Influence of Environmental Factors and Air Composition on the Emission of [alpha]-Pinene from Quercus ilex Leaves.

We studied the emission of [alpha]-pinene from Quercus ilex leaves. Only the abaxial side of the hypostomatous Q. ilex leaf emits [alpha]-pinene. Light induced photosynthesis and [alpha]-pinene emission. However, the response of photosynthesis to dark-to-light transitions was faster than that of [alpha]-pinene, suggesting that ATP controls the emission. The emission was higher at 30 than at 20[deg]C, whereas photosynthesis did not change. Therefore, the relationship between photosynthesis and [alpha]-pinene emission does not always hold. When CO2 was removed from the air, transpiration was stimulated but photosynthesis and [alpha]-pinene emission were inhibited. [alpha]-Pinene inhibition was more rapid under low O2. When CO2 in the air was increased, photosynthesis was stimulated and transpiration was reduced, but [alpha]-pinene emission was unaffected. Therefore, the emission depends on the availability of photosynthetic carbon, is not saturated at ambient CO2, and is not dependent on stomatal opening. The pattern of [alpha]-pinene emission from Q. ilex is different from that of plants having specialized structures for storage and emission of terpenes. We suggest that [alpha]-pinene emitted by Q. ilex leaves is synthesized in the chloroplasts and shares the same biochemical pathway with isoprene emitted by isoprene-emitting oak species.

Evidence of the Photosynthetic Origin of Monoterpenes Emitted by Quercus ilex L. Leaves by 13C Labeling.

The carbon of the four main monoterpenes emitted by Quercus ilex L. leaves was completely labeled with 13C after a 20-min feeding with 99% 13CO2. This labeling time course is comparable with the labeling time course of isoprene, the terpenoid emitted by other Quercus species and synthesized in leaf chloroplasts. It is also comparable with that of phosphoglyceric acid. Our experiment therefore provides evidence that monoterpenes emitted by Q. ilex are formed from photosynthesis intermediates and may share the same synthetic pathway with isoprene. By analyzing the rate and the distribution of labeling in the different fragments, we looked for evidence of differential carbon labeling in the [alpha]-pinene emitted. However, the labeling pattern was quite uniform in the different fragments, suggesting that the carbon skeleton of the emitted monoterpenes comes from a unique carbon source.

Studies on mating plug of two sandfly species, Phlebotomus perniciosus and Phlebotomus papatasi (Diptera: Psychodidae).

A study was undertaken to interpret the nature and function of the "plug like formation" observed inside the spermathecae of many phlebotomine sandflies dissected during field surveys. Trials were carried out on two laboratory reared species, Phlebotomus perniciosus and P. papatasi. The results showed that the "plug like formation" is a true mating plug (MP) containing immotile sperms. Our studies showed also that the MP evolves differently according to the physiological state of the mated female. In blood-fed females, it persists 22-25 hrs post mating. Follows a period of 3-4 days in which the spermathecae acquire different form from that of the virgin spermathecae, but sperms are still undistinguishable. Active sperms appear only a few hours before oviposition. After oviposition, however, spermathecae are void as in the virgin female. Thus, during the complete gonotrophic cycle the spermathecae display five different forms: a) normal and void; b) showing MP; c) distended and yellowish, MP absent; d) active sperms present; e) normal and void. In unfed females, MP was observed to last for 6 days post copula. The results show also that MP is interfering with reinsemination.

[Autostatic hepatic retractor in orthotopic liver transplantation]. / Utilizzo del retrattore epatico autostatico nel trapianto di fegato.

Liver transplantation (LT) is the treatment of choice for acute and chronic liver failure, for hepatocarcinoma and for same metabolic diseases. The shortage of donors leads to use over 60 tears-old donors and to develop new surgical technique to split the liver in 2 grafts. In our institution we set 2 targets: 1) to improve the number of liver transplantations using in situ split liver grafts and old donors, 2) to simplify the surgical technique. Since 1997 we performed 174 LT: 73 with whole size graft from under 60 years old donors, 42 with whole size graft from over 60 years old donors and 59 with split liver grafts. The autostatic hepatic retractor (AHR) was designed to make easier the hepatic hilar dissection and the vascular and biliar anastomoses. The particular steel plate of AHR lifts the inferior surface of the right and left hepatic lobes laying out the hilum to the porta hepatis; its malleability makes possible prolonged atraumatic use in accordance with the anatomical conformation of the liver. AHR is used in LT during the dissection of the left and right hepatic arteries, the dissection of the main portal trunk and its left and right branches, the isolation of the hepatic bile duct; moreover AHF is employed for portal, arterial and biliar anastomoses. In our experience the use of AHR was easy, safe and useful. AHR can help the surgeon during hepato-biliary surgery whenever hilar dissection is required.

