Translocation of cholesterol from leaves to ripening fruits of Solanum khasianum

After foliar application of [4-¹⁴C]cholesterol to a Solanum khasianum shrub during a 6-week period, cholesterol was recovered not only from untreated leaves, but also from fruits at three different stages of maturity. In addition to free [4-¹⁴C]cholesterol, small amounts of [4-¹⁴C]cholesteryl esters but no [4-C¹⁴]cholesteryl glycosides were found in the fruits, treated, and untreated leaves. Thus, cholesteryl glycosides are probably not involved in the translocation of cholesterol. The implications of cholesterol translocation in the kinetics of solasodine Production are discussed.     

Salt and oxidative stress: similar and specific responses and their relation to salt tolerance in Citrus

Salt damage to plants has been attributed to a combination of several factors including mainly osmotic stress and the accumulation of toxic ions. Recent findings in our laboratory showed that phospholipid hydroperoxide glutathione peroxidase (PHGPX), an enzyme active in the cellular antioxidant system, was induced by salt in citrus cells and mainly in roots of plants. Following this observation we studied the two most important enzymes active in elimination of reactive oxygen species, namely, superoxide dismutase (SOD) and ascorbate peroxidase (APX), to determine whether a general oxidative stress is induced by salt. While Cu/Zn-SOD activity and cytosolic APX protein level were similarly induced by salt and methyl viologen, the response of PHGPX and other APX isozymes was either specific to salt or methyl viologen, respectively. Unlike PHGPX, cytosolic APX and Cu/Zn-SOD were not induced by exogenously added abscisic acid. Salt induced a significant increase in SOD activity which was not matched by the subsequent enzyme APX. We suggest that the excess of H₂O₂ interacts with lipids to form hydroperoxides which in turn induce and are removed by PHGPX. Ascorbate peroxidase seems to be a key enzyme in determining salt tolerance in citrus as its constitutive activity in salt-sensitive callus is far below the activity observed in salt-tolerant callus, while the activities of other enzymes involved in the defence against oxidative stress, namely SOD, glutathione reductase and PHGPX, are essentially similar. Received: 10 January 1997 / Accepted: 28 May 1997     

Spectral characteristics of airway opening and chest wall tidal flows in spontaneously breathing preterm infants.

We compared the harmonic content of tidal flows measured simultaneously at the mouth and chest wall in spontaneously breathing very low birth weight infants (n = 16, 1,114 +/- 230 g, gestation age: 28 +/- 2 wk). Airway opening flows were measured via face mask-pneumotachograph (P-tach), whereas chest wall flows were derived from respiratory inductance plethysmography (RIP) excursions. Next, for each, we computed two spectral shape indexes: 1) harmonic distortion (k(d); k(d,P-tach) and k(d,RIP), respectively) defines the extent to which flows deviated from a single sine wave, and 2) the exponent of the power law (s; s(P-tach) and s(RIP), respectively), describing the spectral energy vs. frequency. P-tach and RIP flow spectra exhibited similar power law functional forms consistently in all infants. Also, mouth [s(P-tach) = 3.73 +/- 0.23% (95% confidence interval), k(d,P-tach) = 38.8 +/- 4.6%] and chest wall (s(RIP) = 3.51 +/- 0.30%, k(d,RIP) = 42.8 +/- 4.8%) indexes were similar and highly correlated (s(RIP) = 1.17 x s(P-tach) + 0.85; r(2) = 0.81; k(d,RIP) = 0.90 x k(d,P-tach) + 8.0; r(2) = 0.76). The corresponding time to peak tidal expiratory flow-to-expiratory time ratio (0.62 +/- 0.08) was higher than reported in older infants. The obtained s and k(d) values are similar to those reported in older and/or larger chronic lung disease infants, yet appreciably lower than for 1-mo-old healthy infants of closer age and/or size; this indicated increased complexity of tidal flows in very low birth weight babies. Importantly, we found equivalent flow spectral data from mouth and chest wall tidal flows. The latter are desirable because they avoid face mask artificial effects, including leaks around it, they do not interfere with ventilatory support delivery, and they may facilitate longer measurements that are useful in control of breathing assessment.     

A role for macrophage migration inhibitory factor in the neonatal respiratory distress syndrome

Using a mouse model of neonatal respiratory distress syndrome (RDS), we demonstrate a central role for macrophage migration inhibitory factor (MIF) in lung maturation at the developmental stage when human neonates are most susceptible to RDS. We prematurely delivered mouse pups at embryonic day 18, during the early saccular stage of pulmonary development. Only 8% of the prematurely delivered pups genetically deficient in MIF survived 8 h vs 75% of wild-type controls (p<0.001). This phenotype was corrected when pups of all genotypes were bred from dams heterozygote for MIF deficiency. Local production of MIF in the lung increased at embryonic day 18, continued until full-term at embryonic day 19.5, and decreased in adulthood, thus coinciding with this developmental window. The lungs of pups genetically deficient in MIF were less mature upon histological evaluation, and demonstrated lower levels of vascular endothelial growth factor and corticosterone--two factors that promote fetal lung maturation. In vitro studies support a role for MIF in surfactant production by pulmonary epithelial cells. In a cohort of human neonates with RDS, higher intrapulmonary MIF levels were associated with a lower likelihood of developing bronchopulmonary dysplasia, a sequelae of RDS (p<0.03). This study demonstrates for the first time a role for MIF in lung maturation, and supports a protective role for MIF in newborn lung disease.     

