Biotransformation of 2-(4-methoxybenzyl)-l-cyclohexanone by cell cultures ofSolatium aviculare

During the search for compounds with insect juvenile hormone activity, the biotransformation of 2-(4-methoxybenzyl)-l-cyclohexanone, of 2-(4-methoxybenzyl)-l-cyclohexanone ethylene acetal and of both isomers of 2-(4-methoxybenzyl)-l-cyclohexanol by plant cells was examined. The compounds were metabolized by cell suspension culture of Solatium aviculare Forst. The reaction conditions were optimized and the metabolic products isolated and identified. A scheme of biotransformation pathway has been proposed.     

Characteristics of the microsporidian Enterocytozoon bieneusi: a consequence of its development within short-living enterocytes.

Ultrastructural studies were done on developmental stages of Enterocytozoon bieneusi obtained from HIV seropositive patients suffering from diarrhea. The presence of elaborate multilamellar structures suggest that they give rise to various membrane systems needed for rapid production of disseminating stages.     

Apolipoprotein A-I metabolism in subjects with a PstI restriction fragment length polymorphism of the apoA-I gene and familial hypoalphalipoproteinemia

Familial hypoalphalipoproteinemia (hypoalpha), characterized by a decreased high density lipoprotein level, is associated with an increased incidence of premature cardiovascular disease. Restriction fragment length polymorphism analysis of genomic DNA has detected a polymorphism for the PstI restriction endonuclease near the apoA-I gene, with either a 2.2 or a 3.3 kb fragment. The latter has been previously found to occur with significantly higher frequency in probands of families with familial hypoalpha. ApoA-I was isolated from three unrelated subjects with familial hypoalpha and the 3.3 kb PstI polymorphism of the apoA-I gene, and from normal control subjects. The apoA-I from the hypoalpha subjects was structurally normal as determined by amino acid analysis and by two-dimensional gel electrophoresis. When normal apoA-I and hypoalpha apoA-I were simultaneously injected into either normal controls or hypoalpha subjects, both forms of apoA-I were catabolized at the same rate in the same subject, indicating that the hypoalpha apoA-I is also metabolically normal. Analysis of the kinetics of metabolism of apoA-I in the hypoalpha subjects, compared to the normal controls, revealed that the reduced plasma levels of apoA-I were due to an increased apoA-I fractional catabolic rate, and that the synthetic rate was normal. Based on these results, we conclude that the apoA-I gene in these hypoalpha subjects is normal, and the PstI polymorphism near the apoA-I gene, which is associated with familial hypoalpha, is likely to be a marker for a mutant gene closely linked to, but not in, the apoA-I gene.     

Synthesis and lodination of human (phenylalanine13, tyrosine19) melanin-concentrating hormone for radioreceptor assay

An analogue of human melanin-concentrating hormone (MCH) suitable for radioiodination was designed in which Tyr¹³ and Val¹⁹ of the natural peptide were replaced by phenylalanyl and tyrosyl residues: [Phe¹³, Tyr¹⁹] -MCH. The peptide was synthesized by the continuous-flow solid-phase methodology using Fmocstrategy and Polyhipe PA 500 and PEG-PS resins. The linear MCH peptides with either acetamidomethyl-protected or free cysteinyl residues were purified to homogeneity and cyclized by iodine oxidation, yielding the final product with the correct molecular weight of 2434.61. Radioiodination of the C-terminal tyrosine was carried out enzymatically using solid-phase bound glucose oxidase/lactoperoxidase, followed by purification on a reversed-phase mini-column and by high-pressure liquid chromatography. The resulting [¹²⁵I]-[Phe¹³, Tyr¹⁹]-MCH tracer was the first radiolabelled MCH peptide suitable for radioreceptor assay: saturation binding analysis using mouse G4F-7 melanoma cells demonstrated the presence of 1090 MCH receptors per cell. The dissociation constant (KD ) was 1.18 × 10^?10 M, indicating high-affinity MCH receptors on these cells. MCH receptors were also found in other cell lines such as mouse B16-F1 and G4F and human RE melanoma cells as well as in PC12 and COS-7 cells. Competition binding analyses with a number of other peptides such as α-MSH, neuropeptide Y, substance P and pituitary adenylate cyclase activating peptide, demonstrated that the binding to the MCH receptor is specific. Atrial natriuretic factor was found to be a weak competitor of MCH, indicating topological similarities between MCH and ANF when interacting with MCH receptors.     

ABC transporters mined through comparative transcriptomics associate with organ-specific accumulation of picrosides in a medicinal herb,Picrorhiza kurroa

Protoplasma - Picrorhiza kurroa Royle ex Benth is a valuable medicinal herb of North-Western Himalayas due to presence of two major bioactive compounds, picroside-I and picroside-II used in the...     

