Identification of a Novel Triterpenoid Saponin from Pisum sativum as a Specific Inhibitor of the Diguanylate Cyclase of Acetobacter xylinum

A specific and highly potent inhibitor of diguanylate cyclase,the key regulatory enzyme of the cellulose synthesizing apparatusin the bacterium Acetobacter xylinum, was isolated from extractsof etiolated pea shoots (Pisum sativum). The inhibitor has beenpurified by a multistep procedure, and sufficient amounts ofhighly purified compound (3-8 mg) for spectral analysis wereobtained. The structure of this compound was established as3-O-a-L-rhamnopyranosyl-(l     

Climate change,unpredictable cold waves and possible brakes on plant migration

Aim Increases in annual mean temperature in the course of current climate change are expected to facilitate mass species migration towards higher altitudes and latitudes. However, this migration may be slowed, or even temporarily reversed, by infrequent and unpredictable episodes of low winter temperatures. Iran experienced a severe cold wave in January and February 2008, giving an opportunity to observe the effects on a large number of woody plant species, many growing further north than their natural ranges. Location The study was carried out in the National Botanical Garden of Iran (35°44′20.06″ N; 51°10′25.66″ E). Method To estimate the damage caused to each individual woody plant in the garden, we adopted the following protocol; at the start of the growing season, at the end of March and beginning of April 2008, all woody species were inspected for damage. In the case of evergreens this took the form of obvious damage to foliage, usually manifested as severe browning. In the case of deciduous species, damage was recognized by the failure of all or part of the plant to produce new leaves; all affected individual plants were labelled. In July all labelled plants were rechecked and, based on whole or partial above‐ground die‐back, a final list of damaged individuals was produced. Results As expected, the majority of native and exotic species introduced from cold temperate habitats showed no freezing injuries. Many woody species in the garden were damaged or killed, despite their previous survival and growth, in many cases for up to 40 years. The majority of taxa (101 out of a total of 145) that suffered freezing‐induced damage were evergreens. Main conclusions The results indicate that despite an increase in mean annual temperature, unpredictable lethal cold waves may retard the expansion of plants towards higher altitudes and latitudes. Broadleaved evergreen species from warm climates were particularly badly affected, with many species suffering high rates of mortality.     

Randomized Prospective Comparison of Two Protocols for Head-up Tilt Testing in Patients with Normal Heart and Recurrent Unexplained Syncope

BackgroundThis randomized study was aimed to compare the diagnostic value of two head-up tilt testing protocols using sublingual nitroglycerin for provocation in patients with recurrent unexplained syncope and normal heart.MethodsThe patients with normal findings in physical examination, electrocardiography and echocardiography were randomly submitted to one of upright tilt test protocols. The only difference between two protocols was that nitroglycerin was administered after a five minute resting phase in supine position during protocol B. We also considered eighty normal persons as the control group.ResultsOut of 290 patients that underwent tilt testing, 132 patients were in group A versus 158 patients in group B. Both groups had an identical distribution of clinical characteristics. Tilt test was positive in 79 patients in group A (25 in passive phase, 54 in active phase) versus 96 patients in group B (43 in passive phase, 53 in active phase). There was no significant difference between results in two groups (P value = 0.127). Forty cases were tested with protocol A and forty underwent tilt testing with protocol B. Tilt test was positive in 4 cases with protocol A versus 3 cases in protocol B. The positive rates of tilt testing with protocol A was 60% while it was 61% in protocol B. The specificity of testing with protocol A was 90% and it was 92.5% in protocol B.ConclusionsAccording to our data, adding a period of rest and returning to supine position before nitroglycerin administration had no additional diagnostic yield.     

Adipose tissue mRNA expression of HDAC1, HDAC3 and HDAC9 in obese women in relation to obesity indices and insulin resistance

Molecular Biology Reports - It is well-established that an impaired adipose tissue function and morphology caused by a dysregulated gene expression contribute substantially to obesity. Nowadays,...