Tradition, uses and Biodiversity of rocket (Eruca Sativa, Brassicaceae) in Israel

Eruca sativa (rocket) is a native plant of Israel, documented in the old literature. A survey was conducted of the old literature of ancient Israel, including Jewish, Classical and Islamic sources up to the Middle ages. It was found that rocket was used as a garden crop and spice. It was also known as a medicinal plant and was used as an aphrodisiac, for eye infections, and for digestive and kidney problems. It is important to note that special attention was given in the old times to biodiversity within the rocket species. In the light of its high erucic acid content, native accessions were collected and evaluated as a potential future source of industrial oil. Ten accessions ofEruca sativa were cultivated in Bet-Dagan experimental farm during the 1995/96 growing season. Physiological as well as chemical parameters were recorded. Erucic acid (C 22:1) and eicosenoic acid (C 20:1) contents varied from 33 to 45% and from 7.3% to 9.8%, respectively. Special attention was given to the expressed biodiversity among the accessions and its relation to their origins.     

Improving restoration success through research-driven initiatives: case studies targeting <Emphasis Type="Italic">Pinus pinea</Emphasis> reforestation stock development in Lebanon

Lebanon is located in one of the most ecologically diverse semi-arid regions of the world, characterized by endemism and richness of higher plants, which persist despite centuries of intensive agro-sylvo-pastoral use and more recent urbanization. Extensive deforestation, fires, and potential desertification have advanced concerns over the sustainability of naturally forested ecosystems in Lebanon, with only ca. 13 % forest cover remaining. Despite high numbers of seedlings planted in recent decades, reforestation success in Lebanon has been historically low. Increased success can be achieved through the effective production of high-quality native plant seedlings, capable of survival in increasingly arid climatic and harsh edaphic conditions. Through two trials focused on Pinus pinea as a model species, we aim to use a research-based approach to identify techniques required to produce high-quality seedlings to improve post-transplant performance in Lebanon. The first trial examines the suitability of using controlled release fertilizer for seedling production and evaluates the effect of fertilizer application rates on seedling morphological and tissue nutrient parameters. The second study examines the role of water availability during the three key periods of seedling development in the nursery to identify the optimal irrigation regime needed to achieve functional attributes associated with seedling drought and cold hardiness. Our findings serve as the first data-driven recommendations for improved seedling production in Lebanon and the greater region as well as demonstrate how locally integrated planning can result in effective capacity building.     

Possible Role of Minor H Antigens in the Persistence of Donor Chimerism after Stem Cell Transplantation; Relevance for Sustained Leukemia Remission

Persistent complete donor chimerism is an important clinical indicator for remissions of hematological malignancies after HLA-matched allogeneic stem cell transplantation (SCT). However, the mechanisms mediating the persistence of complete donor chimerism are poorly understood. The frequent coincidence of complete donor chimerism with graft-versus-leukemia effects and graft-versus-host disease suggests that immune responses against minor histocompatibility antigens (mHags) are playing an important role in suppressing the host hematopoiesis after allogeneic SCT. Here, we investigated a possible relationship between donor immune responses against the hematopoiesis-restricted mHag HA-1 and the long-term kinetics of host hematopoietic chimerism in a cohort of 10 patients after allogeneic HLA-matched, HA-1 mismatched SCT. Functional HA-1 specific CTLs (HA-1 CTLs) were detectable in 6/10 patients lysing host-type hematopoietic cells in vitro. Presence of HA-1 CTLs in the peripheral blood coincided with low host hematopoiesis levels quantified by highly sensitive mHag specific PCR. Additionally, co-incubation of host type CD34⁺ cells with HA-1 CTLs isolated after allogeneic SCT prevented progenitor and cobblestone area forming cell growth in vitro and human hematopoietic engraftment in immunodeficient mice. Conversely, absence or loss of HA-1 CTLs mostly coincided with high host hematopoiesis levels and/or relapse. In summary, in this first study, presence of HA-1 CTLs paralleled low host hematopoiesis levels. This coincidence might be supported by the capacity of HA-1 CTLs isolated after allogeneic SCT to specifically eliminate host type hematopoietic stem/progenitor cells. Additional studies involving multiple mismatched mHags in more patients are required to confirm this novel characteristic of mHag CTLs as factor for the persistence of complete donor chimerism and leukemia remission after allogeneic SCT.     

Identification of new biomarkers of bronchopulmonary dysplasia using metabolomics

Metabolomics - Methanol utilization by bacteria is important for various industrial processes. Methylotrophic bacteria are taxonomically diverse and some species promote plant growth and induce...