[Complications of mediterranean spotted fever]. / Complicanze della febbre bottonosa.

Mediterranean spotted fever is an infectious disease due to Rickettsia conori transmitted to man by the dog tick Rhipicephalus sanguineus. The review of a consecutive series of 525 cases, admitted to Caltagirone hospital in the last 20 years, permits the classic clinical picture to be identified by fever, maculopapular eruption and tache noire, and any complications to be visualized. Usually the course of the disease is good, but 12.7% of our cases reported complications such as renal failure, myocarditis, pneumonia, encephalitis, anicteric hepatitis, gastrointestinal bleeding, anaemia and impaired glucose tolerance. The development of a systemic vasculite is the main pathogenetic factor in the origin of systemic complications. Early diagnosis and specific antibiotic treatment may reduce the risk of complications.

Somatic embryogenesis and plant regeneration from cell suspension cultures of Cucumis sativus L.

A procedure for the regeneration of whole cucumber plants (Cucumis sativus L. cv. Poinsett 76) by embryogenesis from cell suspension cultures is described. Embryogenic callus was initiated from the primary leaves of 14-17 day old plants. Suspension cultures of embryogenic cells were grown in liquid Murashige and Skoog basal medium containing 5 uM 2,4,5-trichlorophenoxyacetic acid and 4 uM 6-benzylaminopurine. Suspension cultures were composed of a population of cells that were densely cytoplasmic and potentially embryogenic. Differentiation of embryos was enhanced by washing the suspension culture cells with MS basal medium containing 0.5% activated charcoal and twice with MS basal medium followed by liquid shake cultures in MS basal medium. Sixty to 70 percent of the embryos prewashed with activated charcoal germinated into plantlets with normal morphology. Embryos obtained from suspension cultured cells without prewashing with activated charcoal organized into plantlets with abnormal primary leaves. Morphologically normal plantlets were obtained by excising the shoot tips and transferring them to fresh medium.

RuBP carboxylase determination by enzymic estimation of D-3-PGA formed.

RuBPcarboxylase activity was measured in extracts of barley (Hordeum Vulgare L., cv. HOP) seedlings both with the standard radiometric method and by measuring D-3-phosphoglyceric acid formed enzymically in a two stage assay. In the different conditions used, characterized by different NaHCO3 concentrations, different pH and the presence and absence of oxygen, essentially the same ratio of D-3-PGA formed per (14)CO2 fixed was obtained. This ratio respected the known stoichiometry of two molecules of D-3-PGA formed per CO2 fixed.It is suggested that measurement of D-3-PGA enzymically in a two stage assay can be routinely used for the determination of RuBP case activity instead of the radiometric method. The advantages and the validity of the method are discussed.

RuBP carboxylase determination by enzymic estimation of D-3-PGA formed.

RuBPcarboxylase activity was measured in extracts of barley (Hordeum Vulgare L., cv. HOP) seedlings both with the standard radiometric method and by measuring D-3-phosphoglyceric acid formed enzymically in a two stage assay. In the different conditions used, characterized by different NaHCO3 concentrations, different pH and the presence and absence of oxygen, essentially the same ratio of D-3-PGA formed per (14)CO2 fixed was obtained. This ratio respected the known stoichiometry of two molecules of D-3-PGA formed per CO2 fixed.It is suggested that measurement of D-3-PGA enzymically in a two stage assay can be routinely used for the determination of RuBP case activity instead of the radiometric method. The advantages and the validity of the method are discussed.

[CD30 (ki-1) antigen expression in acute infectious mononucleosis] / L'espresione dell'antigene CD30 (K1-1) nella mononucleosi infettova acuta.

