Studies on chemotaxonomic properties of tomato (Solanum lycopersicum Linn.)

This research investigated the chemotaxonomic properties of Solanum lycopersicum Linn belonging to Solanaceae. The annual herbaceous free branching cultivated crop grows up to 60 cm or more in height. It has simple uniseriate trichomes densely dispersed all over the plant with adaxial and abaxial foliar trichome indices of 27.19% and 19.44% respectively. The compound leaves measure up to 6±3 cm long and 4 ± 2cm wide with serrated margin. The inflorescence has a cyme of 3 to 5 flowers or more. The petals are yellowish, up to 2±1 cm long and 1.5±0.7 cm wide with greenish sepals up to 1.5±0.7 cm long and 0.7±0.3 cm wide. Flowers are axile, hexa-pentamerous up to 1 cm in diameter with bilocular 2 celled ovary. The berry fruit is greenish when unripe and reddish when ripe, up to 5 cm in diameter with seed measuring up to 0.3 cm in diameter. The epidermal studies revealed anisocytic stomata with adaxial and abaxial stomatal indices of 19.30% and 19.64% respectively. The anatomy of mid-ribs and petioles showed bicollateral vasculation. The node is unilacunar. The stem anatomical section is made of 5 to 6 vascular bundles, with petioles associated with 2 rib traces at primary growth phase while at secondary growth phase, the mid-rib and petiole revealed vascular arcs and the stem, rings of open vascular system. Alkaloids, saponins, tannins, phlobatannins, flavonoids and combined anthraquinones were present while free anthraquinones and cardiac glycosides were absent.Keywords: Morphological, Anatomical, Cytological, Phytochemical, Studie

A Novel Frequency Analysis Method for Assessing Kir2.1 and Nav1.5 Currents

Voltage clamping is an important tool for measuring individual currents from an electrically active cell. However, it is difficult to isolate individual currents without pharmacological or voltage inhibition. Herein, we present a technique that involves inserting a noise function into a standard voltage step protocol, which allows one to characterize the unique frequency response of an ion channel at different step potentials. Specifically, we compute the fast Fourier transform for a family of current traces at different step potentials for the inward rectifying potassium channel, Kir2.1, and the channel encoding the cardiac fast sodium current, Nav1.5. Each individual frequency magnitude, as a function of voltage step, is correlated to the peak current produced by each channel. The correlation coefficient vs. frequency relationship reveals that these two channels are associated with some unique frequencies with high absolute correlation. The individual IV relationship can then be recreated using only the unique frequencies with magnitudes of high absolute correlation. Thus, this study demonstrates that ion channels may exhibit unique frequency responses

The Effects of Puerarin on Rat Ventricular Myocytes and the Potential Mechanism

Puerarin, a known isoflavone, is commonly found as a Chinese herb medicine. It is widely used in China to treat cardiac diseases such as angina, cardiac infarction and arrhythmia. However, its cardioprotective mechanism remains unclear. In this study, puerarin significantly prolonged ventricular action potential duration (APD) with a dosage dependent manner in the micromolar range on isolated rat ventricular myocytes. However, submicromolar puerarin had no effect on resting membrane potential (RMP), action potential amplitude (APA) and maximal velocity of depolarization (Vmax) of action potential. Only above the concentration of 10 mM, puerarin exhibited more aggressive effect on action potential, and shifted RMP to the positive direction. Millimolar concentrations of puerarin significantly inhibited inward rectified K+ channels in a dosage dependent manner, and exhibited bigger effects upon Kir2.1 vs Kir2.3 in transfected HEK293 cells. As low as micromolar range concentrations of puerarin significantly inhibited Kv7.1 and IKs. These inhibitory effects may due to the direct inhibition of puerarin upon channels not via the PKA-dependent pathway. These results provided direct preclinical evidence that puerarin prolonged APD via its inhibitory effect upon Kv7.1 and IKs, contributing to a better understanding the mechanism of puerarin cardioprotection in the treatment of cardiovascular diseases

