Liver fatty acid-binding protein in two cases of human lipid storage

Summary FABPs in the various tissues play an important role in the intracellular fatty acid transport and metabolism. Reye's syndrome (RS) and multisystemic lipid storage (MLS) are human disorders characterized by a disturbance of lipid metabolism of unknown etiology. We investigated for the first time L-FABP in these two conditions. Affinity purified antibodies against chicken L-FABP were raised in rabbits, and found to cross-react specifically with partially purified human L-FABP. L-FABP content in liver samples of two patients with RS and MLS was investigated by immuno-histochemistry, SDS-PAGE and ELISA. L-FABP immuno-histochemistry showed increased reactivity in the liver of RS patient and normal reactivity in MLS liver. L-FABP increase in RS liver was confirmed by densitometry of SDS-PAGE and ELISA method. By these two methods the increase amounted to 180% and 199% (p < 0.02), respectively, as compared to controls. A possible role of L-FABP in the pathogenesis of RS is discussed.     

Mapping of neuropeptide Y expression in Octopus brains

Neuropeptide Y (NPY) is an evolutionarily conserved neurosecretory molecule implicated in a diverse complement of functions across taxa and in regulating feeding behavior and reproductive maturation in Octopus. However, little is known about the precise molecular circuitry of NPY-mediated behaviors and physiological processes, which likely involve a complex interaction of multiple signal molecules in specific brain regions. Here, we examined the expression of NPY throughout the Octopus central nervous system. The sequence analysis of Octopus NPY precursor confirmed the presence of both, signal peptide and putative active peptides, which are highly conserved across bilaterians. In situ hybridization revealed distinct expression of NPY in specialized compartments, including potential “integration centers,” where visual, tactile, and other behavioral circuitries converge. These centers integrating separate circuits may maintain and modulate learning and memory or other behaviors not yet attributed to NPY-dependent modulation in Octopus. Extrasomatic localization of NPY mRNA in the neurites of specific neuron populations in the brain suggests a potential demand for immediate translation at synapses and a crucial temporal role for NPY in these cell populations. We also documented the presence of NPY mRNA in a small cell population in the olfactory lobe, which is a component of the Octopus feeding and reproductive control centers. However, the molecular mapping of NPY expression only partially overlapped with that produced by immunohistochemistry in previous studies. Our study provides a precise molecular map of NPY mRNA expression that can be used to design and test future hypotheses about molecular signaling in various Octopus behaviors.     

Balancing crosstalk between 20-hydroxyecdysone-induced autophagy and caspase activity in the fat body during Drosophila larval-prepupal transition

In the fruitfly, Drosophila melanogaster, autophagy and caspase activity function in parallel in the salivary gland during metamorphosis and in a common regulatory hierarchy during oogenesis. Both autophagy and caspase activity progressively increase in the remodeling fat body, and they are induced by a pulse of the molting hormone (20-hydroxyecdysone, 20E) during the larval-prepupal transition. Inhibition of autophagy and/or caspase activity in the remodeling fat body results in 25–40% pupal lethality, depending on the genotypes. Interestingly, a balancing crosstalk occurs between autophagy and caspase activity in this tissue: the inhibition of autophagy induces caspase activity and the inhibition of caspases induces autophagy. The Drosophila remodeling fat body provides an in vivo model for understanding the molecular mechanism of the balancing crosstalk between autophagy and caspase activity, which oppose with each other and are induced by the common stimulus 20E, and blockage of either path reinforces the other path.     

Distribution of nutrients,trace elements,PAHs and radionuclides in sediment cores from Lake Varese (N. Italy)

Sediment cores were collected at 5 stations in Lake Varese. They were analyzed for organic matter, N, P, organic C, Cd, Cr, Cu, Hg, Pb, Zn and PAHs. A sedimentological approach has been applied to estimate the ecological risk from identified pollutants.As in other eutrophic lakes in Northern Italy, this lake is also at considerable risk from heavy metal pollution. Cr, Cu and Cd showed the highest enrichment factors for the last 5 years, 23.4, 8.0 and 7.6 respectively. Other metals had enrichment factors ranging from 1 to 3. Fluoranthene was chosen as a representative PAH, derived from combustion products; its average value in surficial sediments ranged from 100 to 220 ng l^-1 dw. This compound can be a hazard to human health and aquatic life. An evaluation of radionuclide distributions after the recent Chernobyl accident in the USSR (¹³⁴Cs, ¹³⁷C s, ¹³¹I, ¹⁰⁶Ru) provided useful tracers to follow the cycling of pollutants bound to particulate matter in the aquatic ecosystem.     

Limited resistance of hypertrophied skeletal muscle to glucocorticoids

Male hypophysectomized rats were initially assigned to a control or an overloaded group that underwent compensatory hypertrophy of plantaris muscles to steady-state levels following removal of synergistic musculature. Plantaris muscle mass of overloaded animals was higher than that of controls by 38% (391 +/- 8 vs 284 +/- 7 mg) and glucocorticoid cytosol specific binding concentrations, using [3H]triamcinolone acetonide (TA) as the labeled steroid, was also significantly higher in hypertrophied muscles (83.3 +/- 3.9 fmol . mg protein-1) than in control muscles 56.3 +/- 3.9 fmol . mg protein-1). Cortisone acetate (CA) was then administered daily subcutaneously in high, 100 mg; intermediate, 10 mg; or low, 1.0 mg . kg-1 body wt doses. Groups of rats were killed after 1/4, 2 days and 7 days. Absolute muscle mass losses after 7 days of CA treatment were approx 80 mg with high doses and 60 mg with intermediate doses in both hypertrophied and control muscles. The low CA dose did not produce atrophy. The absolute depletion of [3H]TA binding activity with CA treatment was always greater in hypertrophied muscles of high and intermediate dose treated than those of their respective controls, but TA binding capacities remained higher in hypertrophied muscles than in controls at almost all time points in all treatment groups. Unlike previous findings in which the simultaneous initiation of overload prevented glucocorticoid induced muscle wasting, no resistance to the effect of CA treatment was observed when treatment was begun after hypertrophy had occurred.     

A new biallelic DNA polymorphism of the human COL5A1 gene

A cDNA probe of the human COL5A1 gene detects a frequent biallelic PstI polymorphism. Allele A has a frequency of 54% whereas that of allele B is 46%. This restriction fragment length polymorphism provides a useful marker for linkage analysis in 9q34.3.     

Correction of emission spectra in microspectrofluorimetry using a reference lamp: computations.

Accurate correction of emission spectra in microspectrofluorimetry, using a reference lamp, may require that a factor for the emissivity of tungsten be introduced. This is only possible provided that the true temperature of the lamp filament is known. A method is given for obtaining the true temperature from the knowledge of the colour temperature. Also, the values of the spectral concentration of the radiance of the black body, either computed according to Planck's equation or taken from available published tables, have to be converted from energetic units to units of quanta since the photomultiplier is linear not to absorbed power but to units of quanta. When the fluorescence spectra to be corrected extend into the far red it is preferable to use a lower temperature (by lowering the supply voltage) than that for which the lamp is certified. It is possible to determine the new temperature (and then the corresponding spectral distribution) by taking a few pairs of measurements at different wavelengths both at the lower voltage and at the voltage for which the lamp is certified and then introducing these values in a non-linear regression soluble on a PC with a curve fitting program. The microscope tungsten halogen lamp can conveniently be used as a reference, thanks to its small size and its steady spectral characteristics. When high accuracy is required, however, the halogen lamp should be calibrated against a certified ribbon filament lamp.     

Boophilus microplus: characterization of larval phosphomonoesterases and isolation of subcellular fractions with high phosphatase activity.

Phosphomonoesterase activity was determined for a 115,000g pellet and soluble fractions resulting from a subcellular fractioning of a homogenate of larval Boophilus microplus. Both fractions showed maximum phosphatase activity at pH 5.5 and 10. Acid phosphatase (EC 3.1.3.2) activity was found to be greatest in the soluble fraction. When the reaction rate was plotted against homogenate concentration, the soluble acid phosphatase deviated from the linear relationship. For both fractions different thermostability patterns were obtained, inactlvation beginning for the alkaline phosphatase (EC 3.1.3.1) at 45–55 C. When the effect of substrate concentration on activity was studied, deviations from the typical hyperbolic behavior were observed. Homogenization of larvae with 5 mm EDTA buffer failed to yield a low-speed pellet with high alkaline phosphatase activity, as it is expected if absorptive structures sediment. Moreover, total alkaline phosphatase activity recovered by this method is significantly lower than activity recovered when homogenization is carried out without EDTA. Alternately, homogenization with 10 mM Tris buffer and 0.25 M sucrose gave 27,000g and 115,000g fractions with high phosphatase activity when fractioned by centrifugation. Alkaline treatment of the 115,000g fraction with 10 mM Tris buffer, pH 7.8, failed to separate endoplasmic reticulum contaminants without loss of phosphatase activity. When the 115,000g fraction was centrifuged in a sucrose density gradient, two activity peaks, coincident for both acid and alkaline phosphatases, were obtained. Antigenic analysis showed the existence of similar antigenic determinants in both peaks “immunologically” presented in different ways.