The activation antigen CD30 (Ki-1) which is expressed by the lymphocytes T and B is related to the "nerve growth factor" (NFGR) like the receptor of the "tumor necrosis factor" (TNF) and is expressed in the group of large-cell anaplastic lymphoma (ACLC) and Hodgkin's lymphoma and in non-Hodgkin's lymphoma and within the T cells of infectious Mononucleosis. We describe a case of a 18 year-old who contracted Acute Infectious Mononucleosis showing lateral cervical lympho adenopathy. The histologic examination was suggestive for a large-cell anaplastic lymphoma with the antigen CD30, expressed by severa atypical immunoblasts. The remarkable immunoblastic proliferation with Reed-Sternberg-like cells, in milieu polymorphous inflammatory cells present in the course of Infectious Mononucleosis, can simulate large cell anaplastic lymphoma, as well as Hodgkins disease and non-Hodgkins lymphoma. The diagnosis for Infectious Mononucleosis is usually clinical and serological but in cases of cervical lymphnode biopsy a differential diagnosis must be done with positive lymphoma CD30. The criteria to differentiate histologically the Infectious Mononucleosis with large cell anaplastic lymphoma and non-Hodgkin s lymphoma are discussed. Finally, the relationship between Infectious Mononucleosis and lymphoproliferative disease Epstein-Barr virus related is examined.

Culture of soybean mesophyll protoplasts in alginate beads.

Mesophyll protoplasts were isolated from leaves of 10 day old aseptically grown soybean seedlings, or from surface disinfested leaves of 3 week old plants grown in environmental chambers. The protoplasts were encapsulated in 2mm diameter Ca alginate beads. Immobilized protoplasts were induced to divide by culturing in shaker flasks containing an actively growing soybean cell suspension. The feeder cell suspension supported the division of protoplasts independent of the protoplast density in the Ca alginate beads. At day 18 after encapsulation, the alginate matrix was dissolved, releasing viable callus colonies. The feeder cell suspension obviated plating of protoplasts at high density which is usually required for subsequent cell division and colony development. Since the protoplasts were embedded at low density, the cell colonies were derived from single cells.

Photosynthetic properties of leaves of a yellow green mutant of wheat compared to its wild type.

We investigated several photosynthetic parameters of a virescent mutant of durum wheat and of its wild-type. Electron transport rate to ferricyanide was the same in the two genotypes when expressed on leaf area basis while O2 evolution of the leaf tissue in saturating light and CO2 was slightly higher in the yellow genotype. RuBPCase was also slightly higher. Quantum yield per absorbed light was similar in the two genotypes. P700 and Cyt f were less concentrated in the mutant while PS II was only marginally lower. The light response curve of CO2 assimilation indicated higher level of photosynthesis of the mutant in high light, which corresponded to a lower non-photochemical quenching compared to the wild-type. It is concluded that the reaction centres, cyt f and chlorophyll are not limiting factors of electron transport in wheat seedlings and that electron transport capacity is in excess with respect to that needed for driving photosynthesis. Since the differences in photosynthesis reflect differences in RuBPCase activity, it is suggested that this enzyme limits photosynthesis in wheat seedlings also at high light intensities.

Measurements of mesophyll conductance, photosynthetic electron transport and alternative electron sinks of field grown wheat leaves.

Photosynthetic electron transport drives the carbon reduction cycle, the carbon oxidation cycle, and any alternative electron sinks such as nitrogen reduction. A chlorophyll fluorescence- based method allows estimation of the total electron transport rate while a gas-exchange-based method can provide estimates of the electron transport needed for the carbon reduction cycle and, if the CO2 partial pressure inside the chloroplast is accurately known, for the carbon oxidation cycle. The gas-exchange method cannot provide estimates of alternative electron sinks. Photosynthetic electron transport in flag leaves of wheat was estimated by the fluorescence method and gasexchange method to determine the possible magnitude of alternative electron sinks. Under non-photorespiratory conditions the two measures of electron transport were the same, ruling out substantial alternative electron sinks. Under photorespiratory conditions the fluorescence-based electron transport rate could be accounted for by the carbon reduction and carbon oxidation cycle only if we assumed the CO2 partial pressure inside the chloroplasts to be lower than that in the intercellular spaces of the leaves. To further test for the presence of alternative electron sinks, carbon metabolism was inhibited by feeding glyceraldehyde. As carbon metabolism was inhibited, the electron transport was inhibited to the same degree. A small residual rate of electron transport was measured when carbon metabolism was completely inhibited which we take to be the maximum capacity of alternative electron sinks. Since the alternative sinks were small enough to ignore, the comparison of fluorescence and gas-exchange based methods for measuring the rate of electron transport could be used to estimate the mesophyll conductance to CO2 diffusion. The mesophyll conductance estimated this way fell as wheat flag leaves senesced. The age-related decline in photosynthesis may be attributed in part to the reduction of mesophyll conductance to CO2 diffusion and in part to the estimated decline of ribulose 1,5-bisphosphate carboxylase amount.