The RSPO–LGR4/5–ZNRF3/RNF43 module controls liver zonation and size

LGR4/5 receptors and their cognate RSPO ligands potentiate Wnt/β-catenin signalling and promote proliferation and tissue homeostasis in epithelial stem cell compartments. In the liver, metabolic zonation requires a Wnt/β-catenin signalling gradient, but the instructive mechanism controlling its spatiotemporal regulation is not known. We have now identified the RSPO-LGR4/5-ZNRF3/RNF43 module as a master regulator of Wnt/β-catenin-mediated metabolic liver zonation. Liver-specific LGR4/5 loss of function (LOF) or RSPO blockade disrupted hepatic Wnt/β-catenin signalling and zonation. Conversely, pathway activation in ZNRF3/RNF43 LOF mice or with recombinant RSPO1 protein expanded the hepatic Wnt/β-catenin signalling gradient in a reversible and LGR4/5-dependent manner. Recombinant RSPO1 protein increased liver size and improved liver regeneration, whereas LGR4/5 LOF caused the opposite effects, resulting in hypoplastic livers. Furthermore, we show that LGR4(+) hepatocytes throughout the lobule contribute to liver homeostasis without zonal dominance. Taken together, our results indicate that the RSPO-LGR4/5-ZNRF3/RNF43 module controls metabolic liver zonation and is a hepatic growth/size rheostat during development, homeostasis and regeneration

Comparative morpho-anatomical characteristics and phytochemical constituents of Aloe vera Barbadensis miller and Aloe vera var. Chinensis (haw) Berger

This study was set to investigate the comparative morphological and anatomical characteristics of Aloe vera barbadensis Miller and Aloe vera var. chinensis(Haw) Berger. These are evergreen perennials belonging to Asphodelaceae Juss. in the Order Asparagales Link. The former measures up to 80±20cm in height with lanceolate leaves and rosette habit. The leaves have spiny margins decorated with whitish spots on both foliar surfaces which disappear at maturity. The tubular flowers are orange and densely clustered at the stem apex; corolla is yellowish, tubular and up to 2.5±0.5cm in length whereas the latter is 40±10cm in height with rather lightly green rosette leaves and foliar white spots on foliar surfaces maintained at maturity. The two plants are fleshy and succulent with mild bitter taste. Leaves are amphistomatic with tetracytic sunken stomata. The cells of the epidermal layer are nucleated mostly hexagonal and include pentagonal, heptagonal to square or rounded. Stomatal indices for Aloe vera barbadensis adaxial foliar layer is 7.92 % and abaxial 4.76% while Aloe vera var. chinensis adaxial surface is 7.92% and abaxial 3.85%, not significant. Anatomical studies revealed the cell  types from the epidermis, hypodermis, general cortex to the pith are similar in mid-ribs, petioles, stems and nodes. The roots have piths and vasculation is closed type. Phytochemical studies showed the presence of Alkaloids, flavonoids, saponins and tannins in both species, whereas combined anthraquinone was observed absent in both plants. Cardenolide, phlobatannins and free anthraquinones were present in Aloe vera var. chinesis but absent in Aloe vera barbadensis while cyanogenic glycoside was absent in Aloe vera var chinensis but present in Aloe vera barbadensis. The species are used in natural medicine. The information contained in this research would further aid in the taxonomic delimitations of these plants. &nbsp

MELD-XI score and cardiac mortality or transplantation in patients after Fontan surgery

Objective The Fontan operation is a staged palliation for complex congenital heart disease and single ventricle physiology. Perioperative survivors of the Fontan operation experience long-term cardiac complications, including death. Liver and renal dysfunction are reported in these patients and have a direct effect on morbidity and mortality. This study aims to investigate whether the Model for End-stage Liver Disease eXcluding INR score (function of creatinine and total bilirubin, MELD-XI) predicts risk for cardiac mortality or transplantation in patients with Fontan circulation. Design and setting Retrospective, single-centre study. Time of first evaluation was the time of the earliest available MELD-XI score measurement, and follow-up was terminated by a cardiac event or by the last clinical evaluation. Patients Patients surviving after Fontan surgery and evaluated at Boston Children's Hospital between 1993 and 2008. Main outcome measure Composite endpoint of sudden death, death from congestive heart failure or cardiac transplantation. Results The MELD-XI score was calculated as MELDXI= 11.76(loge creatinine)+5.112(loge total bilirubin) +9.44. Ninety-six patients were included (52 male, median age 26 years). After a mean follow-up period of 5.7 years, 18 patients (19%) experienced the composite end point. Baseline MELD-XI score was independently and directly related to the incidence of the composite endpoint (HR for high MELD-XI score group of 7.76, 95% CI 2.05 to 29.33, p=0.008). Conclusions Fontan patients with a higher MELD-XI score have shorter freedom from sudden cardiac death, death from congestive heart failure and cardiac transplantation