate species.

Effects of Postresuscitation N -Acetylcysteine on Cerebral Free Radical Production and Perfusion During Reoxygenation of Hypoxic Newborn Piglets

Hydrogen peroxide (H2O2) and nitric oxide (NO) contribute to the pathogenesis of cerebral hypoxic-ischemic injury. We evaluated the neuroprotective effect of N-acetyl-l-cysteine (NAC, a free radical scavenger) against oxidative stress and perfusion in a model of neonatal hypoxia-reoxygenation (H-R). Piglets (1–3 d, 1.6–2.3 kg) were randomized into a sham-operated group (without H-R) (n = 5) and two H-R experimental groups (2 h normocapnic alveolar hypoxia followed by 4 h reoxygenation) (n = 7/group). Five minutes after reoxygenation, piglets were given either i.v. saline (H-R controls) or NAC (30 mg/kg bolus then 20 mg/kg/h infusion) in a blinded-randomized fashion. Heart rate, mean arterial pressure, carotid arterial blood flow (transit-time ultrasonic probe), cerebral cortical H2O2 and NO production (electrochemical sensor), cerebral tissue glutathione and nitrotyrosine levels (enzyme-linked immunosorbent assay) were examined. Hypoxic piglets were acidotic (pH 6.88–6.90), which recovered similarly in the H-R groups (p > 0.05 versus shams). Postresuscitation NAC treatment significantly attenuated the increase in cortical H2O2, but not NO, concentration during reoxygenation, with lower cerebral oxidized glutathione levels. NAC-treated piglets had significantly higher carotid oxygen delivery and lower cerebral lactate levels than that of H-R controls with corresponding changes in carotid arterial flow and vascular resistance. In newborn piglets with H-R, postresuscitation administration of NAC reduced cerebral oxidative stress and improved cerebral perfusion.

Cyclosporine treatment improves cardiac function and systemic hemodynamics during resuscitation in a newborn piglet model of asphyxia: a dose-response study.

Objectives:Asphyxiated neonates often have myocardial depression, which is a significant cause of morbidity and mortality. Cardioprotective effects of cyclosporine have been observed in adult patients and animals with myocardial infarction. However, the cardioprotective effect of cyclosporine in neonates has not yet been studied. We hypothesize that cyclosporine will improve cardiac function and reduce myocardial injury in asphyxiated newborn piglets. Design:Thirty-six piglets (1–4 days old, weighing 1.4–2.5 kg) were acutely instrumented for continuous monitoring of cardiac output and systemic arterial pressure. After stabilization, normocapnic alveolar hypoxia (10% to 15% oxygen) was instituted for 2 hrs followed by reoxygenation with 100% oxygen for 0.5 hrs and then 21% for 3.5 hrs. A nonasphyxiated, sham-operated group was included (n = 4) to control for effects of the surgical model. Plasma troponin and myocardial lactate concentrations were determined as well as morphologic examinations. Setting:Neonatal asphyxia and reoxygenation. Subjects:Newborn (1–4 days old) piglets. Interventions:Piglets were block-randomized to receive intravenous boluses of cyclosporine A (2.5, 10, or 25 mg/kg) or normal saline (control) at 5 mins of reoxygenation (n = 8/group). Measurements and Main Results:Cardiac index, heart rate, systemic oxygenation, plasma troponin, and left ventricular lactate were measured. Hypoxic piglets had cardiogenic shock (cardiac output 40% to 48% of baseline), hypotension (mean arterial pressure 27–31 mm Hg), and acidosis (pH 7.04). Cyclosporine treatment caused bell-shaped improvements in cardiac output, stroke volume, and systemic oxygen delivery (p < .05 vs. controls). Plasma troponin and left ventricle lactate were higher in controls than that of 2.5 and 10 mg/kg cyclosporine-treated groups (p < .05). Although histologic features of myocardial injury were not different among groups, severe damage was observed in mitochondria of control piglets but attenuated in that of cyclosporine (10 mg/kg) treatment. Conclusions:Postresuscitation administration of cyclosporine causes preservation of cardiac function and attenuates myocardial injury in newborn piglets after asphyxia–reoxygenation. (Crit Care Med 2012; 40:–1244)

Modulatory effects of magnolol on potassium-stimulated 5-hydroxytryptamine release from rat cortical and hippocampal slices

Magnolol, a phenolic constituent of magnolia bark, is a known central nervous system depressant. To examine the possibility that magnolol may elicit its depressant effect by modulating central serotonergic activity, its effect on 35 mM K(+)-stimulated 5-[3H]HT release from rat hippocampal and frontal cortical slices were examined. Inclusion of magnolol (1-100 microM) had no effect on 5-HT release in hippocampal slices but elicited a dose-related inhibition on 5-HT release from cortical slices. The inhibitory effect of magnolol on K(+)-stimulated 5-HT release from the cortex was not affected by either antagonists (metergoline, propranolol, and cyproheptadine) (0.01-10 microM) of various 5-HT receptor subtypes or the voltage-dependent sodium channel blocker tetrodotoxin (1 microM). It is concluded that the suppression of brain 5-HT release by magnolol is site-specific, and the suppression of cortical 5-HT release by magnolol is not via the 5-HT autoreceptors at the 5-HT terminals.

Improving cold tolerance in elderly rats by aminophylline

During severe cold exposure, old rats (23-26 months) were less capable in maintaining normal body temperature as compared to young rats (6-9 months) due to lower rate of heat production (HP). Single injection of optimal doses of aminophylline (AMPY; 10 and 18.7 mg/kg, i.p.), a phosphodiesterase inhibitor which enhances the intracellular cyclic AMP concentration, significantly increased the rate of HP in old rats to levels beyond the control values observed in young rats. Consequently, cold tolerance of the old rats was significantly improved. This AMPY-improved cold tolerance is apparently not due to increased non-shivering thermogenesis (NST) since AMPY failed to enhance norepinephrine-stimulated NST in the old rats. It is likely that AMPY increased substrate mobilization and/or conversion, thereby circumventing the limiting role of substrate availability for shivering thermogenesis. Thus, the age-dependent decrease in cold tolerance may be due to a reduced capacity for substrate mobilization when challenged by cold.