Relative susceptibility of different stages of Rhodnius prolixus to the entomopathogenic hyphomycete Beauveria bassiana.

Laboratory bioassays were conducted to determine the relative susceptibility of eggs, 1st-, 3rd-, 5th-instar nymphs and adults of Rhodnius prolixus to one isolate of the entomopathogenic hyphomycete, Beauveria bassiana. Treatments consisted of directly spraying on insects of increasing doses of inoculum (3 x 10(2) to 3 x 10(5) conidia per cm2). Mortality due to all doses of conidia was very high in the five tested stages of the target insect. Experiments on eggs demonstrated that the fungal isolate was able to kill eggs before they hatched. Both time-mortality and dose-mortality responses showed that the susceptibility of R. prolixus varied according to its stage of development and increased with age. As a matter of fact, at the dose of 3 x 10(3) conidia per cm2, LD 50 varied between 11.2 days in 1st-instar nymphs and 6.4 days in both 5th-instar nymphs and adults. Comparison of LD50 permitted to estimate that 1st-instar nymphs were about 700-fold less susceptible than the two oldest stages.     

An assessment of the breeding range,colony sizes and population of the Westland petrel (Procellaria westlandica)

Abstract

The Westland petrel (Procellaria westlandica) is an endemic New Zealand species and one of the very few burrowing seabird species still breeding on mainland New Zealand. It nests only on a series of coastal ridgelines near to Punakaiki on the West Coast of the South Island. Between 2002 and 2005, surveys were undertaken at 28 of the 29 known colonies. The area occupied by the colonies was 73 ha; most colonies had fewer than 50 burrows, but six colonies had 201–500 burrows and four colonies had more than 1000 burrows. We find that the current breeding range of Westland petrel and the location of individual colonies are similar to those reported in both the 1950s and 1970s. Based on total burrow counts at 28 colonies and burrow occupancy rates determined by annual monitoring, the annual breeding population is estimated to be between 2954 and 5137 breeding pairs.     

La Vegetazione e L'ecologia Di Pratofiorito (Appennino Settentrionale)

Abstract

Ecology and vegetazion of mount Pratofiorito. — The author examines position, climatic conditions, geological nature and vegetation of Mount « Pratofiorito » in the Tuscan Appennine.

Mount Pratofiorito is a residue of secondary rocks and derived soil surrounded by tertiary and quaternary rocks and soil.

Its vegetations is actually constituted by grass-land and so it differs-from that of the neihbouring mountains which comprises the flora has been made. This list was then comparend with spades found in the adjacent beech and helm-oak zones.

From these comparisons one can deduce thath the meadow of « Graminaceae » and « Cyperaceae » growing on Mount Pratofiorito may bed considered as a grass-land resulting from the degradation of an arboreal zone, problably from a beech-wood.     

Impaired muscarinic type 3 (M3) receptor/PKC and PKA pathways in islets from MSG-obese rats

Monosodium glutamate-obese rats are glucose intolerant and insulin resistant. Their pancreatic islets secrete more insulin at increasing glucose concentrations, despite the possible imbalance in the autonomic nervous system of these rats. Here, we investigate the involvement of the cholinergic/protein kinase (PK)-C and PKA pathways in MSG β-cell function. Male newborn Wistar rats received a subcutaneous injection of MSG (4 g/kg body weight (BW)) or hyperosmotic saline solution during the first 5 days of life. At 90 days of life, plasma parameters, islet static insulin secretion and protein expression were analyzed. Monosodium glutamate rats presented lower body weight and decreased nasoanal length, but had higher body fat depots, glucose intolerance, hyperinsulinemia and hypertrigliceridemia. Their pancreatic islets secreted more insulin in the presence of increasing glucose concentrations with no modifications in the islet-protein content of the glucose-sensing proteins: the glucose transporter (GLUT)-2 and glycokinase. However, MSG islets presented a lower secretory capacity at 40 mM K⁺ (P < 0.05). The MSG group also released less insulin in response to 100 μM carbachol, 10 μM forskolin and 1 mM 3-isobutyl-1-methyl-xantine (P < 0.05, P < 0.0001 and P < 0.01). These effects may be associated with a the decrease of 46 % in the acetylcholine muscarinic type 3 (M3) receptor, and a reduction of 64 % in PKCα and 36 % in PKAα protein expressions in MSG islets. Our data suggest that MSG islets, whilst showing a compensatory increase in glucose-induced insulin release, demonstrate decreased islet M3/PKC and adenylate cyclase/PKA activation, possibly predisposing these prediabetic rodents to the early development of β-cell dysfunction.