Ferricytochrome c encapsulated in silica hydrogels: correlation between active site dynamics and solvent structure

Ferricytochrome c encapsulated in silica hydrogels has been prepared by the sol-gel technique following, with some modifications, the procedure originally developed by Zink et al. A suitable preparation of hydrogels enables to have both 'wet' and 'dry' samples. Wet samples have a high water content: as the temperature is lowered below approximately 260 K water freezes and the samples crack. On the contrary, dry samples have a low water content (hydration h approximately 0.35): in these conditions water does not freeze even at cryogenic temperatures and the samples remain transparent and non-cracking. The dynamics of ferricytochrome c and its dependence on the surrounding medium have been studied by optical absorption spectroscopy in the temperature range 10-300 K. At each temperature, spectra were collected both in the Soret region and in the near infrared at approximately 1.45 microm (the water overtone band); this enables to probe the local dynamics of the protein active site as well as the 'structure' of water molecules present in the sample. The data show that sol-gel encapsulation 'per se' does not alter the protein active site dynamics, but rather introduces an increased local heterogeneity. At difference, we find a correlation between active site dynamics and water structure: in the wet hydrogel, freezing of water quenches the ensemble of soft modes linearly coupled to the Soret transition; while, in the dry hydrogel, water does not freeze, and an active site dynamic behavior-similar to the non-freezing water/glycerol solution-is observed.     

Synthetic peptides related to the dermorphins. II. Synthesis and biological activities of new analogues

A new series of analogues of the potent opiate-like peptides dermorphins (mainly tetra- and pentapeptides) were synthesized in order to better evaluate the structure-activity relationships. Relative potencies were referred to dermorphin (H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH₂), the prototype of this class of frog skin peptides. Peripheral opioid activity (guinea pig ileum and mouse vas deferens) was determined for all the dermorphin analogues. For a selected number of them also central analgesic (hot plate and tail-flick tests) and cataleptic activities were assayed in the rat by intracerebroventricular administration.     

The regulation of sulphurated amino acid junctions: fact or fiction in the field of inflammation?

Summary.  The diet of industrialised countries is usually rich in amino acids, which are in part used as a source of calories. However, metabolic alterations are observed in diseased patients and a preferential retention of Sulphurated Amino Acids (SAA) occurs during the inflammatory response. Moreover, it has been demonstrated in a model of an acute sepsis phase of rats that the metabolism of Cysteine is modified. The liver converts Cysteine at a different ratio of Sulphate to Taurine (Tau) i.e. the sulphate production decreases while the Tau conversion increases. The Glutathione (GSH) concentration is greater in the liver, kidneys and other organs and the Cysteine incorporation into proteins is higher in the spleen, lungs and plasma (Acute Phase Proteins) while the Albumin level decreases. The pro-inflammatory cytokines such as Interleukin-1, Interleukin-6 and TNF-α are the main initiators that alter protein and amino acid metabolism. Another important phenomenon is the impairment of Methionine conversion to Cysteine during stress. For example, premature infants or AIDS patients are capable of synthesizing Cysteine from Methionine at a much lower rate. Thus, the metabolic flow through the trans-sulphuration path may be inadequate to meet the Cysteine demand under critical conditions. In this complex picture, an SAA supply may contribute to an immune system regulation. Received November 30, 2001 Accepted January 15, 2002 Published online August 30, 2002 Author's address: Francesco Santangelo, Zambon Group, via Lillo del Duca 10, I-20091 Bresso, Milan, Italy, Email: francesco.santangelo@zambongroup.com     

Electrophysiological studies and identification of possible sex pheromone components of Brazilian populations of the sugarcane borer,Diatraea saccharalis

Virgin female gland extracts of sugarcane moth Diatraea saccharalis (Fabricius) (Lepidoptera: Pyralidae), from three locations in Brazil, have been analyzed. By GC-MS analysis and comparison of the chromatographic retention time of the components of the pheromone gland with those retention times of synthetic standards, we observed the presence of (Z)-hexadec-11-enal (1), hexadecanal (2), (9E,11Z)-hexadecadienal (4), (9Z,11Z)-hexadecadienal (5) and (9E,11E)-hexadecadienal (6), as minor components besides the major constituent (9Z,11E)-hexadecadienal (3) already reported. We found no variations in the composition of the gland extracts deriving from the three Brazilian populations and only two compounds, (Z)-hexadec-11-enal (1) and (9Z,11E)-hexadecadienal (3), elicited antennal responses (GC-EAD). In electroantennography (EAG), however, pure compounds 1 and 3, a binary mixture containing 1 and 3, and a mixture containing all of the six synthetic compounds 1-6 elicited a depolarization in male antennae of D. saccharalis, without any statistically different delay. The EAG responses to the other isomers of 9,11-hexadecadienal were small and not significantly different from the control, except for the (9Z,11Z)-isomer (5) which showed an relatively strong electroantennal activity.     

Mapping of a locus for a familial autosomal recessive idiopathic myoclonic epilepsy of infancy to chromosome 16p13

Myoclonic epilepsies with onset in infancy and childhood are clinically and etiologically heterogeneous. Although genetic factors are thought to play an important role, to date very little is known about the etiology of these disorders. We ascertained a large Italian pedigree segregating a recessive idiopathic myoclonic epilepsy that starts in early infancy as myoclonic seizures, febrile convulsions, and tonic-clonic seizures. We typed 304 microsatellite markers spanning the 22 autosomes and mapped the locus on chromosome 16p13 by linkage analysis. A maximum LOD score of 4.48 was obtained for marker D16S3027 at recombination fraction 0. Haplotype analysis placed the critical region within a 3.4-cM interval between D16S3024 and D16S423. The present report constitutes the first example of an idiopathic epilepsy that is inherited as an autosomal recessive trait.     

Comparative analysis of the facilitating effects induced on muscular periphery by the microstimulation of various cerebellar nuclei

The facilitatory effects evoked on the motor periphery by the activation of neuronal pools in cerebellar nuclei were analized in 13 cats. The aim of the work was to compare the frequency and the characteristics of the motor facilitations induced on the ipsilateral forelimb by the microstimulation of cerebellar foci in the fastigial (CBM or in the interposital (NIA) nucleus. CBM or NIA sites, previously identified for the motor effects, were microstimulated, together with the contralateral motor cortex, to give evidence of the facilitations. It was observed that 51% of the NIA motor sites, 46% of the rostral and 33% of the caudal CBM ones, were able, when activated, to evoke facilitatory effects on at least one muscle. The most frequent motor pattern observed following NIA microstimulation was the contraction of a proximal muscle and simultaneously the facilitation of a distal one. Similar responses were detected upon activation of neuronal pools in both zones of CBM. A good number of CBM foci (39% in the rostral division and 33% in the caudal one), however, was unable to induce facilitation, eliciting, upon stimulation, only massive axial movements. Distal muscles were involved by facilitatory effects in a higher number of cases following NIA stimulation (61% of all the facilitatory responses) than CBM rostral (39%) or caudal (43%) one. Furthermore, a particular characteristic of a good percentage of CBM facilitating foci (36% in rostral and 28% in caudal CBM) was the capability to elicit motor activity in the contralateral side and simultaneously facilitation in the ipsilateral one.(ABSTRACT TRUNCATED AT 250 WORDS)     

Regenerative potential of human muscle stem cells in chronic inflammation

Introduction

Chronic inflammation is a profound systemic modification of the cellular microenvironment which could affect survival, repair and maintenance of muscle stem cells. The aim of this study was to define the role of chronic inflammation on the regenerative potential of satellite cells in human muscle.

Methods

As a model for chronic inflammation, 11 patients suffering from rheumatoid arthritis (RA) were included together with 16 patients with osteoarthritis (OA) as controls. The mean age of both groups was 64 years, with more females in the RA group compared to the OA group. During elective knee replacement surgery, a muscle biopsy was taken from the distal musculus vastus medialis. Cell populations from four RA and eight OA patients were used for extensive phenotyping because these cell populations showed no spontaneous differentiation and myogenic purity greater than 75% after explantation.

Results

After mononuclear cell explantation, myogenic purity, viability, proliferation index, number of colonies, myogenic colonies, growth speed, maximum number of population doublings and fusion index were not different between RA and OA patients. Furthermore, the expression of proteins involved in replicative and stress-induced premature senescence and apoptosis, including p16, p21, p53, hTERT and cleaved caspase-3, was not different between RA and OA patients. Mean telomere length was shorter in the RA group compared to the OA group.

Conclusions

In the present study we found evidence that chronic inflammation in RA does not affect the in vitro regenerative potential of human satellite cells. Identification of mechanisms influencing muscle regeneration by modulation of its microenvironment may, therefore, be more appropriate.     

Molecular diagnostics and personalized medicine in oncology: Challenges and opportunities

Increasing evidence demonstrates that target‐based agents are active only in molecularly selected populations of patients. Therefore, the identification of predictive biomarkers has become mandatory to improve the clinical development of these novel drugs. Mutations of the epidermal growth factor receptor (EGFR) or rearrangements of the ALK gene in non‐small‐cell lung cancer, and BRAF mutations in melanoma are clear examples of driver mutations and predictive biomarkers of response to treatment with specific inhibitors. Predictive biomarkers might also identify subgroups of patients that are not likely to respond to specific drugs, as shown for KRAS mutations and anti‐EGFR monoclonal antibodies in colorectal carcinoma. The discovery of novel driver molecular alterations and the availability of drugs capable to selectively block such oncogenic mechanisms are leading to a rapid increase in the number of putative biomarkers that need to be assessed in each single patient. In this respect, two different approaches are being developed to introduce a comprehensive molecular characterization in clinical practice: high throughput genotyping platforms, which allow the detection of recognized genetic aberrations in clinical samples, and next generation sequencing that can provide information on all the different types of cancer‐causing alterations. The introduction of these techniques in clinical practice will increase the possibility to identify molecular targets in each individual patient, and will also allow to follow the molecular evolution of the disease during the treatment. By using these approaches, the development of personalized medicine for patients with cancer will finally become possible. J. Cell. Biochem. 114: 514–524, 2013. © 2012 Wiley Periodicals